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Digging In Digging In - Vegetableipmasia.org

Digging InA Nutrient ManagementCourse for FarmersDr. Heather DarbyAGRONOMIST AND NUTRIENTMANAGEMENT SPECIALISTKaren HillsCROP AND SOIL TECHNICIANDr. Sid BosworthEXTENSION AGRONOMISTAND INSTRUCTOR


This training manual has been developed by the University ofVermont Extension to facilitate the instruction of a nutrient managementcourse for livestock farmers. During the course, farmers learn todevelop and implement their own nutrient management plans, andgain an understanding of how their plans were put together, and theimportance of nutrient management planning from both economicand environmental perspectives.The course aims to provide a comfortable, small-group, learningopportunity for the farmers. Once the course is finished, classparticipants will have generated nutrient management plans followingVermont’s Natural Resources Conservation Service (NRCS) 590Nutrient Management Standard. A multi-agency educational teamconducts the program. The course is taught over a five-week periodwith participants attending a three-hour session each week. The farmerswill spend approximately fifteen hours in classroom instructionand activities to estimate annual animal manure quantities, documentand plan crop rotations, identify fields with manure spreading restrictions,analyze soil test reports, and calculate on-farm nutrient creditsfor animal manure and legumes. Farmers will also spend an estimatedtwenty hours at home writing their nutrient management plans. Thisguide is designed to present some of the instruction that is given inthe course. In addition, it gives instructions on how to use the UVMExtension Nutrient Management Computer Workbook. This is an Excelfile that will work on computers with Microsoft Excel 1997–2003 ornewer versions.


Copyright ©2009 by University of Vermont ExtensionIssued in furtherance of Cooperative Extension work, Acts of May 8 and June 30,1914, in cooperation with the United States Department of Agriculture. University ofVermont Extension, Burlington, Vermont. University of Vermont Extension, and U.S.Department of Agriculture, cooperating, offer education and employment to everyonewithout regard to race, color, national origin, gender, religion, age, disability,political beliefs, sexual orientation, and marital or familial status.This material is based upon work supported in part by the Cooperative StateResearch, Education, and Extension Service, U.S. Department of Agriculture, underAgreement No. 2008-51130-19504.Every effort has been made to make this publication as complete and accurate aspossible. This text is only a guide, however, and should be used in conjunction withother information sources on crop, soil and farm management. The editors, authorsand publisher disclaim any liability, loss, or risk, personal or otherwise, which isincurred as a consequence, directly or indirectly, of the use and application of anyof the contents of this publication.Any reference to commercial products, trade names, or brand names is for informationonly, and no endorsement or approval is intended.Published April 2009AcknowledgementsThese training materials were partially funded through a grant provided by the VermontAgency of Agriculture Foods and Markets. We would also like to acknowledgethe following individuals for their roles in developing this publication: Dr. WendySue Harper for contributions to Session III and reviewing text; Joanne Youstenfor worksheet development, photographs, and reviewing text; Amanda Gervais forworksheet development and illustrations; Dr. Joel Tilley for worksheet development.Additional illustrations and photographs by Dr. William Jokela, David Heleba, andBen Gabos. Additional reviewing was done by Elaine Burnor, Debra Heleba, Dr.William Jokela, Dr. Fred Magdoff, and Dr. Eric Young. Cover illustration by AmandaGervais.2


ContentsGetting Ready for the Course ................................................................................................5SESSION I: Getting Started .............................................................................................................7LESSON I-1: Nutrient Management ......................................................................................8LESSON I-2: Navigating the Course Binder ..................................................................11EXERCISE I-1: Farm Information Worksheet ...............................................................12LESSON I-3: Maps and Soil Fact Sheets ..........................................................................14EXERCISE I-2: Map and Soil Fact Sheets Checklist ..................................................21LESSON I-4: Soil Sampling ......................................................................................................22EXERCISE I-3: Soil Test Schedule .........................................................................................23EXERCISE I-4: Organizing Your Soil Test Results .......................................................23LESSON I-5: Soil Erosion, RUSLE2, and Choosing a Rotation .........................24EXERCISE I-5: Choosing Rotations that Meet T .........................................................26EXERCISE I-6: Field Inventory Worksheet .....................................................................27EXERCISE I-7: Manure Application Schedule ..............................................................29EXERCISE I-8: Checklist ..............................................................................................................30SESSION II: Understanding Soil Nutrients .............................................................31LESSON II-1: The Dirt on Soil ...............................................................................................32LESSON II-2: The Nitrogen Cycle ........................................................................................36EXERCISE II-1: Calculating Nutrient Availability in Manure .............................40LESSON II-3: The Phosphorus Cycle .................................................................................48LESSON II-4: The P-Index ........................................................................................................52EXERCISE II-2: P-Index Worksheet .....................................................................................53EXERCISE II-3: Checklist ............................................................................................................553


SESSION III: Managing Soil Nutrients ..........................................................................57LESSON III-1: Managing the Plant and Soil Ecosystem .......................................58EXERCISE III-1: Farm Nutrient Balance ...........................................................................65LESSON III-2: Potential Environmental Risks on Your Farm ............................67EXERCISE III-2: Risk Assessment Worksheet ................................................................68LESSON III-3: N- or P-Based Management andManure Spreading Restrictions ...................................................................................70EXERCISE III-3: Checklist ..........................................................................................................72SESSION IV: Putting it All Together ................................................................................73LESSON IV-1: Understanding Potassium ........................................................................74LESSON IV-2: Secondary Nutrients and Micronutrients ......................................77LESSON IV-3: Understanding Nutrient Recommendations ..............................80EXERCISE IV-1: Field Plan Recommendation Worksheet .....................................86EXERCISE IV-2: Checklist ...........................................................................................................93SESSION V: Future Success .......................................................................................................95LESSON V-1: Making Use of Your Plan ..........................................................................96LESSON V-2: Recordkeeping ...................................................................................................99LESSON V-3: Reporting to State and Federal Agencies ....................................... 101LESSON V-4: Updating the Plan ....................................................................................... 103EXERCISE V-1: Checklist ......................................................................................................... 1054


Getting Ready For the Courset is very important that you communicateI with various agencies well in advance of thecourse so that you have all of the necessary materialson day one of the course. It can take as long assix months to collect all of the information listedbelow. Make sure that you allow yourself plentyof time before the course to gather the materialsneeded to complete your Nutrient ManagementPlan (NMP).You will need to have the following pieces ofinformation for Session I:Current Soil Test ResultsSoil test results must be no more than three yearsold. Samples must have been analyzed at the UVMAgricultural and Environmental Testing Lab or atanother lab that uses the modified Morgan extractant.It is best to have soil test results from all farmfields at the time of the class, but at a minimum,50% of fields should have current soil tests.Current Manure AnalysesA manure sample needs to be taken from eachmanure storage facility every year. Therefore, if youhave two manure storage facilities, each one shouldbe sampled at least once per year. This is a requirementbecause the nutrient content of manure varieswidely between different storage facilities, farms,and even between different seasons.Manure Production InformationThis is a calculation of how many gallons or tonsof manure, bedding waste, and waste water are producedon your farm each year. This number shouldbe calculated by a Natural Resources ConservationService (NRCS) employee or a land treatment plannerusing the Vermont manure screening tool. Theamount of waste produced should be calculatedseparately for each manure storage facility.MapsSix different types of maps are required to completea NMP. These maps are usually created by a landtreatment planner or NRCS soil conservationist.A NMP must have each of the following types ofmaps for all land included in the plan.WHAT IS A LAND TREATMENT PLANNER?Aland treatment planner is someone who helpsdevelop maps, crop rotations, and other importantpieces of a nutrient management plan. In Vermont,they work for the local conservation districts.Get to know your local land treatment planner!Proximity. This map shows the location of thefarm in relation to landmarks such as roads andtowns.Conservation Plan. This map gives acreage andFarm Service Agency (FSA) tract and field numbersfor each field, and erodibility and wetland determinations(if they are available).Nitrate Leaching. This map shows the level ofrisk for nitrates to leach through the soil to groundwater.Topographic. This map shows landscape featuresand slope.Environmental Concerns. This map shows thelocation of wetlands, streams, wells, and other sensitiveareas.Soil. This map shows the location of differenttypes of soil on the farm.5


RUSLE2 CalculationsRUSLE2 is a computer program that is used topredict soil loss or erosion from your farm fields.The amount of potential soil loss from each fieldis based on a variety of soil and management factors.Erosion rates are calculated over the course ofthe cropping cycle that is used by the farmer. Theerosion rate for each field must be at or below thetolerable soil loss level for that particular soil type.These calculations will be completed in collaborationwith a NRCS employee or a land treatmentplanner.Soil Fact SheetsEach type of soil present on the farm should havea corresponding fact sheet that lists characteristicsof that soil. These factsheets can be obtained fromNRCS or a land treatment planner.6 / Digging In


SESSION I. . .Getting StartedWhat will be covered in Session I:Introduction to Nutrient Management LessonsLESSON 1: Nutrient ManagementLESSON 2: Navigating the Course BinderLESSON 3: Maps and Soil Fact SheetsLESSON 4: Soil SamplingLESSON 5: Soil Erosion, RUSLE2, and Choosing a RotationTerms to Learn• nutrient management plan• NRCS 590 Nutrient Management Standard• Farm Service Agency land tract and field numbers• T or tolerable soil loss• RUSLE2Exercises1. Farm Information Worksheet2. Map and Soil Fact Sheets Checklist3. Soil Test Schedule4. Organizing Your Soil Test Results5. Choosing Rotations that Meet T6. Field Inventory Worksheet7. Manure Application Schedule8. Checklist7


LESSON I-1. . .Nutrient ManagementYou are here to develop a sound nutrientmanagement plan (NMP) for your farm.Nutrient management planning is a mixture of bestmanagement practices that aim to optimize cropyield and quality, minimize fertilizer input costs, andprotect soil and water. The basic principles of nutrientmanagement are to apply the right amount offertilizer in the right form, in the right place, and atthe right time. If these principles are followed, cropswill be productive, production costs will be minimized,and water resources will be protected. At theend of this course, you will have a NMP that satisfiesstate and federal regulations as dictated by theNRCS 590 Nutrient Management Standard. In additionto meeting regulations, nutrient managementplans can provide many benefits to both your farmand the environment.Nutrient Management CanSave Your Farm MoneyA NMP can save you money. By accuratelyaccounting for the nutrients from your manureapplications and from legume crops in your rotation,you can reduce the amount of commercial fertilizeryou need to purchase. Often this reduction issignificant. The bottom line is that following a NMPoften saves farmers money.The amount of the savings depends on your currentlevel of nutrient crediting. See the sidebar tothe right for an example of the nitrogen (N) fertilizervalue of the manure and legumes generated on a100 cow dairy farm.Nutrient Management CanProtect the EnvironmentA well-developed NMP will help you to farmwithin the needs and limitations of the environment.The driving force behind regulatory nutrientmanagement programs is environmental concerns— specifically, water quality protection. Two of themost crucial nutrients in farming, nitrogen (N) andphosphorus (P), can be harmful to the environmentif they are applied without a proper understandingof their potential impact on water resources. Inaddition, excessive nutrients occur in soil when theyare applied to a crop beyond what is needed foroptimum growth. The results of excessive nutrientapplication are not beneficial to the crop and canbe detrimental to the environment through nutrientlosses to air, surface water, and ground water. Nitrogenis a mobile nutrient and is not easily retainedSAVING MONEYWITH NUTRIENT MANAGEMENTAssumptions:100 cow dairy (N = $ 1.03/lb.)Alfalfa N = $ 6,180(50 acres/year @ 120 lbs. N/acre)Manure N = $ 13,905(27 tons/cow/year @ 5 lbs. N/ton)TOTAL on farm N value = $20,085• 50 acres of hay is rotated annually. Stand densityis 30 to 70% at time of plow-down.N credit = 120 lbs. N/acre.• Manure is from milking cows only. Each cowproduces 27 tons of manure per year. Manureis surface applied, therefore N content is 5 lbs.N/ton.• The value of N is $1.03/lb.• If you currently credit N for manure and plowdowns,you may NOT save money by following anutrient management plan.• If you don’t currently credit N, you canpotentially save a substantial amount on fertilizerpurchases.8 / Digging In


in soils. Nitrogen that is not utilized by plants ortied up in the soil (immobilized) can be lost to theair, lost to groundwater, or carried in runoff to lakesand streams. Nitrogen is readily lost to the air whenit is changed from a liquid to a gas through theprocess of volatilization or denitrification. Nitrogengaseous emissions from manure, fertilizers, andother sources are linked to ozone depletion and acidrain. The main concern with N losses is the leaching(downward movement) of nitrates through the soilinto groundwater. This problem is amplified whenN applications exceed crop removal rates. Excessnitrate in drinking water is a human health concern.Water high in nitrates can inhibit an infant’s abilityto utilize oxygen. Livestock can also be adverselyaffected by elevated nitrate levels in drinking water.The health standard for drinking water is 10 ppmnitrate-N.NUTRIENT LOSSESAIRSURFACEWATERAlgae blooms can turn parts of Lake Champlain greenduring the summer months.Nutrient Management CanImprove Public RelationsChances are, you have neighbors who don’tknow much about agriculture. Farmers need tobe concerned with the image of agriculture heldby the non-farming public. A good NMP is theideal jumping-off point for better public relationsbetween your farm and the community. Efforts todo this will begin with good manure storage, handling,and application. Such efforts will help youspread manure to minimize odor, road spillage, andtraffic hazards or delays. This also applies to watercontamination from cattle standing in bodies ofwater.GROUNDWATERNutrient losses can occur through volatilization into the air,runoff into surface waters, or leaching into groundwater.Phosphorus is the major nutrient promoting algaeand aquatic weed growth in lakes and streams.Phosphorus bound to sediments and in surfacewater runoff can lead to algae blooms and oxygendepletion in freshwater environments, such as LakeChamplain. However, in salt water environments,such as the Gulf of Mexico, N in surface waterrunoff is the major concern with algae blooms andoxygen depletion.What happened here? Maybe the tractor wouldn’t startthis day. An honest mistake like this can be bad for publicrelations.Getting Started / 9


By completing a NMP and implementing bestmanagement practices, you and your neighbors willknow that your farm complies with state regulationsand upholds the highest standards possible tokeep the environment safe and clean.Following the StandardIn this class we will develop our nutrient managementplans based on the NRCS 590 NutrientManagement Standard. What does this mean? Thisstandard is a very specific set of rules developed bythe USDA NRCS that outlines the information thatmust be included in a NMP. The “590” is a codenumber that NRCS has assigned to this collectionof rules and requirements. When a farmer uses soiltests to make decisions about applying fertilizer heor she is practicing a nutrient management strategy.But the farmer may not be taking into account themany environmental factors that affect the transportof nutrients, such as soil type, slope, and distance toa nearby stream. A nutrient management plan meetsthe highest standard of excellence — the NRCS 590Standard.The NRCS 590 Standard requires informationsuch as:• Basic information about the farm, such as area,number of animals, and contact information• Current soil and manure analyses• Crop rotations, cover cropping, and yield goals• Amount of manure produced and nutrient levelsin that manure• Manure and fertilizer application to each field(timing, amount, method)• Characteristics of the soils present on the farm• Detailed maps of environmentally sensitive areas• Environmental factors that affect nutrienttransport• Field by field plan for meeting the nutrient needsof the crop while minimizing movement ofnutrients from the fieldThis class will provide the tools for creating aplan that meets the NRCS 590 Standard. A completecopy of the NRCS 590 Standard can be found inyour class materials. As we go through each sessionwe will continually refer to the 590 Standard.You should take the time to read the standard.Plans meeting this stringent standard have takeninto account many factors specific to a farm anddemonstrate the highest level of stewardship of theenvironment.10 / Digging In


LESSON I-2. . .Navigating the Course BinderIn this class you have been provided with acourse binder and computer workbook containingall the necessary pieces for creating yourvery own NMP. The binder is divided into sectionsto help you navigate through the class and keepthings organized. There is a wealth of informationcontained in this binder, but in order to use it successfullyit will be helpful to familiarize yourselfwith where different information is located. Let’sgo through each section of the binder and describewhat pieces of information you will find there. Duringthe five sessions you will be filling out eachworksheet on the computer. A blank copy is providedin the binder in case you prefer to fill it outby hand first.on your farm. In addition, there are animal wastemanagement system overview, manure productioninformation, and manure application scheduleworksheets. If you export or import manure, youwill need to fill out a special form in this section.Manure Analysis. This is where you will findeverything relating to manure nutrients. There areinstructions on how to sample manure for analysis,instructions for calibrating your manure spreader,and worksheets that will help you calculate thenutrients that are in your farm’s manure.Field Information. In this section, you will listyour crop rotations and yield goals, and calculatecrop nutrient removal rates.Binder SectionsFarm Information. This first sheet is where youwill enter all of the background information aboutyour farm.Maps. Here you will placethe six types of maps createdfor your farm fields. Take aminute to look through themaps to make sure that they areall there and to organize themin a way that makes sense toyou.Soil Information. Behindthis tab you will place the soilfact sheets describing each ofthe soil types that are presenton your farm.Soil Analysis. Your soil testresults go here. In addition, there are instructionsfor taking a good soil sample, a soil test interpretationworksheet, and a soil test schedule.A former Nutrient Management classparticipant keeps his binder handy so hecan easily refer to it.Risk Assessment. By using the Vermont PhosphorusIndex and completing the environmentalconcerns risk assessment, you will be determiningthe risk for nutrient loss to groundwater and surfacewater.Field by Field Planning.Using your soil test results,you will be determining nutrientneeds for your crops andplanning how to meet thosenutrient needs with manureor fertilizer. Through this process,you will allocate all of themanure produced on your farmto your farm fields.Recordkeeping. An importantpart of a NMP is keepingrecords of what happens onyour farm, including manurespreading, fertilizer applications, yields, and anyunexpected changes that you had to make to yourplan.Manure Production. This section containsinformation on using manure as a nutrient sourceReferences. Here you’ll find a checklist of all thecomponents necessary for completing your NMP. InGetting Started / 11


this section you can also read the NRCS 590 Standard.If you are completing this plan for the VermontAgency of Agriculture, you will also need tofill out a form called “Additional NMP Requirementsfor Production Areas.”As you can see, there is a lot to be done in thenext five weeks. This process may seem overwhelmingat first because there is so much informationand paperwork, but don’t worry. We will be takingit one step at a time. More than eighty farmers havealready gone through this class and 99% of themhave completed their plans. You can do it too!EXERCISE I-1. . .Farm Information WorksheetThe first step in creating your NMP is to complete the farm informationworksheet (page 13). The goal of this worksheet is to help youdescribe your farming operation, capturing herd inventory, land use characteristics,agronomic practices, and farm goals. Here you will provide somebasic information about your farm, like in the example. The yellow boxeson the form will clarify what you need to fill out. Fill out the informationto reflect the management practices on your farm.12 / Digging In


Fill in the year for thenext growing season.Talk about any anticipated major changes such as changes to herd size, structures being built oradditional acreage being bought. If you anticipate that things will stay the same, then say so.If you don’t have a typical rotation, use a general one (5–7 yearscorn, 3–6 years hay) or fill this part out after completing your plan.If yougroupyouranimalsdifferentlythan this,fill in thetypicalages foryourcalves andheifers.“Continuously stocked” = animals onpasture. Fill in “number of paddocks” if yourotationally graze.Each watershed has a name and a code assignedto it. Ask your NRCS office for the code for yourwatershed.Getting Started / 13


LESSON I-3. . .Maps and Soil Fact SheetsHere are some examples of the six types ofmaps that are required for your NMP. Youshould have each of these types of maps for allland that is rented or owned. Your maps may havebeen made by a land treatment planner, NRCS,UVM Extension, or a private consultant. Keep inmind that your maps may look different than theseexamples, as each map maker has an individualstyle. The information on them, however, should bethe same. Be sure to refer to the legends on yourown maps to make sure you understand them.Proximity MapThis map shows the location of all tracts of land included in the farm inrelation to the town and road system. The farmstead and headquarters arepinpointed on the map.14 / Digging In


Conservation Plan MapAll farms that are involved in federal programs have been provided FarmService Agency (FSA) land tract and field numbers. The designations mustbe used throughout the plan. If erodibility or wetland determinations havebeen made on your farm, the fields will be marked with those designations.HOW TO READ A CONSERVATION PLAN MAPField name farmer usesIf a community crop hasbeen grown recently on afield it will be designated aseither highly erodible land(HEL), non-highly erodibleland (NHEL), or notdetermined (ND or blank).50 Ac Pc cornFSA 5NHEL30 ac.FSA field numberFSAacreageGetting Started / 15


Nitrate Leaching MapSome soils are very prone to losing N (in the form of nitrate) into groundwater.This is usually a problem in sandier soils. Each type of soil has beenrated low, moderate, or high on the Nitrate Leaching Index. The higher theindex, the more likely it is that nitrates will leach through the soil into thegroundwater. The level of N management on the field will be based on theleaching index. This tool will help you determine the appropriate practicesto minimize N leaching. This is important from both environmental andcrop nutrient perspectives. You want N to be taken up by your crops —not moving into groundwater.Later in the classyou will use thelegend to determinethe dominantNitrate LeachingIndex for eachfield.0–2 LOW2–10 MODERATE>10 HIGH16 / Digging In


Topographic MapThis type of map is familiar to many people. It contains contour lines thatshow the elevation of the area (in feet above sea level). The closer the contourlines are together, the steeper the slope.Getting Started / 17


Environmental Concerns MapEnvironmentally sensitive areas are shown on this map. The map is used tohighlight areas that could be threatened by pollution. This map shows thelocation of designated sensitive areas or resources and the associated nutrientmanagement restrictions such as buffers or setbacks. In the examplebelow, surface waters are shown with a blue line and the required 25-footbuffers are shown with green hash marks. Other sensitive areas such aswetlands, important wildlife habitat, wells, and buffers required aroundwells will be shown on this map.NUTRIENT APPLICATIONSETBACKS ANDRESTRICTIONSSurface waters (i.e. lakes,streams, rivers, ditches) areusually shown in blue.A 25-foot perennial vegetativebuffer must exist atthe top of the bank of surfacewater. These buffers may beharvested and treated withcommercial fertilizer duringthe growing season. No manurecan be applied in thebuffer area.When a public well ispresent, no agricultural activities,including nutrient applications,can occur within 200feet of the area.When a private well ispresent, no manure or nitrogenfertilizer may be appliedwithin 50 feet of the area.However, other commercialfertilizers (with the exceptionof nitrogen) can be appliedduring the growing season.18 / Digging In


Soils MapThere are more than 180 types of soil in the state of Vermont. Each soiltype has its own characteristics, which we’ll be talking about next. Each soiltype is identified by a two letter code. Sometimes there is a third letter thatindicates the slope. For example, that for the soil marked “EnA” below, “En”stands for Enosburg soil and “A” means that there is a 0 to 3% slope. Notethat the boundaries between soil types usually don’t follow field boundaries,so it is common to have more than one type of soil in a field.Getting Started / 19


Soil Fact SheetsThere is a soil fact sheet that describes each of the 180 distinct soil typesfound in Vermont. The fact sheet describes the formation of the soil, depthto water table, and how susceptible the soil is to erosion. We will only beusing part of the information on the soil fact sheet, which is highlighted inthe example below. You should have a soil fact sheet for each soil type onyour farm.MuB:Soil seriesabbreviationDrainageclassMunson silt loam, 3 to 8 percent slopesVermont Soil Fact SheetFranklin County, VermontMUNSON SOILS formed in loamy over clayey glaciolacustrine deposits on lake plains. They are very deep to bedrock andsomewhat poorly drained. These soils have a perched water table at depths of 0.5 to 2.0 feet below the surface from late Fallthrough early Summer. Permeability is moderate in the surface layer, moderately slow to moderate in the subsoil and slow in thesubstratum.This map unit is suited to cultivated crops. It is well suited to hay and pasture. Erosion is a hazard. A seasonal high water tablemay inhibit the establishment of some crops.Important farmland classification: Statewide Land capability: 3 w Vermont Agricultural Value Group: 4dVermont Residential Wastewater Disposal - Group and Subgroup:IIIc.- This unit is marginally suited as a site for soil-based residential wastewater disposal systems, based on a review by the NaturalResources Conservation Service of criteria set forth in the Vermont 2007 Environmental Protection Rules. The depth to theseasonal high water table in association with the minimal slope is the major limitation. A detailed, site-specific analysis is generallyrequired. On-site groundwater level monitoring and determination of induced groundwater mounding is often necessary to establishthe suitability of this unit. Curtain drains may help lower the water table to an acceptable level, however, the minimal slope mayprevent their use in many areas.Soil nameDepth(In)PHYSICAL and CHEMICAL PROPERTIESTypicaltextureClay(Pct)Soilreaction(pH)Permeability(In/Hr)OrganicEROSION FACTORSmatter(Pct) Kw Kf TMunson 0-8 SIL3-10 5.6 - 6.5 0.6-2 3.0-10 .49 .49 28-14 SIL3-16 5.6 - 6.5 0.2-2 0.5-3.0 .49 .4914-40 SICL35-60 5.6 - 7.3 0-0.2 0.0-1.0 .49 .49T(tolerablesoil loss)WATER FEATURESSOIL FEATURESSoil nameHydrologicgroupDepth to seasonalhigh water table(Feet)FrequencyFloodingDurationFrequencyPondingDurationHydricsoil?Depth to bedrock(range in inches)Munson D0.5-2.0 NoneNoneNo---LAND USE LIMITATIONSSoil name Land use Rating Reason **MunsonDwellings with basements: Very limited Depth to saturated zoneMunsonPond reservoir areas: Somewhat limited SlopeAGRICULTURAL YIELD DATACrop nameYield / acreCorn silage22 TonsGrass hay4 TonsGrass-clover5.6 AUMGrass-legume hay 3.5 TonsDepth tobedrockSoil nameMunsonMunsonMunsonHydrologicgroupManagementconcernRatingHarvest equip operability: Poorly suitedRoad suitability:Erosion hazard (off-road):Depth towater tablePoorly suitedSlightFrequencyof floodingWOODLAND MANAGEMENTReasonVermont natural communitiesWetnessValley Clayplain ForestWetness20 / Digging In


EXERCISE I-2. . .Map and Soil Fact Sheets ChecklistBefore you go any further, it is important to make sure that you have allof the maps and soil fact sheets that you will need for the class. Arrangethem in your binder in an order that makes sense to you (maps: by tract number;soil fact sheets: alphabetically) so that you will be able to easily locate them.Put checkmarks in the table below to verify that you have all of your maps.Now look at the soil map for each of your fields and make sure that youhave a soil fact sheet for each type of soil that is on your farm. You can use thetable below to keep track.If you are missing any fact sheets, please contact your course instructor,NRCS, or UVM Extension.MAP CHECKLISTMap TypeTract(s) Tract(s) Tract(s) Tract(s) Tract(s) Tract(s) Tract(s) Tract(s)ProximityConservation PlanNitrateTopographicEnvironmentalConcernsSOIL FACT CHECKLISTSoil Abbreviation Fact Sheet? Soil Abbreviation Fact Sheet? Soil Abbreviation Fact Sheet?MuB✓Getting Started / 21


LESSON I-4. . .Soil SamplingHow to Take a Soil SampleA soil test is the only practical way of telling howmuch fertilizer is needed in a given field. However,the reliability of a soil test is only as good as thesample you submit. The small amount of soil in thesample bag you send to the Agricultural Testing Labmust represent the entire area to be fertilized. Avoidunusual areas, such as those where fertilizer or limehas spilled. Take samples before lime, fertilizer, ormanure are applied. Use only clean equipment forcollecting soil samples.3. The area to be sampled should be as uniform aspossible in terms of soil type and cropping andfertilizing history. For practical purposes it shouldbe an area you expect to fertilize as a unit. Takeat least 15 soil cores or borings for each compositesample on a field of a maximum of 20 acres. Ifa field is more than 20 acres, take two completesamples.4. Insert the probe or auger into the soil to plowdepth or at least 6 inches for hay and otherperennial crops. Insert probe to the plow depth(usually 6-10 inches) for annual crops such ascorn. In general, do not sample any area of afield that varies widely from the rest of the fieldin color, fertility, slope, texture, drainage, or productivity.5. Discard any plant material and mix soil cores in aclean plastic bucket. Be sure to mix samples well.6. Take about 1 cup of the mixed soil cores andplace it in a plastic bag.7. Identify the bag with your name, field name, andsample number.8. Record the field, sample location, and date inyour records.Using a soil probe is the easiest way to get agood soil sample.1. In order to receive your recommendations earlyenough to use them for planning the next cropseason, it is best to take samples in the fall.2. Use a sampling probe or auger, available frommail order catalogs and garden or farm supplyoutlets, is the best tool for sampling and is anecessity if sampling large numbers of fields. Youmay be able to borrow a probe from your localNRCS office.9. Fill out the soil test questionnaire and place itin an envelope with the plastic bag along witha check. If submitting multiple samples, includeone check for total being tested. The sample canbe taken directly to the UVM lab or sent to theaddress below. If you need a copy of the soil testform, it can be found at the following website:http://pss.uvm.edu/ag_testingThe University of VermontAgicultural & Environmental Testing LabHills Science BuildingBurlington, VT 05405Results are normally returned in two weeks.22 / Digging In


EXERCISE I-3. . .Soil Test ScheduleAn important part of developing and maintaining a NMP is to regularlytest your soil. Soil testing is required for each field a minimumof once every three years. Fall is usually the best time for testing, especiallyif you are rotating to a different crop the next year. Soil testing in the fallwill ensure that you have all the necessary parts to complete your NMPduring the winter. Remember that when a field is larger than 20 acres, youshould be taking two separate tests (for example, a field called “Oak Tree”could be split into “Oak Tree North” and “Oak Tree South” for the purposesof soil testing). If the results are substantially different, the sections shouldbe treated as separate fields in the NMP.Completing the Soil Test Schedule worksheet will provide an easy referencefor you to remember which fields to test when soil sampling seasoncomes along. Some people prefer to soil sample all fields at once and otherslike to be on a rotation so they only sample some of their fields each year.Choose the option that works best for you, given your management style.EXERCISE I-4. . .Organizing Your Soil Test ResultsWriting a NMP involves a lot of paper shuffling and good organizationis necessary. In order to minimize confusion, you should firstwrite the FSA land tract and field number on each soil test. Do this even ifyou usually use familiar names (such as “Back Field”) rather than FSA tractand field numbers (such as “356-14”). For your NMP, you will get used tousing tract and field numbers in addition to your regular field names. Next,organize all of your soil sample results in a manner that makes sense forthe farm. For example, some farms put all corn fields first, followed by hayfields. Other farms put owned fields first, followed by rented fields.As you are organizing your soil tests you should start to identify trendson your farm. For example, do you have many fields that are excessive inphosphorus? Do you have fields that are low in potassium? Getting a feelfor your soil test analysis will help you determine appropriate manure andfertilizer rates later in the class. Find the worksheet in your binder calledSoil Test Interpretation and Planning Strategy and fill it out based on yourresults. Filling out this worksheet will help you figure out how to approachthe rest of the NMP based on soil test trends.Getting Started / 23


LESSON I-5. . .Soil Erosion, RUSLE2, and Choosing a RotationAfter studying the soils map it becomes clearthat soil is variable from farm to farm, fieldto field, and even within a field. Climate, soil type,and topography can result in a soil that is moreor less susceptible to erosion than other soil types.Erosion happens when soil has lost its structureand travels from one place to another. It can becarried away by wind or rain and its effects can bedevastating.The dustbowl is an extraordinary example oferosion. In this example of very poor farmingpractices, the land was farmed without providingperennial soil cover. The prairie grasses that held thesoil in place were replaced with year upon year ofannual crops. The soil was over-utilized and developedpoor structure to the point where the windsand rain of the prairies were able to carry the soilparticles, in some cases, all the way to Vermont.Sheet erosion.Ben GabosThree Basic Types of ErosionSheet Erosion. The removal of soil in a uniformsheet-like fashion, which occurs on bare soil andmay not be visible.Rill Erosion. This is a concentrated flow of waterdown small channels. These channels are too largeto be smoothed over with normal tillage.Gulley Erosion. This occurs when large channelsform over time, usually beginning as rill erosion.These channels are too large to be smoothed overwith normal tillage.Rill erosion.Some soils are naturally more erodible thanother soils. Steep and long slopes produce moreerosion than do short and flat slopes. Land use hasa major effect on erosion. Exposing the soil to raindropsand surface runoff dramatically increases erosion.According to the NRCS 590 Standard, the goalis to minimize erosion to a tolerable level inall fields.Gulley erosion.24 / Digging In


DEFINITION OF SOIL EROSIONSoil erosion is a two-phase process:1. Detachment of individual particles from soilaggregates.2. Transport of particles by erosive agents — windor water.Particles are eventually deposited to form newsoils or to fill lakes, reservoirs, or stream channels.be lost without impacting crop yields or production.For the soil in the example below, Munson silt loam,3 to 8 percent slope, the T value is 2. This meansyou can lose up to two tons of soil per acre per yearand this type of soil will be formed fast enough toreplenish the soil lost to erosion. This is acceptableand considered “farming to T.” To comply with theNRCS 590 Standard, all fields on a farm must meetT. A soil loss value for an individual field has beencalculated and can be found on the RUSLE2 sheet.What is RUSLE2?What is T?Every soil has a soil fact sheet that explains the specificcharacteristics of that soil. One characteristicis the soil’s T value. T stands for tolerable soil loss.This is the amount of soil per acre per year that canRUSLE2 stands for Revised Universal Soil LossEquation—Version 2. RUSLE2 is a computer modelthat estimates potential soil loss from rill andinterrill erosion caused by rainfall and overlandflow. It is a complex calculation that takes intoaccount soil type, crops grown, tillage, slope, andVermont Soil Fact SheetFranklin County, VermontMuB: Munson silt loam, 3 to 8 percent slopesMUNSON SOILS formed in loamy over clayey glaciolacustrine deposits on lake plains. They are very deep to bedrock andsomewhat poorly drained. These soils have a perched water table at depths of 0.5 to 2.0 feet below the surface from late Fallthrough early Summer. Permeability is moderate in the surface layer, moderately slow to moderate in the subsoil and slow in thesubstratum.This map unit is suited to cultivated crops. It is well suited to hay and pasture. Erosion is a hazard. A seasonal high water tablemay inhibit the establishment of some crops.Important farmland classification: Statewide Land capability: 3 w Vermont Agricultural Value Group: 4dVermont Residential Wastewater Disposal - Group and Subgroup:IIIc.- This unit is marginally suited as a site for soil-based residential wastewater disposal systems, based on a review by the NaturalResources Conservation Service of criteria set forth in the Vermont 2007 Environmental Protection Rules. The depth to theseasonal high water table in association with the minimal slope is the major limitation. A detailed, site-specific analysis is generallyrequired. On-site groundwater level monitoring and determination of induced groundwater mounding is often necessary to establishthe suitability of this unit. Curtain drains may help lower the water table to an acceptable level, however, the minimal slope mayprevent their use in many areas.Soil nameDepth(In)PHYSICAL and CHEMICAL PROPERTIESTypicaltextureClay(Pct)Soilreaction(pH)Permeability(In/Hr)OrganicEROSION FACTORSmatter(Pct) Kw Kf TMunson 0-8 SIL3-10 5.6 - 6.5 0.6-2 3.0-10 .49 .49 28-14 SIL3-16 5.6 - 6.5 0.2-2 0.5-3.0 .49 .4914-40 SICL35-60 5.6 - 7.3 0-0.2 0.0-1.0 .49 .49T(tolerablesoil loss)WATER FEATURESSOIL FEATURESSoil nameHydrologicgroupDepth to seasonalhigh water table(Feet)FrequencyFloodingDurationFrequencyPondingDurationHydricsoil?Depth to bedrock(range in inches)Munson D0.5-2.0 NoneNoneNo---LAND USE LIMITATIONSSoil name Land use Rating Reason **MunsonDwellings with basements: Very limited Depth to saturated zoneMunsonPond reservoir areas: Somewhat limited SlopeAGRICULTURAL YIELD DATACrop nameYield / acreCorn silage22 TonsGrass hay4 TonsGrass-clover Getting 5.6 AUMStarted / 25Grass-legume hay 3.5 TonsSoil nameManagementWOODLAND MANAGEMENTVermont natural communities


manure application over the course of the croppingcycle. RUSLE2 is a powerful tool for conservationplanning, inventories, and estimating sedimentproduction.Let’s look at a sample RUSLE2 report. You shouldhave something that looks like this for each of yourfields. Notice that the soil type and T value arelisted. There are three different management possibilitieslisted and the soil loss that would occurwith each strategy. A rotation is acceptable if the soilloss is less than T. The two rotations shown in greenhave soil loss values of 1.7 and 1.6, which are lessDo you have a problem with erosion on parts of yourfarm? Check in with your local NRCS representativeto find out ways to address various types of erosionissues.than T (2.0). The top rotation — continuous cornsilage with spring chisel and manure — has a soilloss value of 3.9. Since this is greater than T, it is notan acceptable rotation for this field.EXERCISE I-5. . .Choosing Rotations that Meet TYou should have received RUSLE2 reports (calculating the potentialsoil erosion for different rotations) for each of your fields. Foreach field, select a rotation that meets T by placing an X next to it on yourRUSLE2 report (as in lesson 1-5). The rotation should have a planned soilloss of equal to or less than the T value for the soil. Remember, this shouldbe a rotation that will work for your farm system. If you would like to userotations other than the ones listed on your report, talk to the person whodid the calculations for you to add rotation options for your farm.26 / Digging In


EXERCISE I-6. . .Field Inventory WorksheetNext you will take an inventory of every field you own or rent. Youwill record the field name (the name you call it), the FSA tract andfield number, acres, and soil type (you can find this on your soil map).The order in which you list the fields will be their order for the rest of theworksheets. Use the same order that you used for your soil tests and mapsso that it is easy to find information when you need it later on.In the column labeled “rotation plan,” you will be using the rotation thatyou chose for each field on the RUSLE2 report. Abbreviate the rotationsusing the list at the top of the page. For example, three years of corn silage followedby four years of grass hay would be abbreviated “3CS 4HG.” If you havea field in a continuous crop, use an abbreviation such as “cont HG” forcontinuous grass hay.Under “Year in rotation,” if you are in your second year of corn silageenter “2CS.” If you have a continuous crop, leave this blank.“Current year” is the coming crop season. For this example, written inJanuary ‘09:Current year = 2009/2009 Nutrient Management Planning WorkbookNext year = 2010Field Inventory SheetThe field inventory sheet provides a catalog of all your fields andtheir respective acreage and soil type. In additon, it providesinformation about the crop rotation and realistic yield goals for eachcrop.Producer: Joe FarmerExample Abbreviations:A: Alfalfa CS: Corn Silage CG: Corn GrainHG: Grass Hay SMG: Small Grain SB: SoybeanHL: Legume Hay SS: Sorghum/sudangrassRotation Year inPlan Rotation Current Last 2 Yrs NextYear Ago Year'sFall Spring Summer1 back 345-11 15 MuB 3CS 4HG 2 CS CS CS HG HG 5,000 5,000 202 oak tree 345-12 26.0 FaC cont. HG HG HG HG HG 5,000 5,000 5,000 43 triangle 345-13 5 Le 4CS 2HL 1CS CS HL HL CS 2,500 2,500 2,500 254 behind the barn 362-1 34 MuB pasture P P P P 0 0 05 across the road 362-2 25.5 MuB 3CS 4HG 3 CS CS CS CS HG 5,000 5,000 206 Johnny's house 362-3 8 FaC 3CS 4HG 2 HG HG HG CS HG 5,000 5,000 5,000 478910111213141516171819202122232425262728293031323334Field NameTract &Field #AcresOwnedAcresRentedSoil TypeCrop Information (Current Crop Year = 2009)(Exercise I-6 is continued on the next page)Est. Manure (last year)(gallons or tons)Yield Goal(T/A/Crop)Getting Started / 27


Your yield goal is reported as tons per acre, and should be based onwhat your soils are capable of producing in a good year. Corn silageyields are reported at the harvested moisture. Hay and haylage should bereported as tons of dry matter per acre. Estimate manure spreading rate foreach field for fall, spring, and summer of last year. Also, don’t forget to fillin the box at the bottom of the worksheet. How did you determine youryield goals? Soil fact sheets? Nutrient Weighing Management loads Planning at Workbook harvest?Field Inventory SheetThe field inventory sheet provides a catalog of all your fields andtheir respective acreage and soil type. In additon, it providesinformation about the crop rotation and realistic yield goals for eachcrop.Producer: Joe Farmer9596979899100Field NameTract &Field #AcresOwnedAcresRentedSoil TypeExample Abbreviations:A: Alfalfa CS: Corn Silage CG: Corn GrainHG: Grass Hay SMG: Small Grain SB: SoybeanHL: Legume Hay SS: Sorghum/sudangrassRotationPlanCrop Information (Current Crop Year = 2009)Year inRotation Current LastYear2 YrsAgoNextYear'sEst. Manure (last year)(gallons or tons)Fall Spring SummerTotal Acres: 87.5 26.0 Describe How Yield Goals were Determined:113.5We weighed one load of corn silage and then multiplied by the number of loads per acre.Yield Goal(T/A/Crop)28 / Digging In


EXERCISE I-7. . .Manure Application ScheduleThe Manure Application Schedule worksheet summarizes the timeof year that you apply manure to various crops on the farm. Youranswers in this section should reflect what you normally do on your farm.Remember, there is a winter spreading ban in Vermont from December 15thto April 1st, so no manure is allowed to be spread between those dates.Producer Name:Joe Farmer Date: January 1, 2009Farm Name: Green Valley FarmMANURE APPLICATION SCHEDULECROP Total Land Application Of Manure Is Planned To Occur During Highlighted MonthsGROUP ACRES JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DECCORN 75 X XHAY / LEGUME 126 X X X XPASTURE 5 X X X X X XMANURE SPREADING RESTRICTIONSManure may not be spread:• Within intermittent ditches, diversions, grassedwaterways, drainage ditches, or other areas ofconcentrated flow• Over bedrock outcrops• On frozen or snow-covered ground• Between December 15th and April 1stFrom the NRCS 590 StandardGetting Started / 29


EXERCISE I-8. . .ChecklistHere is a list of items that you should have completed before you go on tothe next session. Those items found in the computer workbook are listedin blue.SESSION I❑ Farm information worksheet❑ Maps (proximity, conservationplan, nitrate leaching, topographic,environmentalconcerns, soils)❑ Soil fact sheets❑ Soil test results organized❑ Soil test interpretation andplanning strategy❑ Soil test schedule❑ RUSLE2 (with your croprotation indicated)❑ Field inventory❑ Manure application schedule30 / Digging In


SESSION II. . .UnderstandingSoil NutrientsWhat will be covered in Session II:A Closer Look at Soil NutrientsLESSON 1: The Dirt on SoilLESSON 2: The Nitrogen CycleLESSON 3: The Phosphorus CycleLESSON 4: The P-IndexTerms to Learn• cation exchange capacity (CEC)• nitrate-N• ammonium-N• phosphorus index (P-index)Exercises1. Calculating Nutrient Availability in Manure2. P-Index Worksheet3. Checklist31


LESSON II-1. . .The Dirt on SoilANMP starts with understanding what’s inyour soil. Do you know what’s in yours? Thisis the essence of nutrient management. Soil is a complexand intricate system.Cornell Soil Health ProgramThe real story of soil lies not in its looks, but in itscharacteristics. Soil has three types of characteristics:physical, chemical, and biological.PhysicalSome physical properties of soil can be seen withthe eye or felt between thumb and finger. With theexception of texture, they are all subject to changecaused by weather and management.Color. Color can indicate soil conditions such asorganic matter content, drainage conditions, degreeof oxidation, and extent of weathering. Darker soilsgenerally contain more organic matter than lightercolored soils.Soil varies in its appearance and ability to grow crops.We can tell by looking at these two soils which would bethe better one for crops, but what is the real difference?Texture. Texture depends upon the amount ofsand silt and clay particles present. A Covington soilis characterized as a clay and may contain around65% clay, 30% silt, and 5% sand.Cornell Soil Health ProgramSOIL-STRUCTURE EVALUATIONGood Condition vs – 2 Moderate Condition vs – 1 Poor Condition vs – 0Good distribution of friablefiner aggregates with nosignificant clodding.Soil contains significant proportionsof both coarse, firm clodsand friable, fine aggregates.Soil dominated by extremelycoarse, very firm clods withvery few finer aggregates.32 / Digging In


Structure. The size and arrangement of structuralpieces called soil aggregates (the crumbs or chunksof soil) affect the amount and types of pores thesoil has, and therefore strongly influence water andoxygen storage and movement through the soil.Internal Drainage. Water drains below the rootzone following saturating rains.Depth. This is the distance from the surface tothe layer that stops downward growth of plantroots (bedrock or extremely compact layer). Depthaffects the capacity for water storage in a soil.Susceptibility to Erosion. Susceptible soils generallyhave a low amount of stable surface aggregatesand/or are poorly drained and/or have highslopes. Soils that have lost part or all of their topsoillayer to erosion are harder to till and not asproductive.pH. pH measures the relative acidity or alkalinityof a soil solution. This measurement is done on ascale from one to fourteen. At a pH of 7.0, the solutionis neutral. Less than 7.0 is acidic and greaterthan 7.0 is basic. The pH condition of the soil ranksamong a number of environmental conditions thataffect the quality of plant growth. Most agriculturalsoils in Vermont are in the range of pH 5 topH 7. The major impact of extremes in pH on plantgrowth is related to availability of plant nutrients.Most agronomic crops prefer soil pH between 6and 7. However, some crops such as blueberriesand cranberries prefer pH below 5. Because pH isexpressed on a logarithmic scale, a difference of onepH unit is a tenfold difference in acidity.Cation Exchange Capacity. Mineral nutrientswithin the soil have either a positive or negativecharge. The nutrients with a positive charge (includingcalcium, magnesium, potassium, ammonium,Building Better Soils for Better Cropsa) cations heldon humusChemicalChemical properties of soil involve the managementof soil nutrients at the most basic level.c) cations held byorganic chelateb) cations heldon clay particleNegatively charged organic matter (humus) and clayparticles play an important role in retaining positivelycharged plant nutrients, or cations, in soils.SOIL PH AND NUTRIENT AVAILABILITYUnderstanding Soil Nutrients / 33


and sodium) are held by negatively charged clayparticles and organic matter. Cation exchangecapacity (CEC) refers to a soil’s ability to retainthese nutrients (because organic matter and clayshave negative charges), rather than having themleached away. The more clay and organic matter ina soil, at near neutral pH, the higher its CEC.Amanda GervaisNutrients. The soil supplies the following essentialnutrients for proper plant growth and production.These nutrients can originate from weatheredminerals or from decomposing organic matter.Nutrients and their plant-available forms:Primary NutrientsNitrate-N (NO 3-)Ammonium-N (NH 4+)- 2-Phosphorus (H 2PO 4and HPO 4)Potassium (K + )Secondary NutrientsCalcium (Ca 2+ )Magnesium (Mg 2+ )Sulfur (SO 42-)MicronutrientsIron (Fe 3+ )Manganese (Mn 2+ )2–Boron (Bo 3)2–Molybdenum (MoO 4)Copper (Cu 2+ )Zinc (Zn 2+ )Chlorine (Cl – )Nickel (Ni 2+ )Cobalt (Co 2+ )The primary nutrients are used in the greatestamount by the plant, and are the ones you are mostconcerned about when creating the NMP.• Nitrogen is part of the chlorophyll molecule.Plants also require nitrogen in order to produceamino acids for building proteins. When deficientin nitrogen, plants become stunted and yellowcoloring appears in older leaves.• Phosphorus is important in developing healthyroot systems, normal seed development, uniformcrop maturation, photosynthesis, respiration, cellSoil nutrients are much like the staves holding a barreltogether. If one stave is too short, or a nutrient is in shortsupply, then plants cannot grow to their maximumpotential.division, and many other processes. Phosphorusdeficiency results in stunted plant growthand purple or reddish pigmentation in the olderleaves.• Potassium is responsible for the regulation ofwater usage in plants, disease resistance, stemstrength, photosynthesis, and protein synthesis.Deficiency in potassium results in scorching ornecrosis of older leaf margins and poor rootsystems. Potassium deficient plants also developslowly.BiologicalBiological properties of soil relate to the livingcomponents. Soil is much more than just lifelessdust; it is composed of living organisms such asearthworms, plant roots, insects, and microorganisms.Microorganisms, in particular, break down theremains of plants and other organisms. This processreleases nutrients that support plant and soil life.Soil has a very diverse biology and forms a delicaterelationship with the plants it sustains. Do nottreat your soil like dirt! Soil needs food and care,just as cows need grain and comfortable shelter.34 / Digging In


USDA Soil Biology PrimerEven though it may not be obvious at first, soil is full of life. Complex food webs exist in the soil ecosystem that helpto cycle nutrients.The Plant and Soil EcosystemPlants depend on soil for air, water, nutrients, andmechanical support. In order to accomplish this, asoil should be maintained in as healthy a conditionas possible.www.physicalgeography.net/fundamentals/10t.htmlSoil is composed of mineral particles, air, water, andorganic matter. Proportions of each vary in different soils,but these are proportions for a typical soil.Keep in mind that soil fertility is a delicate balanceof the physical, biological, and chemicalproperties. To maintain a healthy balance of theseproperties you should try to create a soil that hasthe following characteristics:• Good water infiltration and storage• Good soil tilth• Low rates of erosion• Good levels of organic matter• Contains a high level of biological diversity• The proper pH for the crops you’regrowing• All the essential nutrients in reasonable proportionto crop needsWe will be looking more closely at farming practicesthat help you maintain a balance of nutrients.The first step in maintaining healthy soil is knowinghow much of each nutrient it contains, and howthose nutrients behave in the soil.Understanding Soil Nutrients / 35


LESSON II-2. . .The Nitrogen Cyclegood balance of nutrients begins with theA big three: nitrogen (N), phosphorus (P), andpotassium (K). Let’s get started with nitrogen.Amanda GervaisForms of Nitrogen in the SoilThere are several types of nitrogen in the soil:Organic Nitrogen. Organic matter contains carbon.Aside from mineral forms such as calciumcarbonate (lime), anything with carbon is either livingor was once living. For instance, a field of grassplowed into the soil is considered organic fertilizerbecause it was once a living organism. Any nitrogenbound to the carbon in the dead grass wouldbe considered, by association, organic nitrogen.This kind of nitrogen is not readily available to theplants. It takes microbes to break down the organicmatter into inorganic-N forms that plants can use.Inorganic Nitrogen. Inorganic or mineral nitrogenis present in the soil in many forms:• Nitrate-N (NO 3–). Plants prefer this type of nitrogen,and almost all N taken up by plants is in thisform.• Ammonium-N (NH 4+). This is the first form ofN produced when soil microorganisms convertorganic N into mineral N. Usually it is rapidlychanged into nitrate.• Nitrogen Gas (N 2) This is the type of nitrogenin the air and is the most abundant form in theworld (the air you breathe is 78% N 2). The onlyplants that can extract N from the air are legumes(such as clover, alfalfa, and birdsfoot trefoil). Ifyou plant legumes, you can make your ownnitrogen!• Nitric and Nitrous Oxides (NO and N 2O). Theseare forms of nitrogen that are not utilized byplants but can be utilized by some microbes.Legumes have a special relationship with nitrogen fixingbacteria called rhizobia. Like the alfalfa plant in thispicture, legumes offer rhizobia sugar in exchange for thenitrogen the bacteria provide to the plant.Nitrogen Cycle1. Nitrogen Fixation. Nitrogen gas from theatmosphere is converted to ammonium-N. This isdone by the bacteria living in the nodules on legumeroots. Remember the rhizobium? If you inoculateyour legume seed with the rhizobium bacteria it willhelp ensure that atmospheric nitrogen gas is convertedinto a form that the plant can use. In turn,the plant will pass on some sugar to the bacteriaand give the bacteria a place to live. This is how Nis “fixed.” It becomes available in the soil for othercrops after these legumes or their roots die.If you give a legume a lot of fertilizer it can becomelazy. It will start to take N almost exclusively from thefertilizer.36 / Digging In


Building Better Soils for Better CropsThe nitrogen cycle.2. Nitrogen Uptake This is the process of yourplants taking up ammonium-N or, more commonly,nitrate-N. They then use these forms to make aminoacids and then proteins or other essential chemicals.3. Nitrogen Mineralization. Organic N is convertedto ammonium-N. In most soils it is convertedto nitrate almost immediately. These formscan then be used by plants or other organisms inthe soil.4. Denitrification. Nitrate-N is converted to gas— N 2or nitrous oxide — which then go into theatmosphere. This happens when the soil is saturatedwith water or really compacted. The nitrogen willvolatilize into the air and your soil loses valuablenitrogen.5. Ammonia Volatilization. When urea is appliedto the soil surface and not quickly incorporated, asignificant amount of N may be changed into theform of ammonia-N gas and is lost into the atmosphere.Nitrogen Deficiency SymptomsNitrogen is considered the primary limiting nutrientin many field crops. When corn is N deficientthe plants will become pale, yellowish-green incolor. Nitrogen is a mobile nutrient in the plant, andtherefore symptoms begin on the older, lower leavesand will progress up the plant if the deficiency persists.The symptoms will appear on leaves as a v-shaped yellowing, starting at the tip and progressingdown the midrib toward the leaf base. Inadequatefertilization can result in nitrogen deficiencies; however,weather also plays a major role in nitrogenavailability for the growing crop. In the early seasondeficiencies can be seen when the weather is coldUnderstanding Soil Nutrients / 37


Bill JokelaBill JokelaNitrogen deficiency symptoms on corn are visible as v-shaped yellowing, beginning at the tips of older leaves. Anoverall pale yellowish-green color can also be symptomaticof nitrogen deficiency.and the soils are saturated with water. During themid-season dry soil conditions can result in nitrogendeficiencies. Heavy rainfall during the growingseason can result in nitrogen leaching and henceinadequate nitrogen for the crops. Other factorssuch as flooding can also result in nitrogen losses.Don’t Treat Your Soil Like DirtThe nitrogen cycle is almost entirely biological(controlled by soil organisms), so it is important tomaintain the soil biology that drives it. If there isno soil biology then there are no soil organisms,which means your soil is dead. If your soil is dead,then there will be no nitrogen cycle no matter howmuch fertilizer you use. You must think of your soilas “livestock” that needs to be “fed.” Producing ahealthy, biologically active soil is the key to havingenough nitrogen for crops.Nitrogen and the EnvironmentThe excessive application or misapplication ofnitrogen can have a negative impact on the environment.Nitrogen can be lost to the environment in thefollowing ways:Leaching. Nitrate-N can leach easily as excessrainwater moves through soil to groundwater. ItOnly a fraction of the nitrogen in manure actually getsused by crops. The rest is lost into the atmosphere, leachesbelow the root zone, or remains in an unavailable organicform. Management practices such as incorporatingmanure soon after spreading can improve the fertilizervalue of manure.leaches because it has a negative charge that willrepel, rather than bind to, the negative charge of thesoil particles. Ammonium-N, on the other hand, hasa positive charge so it binds to the soil particles.Runoff and Erosion. When the surface of thesoil, fertilizer, and manure erode in a rain storm,they can carry ammonium-N and organic forms ofnitrogen into the water.Volatilization. Ammonium-N can volatilizethrough the air if it is on the surface of the soil,especially in warm weather. If possible, incorporatefertilizer and manure to avoid these types of losses.Maximizing the Fertilizer Valueof Manure NitrogenNitrogen is easily lost to the air (volatilized) whenammonium-N in manure is converted into ammoniagas. The amount of ammonia volatilization willvary greatly on both the environmental conditionsand management strategies. Losses can range fromclose to 100% for surface application to only a fewpercent when manure is incorporated immediately38 / Digging In


into the soil. While we can’t control the weather,we can minimize N losses through various manuremanagement strategies.If manure is incorporated into the soil, ammonium-Nis brought into direct contact with soilorganic matter and clay, which attracts ammonium-N and keeps it in the soil. Rapid incorporation ofmanure also reduces the chance for runoff and erosioninto nearby waters. Therefore, the best practiceto reduce N losses is to incorporate the manureimmediately after spreading. The longer you waitto incorporate manure, the more nitrogen lost tothe surrounding environment. The table on page43 (“Ammonium-N availability from spring- orsummer-applied manure,” from Table 15 NutrientRecommendations for Field crops in Vermont) showsthat immediate incorporation with standard tillageequipment or injection can increase N availabilityconsiderably.Generally, in the spring most farmers are rapidlyincorporating the manure as soon as it is appliedto corn fields. However, even a brief lag betweenmanure application and incorporation can result ina 30% loss in ammonium-N. There are situations,such as on grass fields, where manure incorporationis not possible. In these situations, wheremanure is primarily surface applied, ammonium-Nlosses can approach 100% if conditions are prime.Recently, there has been interest in alternativemanure incorporation systems such as aerators andvarious injection systems that could be used onboth corn and hay ground. These systems can providerapid incorporation of manure with reducedor no soil tillage, thus keeping more N in the soil tobe made available for plant uptake. There are manytypes of injection systems available but all workon the same general principle, slice the soil anddrop down the manure. There is evidence that deepinjection can effectively reduce ammonia losses onhay fields but the practice has also been shown tocause root damage and occasional yield reductions.Aerator systems poke holes in the soil (prior to, orat the time of, application) and most of the manuremakes its way into the holes. These systems resultin reduced nitrogen runoff and volatilization ascompared to surface applied manure. Some studieshave also documented yield increases as a result ofincreased nitrogen availability to the grass and alleviationof compacted layers.These incorporation systems can also provide ahost of other benefits. The advantages of using arapid manure injection system include: fewer odors,ability to place nutrients directly into the seedbed,and the reduction in nutrient loss via surfacerunoff. There are some potential drawbacks to thesystems such as: they tend to be more expensiveand may not be suitable for all soil types foundin Vermont including steeply sloping ground orstony soils. Of course, like any new practice youimplement, you must weigh all the advantages anddisadvantages before deciding whether a manureinjection system makes sense for your farm.Understanding Soil Nutrients / 39


EXERCISE II-1. . .Calculating Nutrient Availability in ManureWhat’s in your manure? Before starting this class, you should have submitteda manure sample for nutrient analysis at a testing lab. For informationon how to take a manure sample see the instructions at the end of thisexercise.It is necessary to describe your manure and waste handling facility to thestate and federal government. Find the form called “Animal Waste ManagementSystem Overview” in your binder. When filling out this form, be sure to includeeach type of manure storage that you have on the farm as well as how the manureis spread onto the fields.Next we will calculate on-farm nutrients available from manure. The worksheetcan be found on the “Manure Analysis Results” in the computer workbook.To fill out the worksheet you will need your manure analysis results. Ifyou did not get a manure sample tested use the “book values,” which are averagevalues found in the table below.If you only have one manure storage area, you only need to fill out thecolumn called “Storage #1.” If you have two or more separate manure storageareas (two manure pits, or a manure pit and a manure stack), then use a columnfor each storage.Typical values for total nutrient content of manure.(Table 14 from Nutrient Recommendations for Field Crops in Vermont)Species/typeDrymatter Total N NH 4-NOrganicN P 2O 5K 2O Mg Ca% pounds/1,000 gallonsDairy, liquid 7 25 12 13 8 20 4 10% pounds/tonDairy, semi-solid 17 9 3 6 4 7 2 4Dairy, solid (>20% DM) 26 9 2 7 4.5 7 2 6Beef 23 12 3 9 6 12 1.5 —Hog 9 14 8 6 11 11 1.5 —Sheep 25 23 7 16 8 20 2.5 —Poultry, layers 55 50 10 40 50 34 8 10Poultry, broilers 70 73 19 54 63 46 13 30Horse 37 9 1 8 6 11 4 —40 / Digging In


1/6/2009 Nutrient Management Planning WorkbookManure Analysis ResultsProducer: Joe FarmerFarm Name: Green Valley FarmCrop Year: 2009Type of ManureStorage IDLbs of nutrientTotal NNH 4 -NOrganic NP 2 0 5K 2 0% Dry MatterStorage #1Lbs of nutrientLiquidper 1000 gals.25.012.013.08.020.07.0Manure Analysis Results:Storage #2Lbs of nutrientSolid or Semisolidper wet tonYou are able to select the type of manureby clicking on the cell in your workbook.You will see an arrow on the right sideof the cell. Click on that arrow to get adrop-down menu.Storage #3Lbs of nutrientLiquidper 1000 gals.Storage #4Lbs of nutrientSolid or Semisolidper wet tonNote:8,300 lbs = 1,000 gallons1,000 gallons = 4.15 tons of manureStorage 1Total Gallons of Manure ProducedPer Year:Storage 2Total Tons of Manure ProducedPer Year:Storage 3Total Gallons of Manure ProducedPer Year:Storage 4Total Tons of Manure ProducedPer Year:1,357,007This number should be provided to youby NRCS. If you have kept detailedrecords of manure spreading you canuse them to estimate the total amountof manure produced on your farm in ayear.Next, for each storage area you use, fill in the amount of waste producedon your farm each year. You can get this number from your NRCS representative.It is calculated using a formula that takes into account manyfactors on your farm including animal numbers, bedding, water use, andrainfall.(Exercise II-1 is continued on the next page)Understanding Soil Nutrients / 41


Next you will move to the “Manure Storage” tabs in the computer workbook.In these worksheets you will calculate manure N available to cropsbaed on the type of manure, timing of application, and timing of incorporation.You need to fill out one of these for each manure storage facility thatyou have. Fill out all unshaded boxes in the worksheet. The shaded boxes(on the left side) are filled in for you based on the manure analysis numbersyou entered before. You will need to use three different tables foundon page 43 and 44 to fill in the middle numbers in each equation. This willallow you to determine the percentage nitrogen available from manure.12Organic N actsdifferently in welldrained and poorlydrained soil, so wecalculate the creditsseparately.1 2Calculationsfor hay fieldsCalculations forcorn and otherannual crops42 / Digging In


Availability of ammonium nitrogen from spring- or summer-applied manure (% fertilizer N equivalent).(Table 15 from Nutrient Recommendations for Field Crops in Vermont)Dairy cattle or other livestockPoultryTime to incorporationby tillage or rainThin(< 5% DM)Liquid or slurryMedium(5–10% DM)SolidThick orsemi-solid( > 10% DM) (> 20% DM)% availableImmediate/1 hour 95 95 90 95 95< 8 hours 80 70 60 80 901 day 70 55 40 60 852 days 65 50 30 45 803–4 days 65 45 25 35 705–7 days 60 40 25 25 60> 7 days(or non-incorporated)60 40 20 10 50Availability of ammonium nitrogen from fall-applied manure (% fertilizer N equivalent).(Table 16 from Nutrient Recommendations for Field Crops in Vermont)Dairy Cattle or other livestockPoultryTime to incorporationby tillage or rainThin(10% DM) (>20% DM)% availableImmediate/1 hr 40 35 35 40 407 days(or non-incorporated)25 15 10 0 20Understanding Soil Nutrients / 43


Availability (% fertilizer N equivalent) of organic N from manure applied in current and past years.(Table 17 from Nutrient Recommendations for Field Crops in Vermont)Dry matter Soil drainage Tilled SurfaceCurrent year 1 year ago 2 years ago% % available20 or less> 20Well to moderatelywell drainedSomewhat poorly topoorly drainedWell to moderatelywell drainedSomewhat poorly topoorly drained36 24 12 524 16 10 430 20 12 520 14 10 444 / Digging In


EXAMPLE:CALCULATING SPRING/SUMMERSURFACE-APPLIED MANURE N CREDITSLet’s start by looking at the first equation in the worksheet.The worksheet tells us that we will be using Table 15 for this equation:➔➔Let’s say that the manure on your farm is liquid dairywith less than 5% dry matter. You will use values in thecolumn for thin liquid manure. Next, we need to decidewhich row to use based on the time to incorporationof the manure. Since we are doing calculations forsurface-applied manure (on hay fields), which is non-incorporated, we use the last row of numbers. Ournumber is 60. What does this mean? It means that formanure spread in the spring or summer on hay fields,60% of the ammonium nitrogen will be available forcrop use.Remember to convert percentages to decimals:60% = 0.600.60 7.2So for each 1000 gallons of manure spread on ahay field, there are 7.2 lbs. of ammonium nitrogenavailable for the next crop. Do the same thing for eachof the other fields, being sure that you use the tableindicated. The worksheet will automatically do the calculationsfor you.Understanding Soil Nutrients / 45


Manure Nutrients Available for Crop ProductionThe worksheet called “Manure Nutrient Values” will be calculated automaticallyif you have filled out the previous sheets. Here we calculate the totalmanure nutrients on your farm that are available for crop use based onyour manure nutrient analysis and the amount of manure produced. Noticethat phosphorus and potassium are 100% available. Nitrogen availabilityis not 100% and that is why we calculated it separately. These are the totalnutrients that you will be allocating to your fields as you create your nutrientmanagement/2009 Nutrient Management Planning Workbookplan.Producer:Joe FarmerManure Storage 1Phosphorous Availabilty - 100%Manure Nutrient ValuesFarm Name:Green Valley FarmCrop Year:20098.0 1,357,007× ÷ 1000 =P2O5 (lbs/1,000 gal)Total gal Produced10,856Total lbs P 2 O 5 Available For CropsPotassium Availabilty - 100%20.0 1,357,007 27,140×÷ 1000 =K2O (lbs/1,000 gal)Total gal ProducedTotal lbs K 2 O Available For CropsNitrogen Availabilty7.9Total N (lbs/1,000 gal)1,357,00710,775× ÷ 1000 =Total gal Produced Total N lbs Available For CropsManure Storage 2Phosphorous Availabilty - 100%0.0P2O5 (lbs/ton)×0Total tons produced=0Total lbs P 2 O 5 Available For CropsPotassium Availabilty - 100%K2O (lbs/ton)0.0×0Total tons produced=0Total lbs K 2 O Available For CropsNitrogen AvailabiltyTotal N (lbs/ton)0.0×0Total tons produced=0Total N lbs Available For Crops46 / Digging In


HOW TO SAMPLE MANURE FOR NUTRIENT ANALYSISfield-by-field nutrient management programA requires multiple components to maintain adequatefertility for crop growth and development.Animal manure has long been used as a source ofnutrients for crop growth. Standard nutrient valuesfrom manure like those obtained from the NutrientRecommendations for Field Crops in Vermontbooklet are reasonable average values, but an individualfarm’s manure analyses can vary from thoseaverages by 50 percent or more. Species, age ofanimal, feed rations, water use, bedding type, management,and other factors make every farm’s manuredifferent. Because every livestock productionand manure management system is unique, thebest way to assess manure nutrients is by samplingand analyzing the manure at a laboratory. Accuratemanure analyses are essential for proper nutrientmanagement planning, but manure analyses areonly as good as the sample taken. The 590 Standardrequires that a manure analysis be conductedfor each storage facility every year.How to Sample Liquid StorageAgitate and thoroughly mix the manure beforesampling. Make a dipper by fastening a cup to abroomstick or pole and take a sample or two fromthe tank spreader and place them in a pail. Do thisfor multiple loads as the storage is being emptied.How to Sample Non-Liquid StorageUse a garden trowel and pail to collect a sample ofmanure from various spots on a load. Do this for representativeloads as the storage is emptied.How to Sample from Daily SpreadingUse a garden trowel and pail to collect a sample ofmanure from various spots on the spreader. Samplethe loads for two to three consecutive days. Itis recommended to avoid large chunks or pieces ofbedding and to select five to ten sub-samples fromdifferent places in the spreader.Handling the SampleImmediately after sampling the load, thoroughly mixthe contents of the sampling pail, remove a smallamount with a ladle and place it in a plastic jar, thencap it tightly and freeze immediately. Collect severalsub-samples from different loads on different daysand add each new sub-sample to the jar of frozenmaterial and refreeze immediately. Repeat until youfeel that you have a representative bulk sample. Besure that the plastic jar is three-quarters full to allowroom for expansion. Properly preparing the sampleis very important to prevent ammonia loss.Wipe the container to remove any manure thatmay have spilled down the sides. The outside of thecontainer should be clean prior to shipping. Securethe lid firmly and label with its name and date.Joanne YoustenThis method of sampling a manure pit is not recommended.Understanding Soil Nutrients / 47


LESSON II-3. . .The Phosphorus CyclePhosphorus (P) is an essential nutrient forplants and animals. In plants it plays a role inenergy transformation, photosynthesis, respiration,and cell growth. Adequate P is needed for early rootformation and growth as well as for seed formation.Livestock also require P for proper growth. It is anessential component of bones and teeth. Most ofthe world’s soils are deficient in P, but excesses areseen in states like Vermont that have areas with alot of animals, feed imported from other parts of thecountry, and manure. In general, the total amountof available phosphorus in most Vermont soils wasonce quite low, therefore it is ingrained in somefarmers to add phosphorus to fields every year.Would anyone think of putting on a starter fertilizerthat doesn’t contain P?Forms of Phosphorus in the SoilPhosphorus exists in many different forms in soil,including organic, soil solution, “bound,” and primarymineral forms. Organic P is bound to carboncompounds in the soil. It was produced from aonce living organism. Most of the organic-P in agriculturalsoils comes from livestock manure applicationsor crop residues. In order for the organic-Pto become plant available it must be released fromthe carbon bond by microorganisms. Soil solutionP is the soluble inorganic form of P, also knownas orthophosphates (H 2PO 4-or HPO 42-). This is theform taken up by plants, but it is also the form thataccounts for the smallest proportion of the total Pin most soils. Bound P makes up a large proportionof the soil P and is unavailable to plants becauseit is chemically bound to soil particles. P formsinsoluble compounds with different minerals in thesoil such as iron (Fe), aluminum (Al), or manganese(Mn) in acidic soils, or calcium (Ca) in basic soils.Primary mineral P is unavailable in the form ofrocks and minerals.Phosphorus CycleMost P in the soil originates from the weatheringof rocks, and from additions in the form of fertilizeror manure. Plants can only absorb P that hasbecome dissolved in the soil solution. The release ofP to plant roots is controlled by three chemical andbiological processes: 1) when phosphorus-bearingminerals slowly dissolve over long periods of time,2) when P bound to the surface of soil minerals isuncoupled, and 3) when soil organic matter decomposes.Organic P can be mineralized by microbesinto plant available forms. Soil temperaturesbetween 65 and 105°F favor P mineralization oforganic P. Most of the P added to the soil as fertilizerand manure can become rapidly bound by thesoil minerals in chemical forms that are not subjectto rapid release. This can happen one of two ways:The phosphorus cycle in soil.cropsoil.psu.edu/extension/facts/agfacts13.cfm48 / Digging In


• P reacts with Fe, Al, Mn or Ca (precipitation), or• P can be held by soil particles.The availability of P is largely based on soil pH.At a high pH (basic soil), P can precipitate with Ca.For instance, clay soil has lots of calcium or magnesium(also positively charged) that binds quicklywith the P. Once again, your P is rendered unavailableto your plants. At lower pH (acidic soil), Ptends to be bound to Fe and Al compounds in thesoil. Soils that have higher Fe and/or Al contentshave the potential to hold more P than other soils.Phosphorus is in its most plant available formwhen the pH is between 6.2 and 6.5.Because soil P is so easily bound in unavailableforms in the soil, soil solution P is typically verylow, even when plants are able to obtain sufficientquantities. However, at very high soil test levels, Pcan be available to plants in sufficient quantities,but can also be more prone to runoff and evenleaching. In order to assure that plants have sufficientP for growth, a farmer must conduct routinewww.unl.eduPhophorus is fixed by different soil minerals depending on soil pH. Phosphorus ismost available between a pH of 6.2 and 6.5.Apapted from Brady and Weil, 2002.Day 1Soluble phosphorus is addedto the soil and goes intosoil solution, where it ishighly available to the plant.Available and unavailable Pare shown as light circles anddark circles, respectively.Day 5Much of the phosphorus isquickly bound to soil particlesand only some of the P isreadily available to plantroots.Day 10Nearly all of the phosphorushas been tightly bound tosoil particles and is no longerreadily available to the plant.Understanding Soil Nutrients / 49


soil tests. The soil tests will allow the farmer todetermine if the pH must be adjusted to keep P in aplant-available state. In addition, it will also informa farmer if additional P should be added in theform of manure or fertilizer.Phosphorus Deficiency SymptomsPhosphorus deficiency is usually visible on youngcorn plants. Plants deficient in P will be dark greenwith reddish-purplish leaf tips and margins onolder leaves. The newly emerging leaves will notshow the purple coloration. Phosphorus deficientplants will be smaller and grow more slowly thanplants with adequate P levels. Deficiency symptomsnearly always disappear when plants grow to threefeet or taller. It is important to note that some cornhybrids tend to show purple colors at early stagesof growth even though phosphorus nutrition isadequate. Phosphorus is relatively immobile insoils therefore it is important to apply phosphoruswhere newly emerging plant roots can easilyabsorb it. Phosphorus deficiency is not alwayscaused by low soil P levels. Phosphorus deficiencycan be induced when soils are cold, too wet ortoo dry. Other factors that can impact phosphorusuptake include restricted root growth in compactedsoils; and roots injured by insects, herbicides, fertilizers,or cultivation.Phosphorus and the EnvironmentMost P loss to the environment occurs during fieldrunoff events. Phosphorus in runoff is either sediment-bound(attached to soil particles) or dissolvedin water. Sediment-bound phosphorus makes up themajor proportion of P transported from tilled soils.Runoff from grass fields carries little sediment, and isgenerally dominated by the dissolved form. Leachingof P is very rare but is possible under some conditions,especially in fields that have been recently tiled,or on well structured soil with many large pores.As soil test P increases, the potential for sedimentand dissolved P transport in runoff also increases.The soil is not an infinite sink for P. We can reacha saturation point at which the risk of P loss is high.Once saturated, the soluble phosphorus is free toflow and can run into the surrounding water. P caneven leach into the groundwater — something wedidn’t used to think could even happen. The soilonly needs 0.2 to 0.3 milligrams/liter of phosphorus.Algae in the lake only needs one tenth of thatamount. It doesn’t take much high-P runoff to startcausing problems.You have to be careful about the way you managephosphorus. This is especially true with manureapplication. If you are applying manure to increaseyour nitrogen content, keep in mind that themanure is rich in phosphorus content as well. SoAdapted from Sharpley et al. 1984Phosphorus deficiency symptoms on corn usually appearas red or purple coloring on the leaf tips and margins ofolder leaves.Soil test P accumulates at the surface with repeatedapplication of P for ten years.50 / Digging In


as you apply it to increase your nitrogen, you alsoincrease your soil’s P. You could end up doublingyour amount of P to reach the required amountof nitrogen. The problem with excess P is that it ismuch easier to build up than to use up after highlevels are reached.One of the goals of our NMP is to reduce Plosses from agriculture to surface waters. This goalcan be reached by minimizing inputs of P in feedand fertilizer, consistent with modern dairy cow andcrop management, and by balancing inputs withoutputs in crop and animal products. The buildupof P to excessive levels in soils can occur whenany P source, including commercial fertilizer andmanure, is over-applied for a long period of time.The greatest concern is the addition of P to landfrom manure applications.In the Northeast, most animal operations arelocated in grain-deficient areas and require thatgrain for animal feed be imported. This type ofproduction system represents a net import of nutrientsinto Vermont due to the combined inputs ofP-enriched feed, dietary feed supplements, andfertilizer. Manure is then applied near the point ofgeneration and most commonly within the boundariesof the “home farm.” Primary outputs of Pfrom these farms include crop and animal productsthat are removed and utilized off-farm. The flowof nutrients onto the farm is generally out of balancewith the flow of nutrients off the farm. Simplyput, more P is entering the farm boundary than isexiting in the form of salable products. The greatestproblems with excess P occur on farms withrelatively low acreage for the number of animals.In this situation, the amount of manure generatedexceeds the needs of the land.Phosphorus Movement and PollutionPhosphorus moves in two ways:• Runoff and erosion (the major forms ofmovement)• Leaching (less common)There are two types of P that can erode or run off:Sediment-bound Phosphorus. This is phosphorusbound to soil. When soil erodes, the phosphorusbound to that soil is moved into water. 80 to90% of all P loss happens as a result of erosion. Ifyou can greatly reduce erosion, you can significantlydecrease P pollution. P is a limiting nutrientfor algae just as nitrogen is the limiting nutrientfor corn. (P can be a limiting nutrient for crops— although it is not as common as N limitation.)Algae cannot grow without phosphorus.Dissolved phosphorus. This type of P movesfreely in solutions such as water and is readilyavailable. It is difficult to control runoff of dissolvedP. The best management strategy is to make surethat it infiltrates into the ground immediately.Sources of P for potential runoff include both the phosphorus added to the surface from manure and fertilizer as well asdissolved and sediment-bound phosphorus from the soil.Understanding Soil Nutrients / 51


LESSON II-4. . .The P-IndexThe phosphorus index is a tool developed toassess the potential for phosphorus runofffrom individual fields based on soil and field characteristicsand on management practices. Use of theP-index provides a way to identify fields that havea high P runoff potential and require conservationpractices or limitations of manure or fertilizer P. TheP index provides a way to prioritize nutrient managementpractices to the fields that have the highestpotential P loss.The index is based on two variables:• Potential erosion and sediment P• Potential for dissolved P to runoff.This is influenced by the following factors:Type of soil (i.e. clay or sandy). Some soil typesare more prone to runoff or flooding than others.Soil phosphorus and aluminum levels. Theamount of P and Al in your soil will affect the likelihoodof P loss.Water. Which part of Vermont are you in? Areyou at a high elevation that receives more rainfall?Soil erosion rate. This uses the RUSLE2 numberfor the rotation you chose.Timing and rate of manure application. Areyou applying manure in the fall or in the spring orboth?Method and timing of manure incorporation.Do you minimize applied manure’s exposure torain?Method , timing and rate of fertilizer P application.Is the fertilizer broadcasted or injected atplanting?What’s growing. Are you growing a hay crop orcorn? How well is the soil protected by crop residue?Buffer width. What is the distance, in feet, ofgrass or other vegetated buffer between the fieldedge and a waterway or area of seasonal concentratedflow.The P-index gives a relative rating for risk of Ploss from a field. It is better to use the P-index todetermine losses than to rely on soil P levels alonebecause it takes into account the above factors thataffect P movement.Each of your fields will fall into one of four categories,which are described below.Low potential for P movement from site. If farmingpractices are maintained at the current levelthere is a low probability of an adverse impact tosurface waters from P loss.Medium potential for P movement from site. Achance for adverse impacts to surface water exists.High potential for P movement from the site andfor an adverse impact on surface waters to occurunless remedial action is taken. Soil and water conservationas well as P management practices arenecessary to reduce the risk of P movement andwater quality degradation.Very high potential for P movement from the siteand for an adverse impact on surface waters. Remedialaction is required to reduce the risk of P movement.Soil and water conservation practices, plus aP management plan must be put in place to reducepotential for water quality degradation.During the next session, we will discuss whatthese categories mean for your NMP. You will befilling out a P-index for each field on your farm, solet’s look more closely at the worksheet.52 / Digging In


EXERCISE II-2. . .P-Index WorksheetFill out a column for each of your fields.TheP-Indexfor this field is“Medium.”Do not fill in these boxes.They will be automaticallycalculated.Enter from soiltest resultsThe total lbs. of P in the manureapplied will be calculated.Example:5000 gal. manurex 8 lbs. P/1000 gal.= 40 lbs. PIf you need help calculatingfertilizer rates, see page 87Use the RUSLE2 numberfrom the rotation you chose.Corn and row crops:0–20% coverHay: >20% coverSee the illustration on page 53explaining “Total distance tostream” and “Vegetative bufferwidth.”Understanding Soil Nutrients / 53


Examples for Vermont Phosphorus IndexField 1: HayTotal distance to stream = 25 ft.Vegetated buffer width = 25 ft.(minimum required)Manure spreading setback = 25 ft.(within field)Field 2: HayTotal distance to stream = 300 ft.Vegetated buffer width = 25 ft.Manure spreading setback = 0 ft.Field 3: CornTotal distance to stream = 25 ft.Vegetated buffer width = 25 ft.(minimum required)Manure spreading setback = 25 ft.(within field)Here are three different scenarios showing how the distance to stream and vegetatedbuffer width would be entered in the Phosphorus Index.Manure spreadingsetback:Although not requiredunder regulation, theaddition of a manurespreading setback isimplemented to betterprotect water resources.Total distance tostream:Although the streammay be directlyadjacent to a field,installation of therequired bufferincreases total distanceto stream to 25 ft.54 / Digging In


EXERCISE II-3. . .ChecklistHere is a list of items that you should have completed before you go onto the next session. Those items found in the computer workbook arelisted in blue.SESSION I❑ Farm information worksheet❑ Maps (proximity, conservationplan, nitrate leaching, topographic,environmentalconcerns, soils)❑ Soil fact sheets❑ Soil test results organized❑ Soil test interpretation andplanning strategy❑ Soil test schedule❑ RUSLE2 (with your croprotation indicated)❑ Field inventory❑ Manure application scheduleSESSION II❑ Animal waste systemoverview sheet❑ Calculation of amount ofmanure produced❑ Manure test for each storage❑ Manure analysis worksheet❑ Manure storage nitrogencalculations (one for eachmanure storage)❑ Manure nutrient values❑ P-indexUnderstanding Soil Nutrients / 55


SESSION III. . .ManagingSoil NutrientsWhat will be covered in Session III:Minimizing Environmental RisksThrough Nutrient ManagementLESSON 1: Managing the Plant and Soil EcosystemLESSON 2: Potential Environmental Risks on Your FarmLESSON 3: N- or P-Based Management and Manure Spreading RestrictionsTerms to Learn• mineralization• tilth• compaction• farm nutrient balance• dominant soil• nitrogen leaching index• N- or P-based management• manure spreading restrictionExercises1. Farm Nutrient Balance2. Risk Assessment Worksheet3. Checklist57


LESSON III-1. . .Managing the Plant and Soil EcosystemPlants and soil form a complex ecosystem.In terms of nutrient management we havefocused primarily on managing individual nutrientssuch as nitrogen, phosphorus, and potassium. It isimportant that farmers understand that soil fertilitymanagement goes beyond just managing thesenutrients. This lesson will help give you a broaderunderstanding of soil fertility as it exists within thecontext of the plant and soil ecosystem.MoistureTemperatureAirTextureStructureMicrobes, earthworms, etc.David HelebaLightAirWaterPollutantsNutrientspHCECOM = Organic matterThere are many variables integrally involved in sustaininga plant.What’s the Big Deal AboutOrganic Matter?Soil fertility and many of its principles are profoundlyinfluenced by soil organic matter (SOM).Soil organic matter is the portion of soil that isderived from decomposing plants and animals. Forexample, when you plow down a grass field, theleaves and roots become part of the SOM. The soilorganic matter is composed of several different fractionsincluding the living organisms, the fresh residues,and the decomposed residues.Living Organisms. Living organisms makeup about 15% of the soil organic matter. The livingportion of soil includes earthworms, insects,bacteria, fungi, plant roots, and animals such asvoles and moles. These organisms help break downfreshly added plant residues, manures, and otherorganic debris. In the process of breaking downthe debris, the organisms obtain energy and nutrientsand release nutrients that become availablefor plant uptake. This process of nutrient releaseis called mineralization. These organisms also playa role in soil aggregation and disease suppression.These functions will be addressed later.Soil fertility is defined as the ability of a soil toprovide a physical, chemical, and biological environmentfor plants that is health-sustaining. Inorder for farmers to maintain soil fertility there aresix basic principles to achieve:• Soil organic matter levels• Biological activity• Soil tilth• Minimal or no erosion• Proper soil pH• A balance of nutrientsFresh anddecomposingresidues


Fresh and Decomposing Residues. The freshand decomposing residues are another fraction ofthe SOM. In most soils these residues consist of30% or less of the organic matter. Fresh residuesinclude partially decomposed once-living organisms.These residues are generally no more thanthree years old. Again, as these fresh residues aredecomposed by living organisms the nutrientsin the fresh residues are digested. In the process,some nutrients are released to surrounding livingorganisms (mineralization). The relative speed ofdecomposition of these materials is related to thecarbon to nitrogen ratio of the fresh residues addedto the soil. Residues that have a high carbon tonitrogen ratio (C:N) can be slow to decompose. Thisis because the microorganisms require additionalnitrogen to decompose the high carbon materials.Often times these amendments will result in themicroorganisms “tying-up” nitrogen that wouldhave otherwise been available to the crop. Generally,residues with a C:N ratio of 20:1 or less haveenough available nitrogen for rapid decomposition.In addition, the decomposition of fresh residues willalso contribute to improving soil tilth.longer considered food for the living organisms inthe soil. This fraction of organic matter carries anegative charge and is considered essential for othersoil functions including the cation exchange capacity.These residues are anywhere from five to thousandsof years old.Fertility Principle 1 —Maintaining Soil Organic Matter LevelsIt is critical to maintain sufficient levels of organicmatter in the soil. This can be a difficult task forsome farms and requires a diversified approach.Essentially, organic matter can be maintainedthrough additions of a variety of types of organicmatter while simultaneously decreasing losses oforganic matter from the system. On dairy farms theprimary organic matter addition is manure. Otherorganic matter additions can occur from covercrops and crop residues. Even farms with a readilyavailable source of organic matter must work toreduce losses of organic matter from the croppedfields. For example, crop rotations that includeperennial hay crops will reduce organic matterlosses. Hay crops keep the soil from eroding andalso do not require tillage. Aggressive and continuoustillage will reduce organic matter levels in soil.Lastly, it is important to remember that applyingorganic matter also adds nutrients to the soil. Thereforewe must add organic matter in a manner as tonot over-apply nutrients such as phosphorus. TheSOM has a significant influence on several of theother physical and biological aspects of soil fertility.Fertility Principle 2 —Maintaining Soil Biological ActivityDecomposing organic residues provide food for soilorganisms.Well Decomposed Residues. The well decomposedresidues make up the majority of the soilorganic matter (75 to 80%). As you might haveguessed, the well decomposed residues were at onetime living organisms. These residues have beenthoroughly decomposed to unrecognizable carboncompounds. Essentially, these compounds are noThe second principle of soil fertility is to maintainbiological diversity in the soil. The soil food webconsists of a multitude of organisms that range insize but rely heavily on each other for survival. Abiologically diverse soil can have up to 100,000 differenttypes of living organisms.The biology in the soil has many important functionsthat make it possible to have healthy plantsand clean water. The primary activity of most soilorganisms is to grow and reproduce. Soil organismsdepend on interactions with each other to survive.Managing Soil Nutrients / 59


The by-products that come from roots and freshresidues feed the soil organisms. In turn, the soilorganisms will support plant health as they decomposeorganic matter, cycle nutrients, hold nutrients,degrade pollutants, improve soil structure, andcontrol populations of crop pests. Earthworms, forexample, break down large pieces of plant residuesinto smaller pieces for other soil organisms. Earthwormsalso burrow through soil providing lots ofair channels for root growth. Lastly, earthwormssecrete a mucigel as they burrow through the soils.This mucigel is one of the ingredients that help thesoil bind together.Fertility Principle 3 —Maintaining Soil TilthMycorrhizae are symbiotic associations between fungi andplant roots. The mycorrhizal fungus colonizes plant rootsand allows the plant access to more nutrients.The next fertility principle is to maintain soil tilth.Soils in good physical condition are considered tohave good tilth. This means the soil is porous andallows easy infiltration of water and penetration ofroots. The pore space is created by aggregated soil.Soil aggregates are formed when soil particles (sand,silt, clay) become glued together with organic matter,soil organisms, and plant roots. The glue thatholds all of this together come from the plants’To increase and maintain the diversity of organismsin the soil we must take care of the soil “livestock.”Similar to feeding our cows, soil organismsrequire energy, protein, water,oxygen, and a proper habitat.We can provide these key dietingredients by adding a diversityof organic residues. It isprobably obvious from the previoussection that adding freshorganic residues to the soil willfeed the soil life. However, different soil organisms requireslightly different foodstuffs. For example, fungiare common decomposers of plant residues becausethey generally have large amounts of hard-to-decomposecarbon. Bacteria are generally more abundanton green litter of younger plants because they con-CARING FOR YOUR SOIL LIVESTOCKEarthworms are one of the most visible soilorganisms and are often used as indicatorsof a healthy soil. Credit: US Composting Counciltain more simple carbon compounds. The bacteriaand fungi are only able to access plant residues aftershredder organisms, such as earthworms, break residuesinto smaller chunks.Oxygen and air space can beprovided by implementing practicesthat foster good tilth. Soilorganisms do not grow well incompacted soils that containlittle air space. Growing a varietyof plants species can alsocreate diversity of soil life. The plant roots of differentorganisms attract different microorganisms. The takehome message is to treat your soil livestock like youwould your own animals. Think about what practiceswill not only provide adequate food, but a healthy homefor the animals that lie beneath your feet.60 / Digging In


oots and soil microorganisms. These aggregatescome in all shapes, sizes, and levels of stability. Theplacement of aggregates in the soil ecosystem formsthe soil structure. The space between the aggregatesallows room for air and water. Therefore these soilshave fewer issues with erosion and runoff. Theseporous soils also have ample air space. Roots andmicrobes require oxygen and open exploration ofthe soil for optimum growth. The ample pore spaceallows plant roots to explore the soil and accessnutrients freely. Stable aggregates are preferred asthey can resist stress that might afflict the soil. Forexample, a soil that is well aggregated can resistrainfall, harsh tillage, and compaction.The problems start when these aggregates arebroken and remaining soil particles are squishedtogether. We refer to this as compaction. Once thepore space is eliminated it is difficult for roots togrow properly and for microbes to survive. Compactionalso keeps the soils water logged, resultingin anaerobic losses of nutrients. Essentially, nutrientcycling is severely limited without proper porespace.There are three types of compaction that weobserve on farms: surface, plow layer, and subsoilcompaction. Surface compaction is common inannually cropped fields. Surface crusting occurswhen soil is unprotected by surface residue, andraindrops disperse the aggregates by smearing themtogether into a thin layer of soil. Surface compactioncan inhibit the germination of crops andincrease the chance of erosion runoff.Plow layer compaction is also common in ourfields. The causes of plow layer compaction are ero-Soil compaction is a common problem in Vermont fields.sion, reduced SOM levels, and heavy field equipment.Fields that are too wet for tillage are prone tothis type of compaction.Subsoil compaction occurs below the normallytilled surface layer. Subsoil is easily compactedbecause it is commonly wetter and more dense thanthe topsoil. This compaction occurs when a tillageimplement applies pressure to the subsoil or whenheavy equipment with poor weight distributionis run over the surface of the soil. Compaction isalways most severe on wet soils.Certainly the goal of a farmer should be toimplement practices that maintain and improve soiltilth. Maintaining soil tilth first requires the additionof various types of organic matter to the soil.This organic matter increases the biological activityof the soil, resulting in the glues that form aggregates.These aggregates create ample pore spaceto allow for root, air, and water movement in thesoil. Organic matter additions can help reduce thechance of surface and plow layer compaction. It isalso important to maintain soil tilth through tillage.Tillage can be a detriment to soil tilth but also canbe beneficial in alleviating soil compaction. Reducedtillage can increase SOM and reduce traffic on thefields. It is important to work the soil when it isat proper moisture. One rule of thumb is to rollsome soil into a ball and drop it on the ground. Ifit breaks apart when dropped it is a signal that thesoil is dry enough to be worked.Fertility Principle 4 —Preventing ErosionWhen managing fertility it is important to reducenutrient losses to the environment. Erosion is aprinciple mechanism by which valuable topsoil islost from agricultural fields. Eroding soil generallyhas nutrients attached to it. As this soil is movedand deposited, valuable nutrients and organic matterare removed from crop fields. It is important toreduce or eliminate erosion to keep nutrients andorganic matter on the field. Ways to reduce erosionfrom agricultural fields include reducing the speedof water or wind and keeping the soil in a conditionthat will resist the impact of rain and wind.There are many practices that can be implementedto control erosion that will not hinder plantManaging Soil Nutrients / 61


productivity. First, keep the soil covered with plantmaterial as much as possible. For example, thereis a greater chance of losing soil from a row cropthan from a perennial grass crop. The grass cropholds the soil in place and the leaves can providemore coverage of the bare soil. In row crop systems,cover crops can be grown to protect the soil fromerosion during the fall and winter months. Reducedtillage can also reduce erosion. When the soil isturned with a moldboard plow more bare soil isexposed, making it susceptible to erosion. Reducedor no-tillage options will leave more plant residueon the soil surface. However, in the case of cornsilage, where the whole plant is removed, there isminimal residue, even with no-tillage. Cover croppingwill need to be implemented in order to haveenough residue to protect againist erosion. Theresidue can absorb the impact of rain droplets andimprove soil infiltration. In general, soils with higherlevels of organic matter and good structure are lessprone to erosion. The organic matter helps to creategood soil tilth. These soils are better able to absorbrainfall because they have more pore spaces toallow for water flow through the soil.CREATING BIODIVERSITYIt is important to increase biodiversity above andbelow ground. Above-ground biodiversity canboth enhance soil characteristics and help controlpest populations. When crops are grown in monoculturethere is a better chance of significant pestoutbreaks. The living organisms above ground canplay an important role in pest management. To encouragebeneficial insects above ground we mustprovide them with a diversity of food and a properhome. Generally these requirements can be metby making sure that there is more than one cropgrowing in an area. This can be done by plantingbiological or ecological islands; habitat and food forbeneficial organisms; biostrips, flower strips, beetlebanks, strip insectary intercropping, vegetative corridors,or hedge rows. It can also be accomplishedby planting a diversity of crops on the farm. Lastly,the judicious and careful use of pesticides is importantto minimize harm to beneficial organisms.Fertility Principle 5 —Maintaining a Proper Soil pHNext we must remember to maintain the soil pH. Itremains true that spending money on lime is probablythe biggest bang for your fertilizer buck. Aneutral soil is at a pH of 7. An acidic soil would fallHedgerows provide habitat for many beneficialinsects that help control pests.Legumes such as this red clover are an important part of acrop rotation.below 7 and an alkaline pH would rise above 7. ThepH can highly influence the nutrient availability inthe soil. Most crops prefer a pH between 6.0 and6.8. Some crops such as alfalfa prefer a pH of 6.8.This crop will perform poorly when the pH fallsbelow 6. Some of this sensitivity is due to the factthat legumes generally form an association with aspecial type of bacteria. The bacteria have the abilityto fix atmospheric N into plant-available N. Thesebacteria require a soil pH of 6.0 to survive. Molybdenum,which is necessary for nitrogen fixation inlegumes, is more available at a more basic pH.62 / Digging In


Fertility Principle 6 —Maintaining a Balance of NutrientsThe last principle of soil fertility is to balance thenutrients needed by plants while reducing theirimpact on the environment. This probably soundsfamiliar, as it is the primary goal of nutrient management.The goal is to provide what the cropsrequire while being careful not to over-apply variousnutrients. This is difficult to achieve, especiallywhen manure is used as a nutrient source. We wantto make sure that nutrients added to the soil do notbecome environmental hazards.Hopefully from this session you have learned thatthere are many factors that affect soil fertility. It is notas easy as just maintaining N-P-K. Careful managementof the soil’s biological, physical, and chemicalproperties will provide optimum crop production.CHARACTERISTICS OF HEALTHY SOILFarmers usually know when a soil is healthy byits ability to grow healthy crops. Healthy soilshave the following characteristics:• Good soil tilth• Sufficient depth• Sufficient but not an excessive supply ofnutrients• Small populations of plant pathogens and insectpests• Good soil drainage• Large populations of beneficial organisms• Low weed pressure• No chemicals or toxins that may harm the crop• Resistance to degradation• Resilience when unfavorable conditions occurManaging Soil Nutrients / 63


While traditional soil tests measure the chemicalproperties of soil such as pH and nutrient levels,it is well accepted that biological and physical propertiesalso play an important role in soil’s ability to growcrops. This more holistic approach to looking at soil hasbeen called “soil health.” Soil health (or soil quality) canbe defined as the capacity of a soil to function withinecosystem and land use boundaries, to sustain productivity,maintain environmental quality, and promoteplant and animal health (Doran and Parkin, 1994).Since 2001, Cornell University has been developinga test to measure soil health. Twelve indicators ofbiological, physical, and chemical soil properties areused to make a comprehensive assessment. SomeTHE CORNELL SOIL HEALTH TESTThe Cornell soil health report uses a stoplight system to show howyour soil compares with other soils of similar texture. Red indicatesproblem areas.of these indicators include: available water capacity (ameasure of the ability of crops to store water betweenrains), aggregate stability (a measure of how well soilaggregates hold together in rain and resist surfacecrusting), and active carbon (a measure of the soil organicmatter fraction that is available as a food sourcefor microorganisms). The test results show how yoursoil compares with more than a thousand soil samplesthat have been submitted from the northeastern UnitedStates.The procedure for submitting a soil sample for theCornell soil health test is somewhat different than fortraditional soil tests. First of all, the sample should betaken in the spring before the ground is tilled. If you areinterested in submitting a sample fromyour farm, you will need to borrow aspecial piece of equipment called apenetrometer (or soil compactionmeter) as measuring field compactionis part of the test. Biological propertiesare very sensitive to changes intemperature, thus, the sample mustbe kept refrigerated until it is submitted.It is important to follow the samplinginstructions carefully or to gethelp from someone with experiencetaking soil health samples in order toobtain meaningful results.Because of the wide array of teststhat are performed on each sample,the soil health test is more expensivethan a standard chemical soil test.The current cost of a soil health testis $45 per sample (2008 price). Becauseof the cost, it is most economicalto target specific “problem areas”on the farm for sampling and comparethem with “good areas.” Thetest will identify constraints on plantgrowth that exist for a particular soil,but will require interpretation to determinethe best management strategiesfor dealing with constraints.For more information on the Cornellsoil health test, visit the followingwww.hort.cornell.edu/soil-website:health.64 / Digging In


EXERCISE III-1. . .Farm Nutrient BalanceNext we will calculate crop nutrient removal rates in order to determine ifthere is enough crop need for the amount of manure nutrients producedon your farm. You will be using Table 19 which can be found on page 66.In the example below, the farm grows 150 acres of corn grain and has anaverage yield of 120 bushels per acre. From Table 19, we can find the nutrientremoval rate (or nutrient need) per bushel of grain corn (nitrogen 0.75lbs./bushel, phosphorus 0.4 lbs./bushel, potassium 0.3 lbs./bushel). Note thatthe units are different for different crops. The total nutrient need for each cropgrown on the farm will be automatically calculated and totaled. In Session IIyou calculated the nutrients that are available from manure, and those valueswill automatically fill in the “Manure Supplies” row.Now we will look at the most important part of the worksheet — the balance.If the number is positive, this means that you have enough crop needto account for the nutrients in your manure. If the number is negative, it willshow up in red and this indicates that you have too much manure for yourland base. You will need to export some of your manure so that you are in4/6/2009 compliance with state Nutrient regulations. Management Planning WorkbookFarm Nutrient Balance (Based on Crop Removal Rates)Yield X Acres X lbs of nutrients removed per unit of yield = Total Nutrient NeedCrop Removal Rates can be found on Table 19 in "Nutrient Recommendations For Field Crops in Vermont".(See Appendix for Table 19 data)Producer: Joe FarmerFarm Name: Green Valley Farm2009Yield perNitrogenP 2 O 5K 2 OCropAcre Acres lbs/unit Total Need lbs/unit Total Need lbs/unit Total Needcorn grain 120 150 0.75 13,500 0.4 7,200 0.3 5,400corn silage 20 10 9.0 1,800 5.0 1,000 11.0 2,200soybeans 40 60 3.2 7,680 1.0 2,400 1.4 3,360alfalfa 5 40 50.0 10,000 15.0 3,000 50.0 10,000grasses 4 140 40.0 22,400 15.0 8,400 50.0 28,000small grains 80 40 1.1 3,520 0.9 2,880 1.5 4,800Total Crop(s) Need: 58,900 24,880 53,760Manure Supplies: Use Manure NutValue Worksheet* 10,775 10,856 27,140Balance:Estimated Nutrients Needed(Negative # indicates excess)48,125 14,024 26,620*Use the figures from the sheet "Estimate of Manure Nutrients Available for Crop Production" in the Manure Production section.Does this Balance indicate that you have the land base needed for appropriate application of the volume of wastethat your farm produces?yesRemember to fill out this box. A one word answeris sufficient. If all of your balances are positive,then your answer should be “yes.”Managing Soil Nutrients / 65


Typical crop nutrient removal.(Table 19 from Nutrient Recommendations for Field Crops in Vermont)Crop (units)Per unit of yieldRemoval for given yieldN P 2O K 2OTypicalyield/A N P 2O K 2OCorn (bu) .75 0.4 0.3 120 (bu) 90 50 35Corn silage (T) 4 9 5 11 20 (T) 180 100 220Grain Sorghum (bu) 0.5 0.6 0.8 120 (bu) 60 70 95Forage Sorghum (T) 4 9 3 10 15 (T) 135 45 150Sorghum/sudangrass 4 8 7 7 15 (T) 120 105 105Alfalfa (T) 2,5 50 1 15 50 5 (T) 250 75 250Red clover (T) 2,5 40 1 15 40 3.5 (T) 140 55 140Trefoil (T) 2,5 50 1 15 40 3.5 (T) 175 55 140Cool-season grass (T) 2,5 40 15 50 4 (T) 150 60 200Bluegrass (T) 2,5 30 10 30 2.5 (T) 75 25 75Wheat/rye (bu) 3 1.5 1 1.8 60 (bu) 90 60 110Oats (bu) 3 1.1 0.9 1.5 80 (bu) 90 70 120Barley (bu) 3 1.4 0.6 1.5 75 (bu) 105 45 110Soybeans (bu) 3.2 1 1.4 40 (bu) 130 40 56Small grain silage (T) 4 17 7.0 26 40 (bu) 100 40 160Note: Adapted from Beegle, 2003.1Legumes fix all their required nitrogen. However, they also are able to use nitrogen as indicated.2For legume-grass mixtures, use the predominant species in the mixture.3Includes straw.465% moisture.510% moisture.66 / Digging In


LESSON III-2. . .Potential Environmental Risks on Your FarmOne of the goals of nutrient managementplanning is to produce high yield and qualitycrops while protecting the environment. Inorder to minimize the farm’s environmental impactyou must understand the factors that influencethe risk of water pollution. Once these factors areidentified, appropriate control and managementmeasures can be implemented to minimize environmentalpollution.In previous lessons, we have learned how variousnutrients can be lost from our farms. For example,nitrogen can be lost through volatilization, denitrification,leaching, and runoff. Phosphorus can be lostthrough runoff and erosion. It is important to knowhow the soil properties, landscape, and managementpractices on the farm will influence the loss of thesenutrients. Some of these properties cannot be modified,such as soil type and slope. A clay soil will bedenser and more poorly drained than a sandy soil,leading to an increased chance forrunoff. However, there are a numberof cropping practices that canbe implemented or modified tolower the potential impact.Most farmers know their soil andland better than anyone else. Youknow which crops grow best where,what fields require the most tillage,which fields require the most rockpicking, and which fields are closeto ground or surface water. Thegoal of analyzing risk is to combine your knowledgewith scientific principles to reduce the risk of pollution.This is primarily accomplished by the use ofrisk models. We have already learned about severalof these risk models in the other sessions. The firstrisk assessment model is RUSLE2. This programincorporates your management practices as well assoil types and slopes into a computer model anddetermines the potential amount of soil loss fromyour fields. The more soil loss potential, the riskierthe field is in terms of water quality.Vegetated buffer strips betweenfields and waterways help tominimize the risk of nutrientloss to surface water.Another model is the phosphorus or P-index.This program is used to determine the potential forphosphorus erosion and runoff from your fieldsinto surface water. It incorporates your management,soil type, slope, and proximity to water intoits calculation. A high P-index indicates a threat towater quality.Lastly, there is the nitrogen leaching index. Thismodel determines the potential for soil-appliednitrogen (in the form of fertilizer or manure) to beleached into the groundwater. The benefit of thesemodels is that you can change your managementpractices to reduce your potential risk to waterquality. For example, crop rotations with perennialcrops and manure incorporation practices cangreatly reduce nutrient loss.In addition to the risk models, there are otherpotential environmental risks on farms that should benoted and managed. For example, determine wherewaterways and wells are located onthe farm. A waterway might be abrook, stream, river, or sometimes afarm ditch. It is important to identifythese areas and provide appropriatevegetated buffers between agriculturalcrops and the water. The Stateof Vermont requirement for mediumand large farms is 25 feet from thetop of the bank of a water courseto the edge of the agricultural field.This area must be vegetated withgrass and/or other perennial plants where no manureis spread. For small farms the requirement is 10 feetfrom the top of the bank. If you are involved withfederal nutrient management programs, a 25-footbuffer is required regardless of farm size. Identificationof public and private wells is important so thatproper manure spreading setbacks can be determined.While identifying risks is often tedious, it is importantto remember that we need to be responsible stewardsof the land. These risk assessments benefit not onlyour farms but our local communities.Managing Soil Nutrients / 67


EXERCISE III-2. . .Risk Assessment WorksheetIt’s time to fill out the Environmental Concerns Risk Assessmentworksheet. Most of the information you’ll need will come from soilfact sheets, environmental concerns maps, and nitrate leaching maps. Thefirst four columns will be filled out for you by the computer.Environmental ConcernsRisk AssessmentThe environmental concerns risk assessment provides a field by field assessmet to identify environmentally sensitive features.This assessment also provides information on the potential for phosphorus and nitrogen transport from the field to sensitiveEnvironmeRisk AProducer:areas.Producer:Joe FarmerJoe FarmerWater Qual. SiteTract &Dominant Limiting HydrologicDom.DrainageWaterTable Flood Depth toRUSLE2 SoilLoss (asConsiderations(springs, wells,Field Name: Field # Field Acres Soil Soil Group Class Depth Potential Bedrock Planned)etc) Field Name:back 345-11 15.0 MuB Le D Poorly 0-1 None 0.31backoak tree 345-12 26.0 FaC D Poorly 0-1 None 0.31oak treetriangle 345-13 5.0 Le Le D Poorly 1.5-3.0 None 20-40 0.31 Private Well trianglebehind barn 362-1 34.0 MuB Le C Moderately 1.5-3.0 None 1.1behind barnacross road 362-2 25.5 MuB ScA D Poorly 1.0 None 1.5across roadby Johnny's 362-3 8.0 FaC Me C Moderately 1.0-1-5 None 1.3 Stream by Johnny's“Limiting soil” isfound on the soilmap. You’ve chosenthe dominant soilalready, but thelimiting soil is theone that will limityour yield (it canbe the same as thedominant soil insome cases).All information forthese columns canbe found on the soilfact sheets. Fill theseout according to thesoil fact sheet forthe dominant soil(the most prevalentsoil type in thefield). For a reviewof how to read soilfact sheets, go topage 20.This willfill inautomaticallyfrom theP-index.Note any waterquality siteconsiderationsfor this field(springs, wells,etc.).68 / Digging In


This will fill inautomaticallyfrom your P-indexworksheet. Forexplanation of soiltest P categories seeTable 18 below.These will fill inautomaticallyon the computerbased on theinformation youalready entered.They will beexplained in thenext lesson.ntal ConcernsssessmentTract &Field # Field Acres345-11 15.0345-12 26.0345-13 5.0362-1 34.0362-2 25.5362-3 8.0* Buffer Width will vary, depending on Federal / State Regulations that different-sized farms need to meet, or Cost-Share Program participation, or changing rules. Keep Informed of the buffer widths that apply to your farm.Other SiteConsiderations(neighbors, etc)Soil Test PRangeP-Index asPlannedNitrateLeachingPotentialNeed N- orP- BasedMgmt?ManureRestrictionCode(R, Y, G)Special NeedsResidue Sandy Buffers*Medium LOW MODERA N-based GREENOptimum LOW LOW N-based GREEN xLow MEDIUM LOW N-based GREEN xHigh HIGH MODERA P-based YELLOW xMedium LOW HIGH N-based GREEN xHigh VERY LOW P-based REDIs there anythingelse you shouldbe aware of whenyou are planningfor nutrientapplicationon this field?Concernedneighbors? Wetspot in the field?For “Nitrate LeachingPotential” you willneed to use yournitrate leachingmaps and select thedominant category(low, medium, orhigh) for each field.Nitrogen leachingindex categories:0–2 Low2–10 Moderate10–20 HighCheck the appropriatebox if your field hassignificant amountsof crop residue (suchas if you are growinggrain corn), sandysoil, or buffers. Anyof these situationsmay require specialattention whenapplying manure orxfertilizer.xxxxxxVermont soil test categories expressed as pounds per acre (lbs./acre, or pp2m) in elemental form.(Table 18 from Nutrient Recommendations for Field Crops in Vermont)Low Medium Optimum High Excessivelb/acreAvailable P 0–4 4–7 8–15 16–40 >40K 0–100 101–200 201–260 261–325 >325Mg 0–70 71–100 101–200 >200 —Managing Soil Nutrients / 69


LESSON III-3. . .N- or P-Based Management and Manure Spreading Restrictionshe P index is an indicator of the potential forT runoff loss of phosphorus from your fields.The P-index will give you a rating for each field:low, medium, high, or very high. From the resultsof the P-index and your soil test P results, yourfield is designated as requiring either N- or P-basedmanagement. You can find the status of each fieldby looking at the column “Need N- or P-basedmanagement” on the environmental risk worksheet.Whether a field is under N-based or P-based managementwill affect your approach to meeting cropnutrient needs. In a perfect world, we would beable to create a blend of fertilizer that met the exactneeds of each field. Since we are using manure tosatisfy crop needs and we can’t easily change thenutrient composition of the manure, we will likelybe over-applying or under-applying some nutrients.When using 80 manure as a nutrient source, generallythere is a tradeoff between N and P. If you applyenough manure 60 to meet the crop’s N needs, therewill usually be a buildup of P over time.The P-index and your soil tests provide us with40Initial soila way to figure out which type of management test P is 18 ppm isappropriate in each individual field. Let’s define20each type of management:Soil test P (ppm)N-Based Management. 0 You are managing thecrop based on -20its nitrogen 0needs. Manure 20can be 40Annual P surplus (lb/acre/yr)applied at rates needed to meet crop removal ratesFigure 4. Increase in soil test P from applying more Por soil test N recommendations. However, with thisthan a crop needs each year (as Bray–I P). Anegative surplus indicates crop and soil removal.(Adapted from a 25-year study by Barber 1979.)method you must monitor soil test P levels. (Nbasedmanagement will generally result in a buildupof soil P over time, so be sure to continue monitoringsoil test P level.)P-Based Management. You are managing thecrop based on its phosphorus needs. You mayapply only enough manure to meet P crop removalrates or soil test recommendations for P.Manure Spreading RestrictionsOn the risk assessment worksheet you will also finda manure spreading restriction code. This code isset up using a stoplight system with red, yellow, andgreen (see page 71).CornDairy manureP removed (lb/acre)Poultry litterSharpley et al. 2003P added(lb/acre)0 50 100 150P added in manure or removed by cropApplying manure to meet crop N needs (about 200 lbs.Figure 5. Applying manure to meet crop N needsavailable N/acre) adds much more P than corn removes.(about 200 lb available N/acre) adds much more Pthan corn crop needs.not incorporated or they are incorporatedonly to shallow depths,thereby exacerbating P buildup inthe top 2 to 5 inches of soil. In somesituations, P can easily movethrough the soil, as we will discusslater.Continual long-term application offertilizer or manure at levels exceedingcrop needs will increase soil Plevels (fig. 4). In many areas ofintensive, confined animal production,manures are normally appliedat rates designed to meet crop Nrequirements but to avoid groundwaterquality problems created byleaching of excess N. This oftenresults in a buildup of soil test Pabove amounts sufficient foroptimal crop yields. As illustrated infigure 5, the amount of P added in770 / Digging In


Manure Spreading RestrictionsREDFields with a very high P-indexYELLOWFields with a high P-index or soil testlevels greater than 20 ppm. Even ifthe P-index is medium, you mustmanage for P if your soil test exceeds20 ppm.GREENFields with a low to medium P-index▲ ▲ ▲No P may be added through manureapplications. You have to managethese fields carefully in ways that willprevent P runoff and will draw downsoil P levels over time.Manure and fertilizer applicationsare based on P recommendations.P-based management means thatmanure application may not exceedrates of P removal by crops.You can apply manure based on Nrecommendations. Be careful! If youadd 10 lbs. of N per 1000 gallons ofmanure, you will apply 15,000 gallonsof manure to get 150 lbs. of N. Thisalso means you are applying 120 lbs.of P. Your P level will rise over timeand soil test results will show levelsat high or very high. You must managethis before it happens.EXAMPLE OF MANURE CALCULATIONFOR “YELLOW” MANURE SPREADING RESTRICTIONWith a yellow manure spreading restriction, manureapplication may not exceed rates of P removal bycrops. Look at crop removal rates for corn silage:Let’s say your typical yield is 20 tons/acre (see tableon page 66).How many lbs. of P 2O 5are removed per acre?Answer:20 tons x 5 lbs. P 2O 5removed per ton = 100 lbs.So how much P 2O 5can you apply in your manure?Answer: 100 lbs.How much manure do you put down to get 100 lbs.of phosphorus? Refer to the table on page 40.On average there are 8 lbs. of P 2O 5per 1000 gallons ofmanure. You are allowed to put on 100 lbs. of P 2O 5(8 x 12 = 96).12 x 1000 gallons =12,000 gallons of manure per acreRemember that it is best management to not applymore nutrients than the crop needs. Following the soiltest recommendation will minimize nutrient over-application.If you just base your measurements on cropremoval then you won’t utilize all of the nutrients alreadyin your soil. This is a waste of money. In addition,you’ll never bring your phosphorus levels down.Managing Soil Nutrients / 71


EXERCISE III-3. . .ChecklistHere is a list of items that you should have completed before you go on tothe next session. Those items found in the computer workbook are listedin blue.SESSION I❑ Farm information worksheet❑ Maps (proximity, conservationplan, nitrate leaching, topographic,environmentalconcerns, soils)❑ Soil fact sheets❑ Soil test results organized❑ Soil test interpretation andplanning strategy❑ Soil test schedule❑ RUSLE2 (with your croprotation indicated)❑ Field inventory❑ Manure application scheduleSESSION II❑ Animal waste systemoverview sheet❑ Calculation of amount ofmanure produced❑ Manure test for each storage❑ Manure analysis worksheet❑ Manure storage nitrogencalculations (one for eachmanure storage)❑ Manure nutrient values❑ P-indexSESSION III❑ Farm nutrient balance❑ Risk assessment worksheet72 / Digging In


SESSION IV. . .Putting It AllTogetherWhat will be covered in Session IV:The Rest of the StoryLESSON 1: Understanding PotassiumLESSON 2: Secondary Nutrients and MicronutrientsLESSON 3: Understanding Nutrient RecommendationsTerms to Learn• macronutrient• secondary macronutrient• micronutrient• luxury consumptionExercise1. Field Plan Recommendation Worksheet2. Checklist73


LESSON IV-1. . .Understanding PotassiumAlong with N and P, potassium (K) is referredto as a macronutrient because it is foundin such large quantities in most plants. Potassiumis important for plant growth, reproduction, andwinter survival of perennial plants. It is involved inover 60 different enzyme systems in plants, helpsplants resist the effects of drought and extremetemperatures, and increases a plant’s ability to resistdiseases. Potassium is generally not considered anenvironmental problem and therefore we haven’tyet covered it. However, managing potassium isimportant because it is easily leached and can becostly to maintain. Furthermore, when growing feedfor livestock, over-application of K can cause severeherd health issues.Forms of Potassium in the SoilMuch of the potassium in the soil is not available tocrops and is tied up in primary minerals. As theserocks and minerals are broken down over time,they release small amounts of K at a very slow rate.This portion of K (about 10% or less) is referredto as “slowly available.” Only a small amount (lessthan 2%) is available for plant uptake. This isfound in the soil solution and is often referred toas “exchangeable” K because the positively chargedpotassium ions are constantly moving between thenegative charges found in soil particles (the cationexchange capacity, or CEC) and the soil solution.The results you get for K on a soil test report actuallyreflect what is available and do not account forall the K that is not available.The Potassium CycleThe fate of K in the soil can vary. In the soil solution,it can be taken up by the plant or exchangedonto soil particles and/or organic matter. Potassiummoves easily with water, so it can also be leachedAdapted from Brady and Weil, 2002Primary mineralsUnavailable90–98%Forms of potassium in the soil.2:1 ClaysSlowly available1–10%ExchangableSolutionAvailable1–2% .1–.2%74 / Digging In


out of a soil if there is water movement due toheavy rains. This most often occurs on very sandysoils that have a low CEC value. Potassium can alsobe tied up with other minerals and become “fixed”until those minerals break down. Soil pH can alsoinfluence soil K. As pH increases, the number ofexchange sites found on the organic matter alsoincreases, enabling the soil to retain more potassium.Plants take up K in large amounts. The cropremoval rate of K depends on what portions ofthe plant are harvested. Most of the K in a plantis found in the leaves and stems, therefore, wholeplants such as corn silage or hay crops will removea lot of potassium. Grain crops remove much lessK, as long as the remaining residue is recycled backinto the soil. Major sources of potassium includeanimal manure and mineral fertilizers (symbolizedas K 2O on fertilizer labels) mostly in the form ofmuriate of potash (0–0–60), which is also knownas potassium chloride. Animal manures can havesignificant amounts of potassium but can varydepending on the type of animal, method of storage,and amount of water in the manure.Potassium DeficienciesPotassium deficiencies occur when the plantdemand for K exceeds what is available in the soilsolution. K deficiency symptoms include burnedlookinglower leaves, spots near the edges of leaflets,and yellow or dead areas on the edges of leaves.Since K is a mobile nutrient in the plant, deficiencysymptoms usually start in lower leaves.Potassium deficiency can be a problem in soilswith low cation exchange capacities, because thesesoils aren’t able to retain potassium ions. TheseInternational Plant Nutrition InstituteInput tosoilComponentLoss from soilCropharvestPlantresiduesAnimalmanures andbiosolidsMineralfertilizersRunoff anderosionPlantuptakeExchangeablepotassiumLeachingSoil solutionpotassium(K + )MineralpotassiumFixedpotassiumThe potassium cycle.Putting It All Together / 75


Department of Soil Science, University of WisconsinCONSIDERATIONS IN POTASSIUMFERTILIZATIONPotassium deficiency symptoms of corn.• Manure is an excellent source of K and isconsidered 100% available in one croppingseason.• Generally, hay crops only need one K applicationa year. However, split applications of K help toreduce luxury consumption and prevent leachingin sandy soils with low organic matter.• Hay crops generally have their highest levels of Kduring the first growth of the season, therefore, itis usually best to apply an annual application ofK after the first or second cutting rather than inthe spring.Potassium deficiency symptoms of soybeans.get the best yield response out of N fertilization. Itis especially important to maintain adequate soilK levels when growing a mixture of grasses andlegumes. At low soil K levels the grass will almostalways out-compete the legume.soils tend to be sandy with low organic matter. Thisproblem is usually addressed by splitting potassiumapplications.Alfalfa can remove a large amount of potassium(250 lbs./acre for a yield of 5 tons) and thus requiresthat potassium be replaced to maintain high yields.Adequate levels of soil potassium are also importantfor reducing the risk of winter injury in alfalfa.Grasses can remove as much potassium as alfalfa.However, since their fibrous root systems are moreefficient miners of potassium, they are really goodat extracting potassium even from soils testinglow for K. In many cases, adding potassium canimprove grass yields since K has to be adequate toAlfalfa winter injury can be exacerbated by potassiumdeficiency.76 / Digging In


LESSON IV-2. . .Secondary Nutrients and MicronutrientsWWhile N. P, and K are classified as primarymacronutrients, magnesium (Mg), calcium(Ca) and sulfur (S) are classified as secondary macronutrientsbecause they are found at intermediatelevels in plants. Micronutrients, — which includeiron (Fe), zinc (Zn), manganese (Mn), copper (Cu),boron (B), chlorine (Cl), molybdenum (Mo), andnickel (Ni) — are found in very small amounts. Ifyou look at a forage report or a plant tissue test,normally you will see that primary and secondarymacronutrients are reported as percentages, whilemicronutrients are reported in parts per million(ppm). To give you a sense of the differences inscale, the table below gives the sufficiency levels ofnutrients for field corn used in tissue testing. As youcan see, micronutrients are found at much smallerlevels in plants than are macronutrients.Generally, we have not seen deficiency problemswith secondary macronutrients or micronutrients inThe sufficiency levels for corn of most nutrients(measured from the ear leaf at silking time) reportedas both percentages and in parts per million.Nutrient Percent PPMNitrogen (N) 2.5–3.5 25,000–35,000Phosphorus (P) 0.25–0.45 2,500–4,500Potassium (K) 1.7–3.0 17,000–30,000Calcium (Ca) 0.25–0.50 2,500–5,000Magnesium (Mg) 0.13–0.30 1,300–3,000Sulfur (S) 0.21–0.50 2,100–5,000Iron (Fe) 0.0021–0.025 21–250Manganese (Mn) 0.0015–0.03 15 -300Zinc (Zn) 0.002–0.01 20–100Copper (Cu) 0.0006–0.002 6–20Boron (B) 0.0005–0.0025 5–25Snyder, 1998our field and forage crops in Vermont. The exceptionsto this are boron in alfalfa and trefoil and,occasionally, zinc in corn. The infrequency of deficiencyproblems is probably largely due to the greatamounts of animal manure that most of our agriculturalsoils have received over the years. Manureis a good source of most of these nutrients. In addition,when soil is properly limed to maintain anoptimum pH, calcium is usually adequate for mostagronomic crops.There have been some cases of magnesium andzinc deficiencies in corn and boron deficiency inforage legumes, so some additional discussion ofthese is found below. Also, there are some concernsabout sulfur deficiencies, though most studies inNew York and Pennsylvania have not shown widespreadproblems.MagnesiumOn occasion, magnesium deficiencies are found,particularly in field corn. The most obvious symptomof Mg deficiency is interveinal chlorosis onolder leaves. This means that the veins stay green,but the area between the veins turns yellow. This isfairly distinguishable from the deficiency symptomsof other nutrients. Magnesium is a fairly mobilenutrient in the plant, therefore symptoms often firstshow up in the older leaves (similar to N, P, or K).Your soil test should show if a field’s Mg levels arelow. Deficiencies are sometimes associated with bothlow soil Mg levels and high K levels. Both being cations,K will compete with Mg for soil exchange sitesand for plant uptake levels. This is why the UVMsoil recommendation for Mg is based on both factors— a low soil Mg level and a very high soil Klevel.Generally, the least expensive and most practicalway to provide Mg to a crop is to add a high magnesiumlime such as dolomitic limestone when routinelyliming. However, if pH is adequate, a fertilizersuch as sul-po-mag (S, K, and Mg) can be applied.Putting It All Together / 77


Interveinal chlorosis on older leaves is a symptom ofmagnesium deficiency in corn.Low Mg levels in grass pasture are sometimesassociated with grass tetany or hypomagnesemia,a condition in livestock with low blood Mg levels.High N and/or K fertilization can also contribute tothe problem. Although fertilization may help correctMg levels in the forage, it is usually more economicalto supply the animals with Mg in their mineralsupplement. In addition, risks associated with thiscondition can be reduced by avoiding N and K fertilizationin early spring, and by encouraging morelegumes in the pasture mix.become limiting in the future for two reasons.Historically, the two major sources of S were contaminatedfertilizers and air pollution. With modernfertilizers formulated more purely and withair pollution reduced, there is a likelihood that Scould drop below critical levels for high-producingcrops. Research in New York and Pennsylvaniahas not shown this to be a problem so far. In Vermont,it may be less likely that we will have sulfurdeficiency problems because of our heavy applicationsof animal manure in addition to air pollutionemissions. On average, there are about two poundsof S for every ton of manure. By rough estimate,approximately eight pounds per acre per year maybe contributed by air emissions (based on datafrom two monitoring stations in Vermont).It is best to be on the lookout for S problems.Deficiencies are most likely to occur in high rainfallareas on sandy soils with low organic matter thatreceive little or no manure. The best visual symptomis a general yellowing of newest, top leaves (seepicture below). If you suspect S deficiency, tissueanalysis is one way to confirm the problem. Collectsamples from both the suspected area and from“good” areas so you can compare the analyses. Ifthe corn is still in the vegetative stage (25 to 45 daysMontana State UniversitySulfurAlthough there have been no confirmed reportsof sulfur deficiencies in our field crops, many soilfertility specialists warn that this nutrient couldSources of sulfur.Sulfur deficienct corn plant on right.78 / Digging In


old), collect whole plants. If the corn is at tasseland silk stage, collect several ear leaves for analysis.Sufficient levels at either of these stages should bebetween 0.18% and 0.40% of dry matter. For alfalfa,sample whole plants. As with corn, sufficient levelsshould be between 0.18% to 0.40%. You can alsolook at the N to S ratio for alfalfa. It should bebetween 12 and 17.ZincCases of zinc deficiency in corn do show up onoccasion in Vermont. Usually they show up withinthe first month of corn emergence. Symptomsappear on the youngest leaves when corn plants arestill quite young. Visual symptoms include a uniquebanded chlorosis on the leaves and stunted plants.Conditions in which Zn deficiency is most likelyto occur include the following:BoronIn the 1950s, University of Vermont soil scientistsfirst demonstrated that alfalfa and bird’s-foot trefoilneed supplemental boron. Our soils tend to be lowin B. Based on that early work, the general recommendationhas been and still is to apply one to twopounds of B per acre per year to these crops.B deficiency is most likely to occur on coarsetexturedsoils that are easily leached, or when soilpH is above 7.0 (when B becomes highly adsorbedby the soil). You can also get deficiency symptomsduring dry periods. Visual symptoms show up firston the youngest leaves as yellow to reddish necrosisappears along the edges of the leaflets. The plantswill also be stunted and rosette in shape.British Columbia Ministry of Agriculture• Cool spring weather• Sites that receive little or no manure• Acid soils that are heavily limed to bring the pHto 7.0• Soils testing high for P• Highly eroded high lime soilsThe decision to apply zinc as either banded or incorporatedis based on both soil test results and pastobservations of deficiency symptoms. Foliar applicationsof Zn as a rescue treatment for corn alreadyshowing symptoms have had limited success.Owen Plank, University of GeorgiaYellow and red leaf discoloration in alfalfa is typical ofboron deficiency.Sometimes symptoms of boron deficiency areconfused with potato leafhopper damage. Bothoccur in the summer and cause stunted plants.However, the most striking visual symptom of hopperburnis the V-shaped necrosis at the tip of theleaflet — not damage along its edges.Ohio State University ExtensionZinc deficiency in corn.An adult potatoleafhopper.Hopperburn in alfalfa.Putting It All Together / 79


LESSON IV-3. . .Understanding Nutrient RecommendationsApproaches for NutrientRecommendationsWhen you submit a soil sample for testing, theresults and recommendations you get back mayvary from lab to lab. It is important to understandboth what type of chemical extractant a particularlab uses, and how that lab interprets the soil testresults. You should use the same lab whenever possibleso that you get consistent results. There arethree approaches or philosophies to interpretingsoil tests and making fertilization recommendationsfor P, K, Ca, and Mg. The approach taken can significantlyaffect the recommendation rate and, thus,fertilizer costs.Sufficiency Approach. This approach is based onmaintaining a critical level of exchangeable nutrientsin the soil. The assumption is that plant growthis optimized at a certain soil test level if all othernutrients and conditions are adequate for growth.In the following figure, crop yield only reaches itsoptimum potential once the soil test level is at orabove “optimum.” If the soil test is at a low level,then there is a good probability that you wouldget an increase in yield by adding fertilizer. Thisresearch-based approach is most commonly usedby university soil labs, and relies on routine soiltesting to ensure that your soils are at or abovecritical levels.Maintenance Approach. This approach is basedon calculating or estimating the replacement valueof nutrients removed by the crop. Often, a generalfertilization recommendation for a crop that youmight read in a fact sheet or crop guide is based ontypical removal rates. If you know your crop yieldand the nutrient content of your crop, you can simplycalculate the removal rate. The assumption isthat you need to replace that amount of nutrientsto replenish what was taken out of the soil. So, youcould approach your fertilization rates without havingto do soil tests; however, there is a problem withthis approach. For example, plants take up K even ifthey don’t need it. This is called luxury consumptionand can create a false sense of what the crop needsfor fertility. The figure below shows plant growth inresponse to different levels of soil K. At an optimumsoil test level the yield levels off; however, the K contentin the plant continues to go up even at highersoil test levels.Soil Nutrient LevelsThe “sufficiency approach” uses crop yield at different soilnutrient levels to determine fertilization recommendations.Luxury consumption occurs when plants take up morepotassium than they need, sometimes resulting in herdhealth problems when the high potassium forage is fed.80 / Digging In


Soil Cation Balance Approach. This approachis based on the maintenance of certain ratios of K,Ca, and Mg. The problem is that field studies acrossthe Northeast and Midwest have not supported thisapproach when the ratios are maintained withinstrict ranges. This approach often results in overfertilizationof certain nutrients and in higher inputcosts. Since extremely high levels of K can interferewith Mg uptake, fertilization recommendations forMg may be made even if soil test levels of Mg are ata normally optimum level.Combination Approach. On a practical basis, afertilization program is often based on a combinationof approaches. In the case of potassium, thesoil test is important for determining K rates toachieve optimum soil test levels, while estimates ofK crop removal are used to adjust rates dependingon the yield potential of the soil. For some soils thatare inherently high in K, adjustments for Mg arealso made to achieve a reasonable ratio.Making Your Own NutrientRecommendationsThe very last thing you need to do to finish yourNMP is to develop fertilizer and manure applicationrates for your fields.If you asked for nutrient recommendationswhen you submitted your soil samples, you shouldalready have recommendations on your soil testreports. Check each soil test report to make surethat the nutrient recommendation is for the cropthat you are growing this coming season. What ifyou don’t have a recommendation or there is anincorrect recommendation on your soil test? Ineither of these cases, you can make your own recommendationusing the tables on the followingpages. Below is a step by step process for makingyour own nutrient recommendations.Nitrogen RecommendationFor Corn and Other Annual Crops. Use table4 on page 82 to locate the expected yield and soildrainage class to determine nitrogen recommendations.For example, an expected yield of 25 tons ofcorn silage per acre on well drained soil will require150 lbs. of N per acre.For Perennial Forages. Use table 8 on page 82to locate the expected yield on the table to determinenitrogen recommendations. For example, anexpected yield of 5 tons dry matter per acre willrequire 50 lbs. of N per acre per cutting. Therefore,if you are harvesting three cuttings of hay thenyour recommendation is 150 lbs. of N per acre (50lbs. per cutting).Phosphorus RecommendationFor All Crops. Use table 9 on page 83 to locatethe soil test phosphorus (P) level in ppm, thenlocate soil test aluminum (Al) in ppm. For example,if your soil test P is 1.5 ppm and your soil test Al is90 ppm, then your recommendation is 105 lbs. of Pper acre.For Corn. If you are growing corn, you are finishedwith your phosphorus recommendation.For Other Crops. Use table 10 on page 84 toadjust the recommendation according to the cropyou are growing.For example, if your soil test P is 1.5 ppm andyour soil test Al is 90 ppm, then your recommendationis 105 lbs. of P per acre. Then turn to table10 and make an adjustment for topdressing perennialforages. First determine if your soil test P rangeis low, medium, or optimum. Then determine theadjustment. The adjustment for this example requiresa reduction of 20 lbs. of P per acre. Therefore yourrecommendation would be 85 lbs. of P per acre.Potassium RecommendationFor All Crops. Use table 11 on page 85 to locatethe soil test K level in ppm. Next, locate the crop tobe grown and its corresponding yield. This will giveyou the potassium recommendation. For example,if your soil test K is 50 ppm and you are expectingto grow 25 tons of corn silage per acre, then yourpotassium recommendation is 200 lbs. of K peracre.Putting It All Together / 81


Recommended nitrogen rates for annual crops (without credit for manure or previous crops).(Table 4 from Nutrient Recommendations for Field Crops in Vermont)Soil Drainage ClassCornexpected yieldSomewhat poorly topoorly drainedWell Drained tomoderately welldrainedExcessively drainedSilage 1(tons/acre)Grain(bu/acre)N to apply(lbs./acre)15 90 90 80 9020 120 120 100 12025 150 150 130 15030 180 150 2 150 150 2Small grains (oats, wheat, barley, rye), millet 70 50 70Sorghum, sorghum-sudan, sudangrass, sunflower 90 70 90Dry beans, peas, buckwheat 40 30 40Soybeans 0 3 0 3 0 3Note: Reduce N rates for previous crop credits (Table 5) and manure application (Tables 14–17).1Silage yields are wet tons/acre (30–35% DM).230 tons/acre (180 bu/acre) yield are not considered realistic on these soils. Recommendation for 25 tons/acre yield is provided.3A low rate of N (5–10 lbs./acre) may be applied in a 2"x 2" placed starter band, but do not apply in direct contact with the seed.Recommended nitrogen rates for perennial forages.(Table 8 from Nutrient Recommendations for Field Crops in Vermont)Nitrogen to applyPer application(N, lbs./acre)Total per year(N, lbs./acre)Grass (


Recommended base phosphorus rates for selected available P and Al test values(adjust for specific crop based on table on page 85).(Table 9 from Nutrient Recommendations for Field Crops in Vermont)ReactiveAlAvailable P soil testLow Medium Optimum 1 High 2 Excessiveppm0.5 1.5 2.5 3.5 4.1–7 7.1–20 >20ppmP 2O 5to apply, lb./acre10 60 60 40 40 50 0 020 65 60 40 40 50 0 030 75 55 40 40 50 0 040 90 65 40 40 20 0 050 100 70 45 40 20 0 060 110 80 50 40 20 0 070 120 90 55 40 30 0 080 120 95 60 40 30 0 090 120 105 65 40 30 0 0100 120 115 70 40 30 0 0110 120 120 75 40 30 0 0120 120 120 80 40 30 0 0130 120 120 85 40 30 0 0140 120 120 90 40 30 0 0150 120 120 95 40 30 0 0160 120 120 100 40 30 0 0170 120 120 105 40 30 0 0180 120 120 110 40 30 0 0190 120 120 115 40 30 0 0200 120 120 120 40 30 0 0Note: Table shows selected values within each category. Recommended P application rates are based on the following equation:P 2O 5to apply (lb./acre) = [(Al + 36) x (4 – available P)] ÷ 3.1The recommended rate (20 to 30 lb. P 2O 5/acre) is best applied as starter/ row fertilizer at planting for corn or broadcast as a blendwith other nutrients as a topdress on perennial forages.2A low rate of starter fertilizer (10 to 20 lb. P 2O 5/acre) is recommended, especially under conditions of early planting, limited drainage,or conservation tillage.Putting It All Together / 83


Phosphorus (P 2O 5) rate adjustments for different crops.(Table 10 from Nutrient Recommendations for Field Crops in Vermont)CropAvailable P soil test levelLow-medium(0–4 ppm)Optimum(4.1–7 ppm)lb. P 2O 5/acreCorn No change No changeSmall grains, soybeans, dry beans/peas, buckwheat,sorghum, sorghum-sudan, sudangrass, sunflowerSubtract 20No changeEstablishment of perennial forages Add 40 Add 20Topdress alfalfa (>60%) No change No changeTopdress of other perennial forages Subtract 20 No changeConservation planting Subtract 30 Subtract 20 or 30Note: Add or subtract from values in Table 9, but note minimum rates for Low and Medium P test.84 / Digging In


Recommended potassium rates for field crops.(Table 11 from Nutrient Recommendations for Field Crops in Vermont)K soil testLow Medium Optimum High ExcessiveK, ppm: 160K 2O to apply (lbs./acre)Corn for silage 115 or 20 tons/acre 200 160 120 80 60 0 2 025+ tons/acre 240 200 160 120 80 30 0Corn for grain90 or 120 bu/acre 140 100 60 40 30 0 2 0150+ bu/acre 180 140 100 60 30 30 0Alfalfa (> 60%) 3 Topdress2-40 tons/acre 280 240 200 160 100 40 05 tons/acre 320 280 240 200 140 60 06+ tons/acre 360 320 280 240 180 80 0Establishment 240 200 160 120 80 40 0Clover, trefoil, grass, alfalfa (20–60%) 3 Topdress2-4 tons/acre 220 180 140 100 60 0 05+ tons/acre 260 220 180 140 100 0 0Establishment 180 140 100 80 60 0 0Small grains, soybeans,buckwheat, dry beans/peas, millet120 100 80 60 40 0 0Conservation planting 80 60 40 0 0 0 01Corn silage yields are wet tons/acre (30–35% DM)210–20 lb. K 2O/acre recommended as row-applied starter under conditions of early planting, limited drainage, or conservation tillage.3Yields are dry hay equivalent (12–15% moisture). One ton dry hay is equivalent to 2.5 tons haylage (65% moisture).Putting It All Together / 85


EXERCISE IV-1. . .Field Plan Recommendation WorksheetThis is where your NMP really starts to come together. You will fill outone worksheet per field. Much of the information that you have previouslyentered will be transferred to this worksheet. Follow the instructionsbelow to fill out the worksheet.HELPFUL TIPS FOR FIELD PLANNING• Check the soil tests to make sure that eachrecommendation is for the crop to be grown inthe coming season.• Make a new recommendation (if necessary)using the instructions on page 81.Choose whethermanure will beincorporated orsurfaced-applied.If you are growinghay, make sure thelegume percentageis filled in.Fill in the soil testrecommendationfrom your soiltest report (ormake your ownrecommendation).Fill in yournutrient credits.Past nutrientcredits are from“plow down”sods. The amountof N credit givencan be found inthe table called“Nitrogen Creditsfor Previous Crops”on page 87.86 / Digging In


Nitrogen credits for previous crops.(Table 5 from Nutrient Recommendations for Field Crops in Vermont)Fertilizer N creditPrevious CropPrevious yearLb/acreTwo years agoAlfalfa > 60% legume 120 6020–60% 80 40Red clover, trefoil > 60% legume 90 4020–60% 70 30GrassModerate-high level mgmt.(>2 ton/acre yield)Low level mgmt.(2 ton/acre or less)70 3040 20Soybeans, dry beans/peas 30 01. Fill in the amount of manure spread on this field. Remember that youalready estimated the manure spread last year while filling out the fieldinventory worksheet. Be aware that changing the rate of manure appliedwill automatically change the rate of manure P application on the P-index.2. Be aware of the nutrient management basis and the manure restrictioncode on the top right of this worksheet. If you apply too much manureto a field, these may change to reflect the greater risk of P runoff. Rememberthat on P-based fields you cannot exceed crop uptake levels of P. Wherethere is a red manure restriction code, you cannot apply any manure.3. Once all the manure has been applied, look at the tab called ManureDrawdown in the computer workbook to make sure that all of themanure has been allocated. If there is excess or negative manure quantitiesreadjust the sheets.If your farm does not have the land base for the waste produced youneed to consider exporting the manure from the farm. If you need nutrientsyou may consider importing manure from a nearby farm. Regardless ofyour situation if you are exporting or importing manure you must fill out aform to document the transaction. The import/export form can be found inthe class binder.(Exercise IV-1 is continued on the next page)Putting It All Together / 87


Total manurefrom eachstorageManure remaining in this storage4. Print out the field sheets and organize them according to nutrient needs.5. Add fertilizer as needed.The nutrient balance shows remaining crop needs (after nutrientcredits and fertilizer applications). A negative balance indicatesover-application. In the example above, nitrogen and phosphorushave been over-applied by 10 lbs./acre and 36 lbs./acre, respectively.88 / Digging In


FERTILIZER CALCULATIONSFertilizer nutrients are usually expressed as a percentageby weight of the total fertilizer. The threenumbers you often see on a fertilizer bag, x-x-x, arethe percentages of N, P 2O 5, and K 2O, respectively, regardlessof the quantity of the fertilizer (i.e. a 50 lb. bag,a ton, or a 5 ton wagon load). For example, a 12-24-12fertilizer would be 12% N, 24% P 2O 5, and 12% K 2O.For a list of commonly used fertilizers and their analyses,see table 20 on page 92.Working with PercentagesRemember: 1% = one-hundredth = 0.01For example:12% N is the same as 0.1224% P 2O 5is the same as 0.2412% K 2O is the same as 0.12How Many Nutrients Come From FertilizerFor example:If you apply 300 lbs. of 12-24-12, then howmany pounds of each nutrient are you applying?300 lbs. x 12% (0.12) N =36 lbs. of N supplied to plants300 lbs. x 24% (0.24) P 2O 5=72 lbs. of P 2O 5supplied to plants300 lbs. x 12% (0.12) K 2O =36 lbs. of K 2O supplied to plantsCalculating Pounds of a GivenFertilizer NeededTo adjust a fertilizer recommendation, divide by thepercentage of the nutrient.For example:You want to spread urea on a grass hay field. Yournutrient need for the field is 100 lbs. of N per acre.How much 46-0-0 urea fertilizer do you spread toachieve this recommendation?100 lbs. of N ÷ 0.46 = 217 lbs.of urea needed per acreTry this for practice:How much muriate of potash would you need ifyour soil test recommends 150 lbs. of K 2O per acre foryour alfalfa?Calculating Liquid FertilizerTo determine the amounts of nutrients from liquid fertilizer,you must know the density of the liquid. Multiplythe percentage of the nutrient by the pounds of liquidper gallon.For example:What is the analysis of a 9-18-9 liquid fertilizer if theweight of one gallon of a liquid fertilizer is 11.4 lbs.?In each gallon of liquid fertilizer:11.4 lbs. x 0.09 N = 1 lb. of N11.4 lbs. x 0.18 P 2O 5= 2 lbs. of P 2O 511.4 lbs. x 0.09 K 2O = 1 lb. of K 2OSo if you are applying 5 gallons per acre:1 lb. x 5 gallons = 5 lbs. of N2 lbs. x 5 gallons = 10 lbs. of P 2O 51 lb. x 5 gallons = 5 lbs. of K 2OTherefore, to determine how much liquid to apply ingallons, divide the recommended rate by the numberof pounds per gallon of the nutrient.For example:You want to apply 20 lbs. of P 2O 5per acre as astarter fertilizer. Using the same liquid in the exampleabove,20 lbs. P 2O 5÷ 2 lbs. P 2O 5per gallon =10 gallons per acreAt that rate, you’ll also be adding 10 lbs. each of Nand K 2O.Putting It All Together / 89


HOW FAR CAN YOU AFFORD TO HAUL MANURE?Often times, your fields that are nutrient deficient are also far away from thebarn, while the fields behind the barn may be high or excessive in nutrients.With today’s fertilizer prices it may make more sense to haul manure to these fieldsthan it used to. If you are interested in figuring out how far you should be haulingyour manure, the following worksheets can be used to do so.90 / Digging In


These worksheets are also available online in spreadsheet form in the “NutrientManagement” section of the Vermont Crops and Soils website: http://pss.uvm.edu/vtcrops/.Putting It All Together / 91


Nutrient content and other properties of fertilizer materials.(Table 20 from Nutrient Recommendations for Field Crops in Vermont)Fertilizer MaterialChemicalformula 1 %N %P 2O 5%K 2OOther nutrient,% 2 Equiv.acidity 3Saltindex 4Nitrogen sourcesAnhydrous ammonia NH 382 0 0 148 47Urea (NH 2) 2CO 46 0 0 84 75Ammonium nitrate NH 4NO 333–34 0 0 63 105Urea-ammonium nitrate (UAN)(NH 2) 2CO +NH 4NO 328–32 0 0 54 74Ammonium Sulfate (NH 4) 2SO 421 0 0 24 S 112 69Phosphorus sourcesDiammonium phosphate (DAP) (NH 4) 2HPO 418–21 46–53 0 74 34Monoammonium phosphate (MAP) NH 4H 2PO 411–13 48–52 0 65 30Ammonium polyphosphate 10 34 0 53 -Ordinary superphosphateCa (H 2PO 4) 2+CaSO 40 20 0 14 S, 20 Ca 0 8Triple superphosphate Ca (H 2PO 4) 20 46 0 1.5 S, 14 Ca 0 10Potassium, magnesium, sulfur sourcesMuriate of potash KCl 0 0 60-62 0 116Potassium sulfate K 2SO 40 0 50 18 S 0 46Potassium nitrate KNO 313 0 45 -26 74Potassium hydroxide KOH 0 0 70 -89 -Magnesium sulfate MgSO 40 0 010–16 Mg,14–21 S0Magnesium oxide MgO 0 0 0 45 MgSulfate of potash magnesia(Sul-Po-Mag or K-Mag)K 2SO 4MgSO 40 0 2211 Mg,22 S0 43Calcium sulfate (gypsum) CaSO 40 0 0Micronutrient sources15–18 S,19–22 Ca0Borate Na 2BO 420 BSolubor Na 2BO 421 BIron (ferrous) sulfate FeSO 420 Fe, 12 SManganous sulfate MnSO 428 Mn, 16 SZinc sulfate ZnSO 436 Zn, 18 SZinc oxide ZnO 50–80 ZnZinc chelate Zn chelate 6–14 Zn1Water of hydration (H 2O) not included in formula.2Actual analysis varies with specific product formulation. B = boron, Ca = calcium, Fe = iron, Mg = manganese, Zn = zinc.3Pounds of calcium carbonate equivalent/100 lb of fertilizer material. Positive number indicates that the material increases soil acidity, that is,lowers soil pH. Negative numbers indicate that the material reduces acidity, that is, raises soil pH.4Salt index of equal weights of the fertilizer material compared to sodium nitrate which equals 100. Useful for comparing the salt effect ofdifferent fertilizer materials.92 / Digging In


EXERCISE IV-3. . .ChecklistHere is a list of items that you should have completed before you goon to the next session. Those items found in the computer workbookare listed in blue.SESSION I❑ Farm information worksheet❑ Maps (proximity, conservationplan, nitrate leaching,topographic, environmentalconcerns, soils)❑ Soil fact sheets❑ Soil test results organized❑ Soil test interpretation andplanning strategy❑ Soil test schedule❑ RUSLE2 (with your croprotation indicated)❑ Field inventory❑ Manure application scheduleSESSION III❑ Farm nutrient balance❑ Risk assessment worksheetSESSION IV❑ Field plan recommendationworksheets (one per field)❑ Manure drawdown worksheet❑ Manure import/export formand alternative manureutilization form (if applicable)SESSION II❑ Animal waste systemoverview sheet❑ Calculation of amount ofmanure produced❑ Manure test for each storage❑ Manure analysis worksheet❑ Manure storage nitrogencalculations (one for eachmanure storage)❑ Manure nutrient values❑ P-indexPutting It All Together / 93


SESSION V. . .Future SuccessWhat will be covered in Session V:Developing a Sustainable NMPLESSON 1: Making Use of Your PlanLESSON 2: RecordkeepingLESSON 3: Reporting to State and Federal AgenciesLESSON 4: Updating the PlanTerms to Learn• Medium Farm Operation (MFO)• Large Farm Operation (LFO)• Environmental Quality Incentives Program (EQIP)Exercise1. Checklist95


LESSON V-1. . .Making Use of Your Planongratulations! You have written your ownC NMP. Now what? The NMP is not just astack of paperwork to be filed away in a deskdrawer until next year. Instead, it is a working planthat you should refer to throughout the growingseason, especially before planting, spreadingmanure, or fertilizing crops. Chances are that youare not going to carry the whole plan with you inyour tractor, but rather you will leave it somewheresafe and out of the elements. For this reason, youcan print out the Plan Summary in your workbookand put it in the tractor or truck for easy reference.The Plan Summary shows manure and fertilizerapplications for the cropping season. It also indicatesfields that need to be soil tested this year.Using your NMP to Order FertilizerThe nutrient management plan that you just createdcan be a powerful tool on many fronts. Mostimportantly, the information in the plan can helpyou in purchasing fertilizer for your farm. Duringthe field by field planning section of the courseyou entered the nutrient recommendations foryour fields (based on soil tests) and you subtractedthe amount of nutrients contributed by manureThe plan summary provides a concise version of your NMP. Print a copy and keep it handy in your tractor or truck.96 / Digging In


CUSTOM APPLICATORS ANDNUTRIENT MANAGEMENT PLANSIf you hire a custom applicator for spreading manureon your farm, you need to make sure that theequipment operators and the supervisor are awarethat you are following a NMP. Do not just hand yourplan to the custom operators and expect them tointerpret it. Instead, give a clear list of the manureapplication rate for each field and the total numberof loads that each field should get. Have them keepa tally as they spread, to see how close they cometo the amount you requested.Humboldt RCDhay, legume hay). Within these crops, the fields willbe further partitioned into fields with high nutrientneeds and those with lower requirements. Once thegroupings are complete you can make an estimateof the type of fertilizer you might need for thosefields. This information can then be brought tothe fertilizer dealer, who can help develop the bestblend for the crop fertility needs.Making sure that crop nutrientsare applied in the correct amountswhere they are needed can savemoney.For example:Group 1: Corn FieldsSubgroup 1a:Corn with nutrient needs around150 lbs. N - 100 lbs. P - 200 lbs. KGive the custom applicator clear instructions abouthow much manure to spread on each field.Subgroup 1b:Corn with nutrient needs around150 lbs. - N 40 lbs. - P 100 lbs. KGroup 2: Grass Hayapplications. Often you were left with a balance ofnutrients that your crops still need. These nutrientscan be added to the soil in the form of fertilizer. Ofcourse, you can’t purchase different blends of fertilizerfor each field. This is unrealistic from bothpractical and economic standpoints. Once youknow the remaining nutrient needs of your fields,you should start to group together fields that havesimilar needs. In most cases, a farm can group thefields into five or fewer categories. First a farmmight group fields based on crop type (corn, grassSubgroup 2a:Grass with nutrient needs around150 lbs. N - 50 lbs. P - 120 lbs. KSubgroup 2b:Grass with nutrient needs around150 lbs. N - 0 lbs. P - 60 lbs. KThese simple groupings of fertilizer needs foryour fields will enable your salesman to formulatesome blends that work well for your farm.Future Success / 97


Nitrogen is often a limiting nutrient in agriculture, yetit is not measured by standard soil tests. This isbecause it is difficult to predict how much nitrogen willbe available for a crop based on a soil sample takenweeks or months before the time of peak nitrogen demand.In your NMP you credited N from manure youspread before the crop was even planted. However, ifthere are several straight days of rainbefore topdress of corn, you can makea pretty good guess that much of thatmanure N will no longer be availablefor your corn. The tool developed inVermont for fine tuning sidedress Namounts based on field conditions iscalled the pre-sidedress nitrate test(PSNT). The PSNT is not required byNMPs, but is a way to save moneyand take nutrient management to thenext level.The PSNT is performed shortlybefore topdress (when corn is 8 to12 inches tall) and measures theplant-available nitrogen (nitrate) inthe top 12 inches of soil. Because Nis so prone to changing form, the soilTHE PRE-SIDEDRESS NITRATE TESTsample must be dried or refrigerated after it is taken,and delivered to the testing lab the same day. Turnaroundis quick (within 24 hours on business days) sothat you can get your fertilizer on in a timely fashion.As with any test or recommendation, there are somelimitations. The main one is that the PSNT cannot accountfor unexpected changes in conditions after soilUniversity of WisconsinThe pre-sidedress nitrate testis done when the corn is 8 to12 inches high, just beforeits major vegetative growthoccurs.sampling. For example, if unusuallyheavy rains occur a few days aftersampling, significant nitrate can belost to leaching or denitrification. If thisoccurs and if there is time, resamplethe field. If not, adjust the recommendedN rate based on your bestjudgment to account for suspectedlosses.In 2008, the cost for the PSNT was$8.00 at the UVM Agricultural TestingLab. Many farmers have found thatthe PSNT can save them money onfertilizer. For more information, contactUVM Extension or the UVM AgriculturalTesting Lab, or visit the followingwebsite: http://pss.uvm.edu/vtcrops/?Page=articles/PSNTTest.html.98 / Digging In


LESSON V-2. . .RecordkeepingRecordkeeping is a critical part of nutrientmanagement planning. Not only is it importantto know what you planned to do, but alsowhat you actually did. Maybe you had to reallocatesome of the manure being spread because the accessroad to a field was too wet to drive the spreader on.Or maybe you decided not to plow under the alfalfafield that you were planning to plant with corn thisyear. In other words, the weather doesn’t alwayscooperate and sometimes plans have to change. Youare responsible for keeping a record of that change.Keeping records will also make the plan more usefulover time. Recordkeeping will help you refine theplan and make the recommendations more accurate.The most important records to keep are:• Planting and harvest dates• Dates and amounts of manure, compost,and fertilizer applications• Crop yields for each fieldThe NMP recordkeeping requirements are to:• Keep an updated copy of the NMP itself at yourfarm.• Provide copies of current soil tests (check yoursoil test schedule to see which fields needupdated soil samples) and waste tests (one foreach waste storage facility per year).• As you update your plan, keep the old recordson file for five years.There are also record keepingrequirements if you transfermanure off your farm. Maintainrecords showing the date andamount of manure, litter, orprocess wastewater that leavesthe permitted operation, andFigure out a recordkeepingsystem thatworks for you andstick to it.record the name and addressof the recipient. Keeping theimport/export agreement willsatisfy this requirement.Future Success / 99


Yield measurements are extremely important in nutrientmanagement planning. Knowing averageyields will allow you to choose nutrient applications ofmanure and fertilizer that minimize costs, maximize fertilizerefficiency, and reduce potentialenvironmental problems. Yieldsare also critical as a measuring toolto evaluate new products, improvemanagement techniques, and allowyou to make more informed decisionsconcerning feeding practicesfor your livestock. Knowing your foragesupplies for the year in the fallallows you to buy or sell forage atthe time of year that is most financiallyrewarding to your operation.Various methods of measuring yields are availableto producers. The most accurate is to weigh truck orwagonloads going into a silo or barn, and to take drymatter samples then. This is often not feasible due tolimitations of time and necessary equipment (scales).Other methods of yield checks include field samplingand documenting estimated weights of loads.Measuring WagonloadsMeasuring yields by wagonload is probably the mostcommon method used by producers. Ideally youshould weigh average loads to get a representativeload weight. It is important to know the dry matter ofCALCULATING FORAGE YIELDSTruck scales can be used to weighcrop yields.the forage to get an accurate measure of the actual nutrientharvest.Some recent work in Wisconsin found that wagonloads in the 30 to 50% dry matter range averagedaround 5 pounds of dry matter percubic foot of wagon. Suprisingly, theforage density did not vary greatlywith forage type (corn silage or haylage).Working with this information,we can now estimate the load ona wagon by multiplying volume bydensity.For example:A wagon measures 16 ft. long by 7.25 ft. wide and isfilled to a depth of 6 ft.16 ft. x 7.25 ft. x 6 ft. = 696 cubic ft.696 cubic ft. x 5 lbs. dry matter per cubic ft. =3,480 lbs. dry matter or1.74 tons of dry matter yield per acreIf we want to calculate actual weight, we need todivide this figure by the dry matter of the forage (28%).1.74 tons ÷ by 28% =6.96 tons of feed on the wagonAdapted from Calculating Forage Yields on Vermont Farms by Sid Bosworth http://pss.uvm.edu/vtcrops/articles/Calculating ForageYields.pdf100 / Digging In


LESSON V-3. . .Reporting to State and Federal AgenciesAt the end of each season the state and/orfederal government require that you reporton your nutrient management for the previousyear. Whether you report to state or federal agenciesor both will depend on which programs youhave enrolled in. The agency you report to wantsto know what you did and why you did it. Use thisstep by step process when you are ready to fill outpaperwork and gather necessary information tomeet reporting requirements.Required FormsDepending on your program enrollment, you mayneed to send your plan to NRCS and/or the VermontAgency of Agriculture Foods and Markets.Large Farm Operation (LFO). The State of Vermontdefines a LFO as a farm with more than 700mature dairy cows (whether milking or dry), 1000beef cattle or cow/calf pairs, 1000 youngstock orheifers, 500 horses, 55,000 turkeys or 82,000 layinghens (without a liquid manure handling system).Unlike the MFO program, LFO permits are individualto each farm. Refer to the Vermont Agency ofAgriculture website (address on page 104) for additionalinformation on requirements for compliance.Medium Farm Operation (MFO). The State ofVermont defines a MFO as a dairy with 200-699mature animals, whether milking or dry. OtherMFOs include beef operations (300–999) cattle orcow/calf pairs), youngstock and heifer operations(300-999 youngstock or heifers), horse operations(150–499 horses), turkey operations (16,500–54,999turkeys), and egg facilities (25,000–81,999 layinghens without a liquid manure handling system.The State of Vermont requires an annual complianceform. Refer to the MFO general permit forother reporting requirements or refer to the websiteaddress given on page 104.Environmental Quality Incentives Program(EQIP). This program, administered by NRCS, is avoluntary conservation program for farmers andranchers that promotes agricultural production andenvironmental quality as compatible national goals.EQIP offers financial and technical help to assist eligibleparticipants install or implement structural andmanagement practices on eligible agricultural land.If you are enrolled in EQIP, NRCS requires croprecords from the previous crop year. This includesplanting and harvest dates, yields, soil tests, annualmanure test, and dates and amounts of manure, fertilizer,and compost applications.RecordsBoth state and federal agencies require that a farmkeep records. You can use the forms provided in thebinder or make your own.Recordkeeping Summary Sheet. Documentdiscrepancies between what you planned to doand what you actually did on the farm last season.If you did not follow your plan, explain why (i.e.weather). The recordkeeping summary sheet can befound in the class binder. A sample is shown on thenext page.Make Requested ChangesMake any required changes from the previous year.Usually these are listed in a letter sent by the state.Future Success / 101


NUTRIENT MANAGEMENT RECORDKEEPING SUMMARYGeneral InformationProducer:Crop Year:Seasonal EventsDescribe any unexpected weather, pest, equipment, material availability, or labor problems that occurred this year thatcaused you to change your nutrient applications or cropping patterns from what you had planned:Nutrient Application ChangesDescribe how your applications or cropping were different because of these events; on which fields were applicationshigher h / lower than planned? How do you think this will impact the fields' overall nutrient t balance? Do any rotationstineed to be adjusted to maintain adequate erosion control?Implications for Next YearDo you need to alter your plans for next year to compensate for events this year? Do soil or manure tests t need to berepeated sooner that expected? Do fields need to be reseeded ahead of schedule, or rotations adjusted?Name of Nutrient Management Records Reviewer:Date of Review:Recommendations Resulting From Records ReviewThe recordkeeping summary sheet is found in the NMP binder.102 / Digging In


LESSON V-4. . .Updating the PlanIf there have been any changes on your farmsince last year’s NMP, you will need to recordthese changes on the updated NMP. Did you leasea neighbor’s farm to increase your acreage? Did youadd more animals to your herd? Below is an outlineof specific sections of the NMP that may requireupdating.How and When to Modify Each SectionFarm Information Sheet. Change this sheet ifyou have increased your herd size, increased youracreage, changed rotations, changed tillage systems,or if there has been any other major change onyour farm.Maps. Add or modify maps if you have addedadditional farms, tracts, or fields. ContactNRCS or NRCD to make these changes.Soil Information. Add additional soilinformation sheets if you have addedadditional farms, tracts, or fields. Youwill only need to change this section ifyou added new maps. Contact NRCS or your localNatural Resource Conservation District to makethese changes.Soil Analysis. Update this section with new soiltests. Check your soil sampling schedule and modifyit if necessary. Remove old tests and replace themwith new versions, archiving old tests to monitorsoil P levels.Manure Production. Update this section if youhave added additional animal units or have modifiedyour storage units. If you have changed thissection you will need to:• Modify the animal waste overview page• Modify the sheet for manure nutrients availablefor crop production• Reallocate manure on individual field sheets ifnecessaryManure Analysis. Update this section withmanure tests from the past year. Youneed at least one manure sample analysisper year.Field Information. Update thissection if you have added new fields.Update the crop history section.Field by Field Planning. Fill out new field byfield nutrient management sheets if necessary. Newfield sheets will be needed if there are new soil tests.Future Success / 103


ADDITIONAL RESOURCES FOR NUTRIENT MANAGEMENT PLANNINGThe University of Vermont ExtensionSaint Albans office: (802) 524-6501Soil, Nutrient and Manure Managementhttp://pss.uvm.edu/vtcrops/?Page=nutrientmanure.htmlCrops and Soils Homepagehttp://pss.uvm.edu/vtcrops/Nutrient Recommendations for Field Cropsin Vermonthttp://www.uvm.edu/pss/vtcrops/articles/VT_Nutrient_Rec_Field_Crops_1390.pdfAgricultural and Environmental Testing Labhttp://pss.uvm.edu/ag_testing/USDA Natural Resources Conservation Servicein VermontState office: (802) 951-6795 http://www.vt.nrcs.usda.gov/Vermont Soil Survey Informationhttp://www.vt.nrcs.usda.gov/soils/so_stat.htmlKey to the Soils of Vermonthttp://efotg.nrcs.usda.gov/treemenuFS.aspx?Fips=50001&MenuName=menuVT.zipNRCS Manure Screening Toolhttp://www.vt.nrcs.usda.gov/technical/Nutrient_Management/Vermont Department of Agriculture, Foodand Markets(802) 828-2430 http://www.vermontagriculture.com/Vermont Accepted Agricultural Practice (AAPs)http://www.vermontagriculture.com/ARMES/awq/AAP.htmlVermont Medium Farming Operations (MFO)Programhttp://www.vermontagriculture.com/ARMES/awq/MFO.htmlVermont Association of Conservation Districtshttp://www.vacd.org/104 / Digging In


EXERCISE V-1. . .ChecklistBefore you submit your nutrient management plan, check throughit to make sure that all of the necessary information has beencompleted. Worksheets contained in the spreadsheet program are indicatedin blue.SESSION I❑ Farm information worksheet❑ Maps (proximity, conservationplan, nitrate leaching,topographic, environmentalconcerns, soils)❑ Soil fact sheets❑ Soil test results organized❑ Soil test interpretation andplanning strategy❑ Soil test schedule❑ RUSLE2 (with your croprotation indicated)❑ Field inventory❑ Manure application scheduleSESSION II❑ Animal waste systemoverview sheet❑ Calculation of amount ofmanure produced❑ Manure test for each storage❑ Manure analysis worksheet❑ Manure storage nitrogencalculations (one for eachmanure storage)❑ Manure nutrient values❑ P-indexSESSION III❑ Farm nutrient balance❑ Risk assessment worksheetSESSION IV❑ Field plan recommendationworksheets (one per field)❑ Manure drawdown worksheet❑ Manure import/export formand alternative manureutilization form (if applicable)SESSION V❑ For plan updates:❑ Records❑ Revise any applicable parts ofcomputer workbook❑ Recordkeeping summary sheet❑ Any additional forms requiredby program enrollmentFuture Success / 105

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