364 Conservation Tillage Challenges the Moldboard Plow - webapps8

Today, one acre in six in Minnesota is tilledby a new method of preparing ground for planting— conservation tillage. Farmers using thismethod, soil conservationists, and wildlifemanagers claim it offers advantages overtraditional moldboard plowingConservation TillageChallenges theMoldboard PlowWayne Edgerton and Dean MillerTHEMOLDBOARD plow has beenthe primary tillage tool on Minnesotafarms since pioneers used itto break the virgin prairie sod morethan a century ago. But now manyfarmers are leaving their moldboardplows in the shed. The moldboardplow — conventional tillage — completelyturns the soil surface overand leaves it bare. Instead, morefarmers are turning to conservationtillage.Conservation tillage reduces soiland water loss because residue —old stalks, leaves, and roots fromprevious crops — is left on or nearthe soil surface. This residue actslike tiny umbrellas that shield thesoil against erosive wind and rain. Inaddition, the residue makes miniaturedams that hold back excess rainfallso it soaks in and doesn t erodethe soil.The term "conservation tillageincludes four major tillage systems:• No-till planting is performed inone operation. The specializedplanter cuts a slot in the soil, depositsseed and fertilizer, and thenfirms soil over the seed. About 90percent of the soil surface is left undisturbed• Strip-tillage planting is usuallycompleted in one operation. Thismethod normally uses a rotary tillerwhich mixes the residue and soil inthe field to be planted. Twothirdsof the soil surface remainsundisturbed• Till planting scalps the areawhere the seed is planted andpushes the residue between theLate October corn harvest. A combine head approaches a corn cob on thePaul Bischoff farm near Stillwater. After harvest, crop residue left on theground will reduce soil and water loss. (Photo by Tim Smalley, ONR.)37

Conservation Tillageplanted rows. Again, two-thirds ofthe soil surface remains coveredwith residue• A chisel plow or disk tills the entiresoil surface before planting.Much of the residue remains on thesurface.In 1982, Minnesota farmers usedconservation tillage on approximately3.6 million of the state's 23 millionacres of cropland, or about one acreout of every six. That's about twiceas many acres tilled by conservationmethods as in 1976.Conservation tillage is becomingmore popular in other states as well.The U.S. Department of Agriculturepredicts that, by the year 2000, conservationtillage will be used on over80 percent of the nation's cropland.Soil conservationists say that conservationtillage could significantlyreduce Minnesota's 100-million-tonper year soil loss. Other benefits ofconservation tillage: savings in fuel,labor, time, and money; increasedwater filtration and less evaporation;fertilizer and pesticides less likely tobe washed oil the land; yields betterthan conventionally-tilled crops indry years and comparable in otheryears; during fall and winter, morefood and cover available for wildlife.On DNR Land. The Departmentof Natural Resources encouragesconservation tillage on cropland thatit owns or administers. Much of theland is leased to farmers under acash or crop-share arrangement.Many of these farmers use conservationtillage and are pleased with results.Paul Bischoff and his son Timplant corn on about 100 acres nearStillwater. The soil is mostly sandyloam with up to 12 percent slopes."We haven't moldboard-plowedthe land in twelve years, Paul said."We tried chisel plowing for a coupleyears, but we weren t satisfiedwith the erosion control we weregetting. Some of the land had beennotorious for erosion, but we practicallyeliminated our erosion problemwhen we went to no-till four yearsago."The Soil Conservation Serviceestimated that with conventional tillagemethods, the land had a soil lossas high as 18 to 25 tons per acre peryear.No-till brought the soil loss downto fewer than five tons per acre peryear. (According to SCS guidelines,five tons per acre per year or less isgenerally acceptable.)The Bischoffs are sold on no-tillnow, even though their first twoyears were less than satisfactory.Four-bottom moldboard plow, left, turns over residue from last year's cropharvest and leaves raw soil, right, exposed to wind and water erosion.Above: A horse probably pulled this early model of a moldboard plow.39

Conservation Tillage"You need the right machine forno-till," Paul stated. "The planterwe used during our first two yearswas constantly plugging and ouryields were less than with conventionaltillage."In 1982 they switched to a six-rowHiniker planter with John Deereplanter units and eliminated theirplugging problems. "We harvested95 bushels of corn per acre at 20 percentmoisture even though it was adry year. A neighbor's corn yieldedonly half as much with conventionaltillage methods. I don't think we'veever lost significantly in yield, evenwith our trials and tribulations thefirst year."We re saving at least 25 percenton fuel compared to our previoustillage methods. We plant the cropfor less than one gallon of fuel peracre.Wildlife like no-till, too. "We seelots of deer and pheasants in the falland winter," Paul added.Tim Bischoff mentioned anotherbenefit. "Conventional tillage stirsup the soil. We had to pick up rocksevery year. We haven't picked upmany since we went no-till.Firm in Rain. Another advantageof leaving old crop residue on thesoil surface is that farmers can plantin wet weather when conventionaltillage equipment would get stuck."You can plant in rain, Tim said."The soil stays firm, and there's littleapparent compaction problem."The soil will stay warmer if youdon't chop stalks, because the chopperjust spreads a layer of residueinsulation over the ground," he continued."Newer conservation plantersplant right through standingstalks without any problem.Doug Heim leases 66 acres ofDNR land near Elba in southeasternMinnesota — sandy bottomland tosteep, loamy slopes. Fifty acres areplanted in corn; the rest is seeded toalfalfa. This is his first year of tillplanting."Conservation tillage methods arehard to accept at first, Heim said."With crop residue left on the surfaceafter planting, the soil looks differentfrom what fanners are used to.Heim was happy with the tillplantedcrop as it came up. "Thecrop looks great. The seedbed wasTop, left: Spring planting. A no-till planter moves between rows of crop residuefrom last year's harvest. Close-up, bottom, left, of residue on ground.Above: Planter drops seeds in slot between last year's crop rows.41

Conservation TillageLett: Paul Bischoff and son Tim (rear) examine mid-season corn grown by no-tillmethod. Right: After fall harvest, Paul, in box of combine, shows corn cob andkernels before kernels are augered into wagon, then hauled to storage.perfect and we had no problemplanting in stalks. We also had areally good weed kill.Edgar Hansgen, Elba, said he gotinto no-till planting in 1976 to maintainthe productivity of the soil."The reason farmers say conventionaltillage is easier is because they'vespent so many years doing it. No-tillor till planting doesn't take nearly aslong to learn, but farmers mustforget much of what they've learnedabout conventional tillage."No-till or till planting in a fieldthat has good fertility and weed controlshould yield crops equal to conventionaltillage, Hansgen declared.There is a potential for higher yields,too, because farms have better soilstructure and erosion is reduced.Wildlife Benefits. At the CarlosAvery Wildlife Management Area,Lloyd Knudson, DNB wildlife manager,and DNR conservation specialistsDan Rhode and Conrad Christiansonhave been using no-till forseven years.About 220 acres at Carlos Averyhad been leased out and farmed conventionallyuntil DNR bought a JohnDeere conservation planter in 1976."No-till was the only way we couldplant 220 acres of corn with our limitedstaff and time, Knudson said.It took a few years to learn no-till42 THE MINNESOTA VOLUNTEER

methods, he reported. Carlos Averyis located on a sand plain, so the soilis light. "There's not as much roomfor error with no-till and you have tomanage it more intensely, he said."We had better corn in droughtyears than our neighbors who usedconventional tillage.He usually plants corn betweenlast year's corn rows. The stalks areleft for wildlife and not harvested.The residue provides food and coverduring fall and winter. Mallards andteal have been seen nesting in CarlosAvery's no-till corn fields.Advice First. Hansgen and Bischoffrecommended that farmers whowant to try conservation tillageshould talk to someone who's successfulat it. "I don't think a goodmanager who is working with someonewho has experience will haveany problem changing," Hansgensaid.But he doesn t recommend transforminga whole farm the first year.A good way to start is to havesomeone custom plant five to 20acres the first year, then convert thewhole farm in three to five years, hesaid. Another way: Ask advice fromdealers who loan or rent planters tofarmers who want to try conserva-Journal ReviewsConservation TillageThe Soil Conservation Society haspublished a special issue of Journal ofSoil and Water Conservation on conservationtillage.The 192-page issue includes articlesthat assess the positive and negativeimpact of conservation tillage on soil,water, and the environment. Otherarticles review conservation tillagefrom a regional point of view and fromthe perspective of certain crops.Still other articles examine theefforts of agricultural extensionoffices to encourage acceptance ofconservation tillage, the experience offarmers with various tillage systems,and current research in the field.Single copies of this special issueare available from: Soil ConservationSociety of America. 7515 NE AnkenyRoad, Ankeny, IA 50021. Price: $5.tion planting and from Soil and WaterConservation District offices. AgExtension Service and SVVCD/SCSoffices throughout the state also holdconservation tillage meetings, tours,and demonstrations during the yearto help farmers get started. •Wayne Edgerton is a soil and waterconservation specialist with theDNR Division of Waters. Dean Milleris a former public affairs specialist,SCS, St. Paul.-fr -fr ftNature Hints Many Times Before We ListenHow MANY times it thundered before Franklin took the hint? How many applesfell on Newton's head before he took the hint? Nature is always hinting at us. Ithints over and over again. And suddenly we take the hint. — Robert FrostJANUARY-FEBRUARY 1984 43