Sustainable agriculture in the Baltic Sea Region in ... - EcoRegion

Sustainable agriculture in the Baltic Sea Region in ... - EcoRegion

3IntroductionImprintDear Reader,EcoRegion is an important project that supports the realisation of sustainabledevelopment approaches in the whole Baltic Sea Region and contributesto making it a sustainable and prosperous place.sustainable projectsRheinstraße 3412161 BerlinTel +49 (30) 832 1417 40Fax +49 (30) 832 1417 50info@sustainable-projects.euwww.sustainable-projects.euThematic PeriodicalEcoRegion PerspectivesFourth Issue: Sustainable agriculture in the Baltic Sea Region in times of peakphosphorus and global changePublisherCBSS-Baltic21Editorial teams.Pro – Angela Schultz-Zehden, Laura Delsa, Cecilia Torres, Rasmus RelotiusResponsible partnerInstitute for Crop and Soil Science, Julius Kühn-Institute, Braunschweig (Germany)Ewald Schnug, Silvia Haneklaus and Judith SchickDetailed information about the EcoRegion project is published under 2011DisclaimerThis periodical has been produced with the assistance of the European Union.The content of this publication is the sole responsibility of the authors and can inno way be taken to reflect the views of the European Union.Layout & design by:betzemeier usp design, www.betzemeier.comCover photo:© Ewald SchnugISSN 1029-7790In recent years, progress has been made to advance sustainable developmentin the Baltic Sea Region. These efforts are now supported by the EcoRegionproject, which seeks to turn this area into the world’s first EcoRegion, whereeconomical growth goes hand in hand with environmental integrity andsocial justice.The project is based on the unique multi-stakeholder network of Baltic21, which was created for the realisation of the Agenda 21 for theBaltic Sea Region. By way of eight sectoral platforms, Baltic 21 memberscarry out joint actions and cross-sectoral activities to pursue SustainableDevelopment in the Baltic Sea Region and the implementation ofthe Council of the Baltic Sea States Strategy on Sustainable Development2010–2015. Furthermore the project is aligned with the Aalborg Commitments,through which regional governments voluntarily commit to definingclear targets and implementing concrete actions for SustainableDevelopment.Through the EcoRegion project, ten model regions prepare strategic sustainabilityplans and implement a selected set of concrete measures designed toreach these Sustainable Development targets. This process is supported bya capacity building programme on Integrated Sustainability ManagementSystems. Numerous workshops foster the inter-regional, cross-sectoral andsectoral-regional dialogue and understanding on Sustainable Developmentwithin the Baltic Sea Region. In addition, public materials, including a goodpractices database, provide information on how to foster Sustainable Developmenton a regional level.One of the publications produced by the project is the series EcoRegionPerspectives. It presents policies, projects and practices for the sustainabledevelopment of the Baltic Sea Region from various perspectives such as tourism,spatial planning and climate change.We hope this periodical will give readers an insight into the diversity and potentialof innovation and education for sustainable development, and trustthat you will find it both interesting and informative.Dörte Ratzmann,Federal Ministry for the Environment, Nature Conservationand Nuclear SafetyEcoRegion Project Lead PartnerSustainable agriculture in the Baltic Sea RegionPerspectives

45ForewordDear Reader,Every individual is responsible for a sustainable living. With a view tofood this affects in particular one’s dietary habits and food management.A major problem of industrialisation has been the introduction of frozenand processed food and an elevated demand for prime meat parts as it ledto an unbalanced diet with too much fat, sugar and salt, and the disposalof unpopular animal parts. The Federal Ministry of Food, Agriculture andConsumer Protection (BMELV) estimates that in relation to the produce20-75% of the food is disposed, which equals 20 million tonnes of groceriesonly in Germany. FAO valued the dumping of foodstuff to one third of thetotal production worldwide.Personal deficits in the handling of foodstuff need to be compensatedby adequate educational programmes for awareness rising and finallybehavioural change. This is an important contribution to global food securityand a sustainable use of the resource phosphorus (P) which is otherwisedissipated in the environment. Yet another problem that arises is the exportof P in cheap feedstuff and energy crops from developing countries asincreasing world market prices for P may hamper a balanced supply and thusfavour P mining in these areas of the world.But why care about P? The answer to this question is simple. Because P is anon-renewable resource, geogenous P deposits are limited, P is an essentialnutrient for all living organisms and thus is indispensable for food production.Agriculture is the largest consumer of P. In principle it does not matterwhether the global resources satisfy the demand for another 50 or 150 years.It is a matter of fact that food production will be compromised for futuregenerations if the anthropogenic and agricultural P cycle is not closed timely.These are facts that can not be denied and it is five minutes to midnight todevelop a global concept on how to deal with P scarcity in a socially just way.of algorithms to match the small-scale spatial variation of plant available Pin soils with variable rates of organic and mineral fertilisers.It can be expected that recycling of P and thus the use of recycled P fertiliserproducts will play a key role in a sustainable P management. However,conditions need to be strictly defined for their use in order to foreclosenegative environmental impacts. Such negative impacts range from chargingsoils with organic and inorganic xenobiotics for instance if sewage sludge isdirectly applied on agricultural soils to yet unknown effects on soil fauna,wild life and the putative introduction of pathogens if residues from biogasproduction are used that were generated by co-fermentation with sewagesludge or slaughterhouse wastes. Another important aspect is the speciationof P in the recycled product as it is imperative that only products are usedas P fertiliser materials if P exists in a plant available form. This implies thatMBM (meat-and-bone meal) may not be used directly as fertiliser material asthe prevailing P form is apatite which is more or less insoluble on arable soils.Advanced technologies eliminate all those problems by incineration of wasteproducts in combination with a chemical treatment to allow for the requiredplant availability of P.International experts assigned to agricultural stewardship for sustainablephosphorus use contributed to the presented Perspectives and offer significantadvancement of turning the Baltic Sea Region into the first EcoRegionof the world!Silvia Haneklaus and Ewald Schnug,Institute for Crop and Soil Science, Julius Kühn-InstituteCBSS Expert Group on Sustainable Development -Baltic 21 / Task Force on Sustainable AgricultureThe Baltic Sea Region could be among the first regions worldwide toimplement new strategies and technologies for closing the P cycle on farms.Here, the responsibility of farmers is given a turn. What can they do? It startswith a profound agronomic education and the transfer of local knowledge tooptimise crop production in a sustainable way. With a view to P, the requiredknowledge comprises for instance aspects of plant nutrition, soil biology andsoil physics with regard to the P demand of crops, organic P cycle and P lossesthrough erosion and run-off, respectively.Diffuse P losses from agriculture are a major contributor to eutrophication ofwater bodies such as the Baltic Sea. Other relevant issues for a sustainable useP which avoids equally P mining and P surplus are the assessment of a sitespecificoptimum P status to satisfy the P demand of crops, the developmentPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

8Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea9“Peak times” for urban agriculture 1Maxi NachtigallProject Officer, Council ofthe Baltic Sea States (CBSS)Expert Group on SustainableDevelopment, Baltic 21,CBSS SecretariatNowadays humans are the main driverof change to the earth’s ecosystems.We have reached the “man-madeworld” – the Anthropocene – era. 2Science defines nine planetaryboundaries that “humans need torespect in order to avoid catastrophicenvironmental change at continentalto global scale” 3 . Some of theseboundaries we have already crossed.This will have a tremendous impacton the livelihood of our societies andplanet in the future. 4The global phosphorus cycleOne of these planetary boundariesrelates to the global phosphorus andnitrogen cycles. Large-scale conventionalagricultural systems are totallydependent on the continuous inputof phosphate fertilisers producedfrom naturally available phosphaterock. Yet, we are currently hitting“peak phosphorus”. While its exacttiming is controversially debated, itis a certainty that “phosphorus is anexhaustible resource with no substitutes.Shortages will occur.” 5The harmful effects of excessivephosphorus applicationNatural supply of phosphorus is notharmful to our biospheres. However,it becomes a harmful pollutantwhen mined and added to finetunedecosystems by excessive use offertilisers in order to stimulate cropgrowth as practised in conventionalagriculture. 6 As a consequencephosphorus, the friend of life onearth, turns into an enemy, causingalgae blooms and oxygen depletionInnovative solutions for urban farming. © Maxi Nachtigall © Maxi Nachtigallin lakes and seas, killing waterspecies, threatening fresh watersupplies and triggering other chainreactions in the bio-system.The necessity to save phosphorusAs one solution to this dilemma,Stephen R. Carpenter suggests theconservation of phosphorus insteadof the continuation of its waste. 7Amongst others, he highlights farmingas well as food production, distributionand consumption as mainareas in which conservation of phosphorusis not only needed but alsopossible.While farming is mainly done in thecountryside, food production and distributiontakes place in semi-urbanand urban areas. In addition, mainconsumers of agricultural productscan be found in cities and towns. In2008 the urban percentage of theworld‘s population reached 50 %.The global urban population of currently3.3 billion is expected to growto 4.9 billion by 2030. 8 How will wefeed all these city dwellers in the future?Localised farming as a solutionFood production in the Baltic SeaRegion and other parts of the world,post peak oil and peak phosphorus,will depend upon more localisedfarming that is relatively resilient toextreme weather events, can operateeffectively with reduced inputs, andis adaptable to likely increases inweed, pest and disease problems. 9We have to realise that we are livingin a post-food surplus era and adaptour production and consumptionAllotments in Stockholm city center.1 In this article urban farming, urban food productionand urban agriculture are used synonymously.2 Crutzen, Paul J., Eugene F. Stoermer, 2000 inIGBP Newsletter 413 Rockström, Johan et. al. 2009: Planetary bundaries:Exploring the safe operating space for humanityin Ecology and Society 14(2):32;4 Climate change, Rate of biodiversity loss, Nitrogen-phosphoruscycles5 Carpenter, Stephen R. 2011: Phosphorus: Approachingfundamental limits? In StockholmWaterfront, Forum for global issues no. 2 , July20116 ”P is a finite fossil mineral mined for humanuse and added naturally into the Earth Systemthrough geological weathering processes. Thecrossing of a critical threshold of P inflow ot theoceans has been suggested as the key driverbehind global-scale ocean anoxic events, potentiallyexplained past mass extinctions of marine© Maxi Nachtigalllife” in Rockström, Johan et. al. 2009: Planetarybundaries: Exploring the safe operating space forhumanity in Ecology and Society 14(2):327 Carpenter, Stephen R. 2011: Phosphorus: Approachingfundamental limits? In “StockholmWaterfront, Forum for global issues no2 , July20118 The urban percentage of the world’s populationis projected to reach 60 percent by 2030. The3.3 billion global urban population is expectedto grow to 4.9 billion by 2030; Growth in smallercities and towns is expected to account for mostof the urban population increase. EcoRegion project, Focus Group Food – PolicyRecommendations, http://www.baltic-ecoregion.eu10 EcoRegion project, Focus Group Food – PolicyRecommendations, http://www.baltic-ecoregion.euPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

10Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea11patterns accordingly in an integratedway. In the future, the issues of foodsecurity and food safety will gainincreasing importance. 10imbalances and are hotspots ofaccumulation of nitrogen, metalsand phosphorus they also harbour apool of […] resources […]”. 12• Establishment of food sharesystems and communitysupported agriculture, marketsUrban farming en miniature inHamburg Hafencity, Germany.© Maxi NachtigallFarm shop at Manor Wulksfelde, Metropolitainregion of Hamburg, Germany. © CBSS Baltic 21How can we cut down waste onphosphorus, conserve this valuableresource and at the same time securefood supply? We need better planningfor better food which can mean manydifferent things: a healthier andmore sustainable agricultural policyas well as sustainable agriculturethat better addresses modern urbanconsumption patterns. It would alsomean better integrated sustainablefood systems that take into accountthe impacts of climate change,increasing food prices and the needfor balancing food and energysecurity.We need urban consumers that areable to make informed decisions onwhat and how to eat and have cleardemands on how and where foodshould be produced. Consequently,we need to (re)define the possibilitiesfor urban farming and create betterurban-rural linkages to ensure foodsupply in urban environments forfuture generations. “A just andsustainable food system protectsthe land which produces the food,supports the local community,through local production, empowerscommunities through self-relianceand gives them increased food systemsecurity.” 11Urban food production can providethese added values at the sametime as it is taking off the nitrogenand phosphorus pressure from ourfarmlands. “Although cities themselvesshow symptoms of biochemicalThe multifaceted benefits of urbanfarmingIncreased urban farming wouldresult in greener cities that wouldnaturally trigger other benefits suchas decreased energy costs, water useand drainage, reduction of urbanheat islands, absorption of pollutants,increased urban ecology andbiodiversity as well as certain socialand health aspects. “When you startgrowing more food on public lands incities you increase both a lot of socialcohesion, you deepen democracy butyou also create a sense of protectingthe environment. It is no longer onlybushes along the road it means afood supply.” 13 Wherever it is we areliving we have to (re)start thinking ina place-based manner. More practicalmeasures need to be taken in orderto reduce the ecological impact bythe average urban citizen.Some possible solutions to produceurban ecosystem services can belisted as follows:• Rethinking the concept of communitygardens and urban allotments• Creating more locally supportedfarms in metropolitan areas, rooftop gardens and greenhouses• City planning for planting ofedible plants in parks and otherurban open green spaces (includingresidential housing balconies),even animal husbandry• Development of broad educationalprogrammes on small scalefarming, urban agriculture andpermaculture in urban settingsin order to enable communitymembers to implement measuresin a short time frame on a localscale• Less consumption of pre-processedand packaged foodThese solutions would give urbancitizens environmentally soundalternatives to conventional farmingand abounded food systems. Thiswould help us to stay within ourplanetary boundaries. The promotionof sustainable lifestyles and creationof sustainable demand would alsogenerate employment opportunitiesin the eco-innovation and greentechnology sectors as well as in localcommunity work.The Baltic Sea Region could becomea forerunner region of sustainablecities and towns in symbiosis withvibrant rural landscapes and a hometo people with clear sustainabledemands and lifestyles. Thereby, onecould improve the quality of life inurban-rural settings and strengthenurban-rural links. 14 “Cities themselvesdo present both the problem andsolutions to sustainability challengesin an increasingly urbanisedworld” 15 . Urban farming is one of themost important features of urbanresilience and sustainability.Planting devices for the urban gardener at Stockholm gardeningfair.© Maxi Nachtigall11 Roseland, Mark, 2005: Towards SustainableCommunities, p 51-52, New Socitey Publishers12 Grimm, Nancy B. et. al., 2008: Global challengesand the ecology of cities in Science magazine,Vol 319, 8 February 200813Robert Hall, 2011: in ”Notes on..SustainableConsumption and Production”, Baltic 21 filmproduction; CBSS Strategy on Sustainable Development2010-2015,, Nancy B. et al, 2008: Global challengesand the ecology of cities in Science magazine,Vol 319, 8 February 2008PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

12Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea13Need for action in the Baltic Sea areaLeena-MarjaKauranneSenior Specialist,Ministry of theEnvironment, FinlandThe state of the Baltic Sea waterhas drastically deteriorated overthe recent decades. Human activitiesboth at sea and throughout itscatchment area are placing rapidlyincreasing pressure on the marineecosystem. Of the many environmentalchallenges, eutrophication isone of the major problems for thesea and for the lakes and rivers inthe catchment area, especially in thesouthern and eastern parts of theBaltic Sea. It is caused by excessivenitrogen and phosphorus inputs.This leads to problems like increasedalgal blooms, murky waters, oxygendepletion and a lifeless sea bottom.Nutrients enter the Baltic Seavia rivers, through atmosphericdeposition and in direct dischargesfrom pollution sources located alongthe coastline. The riverine dischargesoriginate both from point sources,such as industrial or municipalwastewater plants, and fromdiffuse sources, such as agricultureand forestry, scattered dwellings,traffic and atmospheric depositionwithin river basins. The Baltic Seais connected to the North Sea andto the Atlantic Ocean through thenarrow Danish Straits and Soundareas. Inflows of fresh seawater occurrarely, and poor oxygen conditionsrelease phosphorus accumulated inthe bottom sediments.Agriculture is the main source ofphosphorus and nitrogen inputsto the Baltic Sea accounting forabout 50 % of the total diffuseloads. Managing emissions fromagricultural land and livestockoperations is critical to restore theecological balance of the Baltic Sea.Putting an end to further destructionof the Baltic Sea marine environmentand avoiding an irreversibledisaster calls for immediatewide-scale cross-sectoral action.Failure to react now would undermineboth the prospects for futurerecovery of the sea and its resilienceagainst the climate change and therisk of increasing nutrient loads. Furthermore,inaction will have an impacton resources vital for the futureeconomic prosperity of the wholeregion and would cost tenfold morethan the cost of action. Efforts tocombat eutrophication have alreadybeen and continue to be made inmany different fora at various levelsbut it is a complicated task to curbnutrient loads from diffuse sources.The Helsinki CommissionThe Baltic Marine Environment ProtectionCommission, more usually referredto as the Helsinki Commissionor HELCOM, is an international organisationmade up of the nine BalticSea coastal countries and the EuropeanCommunity, working to protectthe marine environment of theBaltic Sea. HELCOM is the governingbody of the “Convention on the Protectionof the Marine Environmentof the Baltic Sea Area” - also knownas the Helsinki Convention, whichwas signed by all Baltic Sea countriesin 1974 and came into force in 1980.A new updated convention wassigned in 1992 by all states borderingthe Baltic Sea, and the EuropeanCommunity and it entered into forcein 2000. The Convention covers notonly the Baltic Sea, but also the surroundingcatchment area within thecoastal countries. The whole catchmentarea covers 1 600 000 sqkm,which is about four times the areaof the sea itself.The Baltic Sea Action PlanHELCOM has had several approachesin its history for enhancing the stateof the Baltic Sea but the objectiveshave not been reached yet. The latestis the Baltic Sea Action Plan (BSAP).Its ambitious target is to restore thegood ecological status of the Balticmarine environment by 2021. ThePlan was adopted by all nine BalticSea States within the Helsinki Commission(HELCOM) and the EuropeanCommunity at the ministerial meetingon November 15, 2007 in Krakow,Poland. The cross-sectoral planidentifies the specific actions neededto achieve the agreed targets withina given timeframe for the main environmentalpriorities: 1) combatingeutrophication, 2) curbing inputs ofhazardous substances, 3) ensuringmaritime safety and response capacityto accidents at sea, and 4) haltinghabitat destruction and the ongoingdecline in biodiversity.The HELCOM Member States are currentlydeveloping national plans toimplement the Action Plan.The BSAP has strong links to globallegislative frameworks and is alsoseen, for those Parties who are alsoEU Member States, as a contributionto the implementation of key EUdirectives, in particular the MarineStrategy Framework Directive, theWater Framework Directive and theNitrates Directive.Reductions in nutrient inputs haveprimarily been achieved throughimprovements at major pointsources, such as municipal sewagetreatment plants and industrialwastewater outlets. Achievingfurther reductions, such as runofffrom agriculture, is a toughertask considering the rapidlygrowing agricultural sector in theregion. Reducing nutrient lossesfrom agriculture is much morecomplicated than curbing loadsfrom point sources and will involveseveral measures. Due to retentionin soils, groundwater and inlandsurface waters, a reduction ofnitrogen or phosphorus in localemissions will result in less reductionto the Baltic Sea. Additionally, thereis a considerable time-lag betweenthe implementation of agriculturalMarjattaKemppainen-MäkeläSenior Officer,Ministry of Agriculture andForestry, FinlandSubstantial eturophication of the Baltic Sea has taken place, attributable to increased phosphorus supply to theaquatic organisms. Photo from Porvoo, southern Finland© Markku Yli-Hallawater protection measures andany observed effects in lakes andrivers, and even more so for marinewater bodies. This means that loadreductions in marine water bodieswill not be observable for years oreven decades after water protectionPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

14Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea15measures are implemented onsources within catchment.To decrease phosphorus andnitrogen discharges into the BalticSea, the losses from agriculturalactivities and scattered dwellingsto inland surface waters have to bereduced most probably by at least50% from the 1997–2003 averagelevels, depending on the retentionin different catchments.The role of EU legislationIn the future, like up till now, theEU legislation and agricultural policywill play a major role in the state ofthe Baltic Sea. When entering theagricultural subsidy system, the newEU member countries like the Balticstates and Poland will increasetheir agricultural production. Thiswill also increase the intensity offarming with higher risks of nutrientleaching, Around the Baltic Sea,rising living standards in the new EUmember countries and Russia willprobably increase the proportionof animal-sourced food in people’sdiets. The increasing animal productionmay require an expansion ofthe cultivated area, leading to increasingnitrogen and phosphorusleaching. At the EU-level there is nodirect regulation to prevent phosphorusdischarges from agriculture.The Nitrates Directive only regulatesthe nitrogen discharges from agriculture.To reduce phosphorus and nitrogenlosses from countless individual fieldplots and animal production units is ahuge task that calls for identificationof high-risk areas and implementationof cost-efficient and targetedagri-environmental measures. Suchmeasures could for example be cultivationof catch crops, establishmentof buffer zones, restoration and constructionof wetlands, reduction inmechanical treatment of soils, limeapplication, construction of higherstorage capacity for manure and applicationof less than yield-optimalfertiliser amounts. Enlarged andclustered animal farms require moreeffective methods to store, processand distribute manure. Slurry couldfor example be used for bioenergyproduction.To this end, there is a need for interdisciplinaryresearch and advisoryservices and for recognition ofeconomic, social and political constraints.There is a need to take actions bothfor point and diffuse sources in thefollowing areas:• Waste water: municipalities,scattered settlements and singlefamily homes• Agriculture• Transboundary air- and waterbornepollutionObjectives of the Baltic Sea ActionPlan to combat eutrophicationThe BSAP objectives cover the followingtargets: no excessive nutrientconcentrations, clear water, no excessivealgal blooms, natural oxygenlevels, and natural distribution andabundance of plants and animals.HELCOM has estimated that for agood environmental status to beachieved, the maximum total allowableannual nutrient inputs into theBaltic Sea would be 21,000 tonnesof phosphorus and about 600,000tonnes of nitrogen. Over the period1997-2003, average annual inputsamounted to 36,000 tonnes of phosphorusand 737,000 tonnes of nitrogen.Therefore, annual reductionsof some 15 000 tonnes of phosphorusand 135,000 tonnes of nitrogenwould be required to achieve thePlan’s crucial ‘clear water’ objective.However, a slightly decreasing trendin the point-source and riverineloads of both P and N can be seenbetween the years 1990 and 2006but the short-term development hasnot been satisfactory.To decrease nutrient inputs into theBaltic Sea to the maximum allowablelevels, the HELCOM countries haveagreed to take actions no laterthan 2016 to reduce nutrient loadsin waterborne and airborne inputs,aiming to reach good environmentalstatus by 2021. To reach thesereduction targets, each MemberCountry is encouraged to choose themost appropriate and cost-effectivemeasures for its special needs. TheAction Plan duly proposes provisionalcountry-wise annual nutrient inputreduction targets for both nitrogenand phosphorus (see table 1).For addressing the problems ofthe large agro-industrial clusterscontracting states also agreed toidentify individual hotspots suchas major intensive cattle, poultryand pig rearing facilities, whereactions should be prioritised inorder to comply with revisedrequirements for prevention ofpollution from agriculture (AnnexIII of the 1992 Helsinki Convention).The designation of these new “hotspots” has not been accomplishedyet. Environmentally sound manuremanagement has to be assured viaconstruction of adequate manurestorages, proper agri-environmentalmeasures and advisory services andvia identification of agriculturalareas that are critical for nutrientpollution of the Baltic Sea suchas designation of relevant partsof agricultural land as nitratevulnerable zones and performanceof risk assessments of nutrientleaching from agricultural areas.More comprehensive research andnew innovations are needed to solvethe problems.Current progress is slowAccording to the data on totalnutrient loads into the Baltic Seaby 2008 it seems that there hasbeen relatively little progress in thereduction of losses of nutrients fromagriculture within the Baltic Seacatchment area since 2000. In fact,losses from agriculture appear tohave increased in some BSAP membercountries although load figures fordiffuse sources are uncertain due tothe impact of climatic factors anddifferent methodologies applied,making comparisons of loadsbetween years difficult.The first HELCOM Initial Holistic Assessmentof the Environmental Statusof the Baltic Sea based on datafrom the period 2003-2007 concludesthat in addition to selectiveextraction of fish, eutrophicationis the other most dominant humanpressure on the Baltic Sea. Previousmeasures have been taken too lateor have been insufficient to helpcuring the environmental damages.The assessment also points out thatTable 1: Country-wide reduction targets for N and P in tonnes (HELCOMBSAP 2007).Country Phosphorus (tonnes) Nitrogen (tonnes)Denmark 16 17,210Estonia 220 900Finland 150 1,200Germany 240 5,620Latvia 300 2,560Lithuania 880 11,750Poland 8,760 62,400Russia 2,500 6,970Sweden 290 20,780TransbondaryCommon pool*destruction of the Baltic Sea will furthermorehave a severe impact onthe economy of the area. Comparisonof flow normalised loads during1997-2003, which is the referenceperiod for setting provisional reductiontargets in the BSAP, with flownormalised input during 2006-2008indicates a reduction of less than1900 tonnes of nitrogen (2 %) andmore than 3,300 tonnes of phosphorus(10 %).A statistical analysis on flow normalisedriverine load data to the BalticSea shows no significant overalldecrease in nitrogen and phospho-1,660 3,780rus waterborne inputs during 1994-2008. Some countries have obtaineda significant decrease in these loads,while others show increases or decreases,although not statisticallysignificant (p< 0.05). For direct pointsource loads many countries have asignificant reduction in emissionsof nitrogen and phosphorus duringthese 15 years.Pressures should be progressively reducedbecause only further significant,targeted and cost-effective reductionof phosphorus and nitrogenwill result in improved ecosystemhealth of the Baltic Sea.PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

16Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea17Task Force Sustainable Agriculture of Baltic 21Silvia HaneklausSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanyThe actual condition of the BalticSea is alarming. In particular,nitrogen and phosphorus losses fromagriculture, which result in eutrophication,have a strong impact onthe highly sensitive ecosystem. OnNovember 15, 2007 the memberstates of the Helsinki Commission(HELCOM) for protecting the BalticSea decided on a Baltic Sea ActionPlan for reducing nutrient inputs intothe Baltic Sea. This implies, amongothers, the distribution of countryby-countryquota for upper nutrientloads. The Task Force SustainableAgriculture (TFSA) of the Agenda21 for the Baltic Region (Baltic 21)elaborates strategies other than apolitical administrative limitation ofnutrient surpluses and fertiliser usein order to reduce negative impactsof agriculture on the Baltic Sea.Since 2000, the Working GroupAgriculture of HELCOM (HelsinkiCommission for the protection ofthe Baltic Sea) and recently theTask Force Sustainable Agriculture(TFSA) have dedicated their workto adopting and refining goodagricultural practices in relation toregional specifics in order to reducenutrient losses from agriculture. Atthe moment Germany is in chargeof TFSA, represented by the FederalMinistry of Food, Agriculture andConsumer Protection (BMELV) withinthe scope of its marine protectionpolitics. Prof. Dr. Dr. Ewald Schnug ischairman of the group and head ofthe Institute of Crop and Soil Scienceof the Federal Research Centrefor Cultivated Plants, Julius Kühn-Institute (JKI) in Braunschweig.In the line of work of TFSA/Baltic21 expert meetings have beenorganised on a regular basis in theform of international symposia inthe series Protection of Water Bodiesfrom Negative Impacts of Agriculture.Milestones are summarized below.Consensus existed at the symposiumChallenges of Precision Agricultureand Remote Sensing that moderntechnologies such as precisionagriculture, which employs satellitenavigation systems (GPS)and remote sensing, will yieldfertiliser savings and consequentlyimprove environmental quality. Theintroduction of new technologiesin agricultural production will havea significant potential for reducingnutrient losses from agriculture.Experts expect that their proposedinvestment into future technologieswill find broader acceptance byfarmers rather than further legalconfinements.An enforcement of bio-energy inagriculture sounds like a promisingconcept to cope with global change,scarcity of energy and unemployment.However, there is concern aboutwhether this development willcomply with the principle ofsustainability, which postulates "adevelopment that meets the needsof the present without compromisingthe ability of future generations tomeet their own needs". This issuewas addressed during the symposiumon Sustainable development of bioenergyproduction with special view tosoil protection. Our society’s hungerfor energy faces limitations to theEwald SchnugHead of the Institute forCrop and Soil Scienceof Julius Kühn-Institute,GermanyEutrophication of inland waters... © Ewald Schnug ...and marine bodies is a common phenomenon in the Baltic Sea Region. © Ewald SchnugPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

24Baltic Sea Region Policies for reducing P loads to the Baltic SeaBaltic Sea Region Policies for reducing P loads to the Baltic Sea25View of the village© Jörg Schmiedellarger-scale application. This is whatWieck municipality is undertaking inthe EcoRegion project. As Wieck isnot an area of industrial agriculture,but is rather covered by pastures andwoodland, opportunities to act mayseem a bit limited at first sight. Butfood consumption in the village isanother way to approach the issue.The intention is to increase the shareof sustainably produced food cominglargely from organic agriculture inthe region. Organic crop productionusually produces fewer nutrientemissions compared to conventionalagriculture, so this is a well-fitapproach to relieve the Baltic frompolluting substances.Involving stakeholders andimproving consultationTo push regional and organic food,Wieck has partnered with a regionalinitiative called „LändlichFein“(„FinestRural“) which has taken itsseat in the village this year, happyto find both a home and a platform.Its growing membership consists ofgastronomers and hotel keepers fromWieck and the coastal region who tryto serve both organic and regionallyproduced meals instead of „normal“supermarket groceries. Some ofthem offer only organic food, othersas much as it proves possible. Gettingorganic and regional resources forquality cooking can actually be quitea problem, as producers are oftensmall and distribution channelsare not always well developed,especially in far-off and rural areaslike Wieck. Improved consultationfor consumers (where and how toget it) and producers (which channelsto use to bring the produce to wherethe demand is) could change this.Increased supply and demand havebeen promoted by having organicproducts sold locally at a small marketin the village center twice a week.Currently this is only happeningduring the tourist season, but thismay well change in the future.To make the mission complete,cooperation with another organisationhas begun. The „Landaktiv“initiative informs and educateson the topics of organic farmingand food processing as well as onsustainable fishing practices. It isplanned to synchronize the activitiesof the two involved organisationsand Wieck‘s own informational andmarketing activities by establishinga professional consulting pointthat could complement the alreadyexisting national park informationcenter. Current plans see it not onlyfocusing on professional agriculturalproduction, but also addressing andinforming the many tourists that visitthe region about sustainable homegardening. Tourists taking goodideas home are a fitting prerequisitefor a better Baltic Sea ecosystem, asagricultural use on the vast land areasfar away from the seashore (but stillin the catchment area) is a decisivefactor for water quality.Improving water quality locally -regenerating the natural coastlineImproving water quality is alsosomething that Wieck is undertakinglocally. Most of the rather flat groundaround the lagoons was regularlyflooded in former times. This wasterminated 50 years ago by a hugedike building programme in theregion. The lagoons thereby lost mostof the sedimentation areas wherefloating eutrophic debris couldsettle. Regenerating this naturalpurification process by breachingsome dikes will not only be beneficialfor water quality. Floodlands are aparadise for ducks, geese, cranesand waders – birds that are ofinterest for ornithologists visitingthe national park region. Touristsare the main source of income in thevillage, so giving them good reasonsto visit and stay in the municipalityis economically appealing. Wieck istherefore anticipating reinstating400 ha of floodland east of the village– one of the largest coastal dikebreaches in Europe and definitelyone of the future highlights in thenational park. The project still needssome detailed planning and somefinancing issues will have to besolved. But major steps and decisionshave been taken, promising a moreattractive environment for Wieck,a better ecological performancefor the Baltic and the birth of manyfurther activities.PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

26Global perspectives on limited P resourcesGlobal perspectives on limited P resources27Global TraPs: An international effort to promotesustainable use of phosphorus 1Andrea E. UlrichDoctoral Researcher,Global TraPs ScienceManager, Institute forEnvironmental Decision atETH Zürich, Switzerland1 This article is adapted from official Global TraPsdocumentation to which several individuals includingthe authors have contributed. We thankDebbie Hellums and Sampson Agyin-Birikorangfrom IFDC for their helpful comments.Scientists and natural resourcemanagers are concerned about unsustainablemanagement of phosphorus(P) because not only is phosphaterock a finite natural resource, but itsinefficient management can result incontamination of water bodies. It isan established fact that P shortagewill threaten global food security. Aninternational effort, called the GlobalTraPs project, is bringing togetherknowledge and perspectives fromscience, industry, NGOs and otherimportant stakeholders to assess thecurrent state of knowledge, identifygaps and develop options forsustainable P management.Why the focus on phosphorus?Phosphorus is an essential elementof life: it is an indispensable elementin human and animal bodies, naturaland agricultural systems and innumerous natural and industrialprocesses and products. Phosphorusis present in various compounds inall living cells, in the cell membranesand in life-maintaining materialssuch as DNA, RNA and ATP. Thisportends that without phosphorusthere would be no life on earth.The essential nature of P in foodproduction and the finite amount ofnatural P resources (phosphate rockdeposits) have resulted in concernsabout the medium- to long-termavailability, accessibility and qualityof phosphate rock for fertiliser production.Specific concerns relate tothe timing of a “peak” in phosphaterock production, after which it willbecome more expensive to extractphosphate rock and produce P fertiliser.Although recent reports suggestthat current resources and reserves(the latter defined as the currentlyexploitable phosphate rock, giventoday’s economic and technologycontexts) are larger than previouslyindicated (by the data used to predicta peak in P production this century),phosphate rock is a non-renewableelement on which humankind is alreadyhighly and increasingly dependent.Even though concerns about apotential P scarcity exist, farmers inmany developed regions of the worlduse more P fertiliser than annualcrops require. Excess soluble P in theenvironment resulting from industrial,agricultural and non-agriculturalP uses can contaminate groundwaterand surface water resources, causingthe well-known problem of eutrophication.It has been estimated that humanshave roughly doubled or tripledglobal P cycling through mining andprocessing into fertiliser and otherindustrial products and through theinefficient use of these products.Phosphate rock exploration, miningand processing into fertiliser arelikely to increase in the foreseeablefuture given the current increasein food demand to feed the everincreasing global population. Accordingto the International FertilizerIndustry Association (IFA), to keepup with agricultural production, anannual increase of approximatelythree percent in global P demand isexpected by 2015/16, with furtherincreases likely. Due to a growingnumber of factors contributing toerosion, runoff and waste discharge,P typically absorbed by soil particlescan easily escape to contaminatenatural water resources, as in the casein the Baltic Sea. Both the contaminationand availability problemsaround unsustainable P use call forclosed-loop approaches requiring,among others, increased recyclingefforts. Models and technologiesfor environmentally sustainable Pmanagement exist and are beingpracticed in many locations, includingeffective erosion control and manuremanagement, use of urban andmunicipal wastes as fertiliser, andprocessing of P from sludge andmanure as struvite (magnesiumphosphate) for agricultural andindustrial use.The Global TraPs Project: TransdisciplinaryProcesses for SustainablePhosphorus ManagementConcerns and opinions about inefficientP use have been voiced in bothscientific and non-scientific media byindividuals or groups often representingonly the view of a singlestakeholder group. What has beenlacking is a multi-stakeholder foruminvolving differing viewpoints, knowledgeand concerns. This kind ofdialogue is needed to guide and optimisefuture P use through an assessmentof the current knowledge andgaps as well as the development ofoptions for the way forward.The Global TraPs Project (GlobalTransdisciplinary Processes for SustainablePhosphorus Management;2010–2015) is addressing this broadneed. Participants have met for thethird time in August 2011 to considerthe guiding question for the project:“What new knowledge, technologiesand policy options are needed toensure that future phosphorus use issustainable, improves food securityand environmental quality and providesbenefits for the poor?”Global TraPs will bring togetherknowledge and know-how from“practice” (producers and users ofphosphorus, along with those facilitatingtheir efforts, such as extensionand development organisations) and“science” (researchers from variousdisciplines with an interest inphosphorus). This international projecthas broad participation fromscientists, industry, NGOs and othergroups from around the world. Theproject is co-led by the Swiss FederalInstitute of Technology (ETH-NSSI)and the International FertilizerDevelopment Center (IFDC), eachassuming responsibility for leadershipof one facet – “science” (ETH-NSSI)and “practice” (IFDC). It is expectedthat a large number of stakeholders(as many as 300) will be involved andparticipate in the project.The project employs transdisciplinary(Td) methodology to facilitate adialogue of mutual learning. Byintegrating diverse knowledge andperspectives from various stakeholdersand through consensusbuilding, the Td processes resultsin development of socially robustoptions for future policy. Whilefocusing on the global situation,TraPs draws from location-specificcase studies designed to addressspecific issues of interest. StudyRebecca CorsResearch Assistant, Institutefor Environmental Decisionsat ETH Zürich, SwitzerlandPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

30Global perspectives on limited P resourcesGlobal perspectives on limited P resources31Nadine HolzapfelMember of the ResearchGroup Sustainability andClimate Policy at the Universityof Rostock, GermanyLast but not least, slurry as a byproductof factory farming, as wellas P use in feed, ought to be reducedstructurally. As an alternative, lowerlimits in applying farm fertiliser as wellas refraining from using additionalmineral fertiliser could be discussedin order to encourage faster closedloopcycles such as those in organicagriculture. In addition, it would benecessary to improve enforcement ofthe respective regulations. This couldbe achieved by introducing concretenorms, stricter monitoring and a legalbasis not subject to administrativediscretion.Such (and perhaps also other) reformoptions in respect to P fertilisationwould be quite welcome, and havebeen discussed in part for a long time(of course without implementation).Why the administrative regulatoryapproach might not succeedThere are a number of reasons forassuming that the administrativeregulatory approaches will eventuallynot succeed in solving the resourceand environmental problems relatedto phosphorus:• First, the enforcement problemin agriculture can hardly besolved with a command andcontrol regulatory approach,since an endless multitude ofminimal processes would needto be monitored. The vision of a“policeman on every tractor” ishardly realistic. Also, as has beenshown, one cannot solely counton self-regulation in agricultureand elsewhere.• Administrative approaches (commandand control) often havethe disadvantage that they unexpectedlyshift environmentalproblems to other areas. If theEU were to decrease P use,this might trigger intensifiedcultivation outside the EU – or amassive increase in the likewiseproblematic use of green geneticengineering.• There is one more probleminherent to all similar commandand control solutions: administrativelegal systems are oftenprone to individual casebasedexceptions, discretion orweighting. These expectationscan often thwart the spirit ofthe legal norm through frequentapplication.• Further, it is difficult to translateaspects such as “long-termpreservation of food security“into administrative legal criteria(command and control) sincethey do not directly correspond toindividual fertiliser application.• This leads to our centralpoint: The essential problemconcerning ecological impactand resource issues isdemonstrated not so much withone single fertiliser application.Rather, it is the accumulationof many - insignificant whentaken separately – fertiliserapplications and the resultingexcess fertilisation. Intensivelivestock farming also adds tothe problem. This also holds truefor the significant contributionof agriculture to climatechange by energy-intensivefertilisation, methane-releasinglivestock farming and otherenvironment-affecting issues.From an individual perspective,the single adverse effects on thenatural and aquatic environmentoften seem not to be sufficientlyrelevant, yet in total, they addup to substantial adverse effects.The holistic perspective - focusingon reduction of total P quantityIt is therefore necessary to find aregulatory approach that capturesthe required holistic perspective.Only a real decrease in the totalquantity of all phosphorus used(ultimately on a global scale) and atthe same time much more enhancedP recycling can actually achieve thenecessary resource conservationwhile alleviating ecological impacts.Absolutely central to this thinkingis the realisation that creatingregulations solely focusing onefficient P application will not besufficient. Indeed, any reduced Papplication “per plant” in the currentfood crop system represents primafacie a gain. However, if at the sametime the area of currently unusedland is increasingly used for examplefor feed crop cultivation (triggeredby globally rising meat consumption)or for bioenergy plants, the requiredabsolute reduction in P use cannotbe met. This problem of impendingrebound effects is currently reflectedin the climate change discourse -and even here not often enough -yet it also exists within the resourceproblem complex. It should furtherbe pointed out that the resourceissue can ultimately only be solvedon a global scale. A reduction of Pin the EU would certainly help theecological problem of waterways andsoils, yet the resource issue wouldremain – finite global phosphaterock supplies would likely be usedelsewhere.Our global food security would notbe put at risk, because any genuinequantity regulation that includedmanure measurement would makethe production of food of animalorigin unattractive (one calorie offood from animal origin requires fourto twelve plant-based calories), andso food security would probably bestabilised (also as a result of gainedP savings). This is likely to resultin the promotion of ecologicallyadvantageous, cycle-oriented formsof land use, such as organic farming.Apart from natural circulation systemson farms, the agenda could be set forconsistent efforts to recycle P fromresidues, such as from the sewagesector or the waste industry, backinto agriculture. From an ecologicaland health perspective, this impliesclearly counteracting the impendingoverload of soils with heavy metalsand organic pollutants through newrecycling and treatment concepts, atask which has not been sufficientlyintegrated in the past.The fact that thoughts on smallscaleregulatory improvementsalmost exclusively dominate thedebate despite the obvious frictionspresented, might seem moreremarkable than it actually is. Thepreviously described individualtypes of motivation for the public,entrepreneurs, legal practitionersand politicians do indeed promoteapproaches which may demand nosubstantial behavioral changes ofthose involved. Rather, they seeminglyAndrea E. UlrichDoctoral Researcher, GlobalTraPs Science Manager,Institute for EnvironmentalDecision at ETH Zürich, SwitzerlandPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

38Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources39Variability of P uptake by plantsAstrid ObersonSenior Scientist, Group ofPlant Nutrition, Institute ofAgricultural Sciences at ETHZürich, Switzerlandfertiliser would become as availableas water soluble P fertiliser.The exact mechanisms for these longtermtransformations are unknown:on the one hand P added as watersoluble fertilizer can become lessavailable while on the other handorganic P from the organic fertilisercan be mineralised with time. Theimportance of the “organic pathway”to plant P nutrition is probablyrelatively limited in cropped systemswhere microbial P content andturnover are low compared to thehigh plant P demand that is concentratedover a few weeks (e.g. duringstem elongation for cereals) andto the large P exportations by cropproducts. In grasslands, however, this“organic pathway” might play a moreimportant role in plant nutrition asmicrobial P content and turnover canbe very high compared to a relativelyconstant P uptake during the seasonand in relation to P exportations.Finally, besides orthophosphate,organic P compounds as well asorganic P rich colloids (plant debris,micro-organisms) can also be lostfrom the soil either in runoff or byleaching.The fact that organic P is not alwaysas available as the water solubleform of P, or that organic P can belost from the soil, is no reason toneglect soil organic matter input.Organic matter is not only importantas a source of nutrients (N, S, P),but is also important for the cationexchange capacity of the soil andfor the development of an optimalsoil structure which favours waterholdingcapacity, plant root developmentand finally nutrient uptake.Phosphorus (P), in addition tonitrogen (N) and potassium (K)belongs to the group of macronutrientsthat are essential for plantgrowth. A deficiency of P may limitplant growth and yield, reducingthe uptake of other nutrients suchas N and creating a surplus that issubsequently at risk of leaching intoground and surface waters. On theother hand, over-application of P candirectly contribute to losses to waterbodies and result in eutrophication.Therefore, farmers need to choosefertilisation strategies that minimisethe environmental and economicalrisks. Fertiliser recommendationshave to be based either on soilanalysis or on expected P uptakeby plants with the aim of providinga balanced P fertilisation to exactlymeet crop growth requirements.Concentrations of P in plants varybetween different crops, growthstages and plant parts, for examplegrain and straw for wheat. Thecalculation of P uptake by plantsis common practice and involvesknowledge of actual or expectedyield as well as the P content of allplant parts. Depending on the agriculturalmanagement, after harvestingseveral plant parts remain inthe field (e.g. stubble, straw orsugar beet leaves), and thereforeremain within the nutrient cycle.Other major plant parts (e. g. grains,potatoes and beets) are removedfrom the field and transported offsite. Consequently, understandingthe variation of P concentrationsin plants is a prerequisite for sustainableP management.Kerstin PantenSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanyElse K. BünemannSenior Scientist, Group ofPlant Nutrition, Institute ofAgricultural Sciences at ETHZürich, SwitzerlandyThe DOK 1 field experiment in Switzerland compares since 1978 the effect of conventional and organicfarming practices on crop productivity and soil fertility.© Astrid ObersonVariability of nitrogen© Susanne Schroetter1 Experiment on bio-Dynamic, bio-Organic andConventional (K) farming systems, since 1978PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

40Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources41Susanne SchroetterSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanySystematic analysis of plant Pconcentrations started more than100 years ago, but is currently nostandard farm management practice.Table 1 provides some examples of Pcontents for wheat available in theliterature. It can be seen that reportedP concentrations vary substantially.Certain factors influence P uptake bycrops resulting in variable P contents.This variability can be observedspatially, temporally, due to speciesand variety characteristics, as well asmanagement practices, or can be acombination of all of these.As an example of the variation ingrain contents between varieties ofwinter wheat, Table 2 provides somevalues from a variety trial carriedout by Barrier-Guillot et al. in 1992,published in 1996.Such results demonstrate that calculatingreliable estimates of nutrientuptake by plants is challenging. Nevertheless,gross nutrient balances for Pare calculated on an annual basis forall OECD countries. Coefficients usedto calculate the input and output ofa farm or a country are mostly staticvalues averaged across years andvarieties. Most OECD countries usetheir own generated coefficients(Table 3). The data sources and methodologiesused to do this are notalways well understood and reducethe validity of comparisons of suchbalances between countries.The German gross P balance (Figure1) shows that the average P balancehas in recent years fallen towardszero. But, whilst the reduction ofaverage P surplus at the countryscale is a positive development, anational P balance does not provideany insight into the variation insurpluses or deficiencies at a localor even small scale, which can havemajor effects on yields, P availabilityin agricultural soils, and P losses towater resources.The variability at such a small scaleis due to the heterogeneous natureof agricultural fields with regardsto soil texture and organic matterand the fact that the land is oftenundulating. Such heterogeneity canbe minor, with little effect on yieldand nutrient uptake, but can alsobe extreme and substantially impactplant growth. The most influentialparameters are topography and soiltexture, which contribute to theavailability of water and nutrients.Whilst sandy soils have a higher riskof nutrient leaching into groundwaters, clay soils as well as soils withlow pH have a high potential toadsorb P. Therefore, such soils canhave a high total P content but a lowP availability.Figure 2 demonstrates the spatialvariation for winter barley in theyear 2000 for a) yield, b) grain Pcontent, c) calculated P uptake andd) soil P availability. P uptake wascalculated using spatially recordedP concentrations in grain and straw.In this example, barley grain Pcontent varied spatially between0.30 - 0.36 % P across the 25 hafield (Figure 2b). Such significantvariations in P content questionthe validity of the method forFrauke GodlinskiSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanyTable 1: P concentration in winter wheat grain reported in the literature from 1875 – 2009.Table 2: Variation in winter wheat P concentration between varieties in1992 (Barrier-Guillot et al. 1996).PublicationYear of experiment/publicationCountry of experimentP content in winterwheat grains [g kg -1DM]VarietyP content in winter wheatgrains [g kg -1 DM]Von Wolf, E. -/1875 n.a. 2.9Vicking 3.44Boresch, K. et al. -/1931 n.a. 4.1Récital 3.52Pelikan, M. et al. -/1985 Czech Republic 3.6Ritmo 3.63Nikitshen, V. et al. 1984/2008 Russia 3.4Johnston, A.E. et al. 1992/2001 Germany 2.7Thésée 3.66Riband 3.81Sunflowers in a wheat field. © Susanne SchroetterJohnston, A.E. et al. 1996/2001 Great Britain 2.5Fortress 3.88Resch, R. et al. -/2009 Austria 4.0Arche 4.24PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

42Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources43calculating plant P uptake usingdefined P coefficients, as is requiredby German law. Using this approach,German farmers have to prove thattheir holding has not exceeded anaverage annual nutrient surplus of8.7 kg P per hectare over the last sixyears of fertilisation.The P coefficient used for winterbarley in Germany is defined as 3.52kg P per tonne of grain, whilst Figure2b shows major areas which are wellbelow this value. Using the static Pconcentration value to calculate Puptake by the plant biomass of thisfield will most likely overestimateP removal. Consequently, the riskof excessive P application willbe increased, at least in parts ofthe field. The result of uniform Papplications over many years onto aheterogeneous field can be seen inFigure 2d, showing the accumulationof available soil P in areas of the fieldwith lower yield potential caused bysandy soils as well as lower lying partsof the field where P was transportedfrom higher areas. Future spatiallyvariable P applications that takeinto account available soil P as wellas variation in yield potential couldreduce the risk of P losses into waterbodies by wind and water erosion.Figure 1: German gross P balance calculated according to OECD standards using common P coefficients for Germanyas well as the mean P input and output between 1990-2008.Table 3: P contents used in some OECD countries to calculate P-balances in 2004 for spring & winter wheat grain.OECD member state P in wheat grain [kg t -1 ]spring wheatwinter wheatAustralia 2.60 2.60Korea 2.82 2.82Sweden 3.10 3.10Japan 3.36 3.36Italy 3.49 3.49Germany 3.52 3.52Switzerland 3.66 3.82Canada 4.21 3.66Spain 4.80 4.80Figure 2: (a) winter barley yield, (b) P content in grain, (c) P uptake and (d) soil P availability in Mariensee (Lower Saxony, Germany), 2000.PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

44Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources45Higher phosphorus utilisation in croppingsystemsBettina Eichler-LöbermannAssociated Professor, Facultyof Agricultural and EnvironmentalSciences, Universityof Rostock, GermanyAn economical use of phosphorus (P)is a key issue for sustainable agriculture.The integration of P-mobilisingplant species in crop rotation is oneof the most promising agronomicmeasures to improve P utilisation incropping systems.Plants respond to their soil environmentand are able to influence thenutrient availability in the rhizosphere.This has special importancefor P given its low mobilisation insoils. Crop plants have differentstrategies to influence the P uptake.Some plants adapt to low availabilityof P mainly by changing their rootmorphology, others are effectivedue to the high excretion of P-solubilisingcompounds. There are majordifferences in P uptake efficiencynot only between plant species, butalso between genotypes.Under P deficiency plants usually increasetheir root length in relationto the shoot biomass. Due to thisincreased root to shoot ratio, thenutrient requirement and influx persingle root decrease. Mainly monocotyledonousplants, such as cerealsand grasses, have large root lengthand surface. Thus, they can utilise agreater soil volume, which is of vitalimportance with a view to P utilisation.Plant root exudates mainly consist ofa complex mixture of amino acids,organic acids, organic and inorganicions, vitamins, sugars, nucleosidesand enzymes which have direct orindirect effects on the acquisitionof nutrients. The capacity to excreteorganic acids is very pronouncedfor plants with so-called proteoidroots like lupine. Another exampleis oilseed rape, which excretes highamounts of malate and citratewhich cause a better solubility of Caphosphates. This happens due to adecrease of soil pH values while thechelating compounds bind cationsand thus release P. Not only theexcretion of organic acids, but alsothe amount of inorganic ions absorbedby plant roots can influence thesoil pH value. Root exudates alsocontain molecules that control thedeve-lopment of mycorrhizal fungi,which contribute significantly to theP nutrition of various crops.Organic P may comprise up to 80 %of total soil P. Mineralisation and thesubsequent release of phosphatesmakes organic P plant-available. Thisprocess is promoted by enzymes,like acid and alkaline phosphatases.Environmental conditions and plants’growth affect the activity of phosphatasesin soil. High activities ofacid phosphatase were found forexample in soils during cultivation ofamaranth and maize.results were obtained for phaceliaand buckwheat cultivation by theauthor.Thus, it can be concluded that thecombination of many different cropsin a crop rotation is an important contributionto sustainable food systemsand will not only have positive effectson the biodiversity in cropping systems,soil fertility and plant health,but may also help to improve the Putilisation in soils and save P fertilizers.Phacelia© Bettina Eichler-LöbermannCatch cropping is the cultivation ofplants with a short vegetation timebetween the cultivation of two maincrops. Catch crops are mainly used asgreen manure and cover the soil untillate autumn or until the next spring.This has a positive influence on soilfertility and can reduce nutrientlosses from soil. Furthermore, theseplants can improve the P supply ofthe following main crops directlyby modifying soil properties andmobilising P, or indirectly after theirdecomposition, when P is releasedfrom the plant material and providesan easily accessible P pool tosucceeding crops. Very promisingAmaranth© Bettina Eichler-LöbermannPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

46Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources47Setting standards for organic and mineral PfertilisersJudith SchickSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanyPhosphorus (P) is an essential plantnutrient. A sufficient supply forcrops is important to warrant cropproductivity. P deficiency will notonly reduce plant growth, but alsoimpair soil fertility. A surplus of P insoils is not desired either. Erosion ofP-rich topsoil results in increased Pinput into water-bodies which is amajor cause of eutrophication – aserious and consistent condition inthe Baltic Sea.To prevent soil P surpluses in agriculturalsoils, the German FertilisationOrdinance limits the annual surplusfor phosphate to 20 kg P 2O 5/ha. Tomeet this aim, old recommendationsfor the agricultural use of organicand mineral fertilisers have to beevaluated and advanced, site-specificfertiliser algorithms need to bedeveloped for a demand-driven inputof the resource. Then a reductionof P losses to water bodies can beexpected.Besides preventing P surpluses inthe nutrient balance, the input oforganic and inorganic pollutants bymineral and organic P fertilisationincluding recycled products has tobe considered since those productsmay contain considerable amountsof these substances. Once added tothe soil, they can accumulate andenter the food chain. Hence, toensure a safe and sustainable use ofP-containing inorganic and organicfertilisers, it is important to gainan advanced understanding of theproperties of different organic andinorganic fertilisers.Standards for P-containing fertilisersand recycled productsWith view to the scarcity of rockphosphate reserves and increasingprices for mineral fertilisers, the useof organic P from waste materialssuch as manure, sewage sludge orslaughterhouse wastes is of highinterest. One current trend is therapid expansion of biogas facilitiesfor energy production. The residuesfrom these facilities are regularlyapplied on agricultural soils asfertiliser material. In this case it isimportant to enact regulations thatguarantee food safety by settingnorms for recycled products. Theseimply that such commodities mustnot contain any organic xenobioticsand their heavy metal content shouldSilvia HaneklausSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,Germany© Judith Schick Effect of sufficient P-supply... ...and P-deficiency on maize plants © Judith SchickPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

48Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources49Ewald SchnugHead of the Institute forCrop and Soil Scienceof Julius Kühn-Institute,Germanynot lead to an accumulation in soils;another relevant issue is that theyare not contaminated by humantoxicologically-relevant pathogens.These constraints are essential as cofermentationof plant products withsewage sludge or slaughterhousewastes is a common procedure inbiogas plants. However, recycledproducts for instance on the basis offarmyard manure and sewage sludgeashes will play a major role in closingthe P-cycle on farms. Standards for(recycled) fertiliser products need toaddress the speciation of P and todefine a minimum content of plantavailableP, besides the general normsset for food safety.Assessing plant-availability of P bydifferent extraction methodsTo ensure both a sufficient P supplyand prevention of a P surplus onagricultural soils, an estimate of theplant-available amount of fertiliserP is needed. To distinguish betweeninstantly available, medium andlong-term available P fractions,several chemical extraction methodswith different strengths are applied.The German Fertiliser Ordinancecontains 11 methods to assessphosphate solubility; most of themare equal to the methods given by EURegulation 2003/2003 on fertilisers(Kratz et al. 2010). Experimentsin the laboratory and pot trialsshowed that it is possible to reducethe number of standard methods toassess P-solubility of mineral as wellas organic fertilisers to three or four:while water extractability describesP-forms with a high solubility havingan initial effect, the mid-term effectof non-water soluble P-forms canbe best described by an extractionwith ammonium citrate. For theestimation of tradable total P contentof a fertiliser, it is suggested to applythe mineral acid extraction (Kratz etal. 2010).Adjusting P-fertiliser rates formaintaining an optimum P status ofsoilsAgriculture has to strive for a balancedP-input which replaces P taken off byharvest products. In order to do so itis relevant that the only P applied isplant-available and takes part in thesoil P cycle. This means that the plantavailableamount of P in the fertilisermaterial has to be determined nextto the current and optimum P statusin soils. In addition, it is necessaryto assess changes in soil P status inrelation to management practices.Calculation of the so-called P-indextakes into account the local conditionparameters for P uptake capabilitiesof the agricultural area (e.g. soilquality, slope of the field, anddistance to a watercourse) and helpsto determine the risk of P losses towater-bodies in the studied areawhen P is applied to the soil. TheP-index can be applied to evaluatewhich fields are predestined to P lossand to decide if on the particular fieldfurther P application is arguable. Itcan also help to decide if rather anorganic than an inorganic P-sourceshould be applied since this will havea positive influence on soil porosity,aggregate stability and infiltrationcapacity - all of these being factorswhich decrease soil erosion and thusreduce P losses from agriculturalland.Variable, site-specific rateapplication of inorganic and organicP sourcesThe use of inorganic multi-nutrientfertilisers simplifies nutrientapplication on cropland. However,the use of these products causes majorproblems since the spatial variabilityof optimum fertiliser rates betweendifferent nutrients is not correlatedand the nutrient ratio remainsconstant during the completeapplication. This might lead to anundesired surplus or deficiency indifferent areas of the field. To solvethis problem, the spatial variabilityColorimetrical analysis of P-extractionsof soil and crop characteristics shouldbe correspondingly converted intoa spatially variable application offertilisers that matches the localdemand on the field. For mineralmulti-nutrient fertilisers, a strategyfor site-specific fertiliser applicationhas already been designed. However,it is advisable to also develop advisorymodels for a variable, site-specificrate application of organic fertilisers.Thus, it can be expected that by thismeans non-point nutrient losses willbe efficiently reduced at the fieldlevel.© Judith SchickSylvia KratzSenior scientist, Institutefor Crop and Soil Scienceof Julius Kühn-Institute,GermanyPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

50Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources51Phosphorus management in organic farmingHans Marten PaulsenSenior Scientit, Institute ofOrganic Farming, JohannHeinrich von Thünen-Institute (vTI), Trenthorst,GermanyOrganic Farming acts on sites withdifferent P fertilisation historyPrimarily crop production in organicfarming aims to optimise use ofsoil-borne phosphorus (P) and offertiliser P applied. Several long-termexperiments have shown only slightlylower crop yields after decades ofomitted P fertilisation comparedto P-fertilised plots (Gransee andMerbach 2000) showing that P mobilisationfrom the solid phase of thesoil can cover crop demands especiallywhen yield levels are lowercompared to mainstream agriculture.Soil P-reserves are dependent onspecific site conditions and formerfertiliser inputs. For Germany a tremendousadditive surplus of P inputwith fertilisers and feedstuff importsin agriculture is calculated on thebasis of statistical data. For the timebetween 1950-2000 additive P inputexceeded P removal of crops by about800 kg/ha P in the new and 1400kg/ha P in the old German federalstates (Köster and Nieder 2004).Also in other regions of the worlddecades of P fertilisation higher thancrop removal have increased soilP levels. At the same time, 30 % ofthe worldwide agricultural area hasnegative P-balances (McDonald etal. 2011). It is estimated that 40 %of worldwide crops are affected by Pdeficiencies (Vance 2001).yield losses and what measures andstrategies can be used to replenishthe plant available P pool in soils?P budgets of organic farming systemsare often negativeDue to fodder imports and manuremanagement, organic livestock farmsare normally described as havingbalanced or even positive P budgets(Berry et al. 2003) although their Pexport via milk products and bonesof slaughtered animals is higherwhen compared with arable organicfarms. Livestock systems benefit fromthe intensification of nutrient cyclingwith animal keeping indicated by feedcrop production, nutrient transferfrom grassland and use of manures.But if they are using 100% organicfeed from farm-own production andhave no other P imports they willreduce their P reserves by productexport in the long-run. In closedarable organic farming systems specialisedon cash crops a nutrienttransfer between fields via biogasmanurecould be introduced, butgenerally lower capacities exist toincrease the on-farm nutrient cycle.Organic vegetable production oftenrelies on high amounts of nitrogenand P imported by organic manuresor green waste composts. Theseorganic inputs can generate surplusP in soils.fractions except microbial P, which isoften higher under organic than conventionalfarming conditions (Oehl etal. 2001). Extensive analyses of recentP fertilisation trials showed thelimited possibility to predict P supplyto crops by soil analysis values. It wasshown that even if nutrient contentsin the top soil classified by CAL andDL method are ‘very low’ (A) or ‘low’(B) there is only little probabilityto increase yields by additional Pfertilisation (Kuchenbuch and Buczko2011). Thus, P mining in soils withlow available P contents indicatedby negative P budgets might be tolerableeven in the medium or longterm,especially when the lower yieldexpectations of organic farming areconsidered.Soil tests on P for organic farmingA deeper interpretation and active Pmanagement is only possible whenthe availability of P soil reserves canbe described. The role of organicand inorganic P and/or microbialparameters for P supply in organicplant production has to be definedand quantified by suitable soiltests. The common fertiliser recommendationsin organic farmingindicates that the soil test level “low”(B) is sufficient for the typical lowyield expectations. Up to now, nosystematic relation of P from organicUlrich KöpkeHead of the Instituteof Organic Agriculture(IOL), University of Bonn,GermanyOrganic farming is currently benefitingfrom the history of P overfertilisation.Nevertheless, with negativelong-term budgets organic farmingwill increasingly depend on Pamendments in the future (Loes andOegaard 2001). The questions arethen: when will organic farms runinto a definite deficit resulting inGenerally, soils under long-termorganic farming have lower availableP contents than those under conventionalagricultural use (Oehl et al.2002). This does not necessarily meanthat yields are limited due to lack of P.Soils under organic and conventionalfarming mostly differ in inorganicP fractions but seldom in organicCycling of nutrients and P by mulch of clover grass.Paulsen© Hans MartenPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

52Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources53Astrid ObersonSenior Scientist, Group ofPlant Nutrition, Institute ofAgricultural Sciences at ETHZürich, Switzerlandfractions in the soil to P nutrition ofcrops has been found. However, inorganic farming this source is claimedto be of utmost importance insupporting the aim of basing organicproduction on nourishing plantsprimarily through the soil ecosystem.It is assumed that methods of soilanalysis used in the past have underestimatedthe available P resources inMixed cropping of P-efficient white lupin with safflower.central European soils. Also specialsoil tests for organic farming havebeen developed (Haneklaus et al.2005), but the usability of thesemethods for organic agriculturalpractice has not been described andverified.Organic farming systems are usuallypredominantly N-limited and thecrop P needs for yield level under© Hans Marten Paulsenorganic growth conditions are notwell defined. Furthermore, theavailable threshold values used todescribe P supply in plant tissue arederived from systems fertilised withsufficient mineral N and might notbe adequate for lower yield levels.It is obvious that a real P budgetmanagement is not possible withoutfurther information on these basicparameters.Mobilising soil P reserves bybiological measuresUsing suitable root systems andadapted crop rotationsRoot geometry, root-length densityand active root surface area, increasedby mycorrhiza in certain species, areimportant factors influencing theability of plants to unlock nutrientsfrom the solid phase of the soil. Theenhancement of active root surfaceto assure an intensive P exploration ofplants in soil should be an inevitablegoal of agricultural production.P management in organic farmingshould entail a composition of cropplants displaying different rootsystems and capacities for P uptake.For example white lupin andbuckwheat are described as having anefficient P uptake and different speciescan access different soil P reserves(Mat Hassan 2010). Also otherdicots displaying taproot systemscombined with intensive rhizosphereactivity – like lucerne or pea – can beintroduced into organic crop rotationsto strengthen organic P flow.When grown in mixed cropping, Pefficient crops can directly enhancethe P nutrition of the cropping partner.On the other hand, effective Puptake by these plants might alsolimit P that is available for the followingcrops. Also the cultivation,mulching and redistribution of morecommon cover crops like grass clovermay enhance biological P cycling onfarm. The nutrient (and P) value andnutrient relations of the plant tissuecan be influenced by crop type andplant age.Enhancing soil microbial activitySoil microbes colonise the rhizosphere,enhanced by root exudates. P mobilisationfrom insoluble inorganicand organic soil reserves takes placeby soil acidification or exudation ofphosphatases by plants and microbes.Mycorrhiza and their activityincrease with increasing depletionof P soil reserves. But microbes andplants are also competing for theorthophosphate available in thesoil solution. Thus, the net balanceof available P from these biologicalprocesses is difficult to quantify. Itdepends on several environmentalconditions as well as substrate attributes,e.g. the C:P ratio of organicmaterials (Oberson et al. 2010).Organic inputs can stimulate soilmicrobial activity and soil P mobilisation.But since the factors drivingmicrobial P release are not completelyunderstood the prediction of plantavailable P coming from soil microbesis difficult to quantify.Organic farming relies on this biologicalP mobilisation and targetedP fertilisation is often neglected,without knowing the real potentialof these processes for an efficientnutrient management. Due to thesometimes high, but in the short-termGerold RahmannHead of the Institute ofOrganic Farming, JohannHeinrich von Thünen-Institute (vTI), Trenthorst,GermanyPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

54Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources55Roots and worms in the subsoil.© Hans Marten Paulseninsoluble, reserves available in soilas well as the relatively low exportof P by sold products, this theory isattractive but may mine soil P in thelong-term and finally result in P deficiencies.Nevertheless, processes ofP-mobilisation hold promise for increasingthe use efficiency of P addedwith mineral or organic sources(Simpson et al. 2011).P acquisition from the subsoilCompared with the topsoil, spatialaccessibility of the less mobile P inthe subsoil is generally lower. Butespecially under high organic fertilisersupply crop roots can translocatehigh amounts of organic P downwardsby the roots. The proportion ofP in the deeper layers is consideredto range from 25 to 70 % of the totalamount of P in the soil profile. In thesubsoil, roots have been reported togrow predominantly in macroporeseither formed by physical processessuch as swelling and shrinking,or biogenically (old root channelsand earthworm borrows). The areaaround biopores, the so-called drilosphere,is considered as a preferredsite for nutrient acquisition in thesubsoil. Thus, crop-species that canenhance earthworm populationshould be preferred in organic agriculture.Earthworm excreta arecharacterised by higher biologicalactivity and higher content of microbialP and alkaline phosphataseactivity. Thus, roots growing in earthwormbiopores meet higher P contentsin the tapestries of the wallscoated with worm cast (Pankhurst etal. 2002).P delivery from the subsoil is enhancedwhen P content in the topsoil is low,as demonstrated by long-term fieldtrials (Oehl 2002; Wechsung andPagel 1993). Already before topsoilswere extensively fertilised with P, itwas shown by means of 32P tracermethods that the subsoil substantiallycontributed to plant P nutrition. Ina degraded prairie soil it was shown,that continuous alfalfa growth canrestore lost P reserves by P mobilisationfrom stable soil reserves (Daroubet al. 2001).What we should knowThe role of a dense plant rootingsystem in increasing P uptake by physicalmeasures is undoubted. Alsothe importance of chemical and biologicalinteractions in the root zoneis known. But the potential for anincrease in biological P mobilisationthrough management is not quantifiedand it is still unclear to whatextent plants, and soil and rootmicrobes can mobilise the P reservesand feed them into the active soilplantfarm P cycle (Guppy et al. 2009).So these biological measures toenhance P mobilisation are far fromconfirmed knowledge which can beused in management advice. Due tothe complex factors determining Pmobility in soil, each component ofthe P cycle in organic farms should beanalysed to decide on the necessityand the right place for P imports.Of genuine importance for organicsystems might be the role of P forrhizobial N fixation with legumes(Römer and Lehne 2004). In any case,a hidden depletion of available P insoils under long-term organic managementby use of P sources with lowavailability in the soil/plant P circleshould be avoided.Suitable fertilisers must be discussedAfter estimating possible capacitiesof biological P mobilisation andavailable P in soils, suitable P fertilisersand fertilising strategies thatcan be applied in organic farms tocorrect P imbalances have to be identified.Use of P fertilisers – especially rockphosphate, which is widely usedin organic farming – is potentiallylinked to soil contamination withCadmium as well as Uranium (Kratzand Schnug 2005). Furthermore, theuse of rock phosphate is often inadequatebecause most P enters theP budget in more or less insolubleform. When the soil pH is higher than6, P mobilisation from this source isdoubtful and unforeseeable (Arcandand Schneider 2006). Attemptsto increase P availability of rockphosphate by mixtures with slurry,manure or compost, or to increaseinitial P mobilisation by applicationto plants with high P efficiencyimproved P usage only little andunder controlled conditions. Also,the frequently discussed use of rockpowders – e.g. of basaltic or volcanicorigin – as fertiliser in organic farmingis ineffective, due to low nutrient(and also P) contents and low plantavailability. Special developed rockphosphate or bone meal fertilisersgenerating acid phases to dissolveP have not yet been introduced inpractice and are currently not acceptedby EU regulation. At least inspecial cases, the use of soluble Pfertilisers such as superphosphateshould be allowed.The recycling of P containing residuesfrom industry and households shouldalso be reintroduced in organic farmingunder consideration of closednutrient cycles and under strict limitationof possible pollutants in thesources, e.g. in sewage sludge andcomposts (Rahmann et al. 2009).Ethical aspects concerning the useof conventional sources and residuesfrom animal production with lowanimal welfare standards must alsobe discussed. Therefore farm collaborationsthat are shifting plantnutrients, among these also P, by livestockand biogas manure from conventionalto organic systems shouldbe prepared to face public debateson the consistency of nutrient cyclingin organic farming.PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

56Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources57Phosphorus from recycled organic fertilisers –a Norwegian perspectiveAnne BøenResearcher, Bioforsk –Norwegian Institute for Agriculturaland EnvironmentalResearch, NorwayMeat-and-bone meal (right) combined with bottomwood ash (left) has proven promising results as anorganic NPK fertilizer.© Reidun AspmoFood production is the largestconsumer of mined phosphrus (P)worldwide. P is introduced to foodproduction from mineral fertilisersand feedstuffs, with fertiliser as themost important source. Only a smallpart of this P ends up on our forks.During production, processing, tradeand intake of food, P is directed tovarious organic wastes, by-productsand wastewater. Manure makes upthe largest of these secondary P resources,containing around 13,500tonnes per year on a national basis inNorway. In comparison, Norwegianfarmers use around 8,000 tonnes ofP in mineral fertilisers per year. 6,000tonnes of P from food production isfound in organic waste and wastewaterfrom processing, trade andconsumption of food. One third ofthis P is returned to agricultural landwith recycled organic fertilisers andsoil amendments, mainly by sewagesludge and meat-and-bone meal(MBM). MBM is processed low riskslaughtering waste and is utilised asa fertiliser. In addition, around 60 %of the sewage sludge produced inNorway is used in agriculture as soilamendment.Recycling of products based onwaste and wastewater representsa potential risk connected to sanitationand contaminants. The lastdecade there have been nationalrisk assessments for biosolids andmeat-and-bone meal based on lowriskslaughtering waste, concludingthat these products can be safelyused on agricultural land as long asthey follow the process- and productquality standards set in current legislation.As these products are regardedas safe and beneficial to the soil,incineration with possible P recoveryfrom the ashes has so far not beenregarded as an alternative. There arerestrictions on loads and areas wherewaste-based products can be used.Restrictions on loads are related toheavy metal content in the productsand there are no explicit restrictionson P loads. As application loads forthese materials are often decidedby nitrogen (N) fertiliser effect orsoil improvement effects, the P loadoften tends to be higher than theplants’ P demand.When MBM is applied in order tosupply the crop with nitrogen, moreP than the annual plant demandis also applied. Experiments haveestimated the effect of P from MBMduring the first year to be 40-50 %compared to the effect of P frommineral fertiliser. Release of P fromthe bone fraction of MBM is a longtermprocess and MBM has proven tohave a residual effect of P supply thatlasts for several years in Norwegiansoils. It is, however, important tonote that the solubility of MBM is pHdependent and the P fertiliser effectcan be expected to be best on acidicsoils.It has been recommended notto apply any P the year afterapplication of MBM as N fertiliser.In organic farming systems, MBM isrecommended at 80 kg N per hectareto a nitrogen-demanding crop oncein a four or five year crop rotationin order to maintain the P balance.An organic fertiliser based on meatand-bonemeal and wood bottomash is being developed in Norway atpresent.Biosolids originating from sewagesludge are typically applied as soilamendments once in a 10-yearperiod in an amount of 20 tonnes drymatter per hectare. Such applicationrepresents a large amount of totalP (150 – 600 kg per hectare), butdue to the low plant availabilityof P, farmers commonly apply thesame amount of mineral P as usualboth in the application year and thefollowing years. P from biosolids willtherefore often be poorly utilised inthe soil-plant system.Also for manure, efficient P recyclinghas proven to be problematic. Theanimal density in Norway is regulatedas a ratio between animals and landfor application of manure (manureanimal unit, MAU). One MAUrepresents around 14 kg P, whichshould be applied to 0.4 hectares ora larger area. However, the amountof manure on an acreage basis isoften applied according to the crops’demand for nitrogen, leading tohigher applications of manure atareas close to the farm, and almostnothing at more distant fields. Suchpractice results in build-up of highconcentrations of readily available Pin soils, increasing the risk for P lossfrom agricultural land by erosion andleaching.In areas with high animal density, acombination of biogas treatmentand separation of P from the liquiddigestate is regarded as an interestingalternative. Norwegian experimentswith liquid digestate made frommixtures of manure, fish silage andfood waste have shown a very goodeffect as fertiliser, often at the samelevel as mineral NPK fertiliser. Thechallenge with liquid biogas residueis high transport costs, which put aneconomic limitation on use in areasdistant from biogas plants. Althoughdifferent solutions for precipitationand concentration of plant nutrientsin digestates are being investigated,there are so far no obvious andprofitable methods available.Developments in processingtechnology to convert waste andby-products into recycled fertiliserproducts are key factors for moreefficient P recycling. What we arestill waiting for are the legal andeconomic incentives to start theprocess.Meat-and-bone meal applied as NP fertilizer in spring.Trond K. HaraldsenSenior Researcher, Bioforsk– Norwegian Institute forAgricultural and EnvironmentalResearch, Norway© Torbjørn StørenPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

58Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources59How energy from livestock manure can reduceeutrophicationLudwig HermannOutotec, GermanyThe problem of phosphorus recoveryfrom a manufacturer’s point of view60 % of phosphorus losses to theBaltic Sea originate from nonpointsources, 90 % thereof fromagriculture or, more precisely, fromfactory farming. Notwithstandingthe regulatory and voluntary effortsfor higher environmental compatibility,animal husbandry remains akey emitter of excessive phosphorusapplications to soils and subsequentlosses to aquatic bodies.Ecologists claim that only a radicalsystem and management changecan solve the problem. Experienceteaches, however, that radical changesdo not happen without emergency.As a consequence, an evolutionarytechnological approach thatdoes not substantially interfere withcurrent agricultural practices may bea meaningful option.Biomass waste is generally acknowledgedas a sustainable option forenergy generation. Livestock manurein Germany has a gross energy potentialof about 100.000 GWh per year,two times the currently installedwind power capacity. Still, only 15% of it is used, mainly for biogasproduction. Animal excretions areinstead used as a fertiliser, becauseof their significant nutrient concentrationsand other benefits topasture and cropland. However,excessive phosphorus applications onfarmland enhance the risk of nutrientlosses to water-bodies by run-off anderosion. Soils in the vicinity of animalhusbandry farms usually receiveexcessive phosphorus loads becausethere is no cheaper and easier wayof disposing biomass waste than tospray it on agricultural land. As longas waste may be declared as fertiliser,independently from fulfilling ameaningful function or not, excessivenutrient loads to soils will continue.The main problem behind the nonsustainablepractices is the highwater content of most biomasswastes, depending on its origin andvarying between 80 % and 97 %. Thisfact reduces the economic transportrange of these materials to just a fewkilometres.So what to do? The key is energygeneration together with nutrientrecovery. No doubt that biomasswaste is an adequate renewableenergy source. As long as manure isused for biogas generation, moistureis not a problem. But it does notsolve the nutrient problem, becausethe waste from biogas production,digestion residues, contains as muchwater as the input. However, biogasis only a first step to a sustainablesolution. Digestion residues andwaste biomass that is not suitable fordigesters should be incinerated.Incineration of biomass waste,independent from preceding biogasproduction, solves two problemssimultaneously. Firstly, it makesuse of the full energy potential ofbiomass, as digestion residues stillhave an energy potential of 15.000MJ per tonne (Arndt 2009). Secondly,it concentrates the nutrients andfacilitates their transport to the soilswhere they are needed and do notharm the environment.However, to make this vision cometrue, coordinated efforts and researchand development are needed.Framework conditionsPhosphorus (and other nutrients) originatingfrom livestock manure andsewage sludge is unevenly dis-tributedin Germany as shown in the exampleof the Federal States Schleswig-Holstein, Mecklenburg-Vorpommernand Brandenburg – draining to theBaltic Seain comparison to Germanyas a whole (see table 1).Accumulated phosphorus applicationsin Schleswig-Holstein probablyexceed sustainable fertilisationneeds. It has been observed thatfarmers apply relatively high loadsof mineral phosphates though theyuse manure. Breaking down thefigures to applications by region, asintended during the Baltic ManureProject (, will bringto light disparities.The examples of the three GermanFederal States Schleswig-Holstein,Brandenburg, and Mecklenburg-Vorpommern show that not only thenu-trients from animal excretions butalso from human excretions (sewagesludge) are disposed of on agriculturalland as fertiliser materials. Schleswig-Holstein, a Federal State with oneof the highest P-loads from livestockmanure in Germany, prefersagricultural application of sewagesludge rather than alternative,sustainable pathways.Hypothetically, a large proportionof phosphorus taken up by cropsTable 1: Livestock, agricultural land and P 2O 5applications in 3 States and Germany(Source: Destatis 2009 statistical data)BrandenburgMecklenburg-Vorpommernin Germany could be covered in asafe way by renewable sources –livestock manure, sewage sludge andslaughterhouse residues – if theseresources could be applied in thoseregions where they are required andnot where they can be disposed of atlow cost. Pre-conditions to nationwide(phosphorus) fertiliser applicationrates in line with sustainable farmingrecommendations are thatnew fertiliser products be dry andcontain phosphorus in sufficientlyhigh concentrations, and that theagronomic phosphorus efficiency beproven.According to the conversion factorsin use in agricultural policy, each livestockunit produces about 15 m 3 oflivestock manure per year, with anaverage dry substance concentrationSchleswig-HolsteinGermanyLivestock units 577,500 550,700 1,093,700 13,508,000Agricultural land (ha) 1,034,886 1,355,834 651,470 11,877,013P 2O 5from livestock manure and sewagesludge applied per ha in kg per yearP 2O 5from mineral fertilisers per ha inkg per year18.9 18.4 49.7 35.45.1 17.1 41.4 13.9Total P 2O 5per ha in kg per year 24.0 35.5 91.1 49.3PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

60Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources61of 10 %, of which about 80 % isorganic. During anaerobic digestion,it yields at least 3 MWh in the form ofbiogas. Because of the degradationof organic matter into biogas, theresulting digestion residues containonly 7 % dry matter, of which 70% is organic. Tests at the UniversityHohenheim (Germany) have demonstratedthat dried digestion residueswith 10 % humidity yield 15.000 MJor 4.16 MWh per tonne in the formof heat (Arndt 2009).Hypothetically, 13.5 million livestockunits in Germany could thus yieldenergy in the order of 95.000 GWhand more if the total waste fromanimal husbandry is considered. Thisis twice the energy output of all windpower plants at present in operationand may be a significant contributionto future energy supplies.Most of this energy potential hasnot been considered yet because ofthe inefficiency of drying processesin use. The key to accessing thetotal energy potential of livestockmanure, other wet biomass and evensewage sludge is in recycling theenergy that is necessary to evaporatewater. Whereas at present mostof the energy yielded is used forinternal processes and in particularfor drying, recent developments arepromising regarding the technicalfeasibility to significantly increasedrying efficiency. However, a netenergy yield from livestock manureremains a prerequisite for the widespreadimplementation of the proposedconcept.Innovative approachesThe highest phosphorus concentrationin a recycled fertiliser productcan be achieved by mono-incinerationof the targeted waste biomass.Besides phosphorus, potassium, calcium,and sulfur, micronutrients willbe accumulated in the ash. Nitrogenis lost during incineration, but halfof the original N-content can be separatedbefore incineration by aneffective solid-liquid separation.Almost all waste biomass and inparticular manure contains largeamounts of water, up to 97 %. Energygeneration by anaerobic digestiondoes not require dewatering. About15 % of livestock manure in Germanyis already used to producebiogas and this share should increasesubstantially in the near future.Generating energy by anaerobicdigestion, however, has no effect onthe regional distribution of phosphorusbecause the digestion residuesare again sprayed on croplandin the vicinity of animal husbandryfarms.Only mono-incineration can solvethe problem. There are good reasonsto assume that all targeted biomasscould yield a net surplus of energyon top of covering the additional expensesfor material preparation, dewateringand drying.Assuming that the highest energyyield can be achieved by anaerobicdigestion and subsequent monoincineration,all larger animalhusbandry farms should be equippedwith biogas facilities where between30 % and 50 % of organic substancesof livestock manure will be degraded(Arndt 2009). These facilities willyield digestions residues with thecharacteristics shown in table 2.State-of-the-art solid-liquid separationyields a solid phase with 20-30 %dry substance and a liquid phase with2-6 % dry substance. On average,about 75 % of phosphates and 50% of each nitrogen and po-tassiummay be concentrated in the solidphase (Arndt 2009) (see also table3). The nutrients remaining in theliquid phase will continue to be usedfor fertilisation in the vicinity of theanimal husbandry farm – with only25-50 % of the traditional nutrientapplication rates.The solid phase should be shippedto larger mono-incineration facilitieswhere it will be dried andcombusted. Whereas fluidised bedcombustion has proven to be appropriatefor sludge and residues withhigh moisture content, energyeffectivedrying is not state-ofthe-art.However, a few examplesof very effective drying systemsexist in the area of biomass-fueledcombined heat and power (CHP)plants, for instance in Hedensbynand Storuman, northern Sweden,engineered by GreenExergy AB.GreenExergy is one of the few companiesthat have managed to recyclemost of the energy needed forevaporating water from forestryand sawmill residues. The dryer hasa net energy consumption of only150 kWh to evaporate one tonne ofwater, in comparison to 1200-1400kWh for traditional drying processes.If this system could be transferred tosludge and manure drying, monoincinerationof these materials wouldGreenExergy biomass-fueled CHP plant in Storuman, Sweden. The long pipes are part of the steam dryer.© Skellefteå Kraft AByield net energy surpluses and contributesignificantly to energy supplies.The main task for the dryer is toreduce the moisture content in theraw material from feed moisturecontent down to 8-12 %, dependingon the final use of the product.The system shall also facilitatethe feeding and the extraction ofmaterial to, and from the pressuriseddryer. An important task is to recoverthe evaporated steam from the rawmaterial through regeneration oflow pressure steam to other lowtemperature usage.Table 2: Dry substance and nutrient concentrations in digestion residues(Source: Bavarian State Research Center for Agriculture)Digestion residue Dry Substance N totalkg/m 3 NH 4kg/m 3 P 2O 5kg/m 3 K 2O kg/m 3Min. 2.9 2.4 1.5 0.9 2.0Max. 13.2 9.1 6.8 6.0 10.6Average 6.7 5.4 3.5 2.5 5.4Table 3: Nutrient concentration in the solid phase after solid-liquid separation(Source: Bavarian State Research Center for Agriculture)Digestion residue N totalAmmonium P KMin. 52.2% 46.8% 50.0% 47.9%Max. 67.0% 52.8% 89.3% 50.0%Average 57.6% 46.8% 73.3% 49.3%PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

62Baltic Sea Region perspectives on limited P resourcesBaltic Sea Region perspectives on limited P resources63Sustainable Agriculture –Truly Multidisciplinary Cross-cutting ThemesThe technical challenge for the dryerswill be the physical state of livestockmanure and sludge before andduring the drying process. It will bedifficult to prepare the material forthe kind of steam dryers used in theGreenExergy CHP plants. Moreover,sludge is entering into a sticky state ata certain stage of the drying processthat has always been a challenge tosludge dryers. Manure drying has notbeen tested yet.Compared to drying incinerationshould not present any problem.State-of-the-art fluidised bed furnacessuch as those from Outotec Oyj willsafely handle the material. However,high loads of nitrogen, chlorines andsulfur in manure increase the risk ofexcessive nitrogen concentrations inthe flue gas and material corrosion.They are challenging with respect toengineering and material selection.Chicken litter incinerators in the U.K.and the Netherlands have proventhat the fluidised bed technologycan cope with the challenges at largeindustrial scale.The biomass-fueled CHP plant in Storuman at night.Preliminary tests of mono-incinerationof digestion residues with a largershare of livestock manure at HohenheimUniversity yielded an ash with24 % P2O5 and 21 % K2O as primarynutrients and 23 % Calcium as secondarynutrient (Arndt 2009). It is evidentthat a fertiliser with an originalnutrient concentration of 45 % maybe evenly distributed across Germany.If and when heavy metal concentrationsexceed the limits for sustainablefertilisers, the ASH DEC heavymetal separation process may be installedtogether with the incinerator.Even if the proposed approach wouldsignificantly reduce the excessiveapplication of nutrients in regionswith high livestock concentration, itdoes not automatically entail higherplant nutrition efficiency if the ashbasedproduct is not plant available.Consequently, as a last step, the plantavailability of renewable fertilisersneeds to be tested and improved, ifnecessary. Pot and field tests duringthe FP-6 Programme “SUSAN” havedemonstrated that the formation© Skellefteå Kraft ABof magnesium-phosphates duringa thermal process can producephosphate fertilisers with high plantavailability on neutral to acidic soils.The Julius Kühn Institut (JKI), GermanFederal Research Center for CultivatedPlants has successfully tested in-situinoculation of phosphate rock withsulfur and Thiobacillus. Both methodscould significantly increase fertiliserefficiency of renewable phosphatefertilisers. Product development mustnot stop when renewable productscan achieve similar efficiency levels astraditional, water-soluble phosphatefertilisers. There is still potential tofurther increase the plant availabilityof renewable products to obtain highcrop yields with adequate fertiliserapplications.The same rule applies to renewablematerials as to renewable energy: ourplanet is not big enough to sustainsimple replacement of one source bythe other. The key to sustainabilityis closing nutrient and energy cyclesand making the use of resourcesmore effective.What is sustainable agriculture? Thisis one of the key questions for thefuture. In 1998 the Baltic 21 AgricultureSector answered this question byelaborating a goal and definition forsustainable agriculture:“Sustainable agriculture is the productionof high-quality food and otheragricultural products and services in thelong run, with consideration taken toeconomy and social structure in sucha way that the resource base of nonrenewableand renewable resources ismaintained.”Important sub-goals are:• The farmers’ income shouldbe sufficient to provide afair standard of living in theagricultural community.• Farmers should practice productionmethods that do notthreaten human or animal healthor degrade the environment,including biodiversity, and atthe same time minimise theenvironmental problems thatfuture generations must assumeresponsibility for.• Non-renewable resourcesshould be gradually replacedby renewable resources and recirculationof non-renewableresources should be maximized.• Sustainable agriculture shouldmeet the needs of food andrecreation, preserve the landscape,cultural values andhistorical heritage of rural areas,and contribute to the creationof stable, well-developed andsecure rural communities.• The ethical aspects of agriculturalproduction should be secured.A series of three books in the finalstage of production and will soonbe available. They are the concreteoutcome of the Ecosystem Health andSustainable Agriculture project. Herethe importance of an ecosystemapproach as regards sustainableagriculture is highlighted. Sustainableagriculture is a means of securing thenecessary resources for safeguardingglobal food production, biodiversityreserves, recreation needs, waterquality and well developed ruraland wildlife areas. It can also be aneffective means of reducing povertyand achieving the Millennium DevelopmentGoals, as well as mitigatingclimate change. It is also about health,welfare, respect and ethics regardinganimals and man, as well as qualityof food and feed. In other words,the books are truly trans-disciplinaryand represent a new holistic outlookon ecosystem health and sustainableagriculture.These three books are based onexperience from the Baltic Seaand Great Lakes Regions and arewritten by prominent experts andscientists from the two regions. Twonetworks have been involved in theproduction of the books, The BalticUniversity Programme (BUP) and theEnvirovet Baltic Networks. The BUPis a network of approximately 220universities in the drainage basinof the Baltic Sea, which cooperateson sustainable development andstudies of the region, its environmentand its political changes. The programme,founded in 1991 at UppsalaUniversity, Sweden, operates byproducing courses, holding conferencesand seminars. In 2010, theBUP network delivered courses atmore than 100 universities servingnearly 9,500 undergraduate andChristine JakobssonCooperation coordinator,Faculty of Veterinary Medicineand Animal Science,Swedish University of AgriculturalSciences, SwedenPerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

64Baltic Sea Region perspectives on limited P resourcesAnnex65Referencesgraduate students. The EnvirovetBaltic, a network of environmentalhealth scientists and educators fromthe USA and the nine countriesbordering the Baltic Sea, was foundedin 2001 on an initiative of theCollege of Veterinary Medicine atthe University of Illinois and theCentre for Reproductive Biology inUppsala at the Swedish Universityof Agricultural Sciences, along withscientists from universities in theBaltic Sea Region (BSR).The production of these books wasmanaged by BUP and includedseveral educational seminars,training courses, conferences andmeetings on Ecosystem Healthand Sustainable Agriculture. Thesewere held in St. Petersburg andKaliningrad, Russia, in Tallinn andTartu, Estonia, in Jelgava, Latvia, inKaunas and Vilnius, Lithuania, inWarsaw, Poland, in Uppsala, Swedenand in Urbana-Champaign, Illinois,USA. The project has also achievedlarge international recognition as itwas awarded the status of a UnitedNations Partnership for SustainableDevelopment and the status of aBaltic 21 Lighthouse project. Thelatter was awarded by Baltic 21- anAgenda 21 for the Baltic Sea Regionas a good example of an internationalproject on sustainable developmentwithin the Baltic Sea Region. As aresult,it has been presented at manyconferences, such as the UnitedNations Commission for SustainableDevelopment 16 Meeting in May2008, AgroRus 2007 and 2008, Baltic21 Ten Year Anniversary at the RigaSummit in June 2008, and Baltic SeaDays in March 2009. The productionof these books was financed by SIDA,SEPA and SI.We strongly recommend thatreaders study all three volumes inthis educational series:• Sustainable Agriculture (ed.Christine Jakobsson, 500 pp.)• Ecology and Animal Health(ed. Leif Norrgren and JeffreyLevengood, 400 pp.)• Rural Development and LandUse (ed. Ingrid Karlsson and LarsRydén, 300 pp.)The first two books will be printedin October/November 2011 and thethird book a few months later.It is our firm belief that agricultureand related activities can, if wellmanaged, be positive for ecosystemsand biodiversity. Alternatively, agriculturalactivities can also have disastrouseffects on the environmentincluding humans living in the area.Often national goals are not only tosustain the country’s food security,but also to keep an open landscapeand a rural lifestyle. A sustainablerural development has its backbonein a sustainable agriculture.Arcand, M.M. / Schneider, K.D. (2006): Plant- and microbial-based mechanisms to improve theagronomic effectiveness of phosphate rock: a review. Annals of the Brazilian Academy ofSciences 78(4), 791-807.Arndt, M. / Wagner, R. (2009): Einführung in die Gärresteverbrennung, C.A.R.M.E.N. Fachgespräch,Straubing, biomasse Messe 2009.Bavarian State Research Center for Agriculture, Institut für Agroökologie (2009): Einsatz vonGärresten aus der Biogasproduktion als Düngemittel, LfL Information, Dezember 2009.Berry, P.M. / Stockdale, E.A. / Sylvester-Bradley, R. / Philipps, L. / Smith, K.A. / Lord, E.I. / Watson, C.A. /Fortune, S. (2003): N, P and K budgets for crop rotations on nine organic farms in the UK. In: SoilUse Management 19(2), 112-118.Carpenter, S. R. (2011): Phosphorus: Approaching fundamental limits? In: Stockholm Waterfront,Forum for global issues no. 2, July 2011.CBSS Strategy on Sustainable Development 2010-2015,, S.H. / Ellis, B.G. / Robertson, G.P. (2001): Effect of cropping and low-chemical input systemson soil P fractions. In: Soil Science166(4), 281-291.Destatis / Statistisches Bundesamt Wiesbaden (2009): Landwirtschaft in Deutschland und derEuropäischen Union, www.destatis.deEcoRegion project, Focus Group Food: Policy Recommendations, http://www.baltic-ecoregion.euGransee, A. / Merbach, W. (2000): P dynamics in a long-term P fertilisation trial on Luvic Phaezom atHalle. In: Journal of Plant Nutrition and Soil Science 163, 353-357.Grimm, Nancy B. et al. (2008): Global challenges and the ecology of cities. In: Science magazine, 319.Guppy, C.N. / McLaughlin, M.J. (2009): Options for increasing the biological cycling of P in low-inputand organic agricultural systems. In: Crop Pasture Science 60(2), 116-123.Hall, Robert (2011): in ”Notes on Sustainable Consumption and Production”, Baltic 21 filmproduction;, S. / Schnug, E. / Paulsen, H.M. / Hagel, I. (2005): Soil analysis for organic farming. In:Communications in Soil Science and Plant Analysis 36(1-3), 65-79.HELCOM (2004): The Fourth Baltic Sea Pollution Load Compilation (PLC-4). Baltic Sea EnvironmentProceedings 93.HELCOM (2007): HELCOM Baltic Sea Action Plan, HELCOM Ministerial Meeting Krakow, Poland, 15November 2007.Iital, A. / Stålnacke, P. / Deelstra, J. / Loigu, E. / Pihlak, M. (2005): Effects of Large Scale Changes inEmissions on Nutrient Concentrations in Estonian Rivers in the Lake Peipsi Drainage Basin. In:Journal of Hydrology 304, 261-273.Iital, A. / Pachel, K. / Loigu, E. / Pihlak, M. / Leisk, Ü. (2010): Recent trends in nutrient concentrationsin Estonian rivers as a response to large-scale changes in land-use intensity and life-styles. In:Journal of Environmental Monitoring 12, 178-188.Köster, W. / Nieder, R. (2007): Wann ist eine Grunddüngung mit Phosphor, Kalium und Magnesiumwirtschaftlich vertretbar?,, Bodenfruchtbarkeit und Pflanzenernährung,Heft 1, 2. Auflage.Kratz, S. / Haneklaus, S. / Schnug, E. (2010): Chemical and agricultural performance of P-containingrecycling fertilizers. In: vTI - Agriculture and Forestry Research, 60:4.Kratz, S. / Schnug, E. (2005): Schwermetalle in P-Düngern. Landbauforschung Volkenrode, SpecialIssue 286, 37-45.Kuchenbuch, R.O. / Buczko, U. (2011): Re-visiting potassium- and phosphate-fertiliser responses infield experiments and soil-test interpretations by means of data mining. In: Journal of PlantNutrition and Soil Science 174, 171-185.Loes, A.K. / Ogaard, A.F. (2001): Long-term changes in extractable soil P (P) in organic dairy farmingsystems. In: Plant and Soil 237(2), 321-332.Loigu, E. / Leisk, Ü. (2008): Läänemere merekeskkonna kaitse konventsioonist tuleneva Läänemerereostuskoormuste arvutamise projekti (PLC-5) jaoks 2007. aasta reostuskoormuste andmetekogumine, töötlemine ja edastamine (in Estonian).Mat, Hassan H. / Marschner, P. / McNeill, A. (2010): Growth, P uptake in grain legumes and changes insoil P pools in the rhizosphere. 19th World Congress of Soil Science, Soil Solutions for a ChangingWorld, 1 – 6 August, Brisbane, Australia. Published on DVD: 179-181.MacDonald, G.K. / Bennet, E.M. / Potter, P.A. / Ramancutty, N. (2011): From the Cover: Agronomicphosphorus imbalances across the world’s. Proceedings of the National Academy of Sciences108:7, 3086-3091.Oberson, A. / Tagmann, H. / Langmeier, M. / Dubois, D. / Mäder, P. / Frossard, E. (2010): Fresh andresidual phosphorus uptake by ryegrass from soils with different fertilisation histories. In: PlantSoil 334, 391-407.Oehl, F. / Oberson, A. / Probst, M. / Fliessbach, A. / Roth, H. R. / Frossard, E. (2001): Kinetics of microbialphosphorus uptake in cultivated soils. In: Biol. Fertil. Soils 34, 31-41.Oehl, F. / Oberson, A. / Tagmann, H.U. / Besson, J.M. / Dubois, D. / Mader, P. / Roth, H.R. / Frossard, E.PerspectivesSustainable agriculture in the Baltic Sea RegionSustainable agriculture in the Baltic Sea RegionPerspectives

66(2002): Phosphorus budget and P availability in soils under organic and conventional farming. In:Nutrient Cycling in Agroecosystems 62(1), 25-35.Pachel, K. / Klõga, M. / Iital, A. (2011): Scenarios for reduction of nutrient load from point sources inEstonia. In: Hydrology Research (accepted).Pankhurst, C.E. / Pierret, A. / Hawke, B.G. / Kirby, J.M. (2002): Microbiological and chemical propertiesof soil associated with macropores at different depths in a red-duplex soil in NSW. Australia. In:Plant Soil 238, 11-20.Põllumajandusministeerium (2011): Põllumajandussektori 2010. aasta ülevaade (in Estonian).Rahmann, G. / Oppermann, R. / Paulsen, H.M. / Weissmann, F. (2009): Good, but not good enough?Research and development needs in Organic Farming. In: Landbauforschung Völkenrode 59(1),29-40.Rockström, Johan et al. (2009): Planetary bundaries: Exploring the safe operating space for humanity.In: Ecology and Society 14(2).Römer, W. / Lehne, P. (2004): Neglected P and K fertilisation in organic farming reduces N-2 fixationand grain yield in a red clover-oat rotation. In: Journal of Plant Nutrition and Soil Science-Zeitschrift fur Pflanzenernahrung und Bodenkunde 167(1), 106-113.Roseland, Mark. (2005): Towards Sustainable Communities, New Socitey Publishers.Simpson, R. J. / Oberson, A. / Culvenor, R. A. / Ryan, M.H. / Veneklaas, E.J. / Lambers, H. / Lynch, J.P. /Ryan, P.R. / Delhaize, E. / Smith, A. / Smith, S.E. / Harvey, P.R. / Richardson, A.E. (2011): Strategiesand agronomic interventions to improve the phosphorus-use efficiency of farming systems. In:Plant Soil (online first: DOI: 10.1007/s11104-011-0880-1).Statistical Office of Estonia (2006): Agriculture Yearbook.Statistical Office of Estonia (2007): Agriculture in figures.Vance, C.P. (2001): Symbiotic nitrogen fixation and phosphorus acquisition. Plant nutrition in a worldof declining renewable resources. In: Plant Physiology 127, 390-397.Wechsung, G. / Pagel, H. (1993): Akkumulation und Mobilisation von Phosphaten in einer Schwarzerdeim Statischen Dauerversuch Lauchstädt – Betrachtung der P-Bilanz nach 84 Versuchsjahren.Journal of Plant Nutrition and Soil Science 156, 301-306.PerspectivesSustainable agriculture in the Baltic Sea Region

The EcoRegion Perspectives‘ series is published aspart of the EcoRegion project funded by the BalticSea Region Programme 2007-2013.It documents experiences and concepts which showhow sustainable development in the Baltic Searegion can become a reality. Each issue focuses on aspecific sustainability topic such as tourism, territorialcohesion, education and innovation, transportand energy.EcoRegion Perspectives support relevant regionalfora such as the CBSS Expert Group on SustainableDevelopment – Baltic 21 as well as the implementationof the EU Strategy for the Baltic Sea Region.The different EcoRegion Perspectives‘ issues are coordinatedby the EcoRegion partners and reflect awide range of stakeholders with expertise on therespective topics.Perspectives

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