LectureLecture 1.1. IntroductionIntroduction toto AAgriculturalgricultural PPollutionollution CControlontrol IncludingIncluding particularparticular referencereference toto EasternEastern andand CentralCentral EuropeEurope Prepared by Assoc. Prof. Philip Chiverton, SLU 1 PollutionPollution :: ‘‘thethe introductionintroduction byby man,man, directlydirectly oror indirectly,indirectly, ofof substancessubstances oror energyenergy intointo thethe environment,environment, whichwhich areare liableliable toto createcreate hazardshazards toto humanhuman health,health, toto harmharm livingliving resourcesresources andand marinemarine ecosystems’ecosystems’ AgriculturalAgricultural pollutionpollution is,is, thus,thus, thethe directdirect oror indirectindirect introductionintroduction ofof substancessubstances –– particularlyparticularly excessiveexcessive nutrientsnutrients (such(such asas nitratesnitrates (N)(N) andand phosphorousphosphorous (P)(P) )) -- oror energyenergy intointo thethe environmentenvironment asas aa resultresult ofof mansmans agriculturalagricultural activities.activities. 2 HowHow cancan AgriculturalAgricultural PollutionPollution harmharm ourour environment?environment? 3 EutrophicEutrophic meansmeans nutrient-richnutrient-rich,, andand eutrophicationeutrophication literallyliterally meansmeans enrichmentenrichment withwith nutrients,nutrients, althoughalthough nowadaysnowadays thethe termterm isis moremore oftenoften usedused inin aa negativenegative sensesense toto meanmean over-enrichment.over-enrichment. NutrientsNutrients -- especiallyespecially nitrogennitrogen andand phosphorusphosphorus -- areare vitalvital forfor marinemarine life.life. ButBut thethe presencepresence ofof excessiveexcessive nutrientsnutrients cancan seriouslyseriously disturbdisturb thethe functioningfunctioning ofof marinemarine ecosystems.ecosystems. 4 ExcessiveExcessive nutrientnutrient inputsinputs intointo aa waterwater bodybody induceinduce biological,biological, chemicalchemical andand physicalphysical changeschanges inin aquaticaquatic plantplant andand animalanimal communities,communities, oftenoften leadingleading toto oxygenoxygen depletion,depletion, especiallyespecially inin deeperdeeper waters.waters. Greenish,Greenish, murkymurky waterwater isis typicallytypically thethe firstfirst signsign ofof eutrophicationeutrophication asas microscopicmicroscopic plantsplants andand algaealgae growgrow profusely,profusely, consumingconsuming thethe surplussurplus nutrients.nutrients. ButBut algaealgae areare short-lived,short-lived, andand whenwhen theythey diedie theythey sinksink toto thethe bottombottom ofof thethe sea,sea, wherewhere theirtheir decompositiondecomposition usesuses upup oxygen.oxygen. TheThe worstworst affectedaffected areasareas cancan becomebecome completelycompletely anoxicanoxic.. InIn thethe absenceabsence ofof oxygen,oxygen, decompositiondecomposition cancan releaserelease toxictoxic hydrogenhydrogen sulphidesulphide,, poisoningpoisoning organismsorganisms andand makingmaking thethe sea-bedsea-bed lifeless.lifeless. 5 BluegreenBluegreen algalalgal blooms,blooms, GulfGulf ofof FinlandFinland Photos from: Finnish Institute of Marine Research (http://www2.fimr.fi/en/itamerikanta/galleria/15. 6 WeatherWeather conditionsconditions cancan alleviatealleviate oror accelerateaccelerate eutrophicationeutrophication.. Mild,Mild, wetwet winterswinters areare usuallyusually badbad newsnews forfor shallow,shallow, coastalcoastal waters,waters, asas nutrientsnutrients areare washedwashed fromfrom farmlandfarmland intointo rivers,rivers, lakeslakes andand ultimatelyultimately thethe sea.sea. ThisThis createscreates suitablesuitable conditioncondition forfor intenseintense algalalgal bloomsblooms inin thethe spring,spring, whichwhich cancan leadlead toto seriousserious oxygenoxygen depletion,depletion, especiallyespecially ifif thethe summersummer isis thenthen warmwarm andand calm.calm. 7 BluegreenBluegreen algalalgal bloom,bloom, GulfGulf ofof FinlandFinland 66th August,August, 20022002 Photos from: Finnish Institute of Marine Research (http://www2.fimr.fi/en/itamerikanta/galleria/15. 8 Algal bloom on the Fyris River near SLU in Uppsala – the river drains the intensively cultivated agricultural plain of Uppland 9 SoSo thethe riversrivers andand seasseas turnturn greengreen forfor aa whilewhile –– WhoWho cares!?!cares!?! 10 ThereThere areare manymany reasonsreasons whywhy governmentsgovernments andand authoritiesauthorities throughoutthroughout thethe worldworld areare deeplydeeply concernedconcerned aboutabout thethe effectseffects ofof agriculturalagricultural pollution.pollution. NotNot leastleast isis thethe dangerdanger toto 1)1) PublicPublic healthhealth.. InIn drinkingdrinking water,water, highhigh concentrationsconcentrations ofof nitratenitrate cancan causecause methemoglobinemia,methemoglobinemia, aa potentiallypotentially fatalfatal diseasedisease inin infantsinfants alsoalso knownknown asas blueblue babybaby syndrome.syndrome. 2)2) FishFish stocksstocks andand marinemarine biodiversitybiodiversity.. EutrophicationEutrophication destroysdestroys (a)(a) spawningspawning areasareas forfor economicallyeconomically valuablevaluable fish,fish, andand (b)(b) habitatshabitats forfor otherother marinemarine life.life. 3)3) TheThe touristtourist industry.industry. PoisonousPoisonous and/orand/or unsightlyunsightly andand odorousodorous coastalcoastal waterswaters discouragediscourage tourists!tourists! 11 ProblemsProblems andand causescauses -- aa summarysummary . Nutrient over-enrichment of coastal ecosystems generally triggers ecological changes that decrease the biological diversity of bays and estuaries . While moderate N enrichment of some coastal waters may increaseincrease fishfish production,production, over-enrichmentover-enrichment generallygenerally degradesdegrades the marine food web that supports commercially valuable fish. The marked increase in nutrient pollution of coastal waters has been accompanied by an increase in harmful algal blooms, and inin atat leastleast somesome cases,cases, pollutionpollution hashas triggeredtriggered thesethese blooms.blooms. 12 ProblemsProblems andand causescauses cont'dcont'd . High nutrient levels and the changes they cause in water quality and the makeup of the algal community are detrimental to the health of coral reefs and thethe diversitydiversity ofof animalanimal lifelife supportedsupported byby seaweedseaweed andand kelpkelp communities.communities. Research during the past decade confirms that N is the chief culprit in eutrophication and other impacts of nutrient over-enrichment in temperate coastal waters, while P is most problematic in eutrophication of freshwater lakes.lakes. Human conversion of atmospheric N into biologically useable forms, principally synthetic inorganic fertilizers, now matches the natural rate of biological N fixationfixation fromfrom allall thethe landland surfacessurfaces ofof thethe earth.earth. 13 ProblemsProblems andand causescauses cont'dcont'd . Both agriculture and the burning of fossil fuels contribute significantly to non- point flows of N to coastal waters, either as direct runoff or airborne pollutants. N from animal wastes that leaks directly to surface waters or is volatilized to the atmosphere as ammonia may be the largest single source of N that moves from agricultural operations into coastal waters. 14 HowHow dodo differentdifferent agriculturalagricultural activitiesactivities contributecontribute toto pollution,pollution, andand howhow doesdoes thisthis affectaffect ourour groundground andand surfacesurface waters??waters?? 15 AgriculturalAgricultural impactsimpacts onon waterwater qualityquality AgriculturalAgricultural activityactivity 1.1. Tillage/ploughingTillage/ploughing ImpactsImpacts SurfaceSurface waterwater GroundwaterGroundwater Sediment/turbidity: sediments carry phosphorus and pesticides adsorbed to sediment particles; siltation of river beds and loss of habitat, spawning ground, etc. 16 AutumnAutumn ploughingploughing inin SwedenSweden 17 AgriculturalAgricultural activityactivity 2.2. FertilizingFertilizing ImpactsImpacts SurfaceSurface waterwater GroundwaterGroundwater Runoff of nutrients, especially phosphorus, Leaching of nitrate to leadingleading toto eutrophicationeutrophication causingcausing tastetaste andand groundwater; excessive levels odour in public water supply, excess are a threat to public health. algae growth leading to deoxygenating of water and fish kills. 18 FertilizingFertilizing withwith anhydrousanhydrous ammoniaammonia 19 AgriculturalAgricultural activityactivity 3.3. ManureManure spreadingspreading ImpactsImpacts SurfaceSurface waterwater GroundwaterGroundwater Carried out as a fertilizer activity; Contamination of ground-water, spreading on frozen ground results especially by nitrogen inin highhigh levelslevels ofof contaminationcontamination ofof receiving waters by pathogens, metals, phosphorus and nitrogen leadingleading toto eutrophicationeutrophication andand potential contamination. 20 MuckMuck spreadingspreading inin LithuaniaLithuania 21 AgriculturalAgricultural activityactivity 4.4. Feedlots/animalFeedlots/animal paddockspaddocks ImpactsImpacts SurfaceSurface waterwater GroundwaterGroundwater Contamination of surface water with Potential leaching of nitrogen, many pathogens (bacteria, viruses, metals, etc. to groundwater. etc.) leading to chronic public health problems. Also contamination by metals contained in urine and faeces. 22 StockStock yardyard inin SwedenSweden 23