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Environmental Science
Environmental Science 1021F/G
Geoff Stewart

Food and Land III Food and Soil Resources Pests and PesticidesPestunwanted organism that interferes with human activities subjectiveA weed is a plant whose virtues have notyet been discoveredWaldo EmersonPesticidekills or controls undesirable organisms 100 species 1 cause 90 of the damageDisturbs predatorprey cycles in natural ecosystems and polyculturePesticides Types 1 Insecticidesblock reproduction airways nervous system 2 Herbicidesdisrupt plant growth and metabolism 3 Fungicides 4 RodenticidesPesticide HistoryBefore pesticidesCrop rotation vary planting times plant diversity hedgerowsBased on plants natural instinctsFirst generationSulphur lead arsenic mercuryNicotine sulphate pyrethrum rotenoneSecond generationSynthetic organic compounds eg DDT broad and narrowspectrum persistence reduction some naturalThe Case For PesticidesSaves human livesMalaria bubonic plague typhusIncrease food supplies and profits lower costsWork faster and better than alternativesHealth risk may be insignificant compared to benefits30006000 deathyr EPANew pesticides are safer and used at lower rates than older pesticidesThe Case Against Pesticides What are the true costsGenetic resistanceinsects and plantsKill nontarget organisms incl natural predatorsCan increase other pestsHarm wildlifePesticide movementHuman health threat 2000040000 deathsEnvironmental health threatStill 6 decrease in yield loss to pestsEconomic threshold of useUse reduced without yield decrease Alternatives to Synthetic Chemical PesticidesSome based on biomimicry part of Integrated Pest Management IPM 1 Change cultivation practices cultural 2 Biological pest controlInsect birth control hormonespheromonesPredators3 Hot water 4 Geneticallyresistant plantsRecall associated problemsWhat Are the Environmental Issues Food Consumption After the FarmgateEnergy and wastePlant irrigate fertilize apply pest control harvestTransport for processingStore clean cook mix preserve packageTransport to the grocery storeKeep food chilledfrozen displayedTransport and preparation at homerestaurantsDisposal transportHow much energy is used17 of US energy consumption used to get food to the table18 of that for onfarm food production 82 of that for food processing transportation marketing and preparationMost energy is from nonrenewable fossil fuelsRelease GHGs and other pollutantsHow can you decrease the energy cost of your foodChoose locallynativeorganically grown foodfoods in seasonless processed whole foodsfoods with less packagingto eat less meat especially red meat lower trophic levelless energy wastesee next slideto compostto garden Food and Land IV Forests Invasive Species and BiodiversityManaging and Sustaining ForestsForests classified by age and structure 1 Oldgrowth forests 22 2 Secondgrowth forests 63 3 Tree farmsplantations 5
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