3 Answer:Adopt sustainable agriculture (low input practices that cost less and are less damaging)2. Change Food Subsidies3. Coupled with genetic engineering.3. Eat new foods
4 #1. What is sustainable agriculture? Two major ways to increase world’s food production:Increase crop yieldsIncrease the amount of land used
5 Sustainable Agriculture Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological pest control, and minimal use of nonrenewable fossil fuel energy.
6 More Sustainable Agriculture SolutionsMore Sustainable AgricultureMoreLessHigh-yield polycultureSoil erosionSoil salinizationOrganic fertilizersWater pollutionBiological pest controlAquifer depletionOvergrazingIntegrated pest managementOverfishingLoss of biodiversity and agrobiodiversityEfficient irrigationFigure 12.34: More sustainable, low-input agriculture based mostly on mimicking and working with nature has a number of major components. (Concept 12-6). Questions: Which two solutions do you think are the most important? Why?Perennial cropsFossil fuel useCrop rotationGreenhouse gas emissionsWater-efficient cropsSoil conservationSubsidies for unsustainable farmingSubsidies for sustainable farmingFig , p. 310
8 Produce Meat More Efficiently and Humanely Shift to more grain-efficient forms of proteinBeef from rangelands and pastures, not feedlotsDevelop meat substitutes; eat less meat
9 Efficiency of Converting Grain into Animal Protein Figure 12.33: The efficiency of converting grain into animal protein varies with different types of meat. This bar graph show the kilograms of grain required for each kilogram of body weight added for each type of animal. Question: If you eat meat, what changes could you make to your diet that would reduce your environmental impact? (Data from U.S. Department of Agriculture)Fig , p. 309
10 Sustainable Practices A. Diversifying productsCrop rotationConservation tillageContour plowingConsevation tillage reduces erosion & maintains soil. No till, ridge till, mulch till
11 Sustainable Practices B. Low input farming with water/energy conservation
12 Sustainable Practices C. Natural predator/prey relationships over chemical pesticides
13 Sustainable Practices D. Natural fertilizers from manure vs. commercial fertilizers
14 #2. Government Agriculture Policy Government AssistanceKeep food prices artificially lowGive farmers subsidiesEliminate most or all price controls and subsidies and let farmers/fishers respond to market demandFarming = risky Need reliable food supply, so gov. provide forms of assistance
17 Environmentalists think… Use subsidies to reward farmers/fishers/ranchers who:- Protect the soil- Conserve water- Reforest degraded land- Protect and restore wetlands- Conserve wildlife- Practice more sustainableagriculture/fishing/ranching
19 Can combine traits only from closely related species CropCross breedingDesired trait(color)ApplePearOffspringCrossbreedingBest resultsNewoffspringDesiredresultTraditional CrossbreedingSlow processCan combine traits only from closely related species
21 Genetic Engineering/Gene Splicing/GMFs* Inserting alien/preferred gene into valuable plant for new traits, quick results, cheaper
22 Genetic Engineering Wild plants/animals genetic diversity Domesticated plants/animals genetic diversity as certain characteristics are selected forGenetic diversity means species are more susceptible to new strains of disease, increasing risk of total species loss.
23 Phase 1 Make Modified Gene cellIdentify and extractgene with desired traitgeneDNAIdentify and removeportion of DNAwith desired traitPlasmidRemove plasmidfrom DNA of E. coliE. coliDNAInsert extracted DNA(step 2) into plasmid(step3)GeneticallymodifiedplasmidplasmidInsert modifiedplasmid into E. coliGrow in tissueculture tomake copies
24 Phase 2 Make Transgenic Cell Transfer plasmidcopies to a carrieragrobacteriumA. tumefaciens(agrobacterium)Agrobacteriuminserts foreignDNA into plantcell to yieldtransgenic cellPlant cellNucleusHost DNAForeign DNATransfer plasmidto surfacemicroscopic metalparticleUse gene gunto inject DNAinto plant cell
25 Grow Genetically Engineered Plant Phase 3Grow Genetically Engineered PlantTransgenic cellfrom Phase 2Cell division oftransgenic cellsCulture cellsto form plantletsTransgenic plantswith new traitsHalf the time as conventional crossbreedingCuts costsAllows insertion of genes from almost any other organism
26 Genetically Modified Crops and Foods Trade-OffsGenetically Modified Crops and FoodsAdvantagesDisadvantagesNeed less fertilizerUnpredictable genetic and ecological effectsNeed less waterMore resistant to insects, disease, frost, and droughtHarmful toxins and new allergens in foodNo increase in yieldsGrow fasterFigure 12.18: Genetically modified crops and foods can have some or all of the advantages and disadvantages listed here. Questions: Which two advantages and which two disadvantages do you think are the most important? Why?More pesticide-resistant insects and herbicide-resistant weedsMay need less pesticides or tolerate higher levels of herbicidesCould disrupt seed marketMay reduce energy needsLower genetic diversityFig , p. 294
27 Advantages vs. Disadvantages may produce food plants that are more nutritiousdevelop crops resistant to pests/disease/drought/hot/cold/herbicides/acidic-basic soilsdevelop disease resistant vaccines for livestockDID YOU KNOW … 2/3 of food products in US markets contain GM crops!
28 #4 Try New FoodsAnt Larvae, waterbugs, caterpillers, cockroaches, butterflies, fried ants
29 I DON’T WANT TO EAT BUGS… Can we cultivate more land instead? Not really – most land is marginal land with poor fertility/steep slopes and would require high inputs of fertilizer/water/energy which are expensive.
30 How can we increase crop/stock yields? In developed countries:FertilizerPesticidesSelective breedingMachineryGREEN REVOLUTION: increase food production per acre
31 Increase Livestock Yields by: hormone and antibiotic injections. European Union (EU) banned use due to health concerns BUT US/Canada still use practice
32 Should we continue Green Revolution techniques? Without fertilizer, water, and pesticides green revolution varieties are no more productive than traditional varietiesGreen revolution varieties and their needed inputs cost too much for subsistence farming.Grain yields are increasing at a much slower pace.Actual gains from green and gene revolutions may be overstated.Crop yield may start dropping for a number of environmental reasons.Increased loss of biodiversity can limit genetic raw material.
33 Tools to reduce hunger & malnutrition Slow population growthReduce povertySustainable agriculture