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Solutions to Environmental Problems Associated with Food Production

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Presentation on theme: "Solutions to Environmental Problems Associated with Food Production"— Presentation transcript:

1 Solutions to Environmental Problems Associated with Food Production
Ch. 12

2 BUT, I’m HUNGRY! What can we do?

3 Answer: Adopt sustainable agriculture (low input practices that cost less and are less damaging) 2. Change Food Subsidies 3. 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 yields Increase 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
Solutions More Sustainable Agriculture More Less High-yield polyculture Soil erosion Soil salinization Organic fertilizers Water pollution Biological pest control Aquifer depletion Overgrazing Integrated pest management Overfishing Loss of biodiversity and agrobiodiversity Efficient irrigation Figure 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 crops Fossil fuel use Crop rotation Greenhouse gas emissions Water-efficient crops Soil conservation Subsidies for unsustainable farming Subsidies for sustainable farming Fig , p. 310

7 Organic Food Produced without synthetic pesticides, herbicides, & fungicides No GMFs Organic meat/dairy 100% organically grown feed Outdoor pasture No hormones/antibiotics

8 Produce Meat More Efficiently and Humanely
Shift to more grain-efficient forms of protein Beef from rangelands and pastures, not feedlots Develop 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 products Crop rotation Conservation tillage Contour plowing Consevation 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 Assistance Keep food prices artificially low Give farmers subsidies Eliminate most or all price controls and subsidies and let farmers/fishers respond to market demand Farming = 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 sustainable agriculture/fishing/ranching

18 #3 Genetic Engineering Crossbreeding and artificial selection
Genetic engineering (gene splicing) Genetically modified organisms (GMOs)

19 Can combine traits only from closely related species
Crop Cross breeding Desired trait (color) Apple Pear Offspring Cross breeding Best results New offspring Desired result Traditional Crossbreeding Slow process Can combine traits only from closely related species

20 What are Genetically Modified Foods? *

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 for Genetic diversity means species are more susceptible to new strains of disease, increasing risk of total species loss.

23 Phase 1 Make Modified Gene
cell Identify and extract gene with desired trait gene DNA Identify and remove portion of DNA with desired trait Plasmid Remove plasmid from DNA of E. coli E. coli DNA Insert extracted DNA (step 2) into plasmid (step3) Genetically modified plasmid plasmid Insert modified plasmid into E. coli Grow in tissue culture to make copies

24 Phase 2 Make Transgenic Cell
Transfer plasmid copies to a carrier agrobacterium A. tumefaciens (agrobacterium) Agrobacterium inserts foreign DNA into plant cell to yield transgenic cell Plant cell Nucleus Host DNA Foreign DNA Transfer plasmid to surface microscopic metal particle Use gene gun to inject DNA into plant cell

25 Grow Genetically Engineered Plant
Phase 3 Grow Genetically Engineered Plant Transgenic cell from Phase 2 Cell division of transgenic cells Culture cells to form plantlets Transgenic plants with new traits Half the time as conventional crossbreeding Cuts costs Allows insertion of genes from almost any other organism

26 Genetically Modified Crops and Foods
Trade-Offs Genetically Modified Crops and Foods Advantages Disadvantages Need less fertilizer Unpredictable genetic and ecological effects Need less water More resistant to insects, disease, frost, and drought Harmful toxins and new allergens in food No increase in yields Grow faster Figure 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 weeds May need less pesticides or tolerate higher levels of herbicides Could disrupt seed market May reduce energy needs Lower genetic diversity Fig , p. 294

27 Advantages vs. Disadvantages
may produce food plants that are more nutritious develop crops resistant to pests/disease/drought/hot/cold/herbicides/acidic-basic soils develop disease resistant vaccines for livestock DID YOU KNOW … 2/3 of food products in US markets contain GM crops!

28 #4 Try New Foods Ant Larvae, waterbugs, caterpillers, cockroaches, butterflies, fried ants

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: Fertilizer Pesticides Selective breeding Machinery GREEN 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 varieties Green 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 growth Reduce poverty Sustainable agriculture


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