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

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:
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