1. Food, Soil Conservation and Pest Management
APES Ch 13
Food, Soil Conservation and Pest Management

2. Food Security and Nutrition
1 in 6 people in developing countries does not get enough food (most likely due to poverty)
Food security:
Most developing nations can not provide food security to all their people b/c they cant produce enough food or they can’t afford to import.
Also depends on reducing harmful environmental effects of agriculture (erosion, aquifer depletion).

3. Food Security and Nutrition
Chronic hunger:
Malnutrition:
UN Food and Agriculture Organization (FAO) goal is to reduce the # of hungry and malnourished to 400 million by 2015 (as of 2005 there were 852 million)
FAO estimated that 6 million children died each year due to lack of essential food.

4. Food Security and Nutrition
Famine:
Can lead to mass migrations
Usually caused by crop failure due to drought, flood, war or other catastrophic events.
Overnutrition:
Can cause some of the same problems as under-nutrition (lower life expectancy, diseases, lower life quality)

5. Food Production 3 systems that supply most food: Croplands – 77%
Rangelands – 16%
Oceanic fisheries and aquaculture – 7%
All 3 systems have increased since 1960 due to better technology and other advances (fertilizers, pesticides, irrigation).
May not be able to produce enough food by 2050 for the possible 8.5 billion people.
Environmental degradation, pollution, lack of water, overgrazing, overfishing, rising temps., increasing fuel costs

6. Food Production
Only 14 plants and 9 terrestrial animal species supply an estimated 90% of worlds food.
3 types of grain (wheat, rice and corn) provide more than 50%
Many people can’t afford meats, milk and cheese products.
Fish and shellfish make up only 7%

7. Food Production Industrialized agriculture (high input):
80% of worlds food supply is produced this way
Plantation agriculture:
Cash crops (bananas, soybeans, sugarcane, cocoa, peanuts and coffee
Must clear tropical rain forests to plant
Livestock
Most are in feedlots
Use lots of energy and water and produces lots of animal waste and water pollution

8. Natural Capital Croplands Ecological Services Economic Services
• Help maintain water flow and soil infiltration
• Food crops
• Provide partial erosion protection
• Fiber crops
• Can build soil organic matter
Figure 13.6
Natural capital: ecological and economic services provided by croplands. QUESTION: Which two ecological and which two economic services do you think are the most important?
• Crop genetic resources
• Store atmospheric carbon
• Provide wildlife habitat for some species
• Jobs
Fig. 13-6, p. 276

9. Food Production Traditional agriculture (low input)
Traditional subsistence agriculture:
Traditional intensive agriculture:
Interplanting:
Reduces chance of losing all of the years food supply
Polyvarietal cultivation:
Intercropping:
Agroforestry (alley cropping):
Polyculture:
Keeps soil covered, less fertilizer and water use, less pesticides.

10. Soil Erosion and Degradation
Topsoil:
Naturally renewable but very slow (several 100 yrs to make 1 inch)
Soil erosion:
Increases when vegetation is removed
Sheet erosion:
Rill erosion:
Gully erosion:
Major effects of erosion
Loss of soil fertility
Water pollution due to sedimentation runoff

11. Soil Erosion and Degradation
Causes
Consequences
Overgrazing
Worsening
drought
Deforestation
Famine
Erosion
Economic losses
Salinization
Lower living standards
Soil compaction
Natural climate change
Environmental refugees
Figure 13.12
Natural capital degradation: causes and consequences of desertification. QUESTION: How serious is the threat of desertification where you live?
Desertification:
1/3 of the worlds land and 70% of all dryland are suffering from desertification.
Fig , p. 280

12. Less permeable clay layer
Transpiration
Evaporation
Evaporation
Evaporation
Waterlogging
Less permeable clay layer
Figure 13.13
Natural capital degradation: salinization and waterlogging of soil on irrigated land without adequate drainage can decrease crop yields.
Salinization:
Waterlogging:
1. Irrigation water contains small amounts of dissolved salts
1. Precipitation and irrigation water percolate downward.
2. Evaporation and transpiration leave salts behind.
2. Water table rises.
3. Salt builds up in soil.
Fig , p. 281

13. Solutions Soil Salinization Prevention Cleanup Reduce irrigation
Flush soil (expensive and wastes water)
Stop growing crops for 2–5 years
Figure 13.15
Solutions: methods for preventing and cleaning up soil salinization. QUESTION: Which two of these solutions do you think are the most important?
Switch to salt-tolerant crops (such as barley, cotton, sugarbeet)
Install underground drainage systems (expensive)
Fig , p. 281

14. Sustainable Agriculture Through Soil Conservation
Eliminating plowing and breaking up and tilling is key to reduce soil erosion.
Conservation-tillage farming:
Terracing:
Contour farming:
Strip cropping:
Wind breaks:
Use cover crops

15. Sustainable Agriculture Through Soil Conservation
Organic fertilizer:
Animal manure:
Green manure:
Compost:
Commercial inorganic fertilizer:
Contain nitrogen, phosphorus, and potassium
Crop rotation:
Also helps reduce erosion

16. The Green Revolution and its Environmental Impact
Plant monoculture plants
Use large amounts of fertilizer, pesticides and water for higher yield
Increase the # of crops grown per on plot of land through multiple cropping
1st Green Revolution took place between in developed countries
2nd Green Revolution has been taking place since 1967 in developing countries mostly in tropical areas.

17. The Green Revolution and its Environmental Impact
Pros
Has produced more food for growing population
Many countries are now self sufficient with food
Use less land for larger yield
Cons
More fertilizer, pesticides and water
To expensive for subsistence farmers
If expanded- not enough workers (more people moving to cities for jobs)
More irrigation which can lead to more salinization

18. The Green Revolution and its Environmental Impact
More land can be planted with crops but significant expansion of cropland is unlikely over the next few decades for economic and ecological reasons
Loss of agrobiodiversity – the worlds genetic variety of animals and plants used to provide food
Ex: India use to plant 30,000 different types of rice, now only 10 types are used.

19. The Green Revolution and its Environmental Impact
Modern agriculture violates the 4 Principles of Sustainability
Depends heavily on nonrenewable fossil fuels
Too little recycling of crop and animal wastes
Accelerates soil erosion
Does not preserve agrobiodiveristy
Disrupts natural species interactions that help control population sizes and pests.

20. Biodiversity Loss Soil Air Pollution Human Health Water
Loss and degradation of grasslands, forests, and wetlands
Erosion
Water waste
Greenhouse gas emissions from fossil fuel use
Nitrates in drinking water
Loss of fertility
Aquifer depletion
Salinization
Increased runoff and flooding from cleared land
Pesticide residues in drinking water, food, and air
Other air pollutants from fossil fuel use
Waterlogging
Fish kills from pesticide runoff
Desertification
Sediment pollution from erosion
Contamination of drinking and swimming water with disease organisms from livestock wastes
Greenhouse gas emissions of nitrous oxide from use of inorganic fertilizers
Figure 13.18
Natural capital degradation: major harmful environmental effects of food production. According to a 2002 study by the United Nations, nearly 30% of the world’s cropland has been degraded to some degree by soil erosion, salt buildup, and chemical pollution, and 17% has been seriously degraded. QUESTION: Which item in each of these categories do you think is the most harmful?
Fish kills from pesticide runoff
Killing wild predators to protect livestock
Surface and groundwater pollution from pesticides and fertilizers
Loss of genetic diversity of wild crop strains replaced by monoculture strains
Belching of the greenhouse gas methane by cattle
Bacterial contamination of meat
Overfertilization of lakes and rivers from runoff of fertilizers, livestock wastes, and food processing wastes
Pollution from pesticide sprays
Fig , p. 285

21. The Gene Revolution
For years the use of crossbreeding through artificial selection to develop genetically improved varieties of crop strains has been used.
Now genetic engineering is being used (takes a gene of 1 species and inserts it into the DNA of another species)
Takes ½ the time and cost less then crossbreeding
Ex: potatoes resist disease because they contain a certain chicken gene.

22. The Gene Revolution
Nontraditional foods could help provide essential nutrients and lower the need for some crops.
Winged bean has many edible parts and requires little fertilize.
Quinoa plant is called the worlds most nutritious plant and can resist frost and droughts and can grow in saline soils.
Insects are a great source of protein and are easy to “farm”

23. Genetically Modified Crops and Foods
Trade-Offs
Genetically Modified Crops and Foods
Projected Advantages
Projected Disadvantages
Need less fertilizer
Irreversible and unpredictable genetic and ecological effects
Need less water
More resistant to insects, disease, frost, and drought
Harmful toxins in food from possible plant cell mutations
Grow faster
New allergens in food
Lower nutrition
Can grow in slightly salty soils
Increased development of pesticide-resistant insects and plant diseases
Less spoilage
Figure 13.19
Trade-offs: projected advantages and disadvantages of genetically modified crops and foods. QUESTION: Which two advantages and and which two disadvantages do you think are the most important?
Better flavor
Can create herbicide-resistant weeds
Need less pesticides
Tolerate higher levels of herbicides
Can harm beneficial insects
Higher yields
Lower genetic diversity
Fig , p. 287

24. Producing More Meat
Between meat production increased more then 5 fold and is likely to double again by 2050 as more people become affluent.
2 systems for raising livestock
Graze on grass
Feedlots- raise in densely packed areas by feeding them grain and/or fish meal.
Animals given antibiotics and steroids
Accounts for 43% of worlds beef, 50% of pork and 68% of eggs, and 75% of poultry production.
Solutions: people can eat more poultry and fish rather then beef, establish more humane ways to raise livestock in feedlots.

25. Increased meat production
Trade-Offs
Animal Feedlots
Advantages
Disadvantages
Increased meat production
Need large inputs of grain, fish meal, water, and fossil fuels
Higher profits
Concentrate animal wastes that can pollute water
Less land use
Reduced overgrazing
Figure 13.21
Trade-offs: advantages and disadvantages of animal feedlots. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Reduced soil erosion
Antibiotics can increase genetic resistance to microbes in humans
Help protect biodiversity
Fig , p. 289

26. Producing More Meat Catching and raising more fish and shellfish.
Fisheries:
3rd major food producing system.
2/3 comes from oceans, lakes, rivers and ponds
1/3 comes from aquaculture
Scientists project a decline in global fish catch due to overfishing, coastal water pollution and wetland destruction

27. Producing More Meat
125 out of 128 depleted fish stocks could recover with careful management.
Ecolabels help shoppers identify wild fish that have been caught by more sustainable fishing practices.
Walmart said that within 5 yrs it would sell only fish certified by the Marine Stewardship Council)
Govt's subsides given to the fishing industry are a major cause of overfishing.
Subsides $ should be used to buy out some fishing boats and retrain their crew for other occupations

28. Producing More Meat Aquaculture: Fishing farms: Fishing ranches:
Mainly carp in China and India, catfish in US, tilapia and shellfish in other countries

29. Trade-Offs Aquaculture Advantages Disadvantages High efficiency
Needs large inputs of land, feed, and water
High yield in small volume of water
Large waste output
Destroys mangrove forests and estuaries
Can reduce overharvesting of conventional fisheries
Uses grain to feed some species
Figure 13.24
Trade-offs: advantages and disadvantages of aquaculture. QUESTION: Which two advantages and which two disadvantages do you think are the most important?
Low fuel use
Dense populations vulnerable to disease
High profits
Tanks too contaminated to use after about 5 years
Profits not tied to price of oil
Fig , p. 292

30. More Sustainable Aquaculture
Solutions
More Sustainable Aquaculture
• Use less fishmeal feed to reduce depletion of other fish
• Improve management of aquaculture wastes
• Reduce escape of aquaculture species into the wild
• Restrict location of fish farms to reduce loss of mangrove forests and estuaries
Figure 13.25
Solutions: ways to make aquaculture more sustainable and reduce its harmful environmental effects. QUESTION: Which two of these solutions do you think are the most important?
• Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean
• Certify sustainable forms of aquaculture
Fig , p. 293

31. Solutions: Moving Toward Global Food Security
People in urban areas could save money by growing more of their own food.
We can waste less food (70% of food is wasted through spoilage, inefficient processing and plate waste).
US households throw away food worth as much as $43 million/yr – twice the $24 million it would take to eliminate global hunger

32. Solutions: Moving Toward Global Food Security
We can increase global food security by –
Slow pop growth
Reduce poverty
Reduce soil erosion
Halt desertification
Eliminate overgrazing
Slow removal of groundwater
Protect cropland from development
Reduce rate of global warming

33. Protecting Food Resources: Pest Control
Only 100 species cause 90% of the damage to crops
In nature natural enemies control 98% of the potential pests species
Pesticides:

34. Protecting Food Resources: Pest Control
2 generations of pest control
1st generation (copy nature): before 1930s many pesticides were derived from organisms (mostly plants). They were natural defenses.
2nd generation: the development of pesticides in labs. Started in 1939 when DDT was discovered. Some lab made pesticides last in environment for years and can biologically magnified in food chains.
¾ of pesticides is used for crops, ¼ is used for homes, gardens, and golf courses.
Federal Insecticide, Fungicide, Rotenticide Act (FIFRA) is suppose to assess the health risks of the active ingredients in pesticide products.

35. More Sustainable Aquaculture
Solutions
More Sustainable Aquaculture
• Use less fishmeal feed to reduce depletion of other fish
• Improve management of aquaculture wastes
• Reduce escape of aquaculture species into the wild
• Restrict location of fish farms to reduce loss of mangrove forests and estuaries
Figure 13.25
Solutions: ways to make aquaculture more sustainable and reduce its harmful environmental effects. QUESTION: Which two of these solutions do you think are the most important?
• Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean
• Certify sustainable forms of aquaculture
Fig , p. 293

36. Protecting Food Resources: Pest Control
Other ways to control pests:
Fool pest
Provide homes for pest enemies
Implant genetic resistance
Bring in natural enemies
Use insect perfumes
Bring in hormones
Scald pests

37. Sustainable Organic Agriculture
Solutions
Sustainable Organic Agriculture
More
Less
High-yield polyculture
Soil erosion
Soil salinization
Organic fertilizers
Aquifer depletion
Biological pest control
Overgrazing
Overfishing
Integrated pest management
Loss of biodiversity
Efficient irrigation
Loss of prime cropland
Perennial crops
Figure 13.33
Solutions: components of more sustainable, low-throughput agriculture based mostly on mimicking and working with nature. QUESTION: Which four solutions do you think are the most important?
Food waste
Crop rotation
Subsidies for unsustainable farming and fishing
Water-efficient crops
Soil conservation
Population growth
Subsidies for sustainable farming and fishing
Poverty
Fig , p. 302