1. Nutrition, Agriculture, & Pest Management
AP Environmental Science
Unit 6: Part V

2.
Fig. 12.1, p. 261

3. How Food is Produced
14 plants and 9 animal species feed 90% of the world.
The Big 3: wheat, rice, and corn
All of the “Big 3” are annuals that need to be planted each year.
Meat’s Big 3: Beef, chicken & pork (includes milk, eggs & cheese)
2/3’s of the world relies on these grains and meat products.
2/3’s of the world does not eat meat

4. Food Production Croplands [Crops] (77% food supply; 11% of land)
Rangelands [Meat] (16% food supply on 29% land)
Fisheries and aquaculture: (7% food supply)

5. Types of Agricultural Systems
Industrialized Ag. (high input): Uses large amounts of energy (fossil fuels), water, commercial fertilizers and pesticides to produce huge quantities of: a single crop or livestock, produces 4/5 of world’s food.
An increasing number of animals are raised in densely populated feedlots, where animals are fattened up for about 5 weeks to four months and then slaughtered. They eat corn and never see sunlight. Produces water and air pollution.

6. Food Production in the USA
Industrialized “agribusiness” controlled by large multinational corporations. No more “mom and Pop” farms.
Since 1950 we have doubled yield without cultivating more land.

7. U.S. Agriculture
Biggest industry in the U.S. – 18% of the GNP and 19% of all jobs in the private sector.
0.3% of the worlds farm labor force produces 25% of the world’s food and :
U.S. residents spend only 10-12% of their income on food, while 18% is spent in Japan and 40 – 70 % in developing countries.
Cost: 10 units of nonrenewable fossil fuel for every 1 unit of food : energy

8. Types of Agriculture Plantation Agriculture:
primarily in tropical developing countries
Cash crops such as: coffee, bananas, and cocoa.
Large areas of rainforests are cleared for this.

9. Industrialized agriculture Plantation agriculture
Intensive traditional agriculture
Shifting cultivation
Nomadic herding
No agriculture
Fig. 12.2, p. 263

10. Traditional Agriculture
2.7 billion people in developing countries, provides one fifth of the world’s food)
Traditional subsistence farming: raising only enough crops and livestock for the family farm
Traditional intensive agriculture: increased labor, fertilizer & water for the family and enough left over which can be sold for income.

11. The Green Revolution
Green Revolution: Change in agriculture, which lead to increased yield per unit of area. (before, increased yield came from expanding the cultivated area)
1. Planting monocultures of selectively bred or genetically engineered high yield key crops with emphasis on shifting from plant growth to seeds.
2. Using fertilizers, pesticides, & water to produce high yields.
3. Increases intensity and frequency of cropping.

12. First green revolution (developed countries) Second green revolution
(developing countries)
Major International agricultural
Research centers and seed banks
Fig. 12.4, p. 265

13. 2nd Green Revolution:
Fast growing dwarf varieties of rice and wheat bred for tropical and sub tropical climates introduced in developing countries.
The yields are 2 –5 times the traditional methods and it allows multiple cropping which:
Protects biodiversity
Saves land from destruction
Needs fertile soil, water, & extensive fossil fuels to run machinery to produce and apply ample inorganic fertilizers & pesticides.

14. Cropland Forest Irrigated farm land Barren land Rangeland Wetland
Pasture
Urban area
Fig. 12.6, p. 266

15. Livestock:
Raising animals like cattle, horses, oxen, sheep, chicken & pigs to provide food, clothing, fertilizer, fuel, and transportation.

16. Livestock
20% of the world’s land is used for: grazing cattle and sheep.
Cattle used for meat and meat products return fertilizer to land and graze on fallow fields.

17. Livestock 12 – 15% of the methane in the atmosphere comes from cattle.
Nitrogen in commercial fertilizer is converted to NO, a greenhouse gas.
Nitrogen in manure escapes into the air as NH3, which contributes to acid deposition.
Livestock produce 21 times more waste than humans and only ½ is recycled into the soil.

18. Traditional Agriculture:
Interplanting which is growing several crops on the same plot (crop diversity).
Polyvarietal: several varieties of the same crop.
Intercropping: 2 or more different crops that are grown at the same time. These crops “help” one another.
Agroforestry: crops and trees are planted together.
Roots are at different depths
Year around plant coverage protects soil from erosion
Different insects for each crop cut down on the use of insecticides.
Weeds have trouble growing.
Higher yields for each crop are produced.

19. World Food Problems How much has food production increased?
World grain production between has tripled.
Per capita production has increased by 36%
Average food prices dropped by 25%
Amount of food traded quadrupled
Population growth is outdoing food production & distribution

20. Total World Grain Production
2,000
1,500
1,000
500
Grain production
(millions of tons)
1950
1960
1970
1980
1990
2000
2010
Total World Grain Production
Fig. 12.8a, p. 268

21. Per capita grain production (kilograms per person)
400
350
Per capita grain production
(kilograms per person)
300
250
200
150
1950
1960
1970
1980
1990
2000
2010
World Grain Production per Capita
Fig. 12.8b, p. 268

22. Reasons for the slowdown in growth of per capita grain production.
Population 1.2%/yr
Increased affluence which increases demand
Degradation and loss of cropland (due to erosion, industrialization, and urbanization)
Little growth in irrigation since 1980
10% decline in global fertilizer use
Population growth 8 billion by 2025 (6 billion in 1999)
This requires doubling the food production or 2% grain production increase per year compared to a 1.1-% growth between 1990 – This is IF people have a meatless diet
2% per year growth between 1950 to 1990, .5% increase between 2000 and 2004

23. How many people can the world support? It depends upon:
Quality of life or cultural carrying capacity per person.
Whether food production can be increased
Length of food chain with grain and meat eaters.

24. Food and Sub Saharan Africa
Per capita food production dropped by 30% between 1960 – 1994.
Malnutrition and hunger related illnesses cause death for thousands each day.
½ of the population doesn’t have access to safe drinking water (cholera and dysentery result).
Infectious diseases cause ½ of the deaths per year.
Rapid population growth (1 million every 3 weeks  2.9% increase). This creates a young age structure pyramid.

25. Feedback loop Poverty Malnutrition Decreased resistance to disease
High death
rate for
children
energy
ability
to learn
to work
Shortened
life
expectancy
Feedback loop
Fig. 12.9, p. 269

26. Food and Sub Saharan Africa
Tsetse fly blocks development of agriculture (fatal disease in livestock and incurable sleeping sickness in humans).
Severe soil erosion, nutrient poor soils, lack of water for irrigation, increasing desertification and deforestation.
Political turmoil and wars cause reduced agricultural production and cause food storage and distribution system problems.

27. Undernutrition, malnutrition, and over nutrition
Under nutrition: people who can’t grow or buy enough food for their basic needs.
Less than 90% of the daily calories needed: chronically under nourished.
Less than 80% of the calories needed: seriously under nourished. This causes mental retardation and stunted growth. This makes people susceptible to disease and affects 25% of children.

28. Malnutrition:
low amounts of proteins, carbohydrates, fats, vitamins, & minerals. (Usually a low protein, high carbohydrate diets). Some people suffer from undernutrition and malnutrition. (most live in Asia)
Diets low in iron cause anemia and this condition is found most often in Asia, Africa and Latin America
Diets low in zinc and iron cause diarrhea, malaria and pneumonia.
Diets low in iodine (seafood & soil) affects the thyroid gland, which controls metabolic rate.

29. Overnutrition: an excessive intake of food (especially fats).
This accounts for two thirds of the deaths in the U.S. per year.

30. Producing enough food to feed the world.
Enough food is produced, but it is not equally distributed due to differences in soil, climate, and political and economic power.
The principal cause of hunger and malnutrition is poverty.
Food Aid does not work because of corruption in the system, the food does not get to where it needs to go, also the people become dependent on it and fail to farm their own food and it increases their birth rate.

31. Environmental effects of producing food.
Agriculture has a greater harmful impact on air, water, soil, and biodiversity than any other human activity. Degradation of irrigated and rain fed croplands and rangelands costs 42 billion$ in lost crop and livestock output.
Soil erosion, desertification, salinization and water logging irrigated lands will limit producing more food
Loss of water due to droughts means a loss of wild species that provide genetic resources for new foods and improve existing foods

32. Land Lost to Agriculture
czc
Urban expansion (small effect)
Global warming may flood coastal areas.
Soil degradation (1/3 of cropland worldwide abandoned due to soil erosion.

33. Irrigation
Recall, agriculture accounts for 70% of freshwater usage worldwide
Irrigated crops provide 40% of worldwide food
Irrigation increases crop yields 2x-3x.
: Water usage tripled while population increased by 2.7 billion people
World demand of water cannot triple again without causing shortages in crop irrigation, industrial use, basic household needs, and life support.

34. Conserving Agri Water Drip Irrigation
Water harvesting (collecting and saving water runoff)
Drought tolerant varieties of crops

35. Biodiversity Loss Soil
Loss and degradation of habitat from
clearing grasslands and forests and
draining wetland
Fish kills from pesticide runoff
Killing of wild predators to protect
Livestock
Loss of genetic diversity from
replacing thousands of wild crop
Strains with a few monoculture strains
Erosion
Loss of fertility
Salinization
Waterlogging
Desertification
Fig a, p. 271

36. Greenhouse gas emissions from fossil Fuel issue
Air Pollution
Water
Greenhouse gas emissions from fossil
Fuel issue
Other air pollutants from fossil fuel use
Killing of wild predators to protect
Livestock
Pollution form pesticide sprays
Aquifer depletion
Increased runoff and
flooding form land cleared
to grow crops
Sediment pollution from
erosion
Fish kills from pesticide
runoff
Surface and groundwater
pollution form pesticides
and fertilizers
Overfertilization of lakes
And slow-moving rivers
From runoff of nitrates and
Phosphates from
Fertilizers, livestock
Wastes, and food
processing wastes
Fig b, p. 271

37. Nitrates in drinking water Pesticides residues in drinking water,
Human Health
Nitrates in drinking water
Pesticides residues in drinking water,
food, and air
Contamination of drinking and
swimming water with disease organisms
from livestock wastes
Bacterial contamination of meat
Fig c, p. 271

38. Increasing world food production
Increase crop yield?
Improve strains of plants and expand green revolution technology to new parts of the world.
Raise “harvest index” by increasing the photosynthetic product to go into seed instead of stems and leaves for wheat, rice and corn. The physiological limit is at 60%.

39. Increasing world food production
Crossbreeding: selective breeding between plants to increase their size or yield. Limited to DNA that is available in that type of plant. (Like dog breeding)
Genetic Engineering: Splicing a gene from one organisms (not limited to plants) and inserting it into a new plant to create new qualities
The gene revolution: use of genetically engineered foods that are resistant to insects and disease, thrive on less fertilizer, make their own nitrogen fertilizer, do well in slightly salty soils, withstand drought, & use solar energy more efficiently.
Usually crops need ample water, good soil, favorable weather, favorable temperatures, solar intensity, and day length. We can create crops that don’t this.

40. The Gene Controversy Advantages Disadvantages Less fertilizer
Less water
Resistant to disease, insects, drought
Grow faster
Can grow in salty soil
Less spoilage
Better flavor
Less pesticide
Higher yield
Irreversible and unpredictable effects
Harmful toxins and allergens in food possible
Lower nutrition
Can harm beneficial insects
Lower genetic diversity
Can create herbicide and pesticide resistant insects and plants

41. Problems with the Gene Revolution
Large corporations patent the GMO seeds so farmers cannot reuse their seeds from year to year. This has high costs that cannot be paid in developing countries.
Yields may drop due to soil erosion, loss of fertility, increased salinity, becoming waterlogged, polluted from pesticides, nitrates from fertilizers and rapidly breeding pests that become resistant to pesticides.

42. Loss of genetic diversity and crop yields
Crop varieties have decreased (97% in the U.S. from the 1940’s).
Genetic uniformity increased the vulnerability of food crops to pests, diseases and harsh weather.
Wild varieties usually reduce the need for yearly plowing and sowing which reduces soil erosion, which saves water and energy. Usually wild varieties are resistant to viruses and grow in colder and damper habitats.
Storing seeds in seed banks are risky: seeds die and cannot be reintroduced because habitats have changed.

43. New foods?
Winged bean and microlivestock (insects) are potential sources of proteins, vitamins and minerals.
Rely more on perennial crops, which are better adapted to regional soil and climate conditions than animal food crops. Use of perennials reduces energy use, water, soil erosion, and sediment water pollution. This would reduce profits of agribusiness due to the sale of annual seeds, fertilizers, and pesticides.

44. Cultivating more land? 30% of the world’s land is cropland.
Clearing tropical rainforests and irrigating arid land- both of which could have disastrous ecological consequences. Would reduce wildlife habitats, biodiversity & ecological integrity
Nutrient poor soils cannot support crop growth for more than a few years
Irrigation of arid land would require expensive dam projects, large inputs of fossil fuels to pump water long distances, depletion of groundwater supplies, expensive maintenance to prevent erosion, groundwater contamination, salinization and water logging
Could accelerate global warming by increasing methane emissions due to the production of rice and cutting down trees.

45. Producing More Meat Disadvantages of Feedlots Advantages of Feedlots
Need large inputs of fossil fuels, grain, fish meal, and water
Concentrated animal wastes that can pollute water
Antibiotics can increase bacterial resistance in humans
Added Hormones can make humans sick
Inhumane to the animals
Increased meat production
Higher profits
Less land use
Reduced overgrazing
Reduced soil erosion
Help protect biodiversity

46. Catching or raising more fish?
Two thirds of fish from fisheries
One third from aquaculture (fish farming and ranching)
There has been a sevenfold increase in the number of fish caught from 1950 to It has been declining ever since due to depleted fish stocks.
75% of the world’s major fisheries are fished above the sustainable yield.
The fish industry is heavily subsidized by the government allowing overfishing

52. Aquaculture: fish and shellfish raised for food.
Aquaculture supplies 20% of the world’s commercial fish harvest.
Aquaculture has increased 3.3 fold between 1984 and 1996, and is still increasing.
Types of aquaculture
Fish farming – cultivating fish in a controlled environment (pond or tank)
Fish ranching:holding anadromous species in captivity for the first few years, releasing them and then harvesting the adults when they return to spawn. (carp, tilapia, milkfish, clams, oysters)

54. Sustainable fishery management
Owners should show that their harvests are sustainable before they can continue to operate.
Monitor and enforce quotas for fisheries that are set below maximum sustainable yields.
Establish and divide up fish quotas based on fairness, local needs and conditions.
Reduce fishing subsidies to shrink the size of global fishing fleets, etc.

55. Government Food Policies
Control prices: to keep consumers happy, but then farmers cannot make a living.
Provide subsidies: $279 billion in 2004, if weather is good this causes a glut of food which depresses prices and puts farmers in developing countries out of business
Market Forces: Eliminate subsidies, let the market decide prices and provide the poor with help buying the food.

56. Agricultural Policy, Food Aid and Land Reform
* Farming is a risky, difficult proposition. Weather, crop prices, crop pests and diseases, interest rates and the global market affect farming.
Giving farmers subsidies to keep them in business increases food production, the problem is it leads to waste and over taxation and only corn, soy and wheat get big subsidies, things like broccoli do not. This makes vegetables expensive and corn products cheap.
Eliminating price controls and subsidies would affect the poor and low middle class.
Reward those farmers who protect soil, conserve water, reforest, protect and restore wetlands and conserve wildlife.