Chapter 14 Agriculture and Food Resources

Food Security Leftover grains Decreasing Having access to adequate food Carryover stocks Leftover grains Decreasing 2006: lower grain harvest than previous two years

Food Security Consumption of animal products increasing Environmental impacts? China Produces most wheat Largest importer of wheat

World Food Problems U.N. Food and Agriculture Organization 852 million lack adequate food Developing countries Undernutrition Lack of calories WHO estimate182 million children under 5

World Food Problems Malnutrition Lack of calories or nutrients 3 billion worldwide Overnutrition Too many calories Animal saturated fats, sugar, salt United States

Population and World Hunger 86 countries Low income Food deficient Food insecurity Chronic hunger Malnutrition

Food Insecurity

World Hunger Causes Population growth Unequal food distribution Poverty Solutions Control population Promote economic development

World Grain Production 1970-2006 Grain production doubled Grain per person did not increase

Poverty Most common cause of undernutrition and malnutrition More common in rural areas Difficult problem to solve

Industrialized Agriculture Modern agricultural methods Developed countries Inputs Capital Energy Chemicals High yields

Subsistence Agriculture Traditional agricultural methods Developing countries Food for family Inputs Labor Land

Shifting Cultivation Subsistence agriculture Grow crops, then leave land alone Slash-and-burn agriculture Clear forest Grow crops Soil loses productivity quickly Supports small populations

Nomadic Herding Subsistence agriculture Land not suitable for crops Livestock continually move Why?

Intercropping Subsistence agriculture Variety of crops in same field Polyculture Plants mature at different times Different crops harvested throughout the year

Agricultural Challenges Loss of prime farmland Loss of domesticated varieties Improving yields Curbing environmental impacts

Loss of Agricultural Land More than 400,000 acres lost per year in U.S. Suburban sprawl Conservation easements 1996 Farm Bill Protect farmland 30+ years

Loss of Domestic Varieties Farmers using fewer varieties of plants and animals Modern methods Uniformity Maximum production Loss of genetic diversity Save germplasm Tissues May need later

Increasing Crop Yields Food production has increased Green revolution Mid-20th century Modern methods High-yield varieties Chemicals

High-Yield Varieties Done with breeding and biotechnology

Green Revolution Benefits Mexico increased wheat production Indonesia self-sufficient in rice Problems Developing countries dependent on chemicals, machinery High energy costs Too many chemicals

Increasing Crop Yields Demand for grains will increase Can’t increase amount of land Yields can only increase so much Genetic engineering could help Developing countries will need better farming methods

Increasing Livestock Yields Hormones Promote faster growth European Union limits imports of hormone-treated beef: why? Antibiotics Animals grow larger (4 – 5%) Resistant bacteria WHO wants them eliminated U.S. still using

Environmental Impacts Air, water pollution Feedlot agriculture is the norm

Environmental Impacts Pesticides Resistance Farmers use more Residues on food Land degradation Loss of productivity Salinization Habitat fragmentation

Environmental Impacts

Looking Towards The Future Food requirements have been met Environmental problems increasing More food will be needed Vicious circle???

Sustainable Agriculture Maintains soil productivity: conservation techniques Healthy ecological balance Minimal long-term impacts Natural fertilizers

Sustainable Agriculture Less chemicals and antibiotics Water and energy conservation Diverse crops

Sustainable Agriculture Organic agriculture No non-natural chemicals No genetic engineering View the farm as an agroecosystem Second green revolution!

Genetic Engineering Move genes from one species to another Could improve agriculture

Potential Benefits of GM Crops Decrease nutritional deficiencies worldwide: Golden Rice Decreased use of pesticides Heartier plants Feed the world More productive farm animals Better animal vaccines

Potential Drawbacks of GM Crops Cross-pollination with native species Widespread crop failure Food allergies Long-term impacts unknown

Controlling Agricultural Pests Pest: interferes with human welfare or activities Pesticides Help control pests Insecticides Herbicides Fungicides Rodenticides

Pesticides Perfect pesticide Narrow-spectrum Kills only intended organism Breaks down rapidly Stays where applied Doesn’t exist! Broad-spectrum Kills variety of organisms Many used today

Benefits of Pesticides Quick, effective control Protect crops Save lives

Problems With Pesticides Genetic resistance 520 insect species resistant 84 weed species resistant Bioaccumulation Biomagnification

Problems With Pesticides Affect non-target species New pests may emerge

Problems With Pesticides Don’t stay put Pollute water, soil, air ≈ 14 million in U.S. have drinking water with traces of herbicides

Alternatives to Pesticides Biological controls Use naturally occurring organisms Pheromones Hormones Genetics Irradiation

Alternatives to Pesticides

Integrated Pest Management Combination of control methods Keep crop loss to economically tolerable level Sustainable agriculture Management vs. eradication Education critical On the increase

Case Study: DDT and the Bald Eagle 1963: 417 pairs left in lower 48 states Three reasons the population dropped?

Case Study: DDT and the Bald Eagle 1972: DDT banned Bald Eagle Protection Act Endangered Species Act Conservation efforts 2007: more than 7000 nesting pairs in lower 48 Removed from Threatened List