Food and Agriculture

Land Use 11% of the earth’s land is used in agricultural production Less land cultivated in NA now than 100 years ago Why?

Types of Food Production Traditional subsistence agriculture Mostly human and animal labor Enough crop for a family’s survival Where does this exist today?

Types of Food Production Industrialized agriculture high input agriculture Example: Plantation agriculture Used in tropical developing nations Cash crops grown for export May provide non-food products (latex) Provide products that do not make up primary nutrition (tea, coffee)

Ecosystem created by agricultural practices Agroecosystems Ecosystem created by agricultural practices characterized by low Genetic diversity Species diversity Habitat diversity

Agroecosystems Differ from natural ecosystems in five major ways: Attempts to stop ecological succession Species diversity is low Negative effects? Plant crops in an orderly fashion pest control more difficult Simple food chains Plowing ↑ erosion Nutrient loss

Farm Numbers

Number of People Fed Annually By One Farmer

Food Supply 15 to 20 species provide vast majority (90%) of man’s food needs Wheat, rice, corn, potatoes, barley Wheat and rice supply ~60% of human caloric intake 90% of grain grown in NA is used to feed livestock

Meat Sources 20% of the richest countries consume 80% of the world’s meat About 90% of the grain grown in the United States is used for animal feed 16 lbs of grain → 1 lb of meat

World Food Supply and the Environment Enough food, unevenly distributed 815 million people do not have enough to eat Parts of Africa, southeast Asia In richest countries, 11 million do not have enough to eat

Nutritional Requirements Malnutrition Under-nutrition Iron deficiency Leads to anemia Red meat, eggs, legumes, and green vegetables are all good sources of iron. Vitamin A deficiencies Can cause blindness

Malnutrition Cont. Over-nutrition Most common dietary problem in wealthy countries According to U.S. Surgeon General: 62% of Americans are overweight. 33% are obese Famine Causes?

Risk of Inadequate Nutrition

Land Use and Degradation Overgrazing and soil erosion Eliminates millions of acres a year Desertification-degrading once fertile land into desert Surface runoff Dry surface reflects heat, changing wind patterns

Global Soil Degradation

Mechanisms of Erosion Intensive farming practices: Salinization Waterlogging Impairs root growth, roots cannot get oxygen No crop rotation Removal of windbreaks Continued monocultures

Alternatives to Industrial Farming Methods Sustainable Agriculture Through soil conservation Intercropping Crop rotation Agroforestry Contour Plowing

Soil Conservation Cont. Providing Ground Cover No till agriculture Plant cover crops Improved irrigation Drip irrigation

New vs. Old Agriculture

Methods to Increase Food Supply Food distribution modification Teach locals In the 1960s: Green Revolution Mechanization Monocultures of selectively bred or genetically engineered high yield variety of crops (rice, corn, wheat) Corn yields jumped from 25 bushels per acre to 130 per acre in last century. Using high inputs of fertilizer, pesticides, and water on crops to produce high yields Increasing the intensity and frequency of cropping

Genetic Engineering Genetically Modified Organisms (GMO’s) Crops resistant to drought, frost, diseases, pests, etc. Animals that grow faster, gain weight on less food, produce more milk, etc. Estimated at least 70% of all processed foods in NA contain transgenic products.

Is Genetic Engineering Safe ? Environmental and consumer groups have campaigned against transgenic organisms. “Frankenfoods” Opponents fear traits could spread to wild varieties U.S. Food and Drug Administration declined to require labeling of foods containing GMO’s. New varieties are “substantially equivalent” to related traditionally-bred varieties.

How Would You Vote? Do the advantages of genetically engineered foods outweigh their disadvantages? Should labeling of GMOs be required?

Increasing Food Supply: Producing More Meat ½ of the world’s meat is produced by livestock grazing on grass. ½ half is produced under factory-like conditions (feedlots). Concentrated animal feeding operations (CAFOs) High density, confined or allowed very little moving room A CAFO may contain as many as 2500 hogs or 55,000 turkeys in a single building Pros?

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 Reduced soil erosion Antibiotics can increase genetic resistance to microbes in humans Help protect biodiversity Fig. 13-21, p. 289

Catching and Raising More Fish Fisheries third major food-producing system ~55% of annual commercial catch from ocean Overfishing Tragedy of the commons Bycatch ~45% from use of aquaculture to raise marine and freshwater fish

Fishing methods

Raising More Fish Aquaculture: Aquatic Feedlots

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 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

Solutions Managing Fisheries Fishery Regulations Set catch limits well below the maximum sustainable yield Improve monitoring and enforcement of regulations Economic Approaches Sharply reduce or eliminate fishing subsidies Charge fees for harvesting fish and shellfish from publicly owned offshore waters Certify sustainable fisheries Protected areas Establish no-fishing areas Establish more marine protected areas Rely more on integrated coastal management Consumer Information Label sustainably harvested fish Publicize overfished and threatened species Bycatch Use wide-meshed nets to allow escape of smaller fish Use net escape devices for seabirds and sea turtles Ban throwing edible and marketable fish back into the sea Aquaculture Restrict coastal locations for fish farms Control pollution more strictly Depend more on herbivorous fish species Nonnative Invasions Kill organisms in ship ballast water Filter organisms from ship ballast water Dump ballast water far at sea and replace with Deep-sea water

Sustainable Animal Farming Free-range Organic Smaller scale farms

Buy Local! The average American foodstuff travels an estimated 1500 miles before being consumed.