SOIL: A RENEWABLE RESOURCE  Soil is a slowly renewed resource that provides most of the nutrients needed for plant growth and also helps purify water. Soil formation begins when bedrock is broken down by physical, chemical and biological processes called weathering. Soil formation begins when bedrock is broken down by physical, chemical and biological processes called weathering.  Mature soils, or soils that have developed over a long time are arranged in a series of horizontal layers called soil horizons.

SOIL: A RENEWABLE RESOURCE Figure 3-23

Layers in Mature Soils  Infiltration: the downward movement of water through soil.  Leaching: dissolving of minerals and organic matter in upper layers carrying them to lower layers.  The soil type determines the degree of infiltration and leaching.

Soil Profiles of the Principal Terrestrial Soil Types Figure 3-24

Fig. 3-24b, p. 69 Tropical Rain Forest Soil (humid, tropical climate) Acidic light-colored humus Iron and aluminum compounds mixed with clay

Some Soil Properties  Soils vary in the size of the particles they contain, the amount of space between these particles, and how rapidly water flows through them.  TEXTURE Figure 3-25

Chapter 13 Food, Soil Conservation, and Pest Management

Chapter Overview Questions  What is food security?  How serious are malnutrition and overnutrition?  How is the world’s food produced?  How are soils being degraded and eroded, and what can be done to reduce these losses?  What are the advantages and disadvantages of using the green revolution to produce food?

Chapter Overview Questions (cont’d)  What are the environmental effects of producing food?  What are the advantages and disadvantages of using genetic engineering to produce food?  How can we produce more meat, fish, and shellfish?  How can we protect food resources from pests?

Chapter Overview Questions (cont’d)  How do government policies affect food production and food security?  How can we produce food more sustainably?

Core Case Study: Golden Rice - Grains of Hope or an Illusion? Daffodil X Rice Potrykus and Boyer Figure 13-1

Core Case Study: Golden Rice - Grains of Hope or an Illusion?  Golden rice is a new genetically engineered strain of rice containing beta- carotene.  Can inexpensively supply vitamin A to malnourished. Figure 13-1

Core Case Study: Golden Rice - Grains of Hope or an Illusion?  Critics contend that there are quicker and cheaper ways to supply vitamin A.  Scientist call for more evidence that the beta- carotene will be converted to vitamin A by the body.  Concern about decreasing biodiversity Figure 13-1

 Where is this today? Market about Market about Other issues? Intellectual property (70 companies) Who will get it? Will it work? Money spent elsewhere?

FOOD SECURITY AND NUTRITION  Global food production has stayed ahead of population growth. However: One of six people in developing countries cannot grow or buy the food they need. One of six people in developing countries cannot grow or buy the food they need. Others cannot meet their basic energy needs (undernutrition / hunger) or protein and key nutrients (malnutrition). Others cannot meet their basic energy needs (undernutrition / hunger) or protein and key nutrients (malnutrition).

FOOD SECURITY AND NUTRITION  The root cause of hunger and malnutrition is poverty.  Food security means that every person in a given area has daily access to enough nutritious food to have an active and healthy life. Need large amounts of macronutrients (protein, carbohydrates, and fats). Need large amounts of macronutrients (protein, carbohydrates, and fats). Need smaller amounts of micronutrients (vitamins such as A,C, and E). Need smaller amounts of micronutrients (vitamins such as A,C, and E).

FOOD SECURITY AND NUTRITION  One in three people has a deficiency of one or more vitamins and minerals, especially vitamin A, iodine (causes goiter - enlargement of thyroid gland), and iron. Figure 13-2

War and the Environment  Starving children collecting ants to eat in famine-stricken Sudan, Africa which has been involved in civil war since Figure 13-3

Solutions: Reducing Childhood Deaths from Hunger and Malnutrition  There are several ways to reduce childhood deaths from nutrition-related causes: Immunize children. Immunize children. Encourage breast-feeding. Encourage breast-feeding. Prevent dehydration from diarrhea. Prevent dehydration from diarrhea. Prevent blindness from vitamin A deficiency. Prevent blindness from vitamin A deficiency. Provide family planning. Provide family planning. Increase education for women. Increase education for women.

Overnutrition: Eating Too Much  Overnutrition and lack of exercise can lead to reduced life quality, poor health, and premature death. (BMI)  CDC 2014 in US (34.9% obese—adults)  21% (12-19 yrs), 18 % (6-11 yrs)-obese  Americans spend $42 billion per year trying to lose weight.  $24 billion per year is needed to eliminate world hunger.

FOOD PRODUCTION  Food production from croplands, rangelands, ocean fisheries, and aquaculture has increased dramatically.  Wheat, rice, and corn provide more than half of the world’s consumed calories. (BIG THREE)  14 plant and 9 terrestrial animal species supply 90% of food calories. Fish and shellfish are an important source of food for about 1 billion people mostly in Asia and in coastal areas of developing countries. Fish and shellfish are an important source of food for about 1 billion people mostly in Asia and in coastal areas of developing countries.

Animation: Land Use PLAY ANIMATION

Industrial Food Production: High Input Monocultures  About 80% of the world’s food supply is produced by industrialized agriculture. Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures. Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures. Greenhouses are increasingly being used. Greenhouses are increasingly being used. Plantations are being used in tropics for cash crops such as coffee, sugarcane, bananas. Plantations are being used in tropics for cash crops such as coffee, sugarcane, bananas.

Fig. 13-4, p. 275 Plantation agriculture Shifting cultivation Industrialized agriculture No agriculture Intensive traditional ag. Nomadic herding

FOOD PRODUCTION  Satellite images of massive and rapid development of greenhouse food production in Spain from 1974 (left) to 2000 (right). Figure 13-5

Case Study: Industrialized Food Production in the United States  The U.S. uses industrialized agriculture to produce about 17% of the world’s grain. Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides. Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides.  About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy on the table.

Case Study: Industrialized Food Production in the United States  Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food travels an average 2,400 kilometers from farm to plate. Figure 13-7

Industrial Food Production: High Input Monocultures  Livestock production in developed countries is industrialized: Feedlots are used to fatten up cattle before slaughter. Feedlots are used to fatten up cattle before slaughter. Most pigs and chickens live in densely populated pens or cages. Most pigs and chickens live in densely populated pens or cages. Most livestock are fed grain grown on cropland. Most livestock are fed grain grown on cropland. Systems use a lot of energy and water and produce huge amounts of animal waste. Systems use a lot of energy and water and produce huge amounts of animal waste.

Traditional Agriculture: Low Input Polyculture  Many farmers in developing countries use low- input agriculture to grow a variety of crops on each plot of land (interplanting) through: Polyvarietal cultivation: planting several genetic varieties. Polyvarietal cultivation: planting several genetic varieties. Intercropping: two or more different crops grown at the same time in a plot. Intercropping: two or more different crops grown at the same time in a plot. Agroforestry: crops and trees are grown together. Agroforestry: crops and trees are grown together. Polyculture: different plants are planted together. Polyculture: different plants are planted together.

Traditional Agriculture: Low Input Polyculture  Research has shown that, on average, low input polyculture produces higher yields than high-input monoculture. Figure 13-8

Fig. 13-6, p. 276 Natural Capital Croplands Help maintain water flow and soil infiltration Food crops Provide partial erosion protection Fiber crops Can build soil organic matter Crop genetic resources Store atmospheric carbon Provide wildlife habitat for some species Jobs Ecological Services Economic Services

Fig , p. 285 Biodiversity LossSoil Water Air PollutionHuman Health 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 Pesticide residues in drinking water, food, and air Salinization Increased runoff and flooding from cleared land Other air pollutants from fossil fuel use Fish kills from pesticide runoff Waterlogging Sediment pollution from erosion Greenhouse gas emissions of nitrous oxide from use of inorganic fertilizers Contamination of drinking and swimming water with disease organisms from livestock wastes Desertification Killing wild predators to protect livestock Fish kills from pesticide runoff Surface and groundwater pollution from pesticides and fertilizers Belching of the greenhouse gas methane by cattle Loss of genetic diversity of wild crop strains replaced by monoculture strains Bacterial contamination of meat Overfertilization of lakes and rivers from runoff of fertilizers, livestock wastes, and food processing wastes Pollution from pesticide sprays

Desertification: Degrading Drylands  About one-third of the world’s land has lost some of its productivity because of drought and human activities that reduce or degrade topsoil. Figure 13-12

Salinization and Waterlogging  Repeated irrigation can reduce crop yields by causing salt buildup in the soil and waterlogging of crop plants. Figure 13-13

Salinization and Waterlogging of Soils: A Downside of Irrigation  Example of high evaporation, poor drainage, and severe salinization.  White alkaline salts have displaced cops. Figure 13-14

SOIL EROSION AND DEGRADATION  Soil erosion is the movement of soil components, especially surface litter and topsoil, by wind or water.  Soil erosion increases through activities such as farming, logging, construction, overgrazing, and off-road vehicles. Figure 13-9

SOIL EROSION AND DEGRADATION  Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment. Sheet erosion: surface water or wind peel off thin layers of soil. Sheet erosion: surface water or wind peel off thin layers of soil. Rill erosion: fast-flowing little rivulets of surface water make small channels. Rill erosion: fast-flowing little rivulets of surface water make small channels. Gully erosion: fast-flowing water join together to cut wider and deeper ditches or gullies. Gully erosion: fast-flowing water join together to cut wider and deeper ditches or gullies.