SOIL: A RENEWABLE RESOURCESOIL: A RENEWABLE RESOURCE

Soil is a slowly renewed resource that Soil is a slowly renewed resource that provides most of the nutrients needed for provides most of the nutrients needed for plant growth and also helps purify water.plant growth and also helps purify water. Soil formation begins when bedrock is broken Soil formation begins when bedrock is broken

down by physical, chemical and biological down by physical, chemical and biological processes called processes called weatheringweathering..

Mature soilsMature soils, or soils that have developed , or soils that have developed over a long time are arranged in a series of over a long time are arranged in a series of horizontal layers called horizontal layers called soil horizonssoil horizons..

SOIL: A RENEWABLE RESOURCESOIL: A RENEWABLE RESOURCE

Figure 3-23Figure 3-23

Layers in Mature SoilsLayers in Mature Soils

Infiltration: the downward movement of water Infiltration: the downward movement of water through soil.through soil.

Leaching: dissolving of minerals and organic Leaching: dissolving of minerals and organic matter in upper layers carrying them to lower matter in upper layers carrying them to lower layers.layers.

The soil type determines the degree of The soil type determines the degree of infiltration and leaching.infiltration and leaching.

Soil Profiles of the Soil Profiles of the Principal Terrestrial Principal Terrestrial

Soil Types Soil Types

Figure 3-24Figure 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 PropertiesSome Soil Properties

Soils vary in the size Soils vary in the size of the particles they of the particles they contain, the amount contain, the amount of space between of space between these particles, and these particles, and how rapidly water how rapidly water flows through them.flows through them.

TEXTURETEXTURE

Figure 3-25Figure 3-25

Chapter 13Chapter 13

Food, Soil Conservation, Food, Soil Conservation, and Pest Managementand Pest Management

Chapter Overview QuestionsChapter Overview Questions

What is food security?What is food security? How serious are malnutrition and How serious are malnutrition and

overnutrition?overnutrition? How is the worldHow is the world’’s food produced?s food produced? How are soils being degraded and eroded, How are soils being degraded and eroded,

and what can be done to reduce these and what can be done to reduce these losses?losses?

What are the advantages and disadvantages What are the advantages and disadvantages of using the green revolution to produce of using the green revolution to produce food?food?

Chapter Overview Questions (contChapter Overview Questions (cont’’d)d)

What are the environmental effects of What are the environmental effects of producing food?producing food?

What are the advantages and disadvantages What are the advantages and disadvantages of using genetic engineering to produce of using genetic engineering to produce food?food?

How can we produce more meat, fish, and How can we produce more meat, fish, and shellfish?shellfish?

How can we protect food resources from How can we protect food resources from pests?pests?

Chapter Overview Questions (contChapter Overview Questions (cont’’d)d)

How do government policies affect food How do government policies affect food production and food security?production and food security?

How can we produce food more sustainably?How can we produce food more sustainably?

Core Case Study: Golden Rice -Core Case Study: Golden Rice -Grains of Hope or an Illusion?Grains of Hope or an Illusion?

Daffodil X RiceDaffodil X Rice

Potrykus and BoyerPotrykus and Boyer

Figure 13-1Figure 13-1

Core Case Study: Golden Rice -Core Case Study: Golden Rice -Grains of Hope or an Illusion?Grains of Hope or an Illusion?

Golden rice is a new Golden rice is a new genetically genetically engineered strain of engineered strain of rice containing beta-rice containing beta-carotene.carotene.

Can inexpensively Can inexpensively supply vitamin A to supply vitamin A to malnourished.malnourished.

Figure 13-1Figure 13-1

Core Case Study: Golden Rice -Core Case Study: Golden Rice -Grains of Hope or an Illusion?Grains of Hope or an Illusion?

Critics contend that there Critics contend that there are quicker and cheaper are quicker and cheaper ways to supply vitamin A.ways to supply vitamin A.

Scientist call for more Scientist call for more evidence that the beta-evidence that the beta-carotene will be converted carotene will be converted to vitamin A by the body.to vitamin A by the body.

Concern about decreasing Concern about decreasing biodiversitybiodiversity

Figure 13-1Figure 13-1

Where is this today?Where is this today?

Market about 2014.Market about 2014.

Other issues?Other issues?

Intellectual property (70 companies)Intellectual property (70 companies)

Who will get it?Who will get it?

Will it work?Will it work?

Money spent elsewhere?Money spent elsewhere?

FOOD SECURITY AND NUTRITIONFOOD SECURITY AND NUTRITION

Global food production has stayed ahead of Global food production has stayed ahead of population growth. However:population growth. However: One of six people in developing countries cannot One of six people in developing countries cannot

grow or buy the food they need.grow or buy the food they need. Others cannot meet their basic energy needs Others cannot meet their basic energy needs

(undernutrition / hunger) or protein and key (undernutrition / hunger) or protein and key nutrients (malnutrition).nutrients (malnutrition).

FOOD SECURITY AND NUTRITIONFOOD SECURITY AND NUTRITION

The root cause of hunger and malnutrition is The root cause of hunger and malnutrition is poverty.poverty.

Food securityFood security means that every person in a means that every person in a given area has daily access to enough given area has daily access to enough nutritious food to have an active and healthy nutritious food to have an active and healthy life.life. Need large amounts of Need large amounts of macronutrientsmacronutrients (protein, (protein,

carbohydrates, and fats).carbohydrates, and fats). Need smaller amounts of Need smaller amounts of micronutrientsmicronutrients

(vitamins such as A,C, and E).(vitamins such as A,C, and E).

FOOD SECURITY AND NUTRITIONFOOD SECURITY AND NUTRITION

One in three people One in three people has a deficiency of has a deficiency of one or more vitamins one or more vitamins and minerals, and minerals, especially vitamin A, especially vitamin A, iodine (causes goiter iodine (causes goiter - enlargement of - enlargement of thyroid gland), and thyroid gland), and iron. iron.

Figure 13-2Figure 13-2

War and the EnvironmentWar and the Environment

Starving children Starving children collecting ants to eat collecting ants to eat in famine-stricken in famine-stricken Sudan, Africa which Sudan, Africa which has been involved in has been involved in civil war since 1983.civil war since 1983.

Figure 13-3Figure 13-3

Solutions: Reducing Childhood Solutions: Reducing Childhood Deaths from Hunger and MalnutritionDeaths from Hunger and Malnutrition

There are several ways to reduce childhood There are several ways to reduce childhood deaths from nutrition-related causes: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 MuchOvernutrition: Eating Too Much

Overnutrition and lack of exercise can lead to Overnutrition and lack of exercise can lead to reduced life quality, poor health, and premature reduced life quality, poor health, and premature death. (BMI)death. (BMI)

CDC 2014 in US (34.9% obese—adults)CDC 2014 in US (34.9% obese—adults) 21% (12-19 yrs), 18 % (6-11 yrs)-obese21% (12-19 yrs), 18 % (6-11 yrs)-obese Americans spend $42 billion per year trying to lose Americans spend $42 billion per year trying to lose

weight.weight. $24 billion per year is needed to eliminate world $24 billion per year is needed to eliminate world

hunger.hunger.

FOOD PRODUCTIONFOOD PRODUCTION Food production from croplands, rangelands, Food production from croplands, rangelands,

ocean fisheries, and aquaculture has ocean fisheries, and aquaculture has increased dramatically.increased dramatically.

Wheat, rice, and corn provide more than half Wheat, rice, and corn provide more than half of the worldof the world’’s consumed calories. (BIG s consumed calories. (BIG THREE)THREE)

14 plant and 9 terrestrial animal species 14 plant and 9 terrestrial animal species supply 90% of food calories.supply 90% of food calories. Fish and shellfish are an important source of food Fish and shellfish are an important source of food

for about 1 billion people mostly in Asia and in for about 1 billion people mostly in Asia and in coastal areas of developing countries.coastal areas of developing countries.

Animation: Land UseAnimation: Land Use

PLAYANIMATION

Industrial Food Production: Industrial Food Production: High Input MonoculturesHigh Input Monocultures

About 80% of the worldAbout 80% of the world’’s food supply is s food supply is produced by industrialized agriculture.produced by industrialized agriculture. Uses large amounts of fossil fuel energy, water, Uses large amounts of fossil fuel energy, water,

commercial fertilizers, and pesticides to produce commercial fertilizers, and pesticides to produce monocultures.monocultures.

Greenhouses are increasingly being used.Greenhouses are increasingly being used. Plantations are being used in tropics for cash Plantations are being used in tropics for cash

crops such as coffee, sugarcane, bananas.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 PRODUCTIONFOOD PRODUCTION

Satellite images of massive and rapid Satellite images of massive and rapid development of greenhouse food production development of greenhouse food production in Spain from 1974 (left) to 2000 (right).in Spain from 1974 (left) to 2000 (right).

Figure 13-5Figure 13-5

Case Study: Industrialized Food Case Study: Industrialized Food Production in the United StatesProduction in the United States

The U.S. uses industrialized agriculture to The U.S. uses industrialized agriculture to produce about 17% of the worldproduce about 17% of the world’’s grain.s grain. Relies on cheap energy to run machinery, Relies on cheap energy to run machinery,

process food, produce commercial fertilizer and process food, produce commercial fertilizer and pesticides.pesticides.

About 10 units of nonrenewable fossil fuel About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy are needed to put 1 unit of food energy on the table.energy on the table.

Case Study: Industrialized Food Case Study: Industrialized Food Production in the United StatesProduction in the United States

Industrialized agriculture uses about 17% of Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food all commercial energy in the U.S. and food travels an average 2,400 kilometers from travels an average 2,400 kilometers from farm to plate.farm to plate.

Figure 13-7Figure 13-7

Industrial Food Production: Industrial Food Production: High Input MonoculturesHigh Input Monocultures

Livestock production in developed countries Livestock production in developed countries is industrialized:is industrialized: Feedlots are used to fatten up cattle before Feedlots are used to fatten up cattle before

slaughter.slaughter. Most pigs and chickens live in densely populated Most pigs and chickens live in densely populated

pens or cages.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 Systems use a lot of energy and water and

produce huge amounts of animal waste.produce huge amounts of animal waste.

Traditional Agriculture: Low Input Traditional Agriculture: Low Input PolyculturePolyculture

Many farmers in developing countries use low-Many farmers in developing countries use low-input agriculture to grow a variety of crops on input agriculture to grow a variety of crops on each plot of land (interplanting) through:each plot of land (interplanting) through: Polyvarietal cultivationPolyvarietal cultivation: planting several genetic : planting several genetic

varieties.varieties. IntercroppingIntercropping: two or more different crops grown : two or more different crops grown

at the same time in a plot.at the same time in a plot. AgroforestryAgroforestry: crops and trees are grown together.: crops and trees are grown together. PolyculturePolyculture: different plants are planted together.: different plants are planted together.

Traditional Agriculture: Low Input Traditional Agriculture: Low Input PolyculturePolyculture

Research has Research has shown that, on shown that, on average, low input average, low input polyculture produces polyculture produces higher yields than higher yields than high-input high-input monoculture.monoculture.

Figure 13-8Figure 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. 13-18, p. 285

Biodiversity Loss Soil Water Air Pollution Human 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 DrylandsDesertification: Degrading Drylands

About one-third of the worldAbout one-third of the world’’s land has lost s land has lost some of its productivity because of drought some of its productivity because of drought and human activities that reduce or degrade and human activities that reduce or degrade topsoil.topsoil.

Figure 13-12Figure 13-12

Salinization Salinization and and

WaterloggingWaterlogging Repeated Repeated

irrigation can irrigation can reduce crop reduce crop yields by yields by causing salt causing salt buildup in the buildup in the soil and soil and waterlogging of waterlogging of crop plants.crop plants.

Figure 13-13Figure 13-13

Salinization and Waterlogging of Salinization and Waterlogging of Soils: A Downside of IrrigationSoils: A Downside of Irrigation

Example of high Example of high evaporation, evaporation, poor drainage, poor drainage, and severe and severe salinization.salinization.

White alkaline White alkaline salts have salts have displaced cops.displaced cops.

Figure 13-14Figure 13-14

SOIL EROSION AND DEGRADATIONSOIL EROSION AND DEGRADATION

Soil erosion is the Soil erosion is the movement of soil movement of soil components, components, especially surface especially surface litter and topsoil, by litter and topsoil, by wind or water.wind or water.

Soil erosion increases through activities Soil erosion increases through activities such as farming, logging, construction, such as farming, logging, construction, overgrazing, and off-road vehicles.overgrazing, and off-road vehicles.

Figure 13-9Figure 13-9

SOIL EROSION AND DEGRADATIONSOIL EROSION AND DEGRADATION

Soil erosion lowers soil fertility and can Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded overload nearby bodies of water with eroded sediment.sediment. Sheet erosionSheet erosion: surface water or wind peel off : surface water or wind peel off

thin layers of soil.thin layers of soil. Rill erosionRill erosion: fast-flowing little rivulets of surface : fast-flowing little rivulets of surface

water make small channels.water make small channels. Gully erosionGully erosion: fast-flowing water join together to : fast-flowing water join together to

cut wider and deeper ditches or gullies.cut wider and deeper ditches or gullies.