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Land and Land Resources UNIT 8 “If we can't afford to take good care Land and Land Resources of the land that feeds us, we're in Chapter 12 an insurmountable mess.” -Wendell Berry Food, Soil, and Pest Management Notes from Chapter 12 in Living in the Environment

Chapter Summary mental harm, but the is also responsible for large increases in agri- 1. Even though food production has lev- cultural productivity. eled off in the last 25 years, the world still produces enough food to meet the basic 2. Three systems produce foods for hu- nutritional needs of people. However, the man consumption. Croplands produce food cannot be evenly distributed through- mostly grains, about 77% of the world’s out the world, leading to malnutrition and food. Rangelands provide meat, about starvation. Many of these deaths come 16% of the world’s food. Ocean fisheries from malnutrition, which leads to a lack of supply about 7% of the world’s food. resistance to diseases. Modern agricultural 3. Soils are degraded and eroded by wa- techniques create significant environ- ter, wind, and people. is pri-

2 marily caused by flowing water and wind. area of land; uses , which Human activities, such as farming, logging, grows and trees together; and ap- construction, off-road vehicles, etc., also plies polyculture, where various are disturb soil and hasten erosion. In much planted together but mature at different soil there is also salt buildup and waterlog- times. ging. Crops can be planted today with less soil disturbance through conservation- 5. Food production can be increased by , tillage, contour farming, and strip using crossbreeding techniques on similar farming. may also use cover organisms and using genetic engineering crops to help hold the soil in place. Several on different organisms. Genetic engineer- crops planted between trees and shrubs, ing, including using advanced tissue cul- alley cropping, help preserve soil and its ture techniques, is growing in use; but productivity. And windbreaks are used to many people are concerned about the po- prevent soil from being blown away. Con- tential harm such crops may cause. Irrigat- servation and fertilization can be used to ing more land and cultivating more land restore , but fertilizing with com- are additional solutions but they may not mercial brings its own set of prove sustainable. Rangelands can be problems. managed more efficiently, with the land area better protected; but a meat-based 4. The green revolution uses particular diet requires substantially more resources methods to raise crops. are than a -based diet. Overfishing and developed and planted, bred selectively, or habitat degradation dominate the marine genetically engineered to produce high environment; better management of this yields of particular crops. Large amounts food source and protection of the marine of , pesticides, and water are environment would ensure continued avail- added to the crops. Yields of crops are in- ability of fish worldwide. creased through multiple cropping through- out the year. The second green revolution 6. More sustainable agricultural systems since 1967 involved using fast-growing can be created by reducing resource dwarf varieties of wheat and in coun- throughput and working with nature. Tech- tries with tropical and subtropical climates. nologies based on ecological knowledge Traditional : uses interplanting, are used to increase production, to several crops grown together on the same control pests, and to build soil fertility.

3 Such low-input is often more friendly to the environment by using less energy than conventional farming de- mands, and by improving soil fertility. Low- input organic farming is also more profit- able for farmers.

7. Pesticides are chemicals that kill or control populations of organisms we con- sider undesirable. Types include insecti- cides, , , and rodenti- cides. The advantages of using pesticides include the fact that they save lives, in- crease food supplies, lower food cost, in- crease profit for farmers, and work fast. The disadvantages include the accelera- tion of pest resistance to pesticides and pesticides dispersing widely, harming wild- life, and threatening human lives. The Fed- eral Insecticide, , and Rodenti- cide Act established in 1947 and amended in 1972, as well as the 1996 Food Quality Protection Act regulate use in the United States. Alternatives to pesticides in- clude integrated pest management, cultiva- tion practices, food irradiation, genetic en- gineering, biological control, hot water, and pheromones. These all reduce pesticide use but may prove timely, costly, and not as reliable.

4 12-1: What Is Food Security and Why Is It Diffi- cult to Obtain?

Starving Children in Sudan Collect Ants

CORE CASE STUDY: Organic agriculture is a component of in which crops are grown without synthetic pesticides, synthetic inorganic pesticides and genetically modified seeds. Between 2002 and 2008 the global market for or- ganic food doubled, however, it is only practiced on less than 1% of the world’s farmland. Organic farming has a number of environmental advantages over conven- A. Food security means that all or most tional agriculture, though the latter gener- people in a country have daily access to ally leads to higher yields. enough food to be healthy and active.

5 1. Global food production has stayed 1. Chronic undernutrition, or hunger, is ahead of population growth, but one in six when people do not have access to people in developing countries cannot enough food to meet basic energy grow or buy the food they need (face food needs. insecurity).

B. The root cause of food insecurity is poverty.

1. Other obstacles include political up- heaval, war, corruption, and drought or other prolonged weather conditions.

2. It is projected that by the end of the century there is a greater than 90% chance that half of the world’s population 2. Chronic malnutrition occurs when will face food shortages due to climate there is a deficiency of protein or other key change. nutrients. C. People need fairly large amounts of 3. Famine occurs when there is a se- macronutrients (protein, carbohydrates, vere shortage of food in an area that re- fats) and smaller amounts of micronutri- sults in mass starvation. ents (vitamins such as A, C, E) and min- erals (iron, iodine, calcium). D. One in three people has a deficiency of one or more vitamins and minerals, es- pecially vitamin A, iron, and iodine.

6 This woman in Bangladesh has a goiter, an enlargement of the thyroid gland caused by a diet containing too lit- tle iodine.

E. In the developed world, the problem is overnutrition, which leads to obesity, re- duced life quality, poor health, and prema- ture death.

7 12-2 How is Food Produced?

These salad greens are being grown hydroponically (with- out soil) in a . The plant roots are immersed in a trough and exposed to nutrients dissolved in running wa- ter that can be reused.

A. Food production from croplands, 1. Plantation agriculture is a form of rangelands, ocean fisheries, and aquacul- industrialized agriculture that involves pro- ture has increased dramatically. ducing cash crops.

B. Wheat, rice, and corn provide more 2. Increasingly industrialized agricul- than half of the calories in the food con- ture is relying on . sumed by the world’s people. CASE STUDY: involves grow- C. About 80% of the world’s food supply ing plants in nutrient solutions instead of is produced by industrialized agriculture. soil. The advantages over conventional systems are the crops can be grown in- doors, yields are increased, crops can be grown on rooftops, fertilizer and water use

8 are reduced, and there is little or no need , pesticides and irrigation, and for pesticides if crops are grown in a con- multiple cropping systems. trolled environment. Three main draw- backs are that it takes a large investment SCIENCE FOCUS: Soil is a complex to get started, many fear that is requires mix of rock, nutrients, organic material, air, too much technical knowledge, and it water, and living organisms. Although top- could threaten the profits of companies soil is a renewable resource, it is renewed that produce chemicals and equip- very slowly. ment. Layers (horizons) of mature soils D. Many farmers in developing countries O horizon: leaf litter use traditional agriculture to grow a variety of crops on each plot of land. A horizon: topsoil

1. Traditional B horizon: subsoil uses labor and draft animals to supply food for a family, with little left over. C horizon: parent material, often bedrock

2. Traditional intensive agriculture in- volves increased inputs of fertilizer and wa- ter to obtain higher crop yields.

3. Polyculture involves growing several crops simultaneously.

4. Slash and burn agriculture is subsis- tence agriculture that burning and clearing small plots of tropical forest on a rotational CASE STUDY: Food production in the US basis. is characterized by , with a small number of multinational companies E. The large increases in crop production controlling food production and distribu- over the last half of the 20th century are tion. As a result Americans spend only a the result of the green revolution. This in- very small portion of their income on food, cludes selective breeding of crops, use of but are typically not aware of the hidden

9 costs, such as environmental costs and 1. At least 63% of ocean fisheries are de- taxes for subsidies. pleted or overexploited.

A. Traditionally, farmers have relied on 2. is the world’s fastest crossbreeding through artificial selection growing type of food production. to develop improved varieties. Today ge- netic engineering is used to develop im- I. Industrial food production is heavily reli- proved strains. ant on the availability of energy, primarily oil and natural gas. 1. Genetically modified organisms are planted on about 12% of the world’s crop- 1. It takes about 10 units of nonrenew- land. able energy to put 1 unit of food energy on the table. 2. More than 80% of the corn, soybeans and cotton grown in the US are genetically engineered.

G. Between 1961 and 2007 world meat These graphs show that worldwide grain produc- production has increased more than four- tion of wheat, corn, and rice (left), and per capita fold and per capita consumption has dou- grain production (right) grew sharply between 1961 bled. and 2009. The world’s three largest grain- producing countries—China, India, and the United 1. About half the world’s meat comes States, in that order—produce almost half of the world’s grains. In contrast to the United States, from rangelands and pastures. The other most wheat produced in China and India is irri- half is raised on crowded feedlots and in gated. concentrated animal feeding operations (CAFO’s).

2. As a country’s income grows, people tend to eat more meat.

H. A fishery is a concentration of a particu- lar aquatic species suitable for commercial harvest. Aquaculture is the process of rais- ing fish in ponds or enclosures.

10 12-3 What Environmental Problems Arise from Food Production?

than it is forming on more than one-third of the world’s cropland.

A. Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment. Soil is eroding faster

11 1. 70% of the world’s drylands used for agriculture are threatened by desertifi- cation.

Flowing water from rainfall is the leading cause of topsoil ero- sion as seen on this farm in the U.S. state of Tennessee.

Severe desertification: Sand dunes threaten to take over an oasis in the Sahel region of West Africa. Such severe deserti- fication is the result of prolonged drought from natural cli- mate change and destruction of natural vegetation as a re- sult of human activities such as farming and .

D. Repeated irrigation can reduce crop yields by causing salt buildup in the soil (salinization-pictured below) and water- Topsoil erosion is a serious problem in some parts of the world. In 2008, the Chinese government estimated that one- logging of croplands. third of China’s land suffers from serious topsoil erosion.

B. About one-third of the world’s land has lower productivity because of drought and human activities that reduce or de- grade topsoil.

C. Desertification occurs when the pro- ductive potential of topsoil falls by 10% or more.

12 E. Agricultural activities produce signifi- cant amounts of air pollution

1. Industrialized production ac- counts for more greenhouse gasses than all of the world’s cars, busses, and planes emit (18%).

F. Crops grown for biofuels production are expanding, particularly in tropical zones, leading to losses of agrobiodiver- sity.

1. Since 1900, roughly ¾ of the genetic diversity of agricultural crops have been lost.

2. Crop varieties are now stored in gene banks, agricultural research centers, and botanical around the world.

G. New genetically modified food crops could have unintended negative ecologi- cal consequences.

H. Meat production systems have numer- ous environmental impacts. They use huge amounts of energy, produce a lot of waste, pollute groundwater, lead to erosion and degradation of rangelands. Another concern is the widespread use of antibiotics.

13 I. Aquaculture now accounts for roughly half of global seafood production.

1. Advantages include high efficiency, high yield, reduced overharvesting of fisher- ies, low fuel use, and high profits.

2. Disadvantages include large inputs of feed and water, large waste output, loss of habitat, some species are fed fish meal, and dense populations can be vulnerable to disease.

World Seafood Production, Including Both Wild Catch and Aquaculture

14 12-4 How Can We Protect Crops from Pests More Sustainably?

Spiders are important insect predators that are killed by some pesticides. Most spi- ders, including this ferocious-looking wolf spider, do not harm humans.

A. Organisms found in nature control ronment and have significant impacts on populations of most pest species as part human and animal health. of the earth’s free ecological services. D. Modern pesticides save lives, in- B. We use chemicals to repel or kill pest crease food supplies, increase profits for organisms as plants have done for millions farmers, and are fast acting. of years. To help control pest organisms we have developed a variety of pesticides. E. Pesticides do not work forever, as pest species evolve resistance to particu- C. Pesticide use has increased 50-fold lar chemicals (coevolution). and toxicity has increase 10–100 times. Many pesticides are persistent in the envi- F. Pesticides can promote genetic resis- tance to their effects, wipe out natural ene-

15 mies of pest species, create new pest spe- cide, Fungicide and Rodenticide Act (FI- cies, end up in the environment, and some- FRA). times harm wildlife and people. 1. Less than 10% of the active ingredi- G. Pesticides have not reduced crop loss ents in pesticides have been tested for overall. health effects.

I. There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. A number of methods are available.

1. Fool the pest using cultivation prac- tices such as crop rotation.

2. Provide homes for pest enemies.

3. Implant genetic resistance. CASE STUDY: There are many unintended effects of pesticide use. An example 4. Bring in natural enemies. comes from a program directed at ridding 5. Use insect pheromones to lure pest North Borneo of malaria in the 1950’s. It insects into traps or to lure natural preda- was successful, but soon other insects be- tors to crop fields. gan to disappear, then the lizards that fed on them, and finally the cats that fed on 6. Use hormones that disrupt the normal the lizards. In the absence of cats, rats insect life cycle and prevent them from flourished and the people became threat- reaching maturity. The disadvantages are ened by sylvatic plague. that they take weeks to kill an insect, are often ineffective if the infestation is large, H. In the US the Food and Drug Admin- and must be applied at the right time in the istration (FDA), the Department of Agricul- life cycle. ture (USDA) and the Environmental Protec- tion Agency (EPA) regulate the sale and Integrated pest management (IPM) is an use of pesticides under the Federal Insecti- ecological approach to pest control that

16 uses a mix of cultivation and biological methods, and small amounts of selected chemical pesticides as a last resort.

Biologist Rachel Carson (1907–1964) greatly in- creased our understand- ing of the importance of nature and of the harmful effects of the widespread use of pesticides.

17 12-5 How Can We Improve Food Security?

A. Governments use policies to influ- 1. Provide immunization. ence food production. 2. Prevent dehydration. 1. Control prices. 3. Prevent blindness with a vitamin A 2. Provide subsidies. capsule twice a year.

B. Simple and relatively inexpensive ac- tions can have large impacts. One-half to two-thirds of nutrition-related childhood death could be prevented for $5–10 per child per year.

18 12-6 How Can We Produce Food More Sus- tainably?

A. Sustainable agriculture through soil conservation—Soil conservation seeks ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil cov- ered with vegetation. Some additional methods include terracing, contour

19 B. Restore soil fertility using organic fertiliz- ers, reduce soil salinization and desertifi- cation, and use sustainable aquaculture techniques.

planting, strip cropping, agroforestry and the use of windbreaks.

C. Eat lower on the food chain and slow population growth.

CASE STUDY: The largest salmon producer in Canada has turned toward sus- CASE STUDY: Soil erosion in the tainable aquaculture by mimicking a natu- United States during the dust bowl years ral ecosystem. lead to dramatic changes in agricultural policy. D. Meat production is highly inefficient and could be improved by shifting toward more grain-efficient forms of animal pro- tein, such as poultry and plant eating fish as well as by reducing meat consumption.

E. Five strategies to make the transition to a more sustainable agriculture:

20 1. Increase research

2. Establish training programs

3. Set up an international fund to give farmers in poor countries access to sus- tainable agriculture

4. Establish subsidies that encourage sustainable agriculture

5. Mount a massive education program

SCIENCE FOCUS: Perennial polycul- tures have many advantages, including no tilling requirement, reduced erosion, less irrigation, and less chemical fertilizers.

F. Sourcing food locally is an important component of sustainable food produc- tion.

1. Community Supported Agriculture (CSA) and ’s markets provide this.

21