CHAPTER 10:
FOOD, SOIL, AND PEST MANAGEMENT
Objectives
1.
Define food security, and insecurity. Note the main cause of food insecurity. Define malnutrition, chronic
undernutrition or hunger, and overnutrition. Briefly note the present status of global food supply. List factors that can
reduce childhood hunger and malnutrition.
2.
Discuss the 3 sources of human food production. Describe the trends in world food production since 1950. Distinguish
between the 2 common forms of industrialized agriculture, and the 2 common forms of traditional agriculture.
Summarize food distribution problems.
3.
Describe the problems of soil erosion, soil degradation, and desertification. Describe both world and U.S. situations
and explain why most people are unaware of this problem. Describe the problems of salinization and waterlogging of
soils and how they can be controlled.
4.
Define soil conservation. List the common ways to approach the problem of soil erosion. Briefly discuss conservationtillage farming. List the common methods of maintaining or improving soil fertility. Be sure to distinguish between
organic and inorganic fertilizers.
5.
Define the green revolution. Note the 3 stages and the limitations of the green revolution. Note other ways of
maintaining and increasing food production. Define the environmental impacts of agriculture.
6.
Distinguish cross-breeding from genetic engineering. Describe the controversy over genetically-modified foods
(GMFs).
7.
Distinguish traditional meat production from industrialized meat production. Describe the current status of global meat
production and its limitation. Note the relationship between meat production and fishing. Explain how sustainable
meat production can be achieved.
8.
Describe trends in the world fish catch since 1950. Assess the potential for increasing the annual fish catch. Outline the
major causes of overfishing. Evaluate the potential of fish farming and fish ranching for increasing fish production.
9.
Define pests and pesticide, and list five types of pesticides. Distinguish between broad-spectrum and narrow-spectrum
pesticides. Discuss the advantages and disadvantages of modern synthetic pesticides.
10. Note that target insects can become resistant to pesticides. Define integrated pest management (IPM). Analyze the pros
and cons of using IPM as an alternate strategy to chemical pesticides. Note the 2 Federal laws in the U.S. for
regulating the pesticide industry.
11. Note the methods used by governments to encourage food production. Note the 3 approaches to mitigating the harmful
effects of modern agriculture. Explain sustainable agriculture, and list the 4 strategies that can be used to transition
into a sustainable agricultural system.
Food, Soil, and Pest Management
77
Key Terms {(Terms are listed in the same font style as they appear in the text.)}
age of genetic engineering
(p. 212)
agrobiodiversity (p 211)
agroforestry (p. 208)
alley cropping (p. 208)
animal manure (p. 208)
anopheles mosquito (p. 219)
aquaculture (p. 201)
artificial selection (p. 212)
blue revolution (p. 217)
broad-spectrum agents (p. 219)
bycatch (p. 215)
cash crops (p. 202)
chronic undernutrition (p. 200)
commercial inorganic fertilizer
(p. 208)
compost (p. 208)
conservation-tillage farming
(p. 207)
contour farming (p. 208)
crop rotation (p. 208)
croplands (p. 201)
cross-breeding (p. 212)
desertification (p. 206)
feedlots (p. 202)
first green revolution (p. 210)
fisheries (p. 215)
food insecurity (p. 199)
food security (p. 199)
gene revolution (p. 212)
genetic engineering (p. 212)
genetically modified food (GMF)
(p. 213)
green manure (p. 208)
green revolution (p. 209)
high-input agriculture (p. 202)
industrialized agriculture
(p. 202)
integrated pest management
(IPM) (p. 222)
iodine (p. 200)
iron (p. 200)
land degradation (p. 211)
macronutrients (p. 200)
malnutrition (p. 200)
marginal land (p. 210)
micronutrients (p. 200)
minimum-tillage farming (p. 207)
monoculture (p. 202)
multiple cropping (p. 210)
no-till farming (p. 207)
oceanic fisheries (p. 201)
organic agriculture (p. 224)
organic fertilizer (p. 208)
overgrazing (p. 223)
overnutrition (p. 201)
pastures (p. 201)
persistence (p. 219)
pest (p. 218)
pesticides (p. 219)
plantation agriculture
(p. 202)
polyculture (p. 204)
rangelands (p. 201)
salinization (p. 207)
sea ethics(p. 216)
second green revolution
(p. 210)
selective (narrow-spectrum)
agents (p. 219)
shelterbelts (p. 208)
slash-and-burn agriculture
(p. 204)
soil conservation (p. 207)
soil erosion (p. 204)
strip cropping (p. 208)
terracing (p. 208)
traditional agriculture
(p. 203)
traditional intensive
agriculture (p. 204)
traditional subsistence
agriculture (p. 204)
vitamin A (p. 200)
water pollution (p. 204)
waterlogging (p. 207)
windbreaks (p. 208)
Outline
10-1 Improving Food Security: Meeting the nutritional needs of the human population requires reducing poverty and the
harmful environmental impacts of modern agriculture. Despite the half-century achievement of global food surplus, 17%
of humans in developing countries lack sufficient daily food.
A. Food security means that every human has daily access to enough nutritious food to have an active and healthy life.
B. Many developing countries lack national food security, as they do not produce enough food to feed their citizens.
1. Citizens are too poor to buy imported food.
2. Citizens suffer from hunger and chronic malnutrition.
C. People need fairly large amounts of macronutrients (protein, carbohydrates, fats), smaller amounts of micronutrients
(vitamins such as A, C, E), and minerals (iron, iodine, calcium) to be healthy.
1. Chronic undernutrition is suffered by those who cannot grow or buy enough food. Children in this group may
have stunted growth, mental retardation, and be susceptible to infectious diseases.
2. Malnutrition results from insufficient protein and other key nutrients.
D. WHO states that about one in three people suffer from a deficiency of one or more of the following: vitamin A, iron,
and iodine.
E. The UNFAO cites some global improvements:
1. Average calorie consumption rose sharply from 1961 to 2007.
2. Chronically undernourished people decreased from 91.8 million in 1970 to 852 million in 2005.
F. A UNICEF study indicates that 50–60% of hunger and malnutrition deaths could be prevented at an average cost of
$5–10 per child.
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G. Overnutrition is when food intake exceeds energy needs and results in excess body fat. Too little exercise, too many
calories, or both, cause overnutrition. Both overnutrition and undernutrition in people lead to similar health
problems: lower life expectancy, greater susceptibility to disease and illness, lower productivity, and lower life
quality.
10-2
Food Production Trends
A. Human food is produced by croplands, rangelands, and ocean fisheries.
B. Croplands produce 77% of the world’s food.
C. Rangelands produce meat, about 16% of the world’s food.
D. Oceanic fisheries supply 7% of the world’s food.
E. All three systems have increased their food yields since 1950 by switching to mechanical equipment use, and the
increased application of chemical fertilizers, irrigation, pesticides, and high-yield crops—industrialized agriculture.
F. Food to feed the human population must be produced in ever-increasing quantities.
G. The foods that sustain the world are wheat, rice, and corn. They must be replanted each year. 90% of human plant
food comes from only 14 species of plants.
H. The U.S. agricultural system produces 17% of the world’s grain but affects the environment more than any other
industry.
1. Agriculture is bigger than the automotive, steel, and housing industries combined in total annual sales. Large
agribusinesses (huge corporate/family-owned farms) control three-fourths of U.S. food production. Labor and
resource costs, with the exception of pesticides, have decreased since 1950.
2. Agriculture has doubled crop yield of wheat, corn, and soybeans, using no more land since 1940.
3. Considering energy used to grow, store, process, package, transport, refrigerate, and cook all plant and animal
food, about 10 units of nonrenewable fossil fuel is needed to put one unit of food energy on the table.
I. Growing techniques in traditional agriculture, which is practiced by 40% of the global population, produces 20% of
the global food supplies. Here are two varieties: traditional subsistence and traditional intensive agriculture.
10-3 Soil Erosion and Degradation: Soil degradation, the natural and artificial loss of topsoil through mismanagement,
includes soil erosion.
A. Soil erosion and degradation affect crop yield and farming success.
B. Preserving the world’s topsoil is of great importance in feeding the world’s masses.
1. Land degradation occurs when the future ability of the land to support crops, livestock, or wild species is
decreased.
2. Water, wind, and people cause soil erosion; soil components are moved from one place to another.
3. Depletion of plant nutrients in topsoil through farming, logging, construction, overgrazing, and burning
vegetation leads to loss of soil fertility.
4. Eroded soil becomes sediment in surface waters where it pollutes water, kills fish, and clogs irrigation ditches,
channels, reservoirs, and lakes.
5.
Soil is a renewable resource unless eroded faster than it can form.
C. In 1992, a joint UN and World Resources Institute report estimated that topsoil is eroding faster than it is
replenished on 38% of the world’s cropland. In the U.S., although industrialized farming has been a success, 33% of the
original topsoil has been lost.
D. Desertification occurs when the productive potential of arid/semi-arid lands decreases by 10% through a
combination of natural climate change and human activities that reduce or degrade topsoil. China and Nigeria are two
countries experiencing the most desertification.
E. Loss of crop productivity can result from repeated irrigation, which produces salt buildup (or salinization) and
water-logging of plant crops.
F. Soil conservation seeks ways to reduce soil erosion and restore soil fertility.
G. To reduce soil erosion, farmers must eliminate plowing and tilling and keep the soil covered with vegetation.
1. Conventional-tillage farming means plowing in the fall and leaving the soil bare all winter, making it vulnerable
to wind and erosion.
2. Conservation-tillage farming disturbs the soil as little as possible while planting.
3. Minimum-tillage farming allows the soil to rest over the winter. The subsurface soil is broken up and loosened,
but the topsoil is not turned.
4. No-till farming uses special machines to inject seeds, fertilizers, and herbicides into thin slits in the unplowed
soil and, then, cover the slits.
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5.
About 45% of U.S. soil used conservation tillage in 2003. The USDA estimates that using it on 80% of cropland
would reduce soil erosion by 50% or more.
H. Additional methods to reduce soil erosion include terracing, contour faming, strip cropping, alley
cropping/agroforestry, and wind breaks.
I. Soil fertility can be maintained best through soil conservation. The next best thing is to restore some of the nutrients
lost by the use of fertilizers—organic and inorganic.
1. Crop rotation alternates different crops seasonally to replenish the soil, especially if a previous crop has
depleted the soil of certain nutrients.
2. Inorganic fertilizers, used with organic fertilizers, can restore soil fertility.
10-4 Food Security—the Green and the Gene Revolutions: Farmers can produce more food by either farming more land or by
getting higher yields per area of farmland. Since 1950 about 88% of the increase in global food production has involved
increasing the yield of crops per area of farmland, known as the green revolution.
A. The following steps describe this revolution:
1. Key grain crops of plant monocultures are bred or enhanced to produce high-yield varieties.
2. High-yields are sustained by using large amounts of fertilizer, water, and pesticides.
3. The number of crops grown per year is increased through multiple cropping.
B. There have been two green revolutions.
1. The first revolution occurred in developed countries between 1950 and 1970.
2. The second revolution has occurred since 1967 in developing countries with enough rain and/or irrigation
capability, by introducing fast-growing dwarf varieties of rice and wheat, especially for tropical and subtropical
climates.
3. Although per capita grain production did increase from 1950, it started to decline after 1985 partly because
large amounts of grains are routinely fed to livestock to produce meat instead of being used as human food.
C. The success of the green revolution has been limited in some areas by the lack of irrigation water so that more
cropland can be irrigated. Irrigated land per person has decreased since 1978. This is partly explained by the
increasingly rapid rise of world population, the depletion of underground aquifers, the inefficient use of irrigation
water, and salt buildup in soil.
D. Also, coastal croplands are likely to decrease in the future because of rising sea levels from global warming.
E. According to the UNDP, people in urban areas should grow more of their own food—in backyards, in rooftop and
balcony gardens, etc. UN analysts believe that 15% of the global food supply is produced by urban gardens.
F. Much food that is produced is wasted through spoilage, inefficient processing and preparation, and plate waste. It is
estimated that affluent countries waste nearly 70% of their food.
G. Another negative product of the green revolution is the increasing loss of agrobiodiversity—the world’s genetic
variety of animals and plants used to provide food. It is estimated that since 1900 we have lost 75% of original
genetic diversity of agricultural crops.
H. Crossbreeding, which mixes the genes of similar types of organisms, and genetic engineering, which mixes genes of
different organisms, can be used to increase yields of crops. Crossbreeding is a 15-year-plus process. The varieties
are useful only for a few years; then, pests and diseases reduce the effectiveness of the new varieties.
I. Genetic engineering, which splices a gene from one species into the DNA of another species, is creating improved
strains of crops and livestock animals. Bioengineers are developing new varieties of crops that are resistant to cold,
heat, herbicides, insects, parasites, salty or acidic soils, and drought.
J. GMF (genetically modified food) has generated much controversy and fear.
1. GMF may possibly solve the world’s food problems.
2. There are advantages and disadvantages of GMF.
K. The unknowns of genetically modified crops on human health and ecosystems are widespread.
1. GMFs are labeled in Japan, Europe, South Korea, Canada, Australia, and New Zealand.
2. The U.S. Department of Agriculture opposed such labeling.
3. The Ecological Society of America recommended more caution in releasing genetically engineered organisms
into the environment.
4. Several scientists feel that genetic engineering of food is based on two faulty assumptions: That world hunger is
caused by a global shortage of food; and that genetic engineering is the only and best way to increase food
production.
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10-5 Animal Husbandry and Overfishing Issues: Meat and meat products are good sources of high-quality protein. About 50%
of global meat for food is from grazing livestock on natural grazing lands, and the other 50% is from industrialized
animal husbandry. Experts believe that meat production will continue to expand, and this will put pressure on the
world’s fish supply because about 35% of the marine fish supply is used to feed livestock and carnivorous fish raised by
aquaculture.
A. Producing more meat is probably not a viable solution.
1. Meat production uses much water.
2. Meat production uses more than one-third of the world’s grain. In the U.S., meat production consumes 70% of
the country’s grain.
3. Meat produces large amounts of animal waste and pollutes the environment.
4. Livestock production has an enormous impact on grain use and on the world’s catch of fish.
B. A more sustainable form of meat production would involve shifting from forms of animal proteins, such as beef and
pork, to poultry and herbivorous farmed fish.
C. Fisheries make up the third major food-producing system. About 55% of the annual commercial catch of fish and
shellfish comes from the ocean. The rest comes from use of aquaculture to raise marine and freshwater fish like
livestock in ponds and underwater cages.
D. Commercial fish amounts have been declining since 1980.
1. The world’s commercially valuable marine fish are already being overfished.
a. Too few fish have been left to provide breeding stock.
b. Commercial extinction means that it is not profitable to hunt a particular species; it has almost been
eradicated by overfishing.
2. Man has raped the ocean of marine fish species and contributed to their continuing decline by degrading the
environment, destroying habitat, and polluting wetlands, estuaries, coral reefs, salt marshes, and mangroves.
3. Commercial species may be able to come back but will need protection through fishing quotas, restricted use of
particular fishing gear/methods, limits on fishing boats, etc.
E. Government subsidies, price controls, low-interest loans, and grants for fishing gear are major causes of overfishing.
Some of the money should be shifted to buying out some fishing boats and retraining the crews.
F. Aquaculture (the blue revolution) is the process of raising fish and shellfish for food rather than harvesting them in
the seas and inland waters.
1. Fish farming cultivates fish in a controlled environment and harvests them at a particular size.
2. The disadvantages include large inputs of land, water, and feed; large waste outputs; the destruction of
mangrove forests; and dense populations vulnerable to diseases.
3. Increasing both wild and aquaculture fish harvest will only increase food supplies about 1%.
10-6 Protecting Crops From Pests: A pest is any species that interferes with human welfare by competing with us for food,
invading ecosystems, spreading disease, or simply becoming a nuisance.
A. Predators, parasites, and disease organisms found in nature control populations of most pest species as part of the
Earth’s free ecological services.
1. Worldwide, only about 100 species of plants, animals (mostly insects), fungi, and microbes cause about 90% of
the damage to the crops we grow.
2. In natural ecosystems, natural enemies (organisms) control populations of about 98% of potential pest species.
3. Clearing forests, grasslands, and spreading pesticides upsets the checks and balances of natural populations.
B. To help control pest organisms, we have developed a variety of pesticides—insecticides, herbicides, fungicides, and
rodenticides.
C. Plants have naturally produce chemicals to ward off, deceive, or poison herbivores for millions of years; it is a coevolutionary process.
D. Chemists have developed hundreds of synthetic chemicals for use on pests, leading to a 50-fold increase of use and
at least a 10-fold increase in toxicity since 1950.
1. Broad-spectrum pesticide, such as DDT, are toxic to many pests and beneficial species.
2. Narrow-spectrum pesticides, such as organophosphates, target a more specific group of pests.
3. Pesticides vary in their length of persistence.
4. As early as 1962, Rachel Carson warned against relying on synthetic organic chemicals to kill pests.
E. Modern pesticides save lives, increase food supplies, increase farmer’s profits, work fast, and are safer if used
properly.
Food, Soil, and Pest Management
81
F.
Pesticides may kill natural enemies of pest species, create new pest species, linger in the environment, and harm
wildlife and people.
G. Insects can rapidly become genetically resistant to widely used pesticides.
H. Two Federal laws regulate pesticide use in the U.S., but they can be improved.
1. The EPA banned or severely restricted 56 active pesticide ingredients between 1972 and 2004.
2. The 1996 Food Quality Protection Act (FQPA) increased public protection from pesticides.
3. Banned or severely restricted chemicals are still manufactured and exported to other countries.
4. The National Academy of Sciences states that federal laws regulating pesticides are inadequate and poorly
enforced.
5. The pesticide industry disputes the harmful effects of pesticides on human health.
6. The U.S. laws could be improved, but most other countries have not made as much progress as the U.S. has in
regulating pesticides.
I. A mix of cultivation practices and biological and ecological alternatives to conventional chemical pesticides can also
help control pests.
J. Integrated pest management uses a mix of cultivation, biological methods, and small amounts of selected chemical
pesticides as a last resort.
1. The overall aim of integrated pest management (IPM) is to reduce crop damage to an economically tolerable
level. Fields are carefully monitored for damage.
2. The Indonesian government banned 57 of the 66 pesticides used on rice. Within five years, pesticide use
dropped 65% and rice production rose by 15%. A well-designed IPM program can reduce pesticide use and pest
control costs while increasing crop yields.
3. IPM is an important form of pollution prevention that reduces risks to wildlife and human health.
4. Several UN agencies and the World Bank are establishing an IPM facility.
10-7 Sustainable Agriculture: Governments use three ways to encourage food production—price control, provide subsidies,
and ensure a free market environment.
A. There are three main ways to reduce hunger, malnutrition, and the harmful effects of agriculture.
1. Slow population growth.
2. Reduce poverty.
3. Develop and phase in systems of more sustainable or low-input agriculture (organic farming).
a. This relies more on perennial polyculture than on raising annual crops.
b. This relies on use of manure and tilled-in crop residues to build and maintain soil fertility.
c. There is very judicious use of pesticides so that pests have less chance of becoming resistant to pesticides.
B. Four major strategies have been suggested to help farmers make the transition to more sustainable agriculture:
1. Increase research on sustainable agriculture and improving human nutrition.
2. Set up demonstration projects throughout each country for farmers.
3. Provide subsidies and increased foreign aid to encourage its use.
4. Establish training programs in sustainable agriculture for farmers and government agricultural officials;
encourage the creation of college curricula in this area.
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