Food, Soil, and Pest Management Chapter 10
Section 10-1 What is food security and why is it difficult to attain?
Many people suffer from chronic health and malnutrition • Food security means having daily access to enough nutritious food to live an active and healthy life. • One of every six people in less-developed countries is not getting enough to eat, facing food insecurity—living with chronic hunger and poor nutrition, which threatens their ability to lead healthy and productive lives. • The root cause of food insecurity is poverty. • Other obstacles to food security are political upheaval, war, corruption, and bad weather, including prolonged drought, flooding, and heat waves.
Many people suffer from chronic health and malnutrition • To maintain good health and resist disease, individuals need fairly large amounts of macronutrients, such as carbohydrates, proteins and fats, and smaller amounts of micronutrients—vitamins and minerals. • People who cannot grow or buy enough food to meet their basic energy needs suffer from chronic undernutrition, or hunger. • Many suffer from chronic malnutrition—a deficiency of protein and other key nutrients, which weakens them, makes them more vulnerable to disease, and hinders the normal development of children.
Many people do not get enough vitamins and minerals • Chronic lack of iodine can cause stunted growth, mental retardation, and goiter. • Almost one-third of the world’s people do not get enough iodine in their food and water. • According to the FAO and the WHO, eliminating this serious health problem would cost the equivalent of only 2–3 cents per year for every person in the world.
Many people have health problems from eating too much • Overnutrition occurs when food energy intake exceeds energy use, causing excess body fat. • Face similar health problems as those under: lower life expectancy, greater susceptibility to disease and illness, and lower productivity and life quality. • Globally about 925 million people have health problems because they do not get enough to eat, and about 1.1 billion people face health problems from eating too much. • About 68% of American adults are overweight and half of those people are obese. • Obesity plays a role in four of the top ten causes of death in the United States—heart disease, stroke, Type 2 diabetes, and some forms of cancer.
Section 10-2 How is food produced?
Food production has increased dramatically • About 10,000 years ago, humans began to shift from hunting for and gathering their food to growing it and raising animals for food and labor. • Today, three systems supply most of our food. • Croplands produce mostly grains. • Rangelands, pastures, and feedlots produce meat. • Fisheries and aquaculture provide us with seafood. • About 66% of the world’s people survive primarily by eating rice, wheat, and corn. • Only a few species of mammals and fish provide most of the world’s meat and seafood.
Food production has increased dramatically • Since 1960, there has been an increase in global food production from all three of the major food production systems because of technological advances. • Tractors, farm machinery and high-tech fishing equipment. • Irrigation. • Inorganic chemical fertilizers, pesticides, high-yield grain varieties, and industrialized production of livestock and fish.
Industrialized crop production relies on high-input monocultures • Agriculture used to grow crops can be divided roughly into two types: • Industrialized agriculture, or high-input agriculture, uses heavy equipment and large amounts of financial capital, fossil fuel, water, commercial inorganic fertilizers, and pesticides to produce single crops, or monocultures. • Major goal of industrialized agriculture is to increase yield, the amount of food produced per unit of land. • Used on about 25% of the world’s cropland, mostly in more-developed countries, and produces about 80% of the world’s food.
Industrialized crop production relies on high-input monocultures • Plantation agriculture is a form of industrialized agriculture used primarily in tropical less-developed countries. • Grows cash crops such as bananas, soybeans, sugarcane, coffee, palm oil, and vegetables. • Crops are grown on large monoculture plantations, mostly for export to more-developed countries. • Modern industrialized agriculture violates the three principles of sustainability by relying heavily on fossil fuels, reducing natural and crop biodiversity, and neglecting the conservation and recycling of nutrients in topsoil.
Traditional agriculture often relies on low-input polycultures • Traditional agriculture provides about 20% of the world’s food crops on about 75% of its cultivated land, mostly in less-developed countries. • There are two main types of traditional agriculture. • Traditional subsistence agriculture supplements energy from the sun with the labor of humans and draft animals to produce enough crops for a farm family’s survival, with little left over to sell or store as a reserve for hard times. • In traditional intensive agriculture, farmers increase their inputs of human and draft-animal labor, animal manure for fertilizer, and water to obtain higher crop yields, some of which can be sold for income.
A closer look at industrialized crop production • Farmers can produce more food by increasing their land or their yields per acre. • Since 1950, about 88% of the increase in global food production has come from using high-input industrialized agriculture to increase yields in a process called the green revolution. • Three steps of the green revolution: • First, develop and plant monocultures of selectively bred or genetically engineered high-yield varieties of key crops such as rice, wheat, and corn.
A closer look at industrialized crop production • Second, produce high yields by using large inputs of water and synthetic inorganic fertilizers, and pesticides. • Third, increase the number of crops grown per year on a plot of land through multiple cropping. • The first green revolution used high-input agriculture to dramatically increase crop yields in most of the world’s more-developed countries, especially the United States, between 1950 and 1970.
A closer look at industrialized crop production • A second green revolution has been taking place since 1967. Fast-growing varieties of rice and wheat, specially bred for tropical and subtropical climates, have been introduced into middle-income, less-developed countries such as India, China, and Brazil. • Producing more food on less land has helped to protect some biodiversity by preserving large areas of forests, grasslands, wetlands, and easily eroded mountain terrain that might otherwise be used for farming.
A closer look at industrialized crop production • Largely because of the two green revolutions, world grain production tripled between 1961 and 2009. • People directly consume about 48% of the world’s grain production. About 35% is used to feed livestock and indirectly consumed by people who eat meat and meat products. The remaining 17% (mostly corn) is used to make biofuels such as ethanol for cars and other vehicles.
Growth in global grain production of wheat, corn, and rice between 1961-2010
Crossbreeding and genetic engineering produce varieties of crops and livestock • Crossbreeding through artificial selection has been used for centuries by farmers and scientists to develop genetically improved varieties of crops and livestock animals. • Such selective breeding in this first gene revolution has yielded amazing results; ancient ears of corn were about the size of your little finger, and wild tomatoes were once the size of grapes. • Typically takes 15 years or more to produce a commercially valuable new crop variety, and it can combine traits only from genetically similar species. • Typically, resulting varieties remain useful for only 5–10 years before pests and diseases reduce their efficacy.
Crossbreeding and genetic engineering produce varieties of crops and livestock • Modern scientists are creating a second gene revolution by using genetic engineering to develop genetically improved strains of crops and livestock. • Alters an organism’s genetic material through adding, deleting, or changing segments of its DNA to produce desirable traits or to eliminate undesirable ones (gene splicing); resulting organisms are called genetically modified organisms. • Developing a new crop variety through gene splicing is faster selective breeding, usually costs less, and allows for the insertion of genes from almost any other organism into crop cells.
Meat production has grown steadily • Meat and animal products such as eggs and milk are good sources of high-quality protein and represent the world’s second major food-producing system. • Between 1961 and 2010, world meat production—mostly beef, pork, and poultry—increased more than fourfold and average meat consumption per person more than doubled. • Global meat production is likely to more than double again by 2050 as affluence rises and more middle-income people begin consuming more meat and animal products in rapidly developing countries such as China and India.
Fish and shellfish production have increased dramatically • The world’s third major food-producing system consists of fisheries and aquaculture. • A fishery is a concentration of particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water. • Industrial fishing fleets harvest most of the world’s marine catch of wild fish.
Fish and shellfish production have increased dramatically • Fish and shellfish are also produced through aquaculture—the practice of raising marine and freshwater fish in freshwater ponds and rice paddies or in underwater cages in coastal waters or in deeper ocean waters. • Some fishery scientists warn that unless we reduce overfishing and ocean pollution, and slow projected climate change, most of the world’s major commercial ocean fisheries could collapse by 2050.
Section 10-3 What environmental problems arise from industrialized food production?
Serious concern Some concern Stable or nonvegetative Stepped Art Fig. 10-11, p. 214
Drought and human activities are degrading drylands • Desertification in arid and semiarid parts of the world threatens livestock and crop contributions to the world’s food supply. • Desertification occurs when the productive potential of topsoil falls by 10% or more because of a combination of prolonged drought and human activities that expose topsoil to erosion. • The FAO’s 2007 report on the Status of the World’s Forests estimated that some 70% of world’s arid and semiarid lands used for agriculture are degraded and threatened by desertification.
Excessive irrigation has serious consequences • Irrigation boosts productivity of farms; roughly 20% of the world’s cropland that is irrigated produces about 45% of the world’s food. • Most irrigation water is a dilute solution of various salts that are picked up as the water flows over or through soil and rocks. • Repeated annual applications of irrigation water in dry climates lead to the gradual accumulation of salts in the upper soil layers—a soil degradation process called salinization that stunts crop growth, lowers crop yields, and can eventually kill plants and ruin the land.
Excessive irrigation has serious consequences • Severe salinization has reduced yields on at least 10% of the world’s irrigated cropland, and almost 25% of irrigated cropland in the United States, especially in western states • Irrigation can cause waterlogging, in which water accumulates underground and gradually raises the water table; at least one-tenth of the world’s irrigated land suffers from waterlogging, and the problem is getting worse. • Excessive irrigation contributes to depletion of groundwater and surface water supplies.
Genetically modified crops and foods have advantages and disadvantages
Food and biofuel production systems have caused major losses of biodiversity • Natural biodiversity and some ecological services are threatened when forests are cleared and grasslands are plowed up and replaced with croplands used to produce food or biofuels, such as ethanol. • There is increasing loss of agrobiodiversity, the world’s genetic variety of animal and plant species. • In the United States, about 97% of the food plant varieties that were available to farmers in the 1940s no longer exist, except perhaps in small amounts in seed banks and in the backyards of a few gardeners. • The world’s genetic “library,” which is critical for increasing food yields, is rapidly shrinking.
There are limits to expansion of the green revolution • Scientists point out that continuing to increase these inputs eventually produces no additional increase in crop yields. • Since 1978, the amount of irrigated land per person has been declining, due to population growth, wasteful use of irrigation water, soil salinization, and depletion of both aquifers and surface water, and the fact that most of the world’s farmers do not have enough money to irrigate their crops. • We can get more crops per drop of irrigation water by using known methods and technologies to greatly improve the efficiency of irrigation.
There are limits to expansion of the green revolution • Clearing tropical forests and irrigating arid land could more than double the world’s cropland, but much of this land has poor soil fertility, steep slopes, or both. • Cultivating such land usually is expensive, is unlikely to be sustainable, and reduces biodiversity by degrading and destroying wildlife habitats • During this century, fertile croplands in coastal areas are likely to be flooded by rising sea levels resulting from projected climate change. • Food production could drop sharply in some major food-producing areas because of increased drought and longer and more intense heat waves, also resulting from projected climate change.
Animal feedlots and confined animal feeding operations have advantages and disadvantages
Section 10-4 How can we protect crops from pests more sustainably?
Integrated pest management is a component of more sustainable agriculture • Many pest control experts and farmers believe the best way to control crop pests is a carefully designed integrated pest management (IPM) program. • Farmers develop a carefully designed control program that uses a combination of cultivation, biological, and chemical tools and techniques. • The overall aim of IPM is to reduce crop damage to an economically tolerable level. • Farmers first use biological methods (natural predators, parasites, and disease organisms) and cultivation controls (such as rotating crops, altering planting time, and using large machines to vacuum up harmful bugs).
Section 10-5 How can we improve food security?
Use government policies to improve food production and security • Agriculture is a financially risky business because farmers have a good or bad year depending on factors over which they have little control: weather, crop prices, crop pests and diseases, loan interest rates, and global markets. • Governments use two main approaches to influence food production: • Control prices. • Provide subsidies.
Section 10-6 How can we produce food more sustainably?
Drip irrigation (efficiency 90–95%) Center pivot (efficiency 80% with low-pressure sprinkler and 90–95% with LEPA sprinkler) Above- or below-ground pipes or tubes deliver water to individual plant roots. Gravity flow (efficiency 60% and 80% with surge valves) Water usually pumped from underground and sprayed from mobile boom with sprinklers. Water usually comes from an aqueduct system or a nearby river. Fig. 10-24, p. 229