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The Cultural Landscape Chapter 10: Agriculture
Agriculture
The food industry in the United States and Canada is vast, but only a few people are full-time farmers, and they may be more familiar with the operation of computers and advanced machinery than the typical factory or office worker.
The mechanized, highly productive American or Canadian farm contrasts with the subsistence farm found in much of the world.
The most "typical" human—if there is such a person—is an Asian farmer who grows enough food to survive, with little surplus.
This sharp contrast in agricultural practices constitutes one of the most fundamental differences between the more developed and less developed countries of the world.
Approximately one-half of the people in less developed countries are farmers.
The overwhelming majority of them are like the Iqbels, growing enough food to feed themselves, but little more.
LDCs are home to 97 percent of the world's farmers.
In contrast, fewer than 2 percent of the people in the United States are farmers.
Yet the advanced technology used by these farmers allows them to produce enough food for people in the United States at a very high standard, plus food for many people elsewhere in the world.
Geographers study where agriculture is distributed across Earth.
The most important distinction is what happens to farm products.
In less developed regions, the farm products are most often consumed on or near the farm where they are produced, whereas in MDCs farmers sell what they produce.
Geographers observe a wide variety of agricultural practices.
The reason why farming varies around the world relates to the distribution of cultural and environmental factors across space.
Elements of the physical environment, such as climate, soil, and topography, set broad limits on agricultural practices, and farmers make choices to modify the environment in a variety of ways.
Farming is an economic activity that still depends very much on the local diversity of environmental and cultural conditions in each place.
Despite increased knowledge of alternatives, farmers practice distinctive agriculture in different regions and, in fact, on neighboring farms.
Broad climate patterns influence the crops planted in a region, and local soil conditions influence the crops planted on an individual farm.
In each society, farmers possess very specific knowledge of their environmental conditions and certain technology for modifying the landscape.
Within the limits of their technology, farmers choose from a variety of agricultural practices, based on their perception of the value of each alternative.
These values are partly economic and partly cultural.
How farmers deal with their physical environment varies according to dietary preferences, availability of technology, and other cultural traditions.
Farmers select agricultural practices based on cultural perceptions, because a society may hold some foods in high esteem while avoiding others.
Although individual farmers may make specific decisions on a very local scale, agriculture is as caught up in the globalization of the economy as other industries.
Agriculture is big business in MDCs and a major component of international trade connections in LDCs.
After examining the origins and diffusion of agriculture, we will consider the agricultural practices used in LDCs and MDCs.
We will also examine the problems farmers face in each type of region.
Although each farm has a unique set of physical conditions and choice of crops, geographers group farms into several types by their distinctive environmental and cultural characteristics.
KEY ISSUE 1 - Where Did Agriculture Originate?
The origin of agriculture cannot be documented with certainty because it began before recorded history.
Scholars try to reconstruct a logical sequence of events based on fragments of information about ancient agricultural practices and historical environmental conditions.
Improvements in cultivating plants and domesticating animals evolved over thousands of years.
Origins of Agriculture
Agriculture is deliberate modification of Earth’s surface through cultivation of plants and rearing of animals to obtain sustenance or economic gain.
Agriculture originated when humans domesticated plants and animals for their use.
The word cultivate means “to care for," and a crop is any plant cultivated by people.
Hunters and Gatherers
Before the invention of agriculture, all humans probably obtained the food they needed for survival through hunting for animals, fishing, or gathering plants (including berries, nuts, fruits, and roots).
Hunters and gatherers lived in small groups of usually fewer than 50 persons, because a larger number would quickly exhaust the available resources within walking distance.
The men hunted game or fished, and the women collected berries, nuts, and roots.
This division of labor sounds like a stereotype but is based on evidence from archaeology and anthropology.
They collected food often, perhaps daily.
The food search might take only a short time or much of the day, depending on local conditions.
The group traveled frequently, establishing new home bases or camps.
The direction and frequency of migration depended on the movement of game and the seasonal growth of plants at various locations.
We can assume that groups communicated with each other concerning hunting rights, intermarriage, and other specific subjects.
For the most part, they kept the peace by steering clear of each other's territory.
Today, perhaps a quarter-million people, or less than 1.005 percent of the world’s population, still survive by hunting and gathering rather than by agriculture.
Examples include Spinifex (also known as Puila Nguru) people, who live in Australia’s Great Victorian Desert; the Sentinelese people, who live in India's Andaman Islands; and the Bushmen, who live in Botswana and Namibia.
Contemporary hunting and gathering societies are isolated groups living on the periphery of world settlement, but they provide insight into human customs that prevailed in prehistoric times, before the invention of agriculture.
Invention of Agriculture
Why did most nomadic groups convert from hunting, gathering, and fishing to agriculture?
Geographers and other scientists agree that agriculture originated in multiple hearths around the world.
They do not agree on when agriculture originated and diffused or why.
Southwest Asia has an early center of crop domestication.
The earliest crops domesticated in Southwest Asia are thought to have been barley and wheat, around 10,000 years ago.
Lentil and olive were also early domestications in Southwest Asia.
From this hearth, cultivation diffused west to Europe and east to Central Asia.
Rice is now thought to have been domesticated in East Asia more than 10,000 years ago, along the Yangtze River in eastern China.
Millet was cultivated at an early date along the Yellow River.
Sorghum was domesticated in central Africa around 8,000 years ago.
Yams may have been domesticated even earlier.
Millet and rice may have been domesticated in sub-Saharan Africa independently of the hearth in East Asia.
From central Africa, domestication of crops probably diffused further south in Africa.
In Latin America, two important hearths of crop domestication are thought to have emerged in Mexico and Peru around 4,000 to 5,000 years ago.
Mexico is considered a hearth for beans and cotton, and Peru for potatoes.
Squashes may have been first domesticated in a third hearth in the Americas, in southeastern present-day United States, as well as in Mexico.
The most important contribution of the Americas to crop domestication, maize (corn), may have emerged in the two hearths independently around the same time.
From these two hearts, cultivation of maize and other crops diffused northward into North America and southward into tropical South America.
Animals were also domesticated in multiple hearths at various dates.
Southwest Asia is thought to have been the hearth for the domestication of the largest number of animals that would prove to be most important for agriculture, including cattle, goats, pigs, and sheep, between 8,000 and 9,000 years ago.
Domestication of the dog is thought to date from around 12,000 years ago, also in Southwest Asia.
The horse is considered to have been domesticated in Central Asia; diffusion of the domesticated horse is thought to be associated with the diffusion of the Indo-European language.
Inhabitants of Southwest Asia may have been the first to integrate cultivation of crops with domestication of herd animals such as cattle, sheep, and goats.
These animals were used to prepare the land before planting seeds and, in turn, were fed part of the harvested crop.
Other animal products, such as milk, meat, and skins, may have been exploited at a later date.
This integration of plants and animals is a fundamental element of modern agriculture.
Scientists do not agree on whether agriculture originated primarily because of environmental factors or cultural factors.
Probably a combination of both factors contributed.
Those favoring environmental reasons point to the coinciding of the first domestication of crops and animals with climate change around 10,000 years ago.
This marked the end of the last ice age, when permanent ice cover receded from Earth's midlatitudes to polar regions, resulting in a massive redistribution of humans, other animals, and plants at that time.
Alternatively, human behavior may be primarily responsible for the origin of agriculture.
A preference for living in a fixed place rather than as nomads may have led hunters and gatherers to build permanent settlements and to store surplus vegetation there.
In gathering wild vegetation, people inevitably cut plants and dropped berries, fruits, and seeds.
These hunters probably observed that, over time, damaged or discarded food produced new plants.
They may have deliberately cut plants or dropped berries on the ground to see if they would produce new plants.
Subsequent generations learned to pour water over the site and to introduce manure and other soil improvements.
Over thousands of years, plant cultivation apparently evolved from a combination of accident and deliberate experiments.
That agriculture had multiple origins means that, from earliest times, people have produced food in distinctive ways in different regions.
This diversity derives from a unique legacy of wild plants, climatic conditions, and cultural preferences in each region.
Improved communications in recent centuries have encouraged the diffusion of some plants to varied locations around the world.
Many plants and animals thrive across a wide portion of Earth's surface, not just in their place of original domestication.
Only after 1500, for example, were wheat, oats, and barley introduced to the Western Hemisphere and maize to the Eastern Hemisphere.
Subsistence and Commercial Agriculture
The most fundamental differences in agricultural practices are between those in LDCs and those in MDCs.
Farmers in LDCs generally practice subsistence agriculture, whereas farmers in MDCs practice commercial agriculture.
Subsistence agriculture, found in LDCs, is the production of food primarily for consumption by the farmer's family.
Commercial agriculture, found in MDCs, is the production of food primarily for sale off the farm.
The most widely used map of world agricultural regions is based on work done by geographer Derwent Whittlesey in 1936.
Whittlesey identified 11 main agricultural regions, plus an area where agriculture was nonexistent.
Whittlesey's 11 regions are divided between 5 that are important in LDCs and 6 that are important in MDCs.
Similarities between the agriculture and climate maps are striking.
For example, pastoral nomadism is the predominant type of agriculture in the Middle East, which has a dry climate, whereas shifting cultivation is the predominant type of agriculture in central Africa, which has a tropical climate.
Note the division between southeastern China (warm midlatitude climate, intensive subsistence agriculture with wet rice dominant) and northeastern China (cold midlatitude climate intensive subsistence agriculture with wet rice not dominant).
In the United States, much of the West is distinguished from the rest of the country according to climate (dry) and agriculture (livestock ranching).
Thus, agriculture varies between the dry lands and the tropics within LDCs—as well as between the dry lands of LDCs and MDCs.
Because of the problems involved with the concept of environmental determinism, geographers are wary of placing too much emphasis on the role of climate.
Cultural preferences also explain agricultural differences in areas of similar climate.
Hog production is virtually nonexistent in predomimmtly Muslim regions because of that religion's taboo against consuming pork products.
Wine production is relatively low in Africa and Asia, even where the climate is favorable for growing grapes, because of alcohol avoidance in predominantly non-Christian countries.
Five principal features distinguish commercial agriculture from subsistence agriculture:
Purpose of farming
Percentage of farmers in the labor force
Use of machinery
Farm size
Relationship of farming to other businesses
Purpose of Farming
Subsistence and commercial agriculture are undertaken for different purposes.
In LDCs, most people produce food for their own consumption.
Some surplus may be sold to the government or to private firms, but the surplus product is not the farmer’s primary purpose and may not even exist some years because of growing conditions.
In commercial fanning, farmers grow crops and raise aminals primarily for sale off the farm rather than for their own consumption.
Agricultural products are not sold directly to consumers but to food-processing companies.
Large processors, such as General Mills and Kraft, typically sign contracts with commercial farmers to buy their grain, chickens, cattle, and other output.
Farmers may have contracts to sell sugar beets to sugar refineries, potatoes to distilleries, and oranges to manufacturers of concentrated juices.
Percentage of Farmers in the Labor Force
In MDCs, around 5 percent of workers are engaged directly in farming, compared to around 50 percent in LDCs.
The percentage of farmers is even lower in North America—only around 2 percent.
Yet the small percentage of farmers in the United States and Canada produces not only enough food for themselves and the rest of the region but also a surplus to feed people elsewhere.
The number of farmers declined dramatically in MDCs during the twentieth century.
The United States had about 6 million farms in 1940 and 4 million in 1960; the number has stabilized during the past quarter-century at around 2 million.
Both push and pull migration factors have been responsible for the decline: People were pushed away from farms by lack of opportunity to earn a decent income, and at the same time they were pulled to higher-paying jobs in urban areas.
Use of Machinery
In MDCs, a small number of farmers can feed many people because they rely on machinery to perform work, rather than relying on people or animals.
In LDCs, farmers do much of the work with hand tools and animal power.
Traditionally, the farmer or local craftspeople made equipment from wood, but beginning in the late eighteenth century, factories produced farm machinery.
The first all-iron plow was made in the 1770s and was followed in the nineteenth and twentieth centuries by inventions that made farming less dependent on human or animal power.
Tractors, combines, corn pickers, planters, and other factory-made farm machines have replaced or supplemented manual labor.
Transportation improvements have also aided commercial farmers.
The building of railroads in the nineteenth century, and highways and trucks in the twentieth century, have enabled farmers to transport crops and livestock farther and faster.
Cattle arrive at market heavier and in better condition when transported by truck or train than when driven on hoof.
Crops reach markets without spoiling.
Commercial farmers use scientific advances to increase productivity.
Experiments conducted in university laboratories, industry, and research organizations generate new fertilizers, herbicides, hybrid plants, animal breeds, and farming practices, which produce higher crop yields and healthier animals.
Access to other scientific information has enabled farmers to make more intelligent decisions concerning proper agricultural practices.
Some farmers conduct their own on-farm research.
Electronics also help commercial farmers.
Global positioning systems (GPS) determine the precise coordinates for spreading different types and amounts of fertilizers.
Satellite imagery monitors crop progress.
Yield monitors attached to combines determine the precise number of bushels being harvested.
Farm Size
The average farm size is relatively large in commercial agriculture, especially in the United States and Canada, with U.S. farms averaging about 180 hectares ( 449 acres).
Despite their size, most commercial farms in MDCs are family owned and operated—98 percent in the United States.
Commercial farmers frequently expand their holdings by renting nearby fields.
Commercial agriculture is increasingly dominated by a handful of large farms.
In the United States, the largest 5 percent of farms produced 75 percent of the country's total agriculture.
Large size is partly a consequence of mechanization.
Combines, pickers, and other machinery perform most efficiently at very large scales, and their considerable expense cannot be justified on a small farm.
As a result of the large size and the high level of mechanization, commercial agriculture is an expensive business.
Farmers spend hundreds of thousands of dollars to buy or rent land and machinery before beginning operations.
This money is frequently borrowed from a bank and repaid after the output is sold.
Although the United States currently has fewer farms and farmers than in 1900, the amount of land devoted to agriculture has increased.
The United States had 60 percent fewer farms and 85 percent fewer farmers in 2000 than in 1900, but 13 percent more farmland, primarily because of irrigation and reclamation.
However, the amount of U.S. farmland has declined from its all-time peak around 1960.
Primarily because of the expansion of urban areas, the United States has been losing 500,000 hectares (1.2 million acres) per year from its 400 million hectares (l billion acres) of farmland.
A more serious problem in the United States has been the loss of 200,000 hectares (500,000 acres) of the most productive farmland, known as prime agricultural land, as urban areas sprawl into the surrounding countryside.
Relationship of Farming to Other Businesses
Commercial farming is closely tied to other businesses.
The system of commercial farming found in the United States and other MDCs has been called agribusiness because the family farm is not an isolated activity but is integrated into a large food-production industry.
Commercial farmers make heavy use of modem communications and information technology to stay in touch and keep track of prices, yields, and expenditures.
Although farmers are less than 2 percent of the U.S. labor force, around 20 percent of U.S. labor works in food production and services related to agribusiness-food processing, packaging, storing, distributing, and retailing.
Agribusiness encompasses such diverse enterprises as tractor manufacturing, fertilizer production, and seed distribution.
Although most farms are owned by individual families, many other aspects of agribusiness are controlled by large corporations.
KEY ISSUE 2 - Where Are Agricultural Regions in LDCs?
This section considers four agricultural types characteristic of LDCs—shifting cultivation, pastoral nomadism, intensive subsistence, and plantation.
Intensive subsistence agriculture is divided into two regions, depending on the choice of crop.
Shifting Cultivation
Shifting cultivation is practiced in much of the world’s Humid Low Latitude, or A climate regions, which have relatively high temperatures and abundant rainfall.
It is practiced by roughly 250 million people across 36 million square kilometers (14 million square miles), especially in the tropical rainforests of South America, Central and West Africa, and Southeast Asia.
Characteristics of Shifting Cultivation
Two distinctive features of shifting cultivation are:
Farmers clear land for planting by slashing vegetation and burning the debris (shifting cultivation is sometimes called slash-and-burn agriculture).
Farmers grow crops on a cleared field for only a few years until soil nutrients are depleted and then leave it fallow (nothing planted) for many years so the soil can recover.
People who practice shifting cultivation generally live in small villages and grow food on the surrounding land, which the village controls.
Well-recognized boundaries usually separate neighboring villages.
THE PROCESS OF SHIFTING CULTIVATION.
Each year villagers designate for planting an area surrounding the settlement.
Before planting, they must remove the dense vegetation that typically covers tropical land.
Using axes, they cut down most of the trees, sparing only those that are economically useful.
An efficient strategy is to cut down selected large trees, which bring down smaller trees that may have been weakened by notching.
The undergrowth is cleared away with a machete or other long knife.
On a windless day, the debris is burned under carefully controlled conditions.
The rains wash the fresh ashes into the soil, providing needed nutrients.
Before planting, the cleared area, known by a variety of names in different regions, including swidden, lading, milpa, chaw, and kaingin is prepared by hand, perhaps with the help of a simple implement such as a hoe; plows and animals are rarely used.
The only fertilizer generally available is potash (potassium) from burning the debris when the site is cleared.
Little weeding is done the first year that a cleared patch of land is farmed; weeds may be cleared with a hoe in subsequent years.
The cleared land can support crops only briefly, usually 3 years or less.
In many regions, the most productive harvest comes in the second year after burning.
Thereafter, soil nutrients are rapidly depleted and the land becomes too infertile to nourish crops.
Rapid weed growth also contributes to the abandonment of a swidden after a few years.
When the swidden is no longer fertile, villagers identify a new site and begin clearing it.
They leave the old site uncropped for many years, allowing it to become overrun again by natural vegetation.
The field is not actually abandoned; the villagers will return to the site someday, perhaps as few as 6 years or as many as 20 years later, to begin the process of clearing the land again.
In the meantime, they may still care for fruit-bearing trees on the site.
If a cleared area outside a village is too small to provide food for the population, then some of the people may establish a new village and practice shifting cultivation there.
Some farmers may move temporarily to another settlement if the field they are clearing that year is distant.
CROPS OF SHIFTING CULTIVATION.
The crops grown by each village vary by local custom and taste.
The predominant crops include upland rice in Southeast Asia, maize (com) and manioc (cassava) in South America, and millet and sorghum in Africa.
Yams, sugarcane, plantain, and vegetables are also grown in some regions.
These crops have originated in one region of shifting cultivation and have diffused to other areas in recent years.
The Kayapo people of Brazil's Amazon tropical rain forest do not arrange crops in the rectangular fields and rows that are familiar to us.
They plant in concentric rings.
At first, they plant sweet potatoes and yams in the inner area.
In successive rings go corn and rice, manioc, and more yarns.
In subsequent years the inner area of potatoes and yarns expands to replace com and rice.
The outermost ring contains plants that require more nutrients, including papaya, banana, pineapple, mango, cotton, and beans.
It is here that the leafy crowns of cut trees fall when the field is cleared, and their rotting releases more nutrients into the soil.
Most families grow only for their own needs, so one swidden may contain a large variety of intermingled crops, which are harvested individually at the best time.
In shifting cultivation a "farm field" appears much more chaotic than do fields in MDCs, where a single crop such as com or wheat may grow over an extensive area.
In some cases, families may specialize in a few crops and trade with villagers who have a surplus of others.
OWNERSHIP AND USE OF LAND IN SHIFTING CULTIVATION.
Traditionally, land was owned by the village as a whole rather than separately by each resident.
The chief or ruling council allocated a patch of land to each family and allowed it to retain the output.
Individuals may also have had the right to own or protect specific trees surrounding the village.
Today, private individuals now own the land in some communities, especially in Latin America.
Shifting cultivation occupies approximately one-fourth of the world's land area, a higher percentage than any other type of agriculture.
However, less than 5 percent of the world's people engage in shifting cultivation.
The gap between the percentage of people and land area is not surprising, because the practice of moving from one field to another every couple of years requires more land per person than do other types of agriculture.
Future of Shifting Cultivation
Land devoted to shifting cultivation is declining in the tropics at the rate of about 75,000 square kilometers (30,000 square miles), or 0.2 percent, per year according to the United Nations.
The amount of Earth's surface allocated to tropical rain forests has already been reduced to less than half of its original area, for until recent years the World Bank supported deforestation with loans to finance development schemes that required clearing forests.
Shifting cultivation is being replaced by logging, cattle ranching, and the cultivation of cash crops.
Selling timber to builders or raising beef cattle for fast-food restaurants are more effective development strategies than maintaining shifting cultivation.
LDCs also see shifting cultivation as an inefficient way to grow food in a hungry world,
Indeed, compared to other forms of agriculture, shifting cultivation can support only a small population in an area without causing environmental damage.
To its critics, shifting cultivation is at best a preliminary step in economic development.
Pioneers use shifting cultivation to clear forests in the tropics and to open land for development where permanent agriculture never existed.
People unable to find agricultural land elsewhere can migrate to the tropical forests and initially practice shifting cultivation.
Critics say it then should be replaced by more sophisticated agricultural techniques that yield more per land area.
Defenders of shifting cultivation consider it the most environmentally sound approach for the tropics.
Practices used in other forms of agriculture, such as fertilizers and pesticides and permanently clearing fields, may damage the soil, cause severe erosion, and upset balanced ecosystems.
Large-scale destruction of the rain forests also may contribute to global warming.
When large numbers of trees are cut, their burning and decay release large volumes of carbon dioxide.
This gas can build up in the atmosphere, acting like the window glass in a greenhouse to trap solar energy in the atmosphere, resulting in the "greenhouse effect."
Elimination of shifting cultivation could also upset the traditional local diversity of cultures in the tropics.
The activities of shifting cultivation are intertwined with other social, religious, political, and various folk customs.
A drastic change in the agricultural economy could disrupt other activities of daily life.
As the importance of tropical rain forests to the global environment has become recognized, LDCs have been pressured to restrict further destruction of them.
In one innovative strategy, Bolivia agreed to set aside 1.5 million hectares (3. 7 million acres) in a forest reserve in exchange for cancellation of $650,000,000 of its debt to developed countries.
Meanwhile, in Brazil's Amazon rainforest, deforestation has increased from 2. 7 million hectares (7 million acres) per year during the 1990s to 3.1 million hectares (8 million acres) since 2000.
Pastoral Nomadism
Pastoral nomadism is a form of subsistence agriculture based on the herding of domesticated animals.
The word pastoral refers to sheepherding.
It is adapted to dry climates, where planting crops is impossible.
Pastoral nomads live primarily in the large belt of arid and semiarid land that includes Central and Southwest Asia and North Africa.
The Bedouins of Saudi Arabia and North Africa and the Masai of East Africa are examples of nomadic groups.
Only about 15 million people are pastoral nomads, but they sparsely occupy about 20 percent of Earth's land area.
Characteristics of Pastoral Nomadism
Unlike other subsistence farmers, pastoral nomads depend marily on animals rather than crops for survival.
The animals provide milk, and their skins and hair are used for clothing and tents.
Like other subsistence farmers, though, pastoral nomads consume mostly grain rather than meat.
Their animals are usually not slaughtered, although dead ones may be consumed.
To nomads, the size of their herd is both an important measure of power and prestige and their main security during adverse environmental conditions.
Some pastoral nomads obtain grain from sedentary subsistence farmers in exchange for animal products.
More often, part of a nomadic group—perhaps the women and children—may plant crops at a fixed location while the rest of the group wanders with the herd.
Nomads might hire workers to practice sedentary agriculture in return for grain and protection.
Other nomads might sow grain in recently flooded areas and return later in the year to harvest the crop.
Yet another strategy is to remain in one place and cultivate the land when rainfall is abundant; then, during periods that are too dry to grow crops, the group can increase the size of the herd and migrate in search of food and water.
CHOICE OF ANIMALS.
Nomads select the type and number of animals for the herd according to local cultural and physical characteristics.
The choice depends on the relative prestige of animals and the ability of species to adapt to a particular climate and vegetation.
The camel is the most highly desired animal in North Africa and Southwest Asia, along with sheep and goats.
The horse is particularly important in Central Asia.
Camels are well suited to arid climates because they can go long periods without water, carry heavy baggage, and move rapidly, but they are particularly bothered by flies and sleeping sickness and have a relatively long gestation period—12 months from conception to birth.
Goats need more water than do camels but are tough and agile and can survive on virtually any vegetation, no matter how poor.
Sheep are relatively slow-moving and affected by climatic changes; they require more water and are more selective as to which plants they will eat.
The minimum number of animals necessary to support each family adequately varies according to the particular group and animal.
The typical nomadic family needs 25 to 60 goats or sheep or 10 to 25 camels.
MOVEMENTS OF PASTORAL NOMADS.
Pastoral nomads do not wander randomly across the landscape but have, a strong sense of territoriality.
Every group controls a piece of territory and will invade another group's territory only in an emergency or if war is declared.
The goal of each group is to control a territory large enough to contain the forage and water needed for survival.
The actual amount of land a group controls depends on its wealth and power.
The precise migration patterns evolve from intimate knowledge of the area's physical and cultural characteristics.
Groups frequently divide into herding units of five or six families and choose routes based on the most likely water sources during the various seasons of the year.
The selection of routes varies in unusually wet or dry years and is influenced by the condition of their animals and the area's political stability.
Some pastoral nomads practice transhumance, which is seasonal migration of livestock between mountains and lowland pasture areas.
Pasture is grass or other plants grown for feeding grazing animals, as well as land used for grazing.
Sheep or other animals may pasture in alpine meadows in the summer and be herded back down into valleys for winter pasture.
The Future of Pastoral Nomadism
Agricultural experts once regarded pastoral nomadism as a stage in the evolution of agriculture—between the hunters and gatherers who migrated across Earth's surface in search of food and sedentary farmers who cultivated grain in one place.
Because they had domesticated animals but not plants, pastoral nomads were considered more advanced than hunters and gatherers but less advanced than settled farmers.
Pastoral nomadism is now generally recognized as an offshoot of sedentary agriculture, not as a primitive precursor of it.
It is simply a practical way of surviving on land that receives too little rain for cultivation of crops.
The domestication of animals—the basis for pastoral nomadism—probably was achieved originally by sedentary farmers, not by nomadic hunters.
Pastoral nomads, therefore, had to be familiar with sedentary farming, and in many cases, they practiced it.
Today, pastoral nomadism is a declining form of agriculture, partly a victim of modern technology.
Before recent transportation and communications inventions, pastoral nomads played an important role as carriers of goods and information across the sparsely inhabited dry lands.
They used to be the most powerful inhabitants of the dry lands, but now, with modern weapons, national governments can control the nomadic population more effectively.
Government efforts to resettle nomads have been particularly vigorous in China, Kazakhstan, and several Southwest Asia countries, including Israel, Saudi Arabia, and Syria.
Nomads are reluctant to cooperate, so these countries have experienced difficulty in trying to force their settlement in collectives and cooperatives.
Governments force groups to give up pastoral nomadism because they want the land for other uses.
Land that can be irrigated is converted from nomadic to sedentary agriculture.
Some nomads are encouraged to try sedentary agriculture or to work for mining or petroleum companies.
Others are still allowed to move about, but only within ranches of fixed boundaries.
In the future, pastoral nomadism will be increasingly confined to areas that cannot be irrigated or that lack valuable raw materials.
Intensive Subsistence Agriculture
Shifting cultivation and pastoral nomadism are forms of subsistence agriculture found in regions of low density.
But three-fourths of the world's people live in LDCs, and the form of subsistence agriculture that feeds most of them is intensive subsistence agriculture.
The term intensive implies that farmers must work intensively to subsist on a parcel of land.
In densely populated East, South, and Southeast Asia, most farmers practice intensive subsistence agriculture.
The typical farm in Asia's intensive subsistence agriculture regions is much smaller than elsewhere in the world.
Many Asian farmers own several fragmented plots, frequently a result of dividing individual holdings among several children over several centuries.
Because the agricultural density—the ratio of farmers to arable land—is so high in parts of East and South Asia, families must produce enough food for their survival from a very small area of land.
They do this through careful agricultural practices, refined over thousands of years in response to local environmental and cultural patterns.
Most of the work is done by hand or with animals rather than with machines, in part due to abundant labor, but largely from lack of funds to buy equipment.
To maximize food production, intensive subsistence farmers waste, virtually no land.
Corners of fields and irregularly shaped pieces of land are planted rather than left idle.
Paths and roads are kept as narrow as possible to minimize the loss of arable land.
Livestock are rarely permitted to graze on land that could be used to plant crops, and little grain is grown to feed the animals.
Intensive Subsistence with Wet Rice Dominant
The intensive agriculture region of Asia can be divided between areas where wet rice dominates and areas where it does not.
The term wet rice refers to the practice of planting rice on dry land in a nursery and then moving the seedlings to a flooded field to promote growth.
Wet rice occupies a relatively small percentage of Asia's agricultural land but is the region's most important source of food.
Intensive wet-rice farming is the dominant type of agriculture in Southeast China, East India, and much of Southeast Asia.
Successful production of large yields of rice is an elaborate process that is time-consuming and done mostly by hand.
The consumers of the rice also perform the work, and all family members, including children, contribute to the effort.
Growing rice involves several steps.
First, a farmer prepares the field for planting, using a plow drawn by water buffalo or oxen.
The use of a plow and animal power is one characteristic that distinguishes subsistence agriculture from shifting cultivation.
The plowed land is then flooded with water.
Too much or too little can damage the crop—a particular problem for farmers in South Asia who depend on monsoon rains, which do not always arrive at the same time each summer.
Before planting, dikes and canals are repaired to ensure the right quantity of water in the field.
The flooded field is called a sawah in the Austronesian language widely spoken in Indonesia, including Java.
Europeans and North Americans frequently, but incorrectly, call it a paddy, the Malay word for wet rice.
The customary way to plant rice is to grow seedlings on dry land in a nursery and then transplant the seedlings into the flooded field.
Typically, one-tenth of a sawah is devoted to the cultivation of seedlings.
After about a month they are transferred to the rest of the field.
Rice plants grow submerged in water for approximately three-0fourthts of the growing period.
Another method of planting rice is to broadcast dry seeds by scattering them through the field, a method used to some extent in South Asia.
Rice plants are harvested by hand usually with knives.
To separate the husks, known as chaff, from the seeds, the heads are threshed by beating them on the ground or treading on them barefoot.
The threshed rice is placed in a tray, and the lighter chaff is winnowed—that is, allowed to be blown away by the wind.
If the rice is to be consumed directly by the farmer, the hull, or outer covering, is removed by mortar and pestle.
Rice that is sold commercially is frequently whitened and polished, a process that removes some nutrients but leaves rice more pleasing in appearance and taste to many consumers.
Wet rice is most easily grown on flat land, because the plants are submerged in water much of the time.
Thus most wet-rice cultivation takes place in river valleys and deltas.
But the pressure of population growth in parts of East Asia has forced expansion of areas under rice cultivation.
One method of developing additional land suitable for growing rice is to terrace the hillsides of river valleys.
Land is used even more intensively in parts of Asia by obtaining two harvests per year from one field, a process known as double cropping.
Double cropping is common in places that have warm winters, such as South China and Taiwan, but is relatively rare in India , where most areas have dry winters.
Normally, double cropping involves alternating between wet rice, grown in the summer when precipitation is higher, and wheat, barley, or another dry crop, grown in the drier winter season.
Crops other than rice may be grown in the wet-rice region in the summer on nonirrigated land.
Intensive Subsistence with Wet Rice Not Dominant
Climate prevents farmers from growing wet rice in portions of Asia, especially where summer precipitation levels are too low and winters are too harsh.
Agriculture in much of interior India and northeast China is devoted to crops other than wet rice.
Wheat is the most important crop, followed by barley.
Various other grains and legumes are grown for household consumption, including millet, oats, corn, kaoliang, sorghum, and soybeans.
Also grown are some crops sold for cash, such as cotton, flax, hemp, and tobacco.
Aside from what is grown, this region shares most of, the characteristics of intensive subsistence agriculture the wet-rice region.
Land is used intensively and worked primarily by human power with the assistance of some hand implements and animals.
In milder parts of the region where wet rice does not dominate, more than one harvest can be obtained some years through skilled use of crop rotation, which is the practice of rotating use of different fields from crop to crop each year to avoid exhausting the soil.
In colder climates, wheat or another crop is planted in the spring and harvested in the fall, but no crops can be sown through the winter.
Since the Communist Revolution in 1949, private individuals have owned little agricultural land in China.
Instead, the Communist government-organized agricultural producer communes, which typically consisted of several villages of several hundred people.
By combining several small fields into a single large unit, China's government hoped to promote agricultural efficiency—scarce equipment and animals and larger improvement projects, such as flood control, water storage, and terracing, could be shared.
In reality, productivity did not Increase as much as the government had expected because People worked less efficiently for the commune than when working for themselves.
China has therefore dismantled the agricultural communes.
The communes still hold legal title to agricultural land, but villagers sign contracts entitling them to farm portions of the land as private individuals.
Chinese farmers may sell to others the right to use the land and to pass on the right to their children.
Reorganization has been difficult because irrigation systems, equipment, and other infrastructure were developed to serve large communal farms rather than small individually managed ones, which cannot afford to operate and maintain the machinery.
But production has increased greatly.
Plantation Farming
The plantation is a form of commercial agriculture found in the tropics and subtropics, especially in Latin America, Africa, and Asia.
Although generally situated in LDCs, plantations are often owned or operated by Europeans or North Americans and grow crops for sale primarily to MDCs.
Crops are normally processed at the plantation before shipping because processed goods are less bulky and are therefore h A . . d cheaper to ship long distances to the North American and European markets.
A plantation is a large farm that specializes in one or two crops.
Among the most important crops grown, on plantations are cotton, sugarcane, coffee, rubber, and tobacco.
Also produced in large quantities are cocoa, jute, bananas, tea, coconuts and palm oil.
Latin American plantations are more likely to grow coffee, sugarcane, and bananas, whereas Asian plantations may provide rubber and palm oil.
Crops such as tobacco, cotton, and sugarcane, which can be planted only once a year, are less likely to be grown on large plantations today than in the past.
Because plantations are usually situated in sparsely settled locations, they must import workers and provide them with food, housing, and social services.
Plantation managers try to spread the work as evenly as possible throughout the year to make full use of the large labor force.
Where the climate permits, more than one crop is planted and harvested annually.
Rubber-tree plantations try to spread the task of tapping the trees throughout the year.
Until the Civil War, plantations were important in the U.S. South, where the principal crop was cotton, followed by tobacco and sugarcane.
Demand for cotton increased dramatically after the establishment of textile factories in England at the start of the Industrial Revolution in the late eighteenth century.
Cotton production was stimulated by the improvement of the cotton gin by Eli Whitney in 1793 and the development of new varieties of cotton that were harder and easier to pick.
Slaves brought from Africa performed most of the labor until the abolition of slavery and the defeat of the South in the Civil War.
Thereafter, plantations declined in the United States; they were subdivided and either sold to individual farmers or worked by tenant farmers.
KEY ISSUE 3 - Where Are Agricultural Regions in MDCs?
Commercial agriculture in MDCs can be divided into six main types.
Each type is predominant in distinctive regions within MDCs, depending largely on climate.
Mixed Crop and Livestock Farming
Mixed crop and livestock farming is the most common for commercial agriculture in the United States west of the Appalachians and east of 98° west longitude and in much of Europe from France to Russia.
Characteristics of Mixed Crop and Livestock Farming
The most distinctive characteristic of mixed crops and livestock farming is its integration of crops and livestock.
Most of the crops are fed to animals rather than consumed directly by humans. In turn, the livestock supply manure to improve soil fertility to grow more crops.
A typical mixed crop and livestock farm devotes nearly all la~d area to growing crops but derives more than three-fourths of its income from the sale of animal products, such as beef, milk, and eggs.
In the United States, pigs are often bred directly on the farms, whereas cattle may be brought in to be fattened on corn.
Mixing crops and livestock permits farmers to distribute the workload more evenly through the year.
Fields require less attention in the winter than in the spring, when crops are planted, and in the fall when they are harvested.
Meanwhile, livestock require year-long attention.
A mix of crops and livestock also reduces seasonal variations in income; most income from crops comes during the harvest season, but livestock products can be sold throughout the year.
In the United States, corn (maize) is the crop most frequently planted in the mixed crop and livestock region because it generates higher yields per area than other crops
Some of the corn is consumed by people as oil, margarine, and other food products, but most is fed to pigs and cattle.
The most important mixed crop and livestock farming region in the United States—extending from Ohio to the Dakotas, with its center in Iowa—is frequently called the Corn Belt, because around half of the cropland is planted in corn.
Soybeans have become the second most important crop in the U.S. mixed commercial farming region.
Like corn, soybeans are mostly used to make animal feed.
Tofu (made from soybean milk) is a major food source, especially for people in China and Japan.
Soybean oil is widely used in U.S. foods, but as a hidden ingredient.
Crop Rotation
Mixed crop and livestock farming typically involves crop rotation.
The farm is divided into a number of fields, and each field is planted on a planned cycle, often of several years.
The crop planted changes from one year to the next, typically going through a cycle of two or more crops, and perhaps a year off low before the cycle is repeated.
Crop rotation helps maintain the fertility of a field because various crops deplete the soil of certain nutrients but restore others.
Crop rotation contrasts with shifting cultivation, in which nutrients depleted from a field are restored only by leaving the field fallow (uncropped) for many years.
In any given year, crops cannot be planted in most of an area's fields, so overall production in shifting cultivation is much lower than in mixed commercial farming.
A two-field crop-rotation system was developed in Northern Europe as early as the fifth century.
A cereal grain, such as oats, wheat, rye, or barley, was planted in Field A one year, while Field B was left fallow.
The following year Field B was planted but A left fallow, and so forth.
Beginning in the eighth century a three-field system was introduced.
The first field was planted with a winter cereal, the second with a spring cereal, and the third was left fallow.
As a result, each field yielded four harvests every 6 years, compared to three every 6 years under the two-field system.
A four-field system was introduced in Europe during the eighteenth century.
The first year, the farmer could plant a root crop (such as turnips) in Field A, a cereal in Field B, a "rest" crop (such as clover, which helps restore the field) in Field C, and a cereal in Field D.
The second year, the farmer might select a cereal for Field A, a rest crop for Field B, a cereal for Field C, and a root for Field D.
The rotation would continue for two more years before the cycle would start again.
Each field thus passed through a cycle of four crops—root, cereal, rest crop, and another cereal.
Cereals such as wheat and barley were sold for flour and beer production, and straw (the stalks remaining after the heads of wheat are threshed) was retained for animal bedding.
Root crops such as turnips were fed to the animals during the winter.
Clover and other "rest" crops were used for cattle grazing and restoration of nitrogen to the soil.
Dairy Farming
Dairy farming is the most important commercial agriculture practiced on farms near the large urban areas of the Northeast United States, Southeast Canada, and Northwest Europe.
Dairying has also become an important type of farming in South and East Asia.
Traditionally, fresh milk was rarely consumed except directly on the farm or in nearby villages.
With the rapid growth of cities in MDCs during the nineteenth century, demand for the sale of milk to urban residents increased.
Rising incomes permitted urban residents to buy milk products, which were once considered luxuries.
Regional Distribution of Dairying
For most of the twentieth century, the world's milk production was clustered in a handful of MDCs.
However, the share of the world's dairy farming conducted in LDCs has risen dramatically, from 26 percent in 1980 to 51 percent in 2007.
ln the twenty-first century, India has become the world's largest milk producer, ahead of the United States, the traditional leader, and China and Pakistan have passed Russia as third and fourth-largest.
ln MDCs, dairying is the most important type of commercial agriculture in the first ring outside large cities because of transportation factors.
Dairy farms must be closer to their market than other types of farms because their products are highly perishable.
The ring surrounding a city from which milk can be supplied without spoiling is known as the milkshed.
Improvements in transportation have permitted dairying to be undertaken farther from the market.
Until the 1840s, when railroads were first used for transporting dairy products, milksheds rarely had a radius beyond 50 kilometers (30 miles).
Today, refrigerated railcars and trucks enable farmers to ship milk more than 500 kilometers (300 miles).
As a result, nearly every farm in the U.S. Northeast and Northwest Europe is within the milkshed of at least one urban area.
Dairy farmers, like other commercial farmers, usually do not sell their products directly to consumers.
Instead, they generally sell milk to wholesalers, who distribute it in turn to retailers.
Retailers then sell milk to consumers in shops or at home.
Farmers also sell milk to butter and cheese manufacturers.
The choice of product varies within the U.S. dairy region, depending on whether the farms are within the milkshed of a large urban area.
In general, the farther the farm is from large urban concentrations, the smaller is the percentage of output devoted to fresh milk.
Farms located farther from consumers are more likely to sell their output to processors who make butter, cheese, or dried, evaporated, and condensed milk.
The reason is that these products keep fresh longer than milk does and therefore can be safely shipped from remote farms.
In the East, virtually all milk is sold to consumers living in New York, Philadelphia, Boston, and the other large urban areas.
Farther west, most milk is processed into cheese and butter.
Most of the milk in Wisconsin is processed, for example, compared to only 5 percent in Pennsylvania.
The proximity of northeastern farmers to several large markets accounts for these regional differences.
Countries likewise tend to specialize in certain products.
New Zealand, the world's largest per capita producer of dairy products, devotes about 5 percent to liquid milk, compared to more than 50 percent in the United Kingdom.
New Zealand farmers do not sell much liquid milk, because the country is too far from North America and Northwest Europe, the two largest relatively wealthy population concentrations.
Challenges for Dairy Farmers
Like other commercial farmers, dairy farmers face economic difficulties because of declining revenues and rising costs.
Dairy farmers who have quit most often cite lack of profitability and excessive workload as reasons for getting out of the business.
Distinctive features of dairy farming have exacerbated the economic difficulties:
Labor-intensive. Cows must be milked twice a day, every day; although the actual milking can be done by machines, dairy farming nonetheless requires constant attention throughout the year.
Winter Feed. Dairy farmers face the expense of feeding the cows in the winter, when they may be unable to graze on grass. In Northwest Europe and in the Northeastern United States, farmers generally purchase hay or grain for winter feed. In the western part of the U.S. dairy region, crops are more likely to be grown in the summer and stored for winter feed on the same farm.
Grain Farming
Some form of grain is the major crop on most farms.
Grain is the seed from various grasses, like wheat, corn, oats, barley, rice, millet, and others.
Commercial grain agriculture is distinguished from mixed crop and livestock farming because crops on a grain farm are grown primarily for consumption by humans rather than by livestock.
Farms in LDCs also grow crops for human consumption, but the output is directly concerned by the farmers.
Commercial grain farms sell their output to manufacturers of food products, such as breakfast cereals and snack-food makers.
The most important crop grown is wheat, used to make bread flour.
Wheat generally can be sold for a higher price than other grains, such as rye, oats, and barley, and it has more uses as human food.
It can be stored relatively easily without spoiling and can be transported a long distance.
Because wheat has a relatively high value per unit weight, it can be shipped profitably from remote farms to markets.
Wheat's significance extends beyond the amount of land or number of people involved in growing it.
Unlike other agricultural products, wheat is grown to a considerable extent for international trade and is the world's leading export crop.
The United States and Canada account for about half of the world's wheat exports; consequently, the North American prairies are accurately labeled the world's "breadbasket."
The ability to provide food for many people elsewhere in the world is a major source of economic and political strength for these two countries.
The largest commercial producer of grain by far is the United States.
Large-scale commercial grain production is found in only a few other countries, including Canada, Argentina, Australia, France, and the United Kingdom.
Commercial grain farms are generally located in regions that are too dry for mixed crop and livestock agriculture.
Within North America, large-scale grain production is concentrated in three areas:
The winter-wheat belt through Kansas, Colorado, and Oklahoma. The· crop is planted in the autumn and develops a strong root system before growth stops for the winter. The wheat survives the winter, especially if it is insulated beneath a snow blanket, and is ripe by the beginning of summer.
The spring-wheat belt through the Dakotas, Montana, and southern Saskatchewan in Canada. Winters are usually too severe for winter wheat in this region, so spring wheat is planted in the spring and harvested in the late summer.
The Palouse region of Washington State.
Large-scale grain production, like other commercial farming ventures in MDCs, is heavily mechanized, conducted on large farms, and oriented to consumer preferences.
The McCormick reaper (a machine that cuts grain standing in the field), invented in the 1830s, first permitted large-scale wheat production.
Today the combine machine performs in one operation the three tasks of reaping, threshing, and cleaning.
Unlike work on a mixed crop and livestock farm, the effort required to grow wheat is not uniform throughout the year.
Some individuals or firms may therefore have two sets of fields—one in the spring-wheat belt and one in the winter-wheat belt.
Because the planting and harvesting in the two regions occur at different times of the year, the workload can be distributed throughout the year.
In addition, the same machinery can be used in the two regions, thus spreading the cost of the expensive equipment.
Combine companies start working in Oklahoma in early summer and work their way northward.
Livestock Ranching
Ranching is the commercial grazing of livestock over an extensive area.
This form of agriculture is adapted to semiarid or arid land and is practiced in MDCs where the vegetation is too sparse and the soil too poor to support crops.
The importance of ranching in the United States extends beyond the people who choose this form of commercial farming.
Its prominence in popular culture, especially in Hollywood films and television, has not only helped to draw attention to this form of commercial farming but has also served to illustrate albeit in sometimes romanticized ways, the crucial role that ranching played in the history and settlement of areas of the United States.
Cattle ranching in Texas, as glamorized in popular culture, did actually dominate commercial agriculture, but only for a short period—from 1867 to 1885.
Cattle ranching expanded in the United States during the 1860s because of the demand for beef in the East Coast cities.
If they could get their cattle to Chicago, ranchers were paid $30 to $40 per head, compared to only $3 or $4 per head in Texas.
Once in Chicago, the cattle could be slaughtered and processed by meat-packing companies and shipped in packages to conmusers in the East.
To reach Chicago, cattle were driven on hoof by cowboys over trails from Texas to the nearest railhead.
There the cattle were driven into cattle cars for the rest of their journey.
The western terminus of the rail line reached Abilene, Kansas, in 1867.
Wichita, Caldwell, Dodge City, and other towns in Kansas took their turns as the main destination for cattle driven north on trails from Texas.
The most famous route from Texas northward to the rail line was the Chisholm Trail, which began near Brownsville at the Mexican border and extended northward through Texas.
Cattle ranching declined in importance during the 1880s after it came into conflict with sedentary agriculture.
Most early U.S. ranchers adhered to "the Code of the West," although the system had no official legal status.
Under the code, ranchers had range rights—that is, their cattle could graze on any open land and had access to scarce water sources and grasslands.
The early cattle ranchers in the West owned little land, only cattle.
The U.S. government, which owned most of the land used for open grazing, began to sell it to farmers to grow crops, leaving cattle ranchers with no legal claim to it.
For a few years the ranchers tried to drive out the farmers by cutting fences and then illegally erecting their own fences on public land, and range wars" flared.
The farmers' most potent weapon proved to be barbed wire, first commercially produced in 1873.
The farmers eventually won the battle, and ranchers were compelled to buy or lease land to accommodate their cattle.
Large cattle ranches were established, primarily on land that was too dry to support crops.
Ironically, 60 percent of cattle grazing today takes place on land leased from the U.S. government.
With the spread of irrigation techniques and hardier crops, land in the United States has been converted from ranching to crop growing.
Ranching generates lower income per area of land, although it has lower operating costs.
Cattle are still raised on ranches but are frequently sent for fattening to farms or to local feedlots along major railroad and highway routes rather than directly to meat processors.
Commercial ranching is conducted in several other MDCs.
The interior of Australia was opened for grazing in the nineteenth century, although sheep are more common than cattle.
Ranching is rare in Europe, except in Spain and Portugal.
In South America, a large portion of the pampas of Argentina, southern Brazil, and Uruguay are devoted to grazing cattle and sheep.
The cattle industry grew rapidly in Argentina in part because the land devoted to ranching was relatively accessible to the ocean, making it possible for meat to be transported to overseas markets.
Ranching has followed similar stages around the world.
First was the herding of animals over open ranges, in a seminomadic style.
Then ranching was transformed into fixed fanning by dividing the open land into ranches.
When many of the farms converted to growing crops, ranching was confined to the drier lands.
To survive, the remaining ranches experimented with new methods of breeding and sources of water and feed.
Ranching has become part of the meat-processing industry rather than an economic activity carried out on isolated farms.
In this way, commercial ranching differs from pastoral nomadism, the form of animal herding practiced in less developed regions.
Mediterranean Agriculture
Mediterranean agriculture exists primarily on the lands that border the Mediterranean Sea in Southern Europe, North Africa, and western Asia.
Farmers in California, central Chile, the southwestern part of South Africa, and southwestern Australia practice Mediterranean agriculture as well.
These Mediterranean areas share a similar physical environment.
Every Mediterranean area borders a sea and most are on west coasts of continents (except for some lands surrounding the Mediterranean Sea).
Prevailing sea winds provide moisture and moderate the winter temperatures.
Summers are hot and dry, but sea breezes provide some relief.
The land is very hilly, and mountains frequently plunge directly to the sea, leaving very narrow strips of flat land along the coast.
Farmers derive a smaller percentage of income from animal products in the Mediterranean region than in the mixed crop and livestock region.
Livestock production is hindered during the summer by the lack of water and good grazing land.
Some farmers living along the Mediterranean Sea traditionally used transhumance to raise animals, although the practice is now less common.
Under transhumance, animals—primarily sheep and goats—are kept on the coastal plains in the winter and transferred to the hills in the summer.
Most crops in Mediterranean lands are grown for human consumption rather than for animal feed.
Horticulture which is the growing of fruits, vegetables, and flowers—and tree crops form the commercial base of Mediterranean farming.
A combination of local physical and cultural characteristics determines which crops are grown in each area.
The hilly landscape encourages farmers to plant a variety of crops within one fanning area.
In the lands bordering the Mediterranean Sea, the two most important cash crops are olives and grapes.
Two-thirds of the world's wine is produced in countries that border the Mediterranean, especially Italy, France, and Spain.
Mediterranean agricultural regions elsewhere in the world produce most of the remaining one-third.
The lands near the Mediterranean Sea are also responsible for a large percentage of the world's supply of olives, an important source of cooking oil.
Despite the importance of olives and grapes to commercial farms bordering the Mediterranean Sea, approximately half of the land is devoted to growing cereals, especially wheat for pasta and bread.
As in the U.S. winter-wheat belt, the seeds are sown in the fall and harvested in early summer.
After cultivation, cash crops are planted on some of the land, whereas the remainder is left fallow for a year or two to conserve moisture in the soil.
Cereals occupy a much lower percentage of the cultivated land in California than in other Mediterranean climates.
Instead, a large portion of California farmland is devoted to fruit and vegetable horticulture, which supplies much of the citrus fruits, tree nuts, and deciduous fruits consumed in the United States.
Horticulture is practiced in other Mediterranean climates, but not to the extent found in California.
The rapid growth of urban areas in California, especially Los Angeles, has converted high-quality agricultural land into housing developments.
Thus far, the loss of farmland has been offset by the expansion of agriculture into arid lands.
However, farming in dry lands requires massive irrigation to provide water.
In the future, agriculture may face stiffer competition for the Southwest's increasingly scarce water supply.
Commercial Gardening and Fruit Farming
Commercial gardening and fruit farming is the predominant type of agriculture in the U.S. Southeast.
The region has a long growing season and humid climate and is accessible to the large markets of New York, Philadelphia, Washington, and other eastern U.S. urban areas.
The type of agriculture practiced in this region is frequently called truck farming, from the Middle English word truck, meaning bartering or the exchange of commodities.
Truck farms grow many of the fruits and vegetables that consumers in more developed societies demand, such as apples, asparagus, cherries, lettuce, mushrooms, and tomatoes.
Some of these fruits and vegetables are sold fresh to consumers, but most are sold to large processors for canning or freezing.
Truck farms are highly efficient large-scale operations that take full advantage of machines at every stage of the growing process.
Truck farmers are willing to experiment with new varieties, seeds, fertilizers, and other inputs to maximize efficiency.
Labor costs are kept down by hiring migrant farm workers, some of whom are undocumented immigrants from Mexico who work for very low wages.
Farms tend to specialize in a few crops, and a handful of farms may dominate national output of some fruits and vegetables.
A form of truck farming called specialty farming has spread to New England.
Farmers are profitably growing crops that have limited but increasing demand among affluent consumers, such as asparagus, peppers, mushrooms, strawberries, and nursery plants.
Specialty farming represents a profitable alternative for New England farmers, at a time when dairy farming is declining because of relatively high operating costs and low milk prices.
KEY ISSUE 4 - Why Do Farmers Face Economic Difficulties?
Commercial and subsistence farmers face comparable challenges.
Both commercial and subsistence farmers have difficulty generating enough income to continue farming.
The underlying reasons, though, are different.
Commercial farmers can produce a surplus of food, whereas many subsistence farmers are barely able to produce enough food to survive.
Challenges for Commercial Farmers
Commercial farmers are in some ways victims of their own success.
Having figured out how to produce large quantities of food, they face low prices for their output.
Government subsidies help prop up farm income, but many believe that the future health of commercial farming rests with embracing more sustainable practices.
Importance of Access to Markets
Because the purpose of commercial farming is to sell produce off the farm, the distance from the farm to the market influences the farmer's choice of crop to plant.
Geographers use the von Thünen model to help explain the importance of proximity to market in the choice of crops on commercial farms.
Johann Heinrich von Thünen, an estate owner in northern Germany, first proposed the model in 1826 in a book titled The Isolated State.
According to the model, which was later modified by geographers, a commercial farmer initially considers which crops to cultivate and which animals to raise based on market location.
In choosing an enterprise, the farmer compares two costs—the cost of the land versus the cost of transporting products to market.
Von Thünen based his general model of the spatial arrangement of different crops on his experiences as owner of a large estate in northern Germany during the early nineteenth century.
He found that specific crops were grown in different rings around the cities in the area.
Market-oriented gardens and milk producers were located in the first ring out from the cities.
These products are expensive to deliver and must reach the market quickly because they are perishable.
The next ring out from the cities contained wood lots, where timber was cut for construction and fuel; closeness to market is important for this commodity because of its weight.
The next rings were used for various crops and for pasture; the specific commodity was rotated from one year to the next.
The outermost ring was devoted exclusively to animal grazing, which requires lots of space.
The model assumed that all land in a study area had similar site characteristics and was of uniform quality, although von Thünen recognized that the model could vary according to topography and other distinctive physical conditions.
For example, a river might modify the shape of the rings because transportation costs change when products are shipped by water routes rather than over roads.
The model also failed to consider that social customs and government policies influence the attractiveness of plants and animals for a commercial farmer.
Although von Thünen developed the model for a small region with a single market center, it is also applicable on a national or global scale.
Farmers in relatively remote locations who wish to sell their output in the major markets of Western Europe and North America, for example, are less likely to grow highly perishable and bulky products.
Overproduction in Commercial Farming
Commercial farmers suffer from low incomes because they are capable of producing much more food than is demanded by consumers in MDCs.
A surplus of food can be produced because of widespread adoption of efficient agricultural practices.
New seeds, fertilizers, pesticides, mechanical equipment, and management practices have enabled farmers to obtain greatly increased yields per area of land.
The experience of dairy farming in the United States demonstrates the growth in productivity.
The number of milk cows in the United States decreased from 10.8 million to 9.3 million between 1980 and 2008.
But milk production increased from 128 billion to 190 billion pounds—yield per cow thus nearly doubled in the period.
Although the food supply has increased in MDCs, demand has remained constant, because the market for most products is already saturated.
In MDCs, consumption of a particular commodity may not change significantly if the price changes.
Americans, for example, do not switch from Wheaties to Corn Flakes if the price of com falls more rapidly than wheat.
Demand is also stagnant for most agricultural products in MDCs because of low population growth.
The U.S. government has three policies that are supposed to address the problem of excess productive capacity:
Farmers are encouraged to avoid producing crops that are in excess supply. Because soil erosion is a constant threat, the government encourages planting fallow crops, such as clover, to restore nutrients to the soil and to help hold the soil in place. These crops can be used for hay, forage for pigs, or to produce seeds for sale.
The government pays farmers when certain commodity prices are low. The government sets a target price for the commodity and pays farmers the difference between the price they receive in the market and a target price set by the government as a fair level for the commodity. The target prices are calculated to give farmers the same price for the commodity today as in the past, when compared to other consumer goods and services.
The government buys surplus production and sells or donates it to foreign governments. In addition, low-income Americans receive food stamps in part to stimulate their purchase of additional food.
The United States has averaged about $16 billion a year on [arm subsidies in recent years.
Annual spending varies considerably from one year to the next: Subsidy payments are lower in years when market prices rise and production is down, typically as a result of poor weather conditions in the United States or political problems in other countries.
Farming in Europe is subsidized even more than in the United States.
More farmers receive subsidies in Europe, and they receive more than American farmers.
The high subsidies are a legacy of a long-standing commitment by the European Union to maintain agriculture in its member states, especially in France.
Supporters point to the preservation of rural village life in parts of Europe, while critics charge that Europeans pay needlessly high prices for food as a result of the subsidies.
Government policies in MDCs point out a fundamental irony in worldwide agricultural patterns.
In an MDC such as the United States, farmers are encouraged to grow less food, whereas LDCs struggle to increase food production to match the rate of growth in the population.
Sustainable Agriculture
Some commercial farmers are converting their operations to sustainable agriculture, an agricultural practice that preserves and enhances environmental quality.
Farmers practicing sustainable agriculture typically generate lower revenues than do conventional farmers, but they also have lower costs.
An increasingly popular form of sustainable agriculture is organic farming.
However, some organic farms, especially the larger ones, may rely in part on nonsustainable practices, such as use of fossil fuels to operate tractors.
Worldwide, 32.2 million hectares (79 million acres), or 0.24 percent of farmland. was classified as organic in 2007.
Australia was the leader with 2 million of the hectares, or 37 percent of the worldwide total.
Argentina, Brazil, the United States, China, Italy, India, Spain, Uruguay, and Germany together accounted for 40 percent of the worldwide total.
Three principal practices distinguish sustainable agriculture (and at its best, organic farming) from conventional agriculture:
Sensitive land management
Limited use of chemicals
Better integration of crops and livestock
SENSITIVE LAND MANAGEMENT.
Sustainable agriculture protects soil in part through ridge tillage, which is a system of planting crops on ridge tops.
Crops are planted on 10-to 20-centimeter (4- to 8-inch) ridges that are formed during cultivation or after harvest.
The crop is planted on the same ridges, in the same rows, year after year.
Ridge tillage is attractive for two main reasons—lower production costs and greater soil conservation.
Production costs are lower with ridge tillage in part because it requires less investment in tractors and other machinery than conventional planting.
An area that would be prepared for planting under conventional farming with three to five tractors can be prepared for ridge tillage with only one or two tractors.
The primary tillage tool is a row-crop cultivator that can form ridges.
There is no need for a plow, or field cultivator, or a 300-horsepower four-wheel-drive tractor.
With ridge tillage, the space between rows needs to match the distance between wheels of the machinery.
If 75 centimeters (30 inches) are left between rows, tractor tires will typically be on 150-centimeter (60-inch) centers and combine wheels on 300-centimeter (120-inch) centers.
Wheel spacers are available from most manufacturers to fit the required spacing.
Ridge tillage features a minimum of soil disturbance from harvest to the next planting.
A compaction-free zone is created under each ridge and in some row middles.
Keeping the trafficked area separate from the crop-growing area improves soil properties.
Over several years the soil will tend to have increased organic matter, greater water-holding capacity, and more earthworms.
The channels left by earthworms and decaying roots enhance drainage.
Ridge tillage compares favorably with conventional farming for yields while lowering the cost of production.
Although more labor-intensive than other systems, it is profitable on a per-acre basis.
In Iowa, for example, ridge tillage has gained favor for production of organic and herbicide-free soybeans, which sell for more than regular soybeans.
LIMITED USE OF CHEMICALS.
In conventional agriculture, seeds are often genetically modified to survive when herbicides and insecticides are sprayed on the fields to kill weeds and insects.
These are known as "RoundupReady" seeds because its creator Monsanto Corp. sells its weedkillers under the brand name "Roundup."
"Roundup-Ready" seeds were planted in 80 percent of all soybean acreage, 54 percent of all cotton acreage, and 12 percent of all com acreage in the United States in 2003.
Aside from adverse impacts on soil and water quality, widespread use of "Roundup-Ready" seeds is causing some weeds to become resistant to the herbicide.
Sustainable agriculture, on the other hand, involves application of limited if any herbicides to control weeds.
In principle, farmers can control weeds without chemicals, although it requires additional time and expense that few farmers can afford.
Researchers have found that combining mechanical weed control with some chemicals yields higher returns per acre than relying solely on one of the two methods.
Ridge tilling also promotes decreased use of chemicals, which can be applied only to the ridges and not the entire field.
Combining herbicide banding—which applies chemicals in narrow bands over crop rows—with cultivating may be the best option for many farmers.
INTEGRATED CROP AND LIVESTOCK.
Sustainable agriculture attempts to integrate the growing of crops and the raising of livestock as much as possible at the level of the individual farm.
Animals consume crops grown on the farm and are not confined to small pens.
In conventional farming, integration between crops and livestock generally takes place through intermediaries rather than inside an individual farm.
Mixed crop and livestock is a common form of farming in many LDCs and in the Corn Belt of the United States.
But many farmers in the mixed crop and livestock region actually choose to only grow crops or raise more animals than the crops they grow can feed.
They sell their crops off the farm or purchase feed for their animals from outside suppliers.
Integration of crops and livestock reflects a return to the historical practice of mixed crop and livestock farming, in which growing crops and raising animals were regarded as complementary activities on the farm.
This was the common practice for centuries until the mid-1900s when technology, government policy, and economics encouraged farmers to become more specialized.
Sustainable agriculture is sensitive to the complexities of biological and economic interdependencies between crops and livestock:
Number of livestock. The correct number, as well as the distribution, of livestock for an area is determined based on the landscape and forage sources. Prolonged concentration of livestock in a specific location can result in permanent loss of vegetative cover, so the farmer needs to move the animals to reduce overuse in some areas. Growing row crops on the more level land while confining pastures to steeper slopes will reduce soil erosion, so it may be necessary to tolerate some loss of vegetation in specific locations. The farmer may need to balance the need to secure livestock inside fences with the convenience of tilling large unfenced fields through the use of temporary fencing.
Animal confinement. The moral and ethical debate over animal welfare is particularly intense regarding confined livestock production systems. Confined livestock are a source of surface and ground water pollutants, particularly where the density of animals is high. Expensive waste management facilities are a necessary cost of confined production systems. If animals are not confined, manure can contribute to soil fertility. However, quality of life in nearby communities may be adversely affected by the smell.
Management of extreme weather conditions. Herd size may need to be reduced during periods of short- and long-term droughts. On the other hand, livestock can buffer the negative impacts of low rainfall periods by consuming crops that in conventional farming would be left as failures. Especially in Mediterranean climates such as California's, properly managed grazing significantly reduces fire hazards by reducing fuel buildup in grasslands and brushlands.
Flexible feeding and marketing. This can help cushion farmers against trade and price fluctuations. and, in conjunction with cropping operations, make more efficient us~ of farm labor. Feed costs are the largest single variable cost in any livestock operation. Most of the feed may come from other enterprises on the ranch, though some is usually purchased off the farm. Feed costs can be kept to a minimum by monitoring animal condition and performance and understanding seasonal variations in feed and forage quality on the farm.
Challenges for Subsistence Farmers
Two issues discussed in earlier chapters influence the choice of crops planted by subsistence farmers:
Subsistence farmers must feed an increasing number of people because of rapid population growth in LDCs.
Subsistence farmers must grow food for export instead of for direct consumption due to the adoption of the international trade approach to development.
Subsistence Farming and Population Growth
Population growth influences the distribution of types of subsistence farming, according to economist Ester Boserup.
It compels subsistence farmers to consider new farming approaches that produce enough food to take care of the additional people.
For hundreds if not thousands of years, subsistence farming in LDCs yielded enough food for people living in rural villages to survive, assuming no drought, flood, or other natural disaster occurred.
Suddenly in the late twentieth century, the LDCs needed to provide enough food for a rapidly increasing population as well as for the growing number of urban residents who cannot grow their own food.
According to Boserup, subsistence farmers increase the supply of food through intensification of production, achieved in two ways:
Adoption of new farming methods. Plows replace axes and sticks. More weeding is done, more manure applied, more terraces carved out of hillsides, and more irrigation ditches dug. The additional labor needed to perform these operations comes from the population growth. The farmland yields more food per area of land, but with the growing population, output per person remains about the same.
Land is left fallow for shorter periods. This expands the amount of land area devoted to growing crops at any given time. Boserup identified five basic stages in the intensification of farmland:
Forest Fallow. Fields are cleared and utilized for up to 2 years and left fallow for more than 20 years, long enough for the forest to grow back.
Bush Fallow. Fields are cleared and utilized for up to _8 years and left fallow for up to 10 years, long enough for small trees and bushes to grow back.
Short Fallow. Fields are cleared and utilized for perhaps 2 years (Boserup was uncertain) and left fallow for up to 2 years, long enough for wild grasses to grow back.
Annual Cropping. Fields are used every year and rotated for a few months with planting legumes and roots.
Multi cropping. Fields are used several times a year and never left fallow.
Contrast shifting cultivation, practiced in regions of low population density, such as central Africa, with intensive subsistence agriculture, practiced in regions of high population density, such as East Asia.
Under shifting cultivation, cleared fields are utilized for a couple of years, then left fallow for 20 years or more.
This type of agriculture supports a small population living at low density.
As the number of people living in an area increases (that is, the population density increases) and more food must be grown, fields will be left fallow for shorter periods of time.
Eventually, farmers achieve the very intensive use of farmland characteristic of areas of high population density.
Subsistence Farming and International Trade
To expand production, subsistence farmers need higher-yield seeds, fertilizer, pesticides, and machinery.
Some needed supplies can be secured by trading food with urban dwellers.
For many African and Asian countries, though, the main way to obtain agricultural supplies is to import them from other countries.
However, they lack the money to buy agricultural equipment and materials from MDCs.
To generate the funds they need to buy agricultural supplies, LDCs must produce something they can sell in MDCs.
The LDCs sell some manufactured goods, but most raise funds through the sale of crops in MDCs.
Consumers in MDCs are willing to pay high prices for fruits and vegetables that would otherwise be out of season or for crops such as coffee and tea that cannot be grown in MDCs because of the climate.
In an LDC such as Kenya, families may divide by gender between traditional subsistence agriculture and contributing to international trade.
Women practice most of the subsistence agriculture—that is, growing food for their families to consume—in addition to the tasks of cooking, cleaning, and carrying water from wells
Men may work for wages, either growing crops for export or at jobs in distant cities.
Because men in Kenya frequently do not share the wages with their families, many women try to generate income for the household by making clothes, jewelry, baked goods, and other objects for sale in local markets.
The sale of export crops brings an LDC foreign currency, a portion of which can be used to buy agricultural supplies.
But governments in LDCs face a dilemma: The more land that is devoted to growing export crops, the less that is available to grow crops for domestic consumption.
Rather than helping to increase productivity, the funds generated through the sale of export crops may be needed to feed the people who switched from subsistence farming to growing export crops.
Drug Crops
The export crops chosen in some LDCs, especially in Latin America and Asia, are those that can be converted to drugs.
Marijuana, the most popular drug, is estimated to be used by 140 million worldwide.
Cocaine and heroin, the two leading, especially dangerous drugs, are abused by 15 million and 14 million people, respectively, worldwide.
The United Nations estimated that in 1998 the incomes of 4 million people, primarily in Asia and Latin America, were dependent on cultivation of the opium poppy or coca leaf.
Heroin is derived from raw opium gum, which is produced by the opium poppy plant.
Afghanistan is the source of around 80 percent of the world’s opium; most of the remainder is grown in Myanmar (Burma).
Most consumers are located in Central Asia.
One-half of the world's coca leaf is grown in Columbia, and most of the remainder in neighboring Peru and Bolivia.
Most of the processing of cocaine, as well as its distribution to the United States and other MDCs, is based in Colombia.
Marijuana, produced from the Cannabis sativa plant, is cultivated widely around the world.
The overwhelming majority of the marijuana that reaches the United States is grown in Mexico.
Cultivation of C. sativa is not thought to be expanding worldwide, whereas opium poppies and coca leaf are.
Strategies to Increase the Food Supply
Four strategies are being employed to increase the world's food supply:
Expanding the land area used for agriculture
Increasing the productivity of land now used for agriculture
Identifying new food sources
Increasing exports from other countries
Challenges underlie each of these strategies.
Expanding Agricultural Land
Historically, world food production has increased primarily by expanding the amount of land devoted to agriculture.
When the world's population began to increase more rapidly in the late eighteenth and early nineteenth centuries, during the Industrial Revolution, pioneers could migrate to uninhabited territory and cultivate the land.
Sparsely inhabited land suitable for agriculture was available in western North America, central Russia, and Argentina's pampas.
Two centuries ago people believed that good agricultural land would always be available for willing pioneers.
Today few scientists believe that further expansion of agricultural land can feed the growing world population.
At first glance, new agricultural land appears to be available because only 11 percent of the world's land area is currently cultivated.
In fact, cultivated land has been expanding in Africa at a rate of 1 percent per year.
But population in Africa is increasing more than 2 percent per year.
Worldwide, despite the recent decline in the natural increase, agricultural land is expanding more slowly than population.
In some regions, farmland is abandoned for lack of water.
Especially in semiarid regions, human actions are causing land to deteriorate to a desert-like condition, a process called desertification (more precisely, semiarid land degradation).
Semiarid lands that can support only a handful of pastoral nomads are overused because of rapid population growth.
Excessive crop planting, animal grazing, and tree cutting exhaust the soil's nutrients and preclude agriculture.
The Earth Policy Institute estimates that 2 billion hectares (5 million acres) of land have been degraded around the world.
Overgrazing is thought to be responsible for 34 percent of the total, deforestation for 30 percent, and agricultural use for 28 percent.
The United Nations estimates that desertification removes 27 million hectares (70 million acres) of land from agricultural production each year, an area roughly equivalent to Colorado.
Excessive water threatens other agricultural areas, especially drier lands that receive water from human-built irrigation systems.
If the irrigated land has inadequate drainage; the underground water level rises to the point where roots become waterlogged.
The United Nations estimates that 10 percent of all irrigated land is waterlogged, mostly in Asia and South America.
If the water is salty, it can damage plants.
The ancient civilization of Mesopotamia may have collapsed in part because of waterlogging and excessive salinity in its agricultural lands near the Tigris and Euphrates rivers.
Urbanization can also contribute to reducing agricultural land.
As urban areas grow in population and land area, farms on the periphery are replaced by homes, roads, shops, and other urban land uses.
In North America, farms outside urban areas are left idle until the speculators who own them can sell them at a profit to builders and developers, who convert the land to urban uses.
Increasing Productivity
Population grew at the fastest rate in human history during the second half of the twentieth century.
Many experts forecast massive global famine, but these dire predictions did not come true.
New agricultural practices have permitted farmers worldwide to achieve much greater yields from the same amount of land.
The invention and rapid diffusion of more productive agricultural techniques during the 1970s and 1980s is called the green revolution.
The green revolution involves two main practices—the introduction of new higher—yield seeds and the expanded use of fertilizers.
Because of the green revolution, agricultural productivity at a global scale has increased faster than population growth.
Scientists began an intensive series of experiments during the 1950s to develop a higher-yield form of wheat.
A decade later, the "miracle wheat seed" was ready.
Shorter and stiffer than traditional breeds, the new wheat was less sensitive to variation in day length, responded better to fertilizers, and matured faster.
The Rockefeller and Ford foundations sponsored many of the studies, and the program's director, Dr. Norman Borlaug, won the Nobel Peace Prize in 1970.
The International Rice Research Institute, established in the Philippines by the Rockefeller and Ford foundations, worked to create a miracle rice seed.
During the 1960s, their scientists introduced a hybrid of Indonesian rice and Taiwan dwarf rice that was hardier and that increased yields.
More recently, scientists have developed new high-yield maize (corn).
The new miracle seeds were diffused rapidly around the world.
India's wheat production, for example, more than doubled in 5 years.
After importing 10 million tons of wheat annually in the mid-1960s, India by 1971 had a surplus of several million tons.
Other Asian and Latin American countries recorded similar productivity increases.
The green revolution was largely responsible for preventing a food crisis in these regions during the 1970s and 1980s.
To take full advantage of the new miracle seeds, farmers must use more fertilizer and machinery.
Farmers have known for thousands of years that application of manure, bones, and ashes somehow increases, or at least maintains, the fertility of the land.
Not until the nineteenth century did scientists identify nitrogen, phosphorus, and potassium (potash) as the critical elements in these substances that improved fertility.
Today these three elements form the basis for fertilizers—products that farmers apply to their fields to enrich the soil by restoring lost nutrients.
Nitrogen, the most important fertilizer, is a ubiquitous substance.
China is the leading producer of nitrogen fertilizer.
Europeans most commonly produce a fertilizer known as urea, which contains 46 percent nitrogen.
In North America, nitrogen is available as ammonia gas, which is 82 percent nitrogen but more awkward than urea to transport and store.
Both urea and ammonia gas combine nitrogen and hydrogen.
The problem is that the cheapest way to produce both types of nitrogen-based fertilizers is to obtain hydrogen from natural gas or petroleum.
As fossil-fuel prices increase, so do the prices for nitrogen-based fertilizers, which then become too expensive for many farmers in LDCs.
In contrast to nitrogen, phosphorus, and potash reserves are not distributed uniformly across Earth's surface.
Phosphate rock reserves are clustered in China, Morocco, and the United States.
Proven potash reserves are concentrated in Canada, Russia, and Ukraine.
Farmers need tractors, irrigation pumps, and other machinery to make the most effective use of the new miracle seeds.
In LDCs, farmers cannot afford such equipment and cannot, in view of high energy costs, buy fuel to operate the equipment.
To maintain the green revolution, governments in LDCs must allocate scarce funds to subsidize the cost of seeds, fertilizers, and machinery.
Identifying New Food Sources
A third alternative for increasing the world's food supply is to develop new food sources.
Three strategies being considered are to cultivate the oceans, to develop higher-protein cereals, and to improve palatability of rarely consumed foods.
CULTIVATING OCEANS.
At first glance, increased use of food from the sea is attractive.
Oceans are vast, covering nearly three-fourths of Earth's surface and lying near most population concentrations.
Historically the sea has provided only a small percentage of the world food supply.
About two thirds of the fish caught from the ocean is consumed directly, whereas the remainder is converted to fish meal and fed to poultry and hogs.
Hope grew during the mid-twentieth century that increased fish consumption could meet the needs of a rapidly growing global population.
Indeed, the world's annual fish catch increased from around 30 million tons in 1950 to 100 million tons in 1990.
However, the population of some fish species declined because they were harvested faster than they could reproduce.
Overfishing has been particularly acute in the North Atlantic and Pacific oceans.
Because of overfishing, the population of large predatory fish, such as tuna and swordfish, declined by 90 percent in the past half-century.
The United Nations estimates that one-quarter of fish stocks have been overfished and one-half fully exploited, leaving only one-fourth underfished.
Consequently, the total world fish catch has remained relatively constant since the 1980s despite population growth.
To protect fishing areas, many countries have claimed control of the oceans within 200 nautical miles of the coast.
These countries have the right to seize foreign fishing vessels that venture into the so-called exclusive economic zone.
DEVELOPING HIGHER-PROTEIN CEREALS.
A second possible new food source is higher-protein cereal grains.
People in MDCs obtain protein by consuming meat, but people in LDCs generally rely on wheat, com, and rice, which lack certain proteins.
Scientists are experimenting with hybrids of the world's major cereals that have higher protein content.
People can also obtain needed nutrition by consuming foods that are fortified during processing with vitamins, minerals, and protein-carrying amino acids.
This approach achieves better nutrition without changing food consumption habits.
However, fortification has limited application in LDCs, where most people grow their own food rather than buy processed food.
IMPROVING PALATABILITY OF RARELY CONSUMED FOODS.
To fulfill basic nutritional needs, people consume types of food adapted to their community's climate, soil, and other physical characteristics.
People also select foods on the basis of religious values, taboos, and other social customs that are unrelated to nutritional or environmental factors.
A third way to make more effective use of existing global resources is to encourage consumption of foods that are avoided for social reasons.
A prominent example of an underused food resource in North America is the soybean.
Although the soybean is one of the region's leading crops, most of the output is processed into animal feed, in part because many North Americans avoid consuming tofu, sprouts, and other recognizable soybean products.
However, burgers, franks, oils, and other products that are made from soybeans but do not look like soybeans are more widely accepted in North America.
New food products have been created in LDCs as well.
In Asia, for example, high-protein beverages made from seeds resemble popular soft drinks.
Krill (a term for a group of small crustaceans) could be an important source of food from the oceans.
The krill population has increased rapidly in recent years because overhunting has reduced the number of whales that eat krill.
The Soviet Union was a major harvester of krill, used primarily to feed chickens and livestock.
Since the breakup of the Soviet Union in the early 1990s, the world krill harvest has declined substantially.
Because krill deteriorates rapidly new processing methods could substantially increase the harvest for human food; unfortunately, krill does not taste very good.
Increasing Trade
A fourth alternative for increasing the world's food supply is to export more food from countries that produce surpluses.
The three top export grains are wheat, maize (corn), and rice.
Few countries are major exporters of food, but increased production in these countries could cover the gap elsewhere.
Before World War II, Western Europe was the only major grain-importing region.
Prior to their independence, colonies of Western European countries supplied food to their parent states.
Asia became a net grain importer in the 1950s, Africa and Eastern Europe in the 1960s, and Latin America in the 1970s.
Population increases in these regions largely accounted for the need to import grain.
By 1980 North America was the only major exporting region in the world.
In response to the increasing global demand for food imports, the United States passed Public Law 480, the Agricultural, Trade, and Assistance Act of 1954 (frequently referred to as "P.L-480").
Title I of the act provided for the sale of grain at low-interest rates, and Title II gave grants to needy groups of people.
The United States remains the world's leading exporter of grain by a wide margin, accounting for one-third of the total exports of the three leading grains, including more than one-half of all maize exports and more than one-fourth of all wheat exports.
Elsewhere in the world the picture has changed in the twenty-first century.
From net importers of grain, South Asia and Southeast Asia have now become net exporters.
Thailand has replaced the United States as the leading exporter of rice accounting for one-third of the world total, followed by India in second place with one-sixth.
Vietnam and Pakistan ranked fourth and fifth, respectively, in rice exports in 2004, behind the United States in third place.
Japan is by far the world's leading grain importing country, followed by China.
Japan is the leading importer of maize and China of wheat, and both rank among leading rice importers.
On a regional scale, Southwest Africa (with Northern Africa) has become the leading net importer of all three major grains, and Saudi Arabia was the world's leading importer of rice in 2007.
Sub-Saharan Africa also ranks among the leaders in net imports of all three grains.