African Agriculture

Rice field in Africa

Soil and climatic conditions throughout Africa determine not only agricultural practices, such as which crops can be grown, but also whether plant life is capable of sustaining livestock on the land and enabling fishing of the oceans.

Rainfall—the dominant influence on agricultural output—varies greatly among Africa’s fifty-six countries. Without irrigation, agriculture requires a reliable annual rainfall of more than 30 inches (75 centimeters). Portions of Africa have serious problems from lack of rainfall, such as increasing desertification and periods of drought.

Food output has declined, with per capita food production 10 percent less in the 1990’s than it was in the 1980’s. In most African countries, however, more than 50 percent, and often 80 percent, of the population works in agriculture, mostly subsistence agriculture. Large portions of the continent, such as Mali and the Sudan, have the potential of becoming granaries to much of the continent and producing considerable food exports.

Experimental Crops

Experimental Crops

Experimental crops are foodstuffs with the potential to be grown in a sustainable manner, produce large yields, and reduce people’s reliance on the traditional crops wheat, rice, and corn.

Shifting from a hunter-gatherer society to an agrarian society led to increasingly larger-scale agricultural production that involved selecting local crops for domestication. In recent history there has been a reduction in the number of agricultural crops grown for human consumption.

There are estimated to be at least 20,000 species of edible plants on earth, out of more than 350,000 known species of higher plants. However, only a handful of crops feed most of the world’s people.

Agricultural Revolution

Agricultural Revolution

The agricultural revolution marked the transition by humans from hunting and gathering all their food to domesticating plants for food.

People first obtained their food by scavenging kills made by other animals, by hunting animals, and by gathering wild food plants. Between ten thousand and twelve thousand years ago, people began to use plants in new ways. Some scientists and historians call this period of time the "agricultural revolution".

Agricultural Beginnings

Before the 1960’s,many scientists and historians believed that hunter-gatherers abruptly switched from foraging to farming. Those who thought that agriculture arose quickly coined the term "agricultural revolution".

Marine Agriculture

Marine Agriculture

Marine agriculture uses techniques of artificial cultivation, such as growing, managing, and harvesting, and applies them to marine plants and animals. The products are then used for human consumption.

Marine agriculture is also known as mariculture or aquaculture, although aquaculture is a more general term referring to both freshwater and marine farming of organisms. The world’s oceans cover approximately three-fourths of the globe, including vast regions of unexplored life and landforms.

The potential for exploiting the oceans agriculturally is great but currently meets significant obstacles. Because of the expense of equipment and personnel involved, most marine species are not cultivated.

Modern Agriculture Problems

Modern Agriculture

Many current problems in agriculture are not new. Erosion and pollution, for example, have been around as long as agriculture. However, agriculture has changed drastically within its ten-thousand-year history, especially since the dawn of the Industrial Revolution in the seventeenth century.

Erosion and pollution are now bigger problems than before and have been joined by a host of other issues that are equally critical—not all related to physical deterioration.

Monoculture

Modern agriculture emphasizes crop specialization, also known as monoculture. Farmers, especially in industrialized regions, often grow a single crop on much of their land. Problems associated with this practice are exacerbated when a single variety or cultivar of a species is grown. Such a strategy allows the farmer to reduce costs, but it also makes the crop, and thus the farmand community, susceptible to widespread crop failure.

Traditional Agriculture

Traditional Agriculture

Two agricultural practices that are widespread among the world’s traditional cultures, slash-and-burn agriculture and nomadism, share several features. Both are ancient forms of agriculture, both involve farmers not remaining in a fixed location, and both can pose serious environmental threats if practiced in a nonsustainable fashion.

The most significant difference between the two is that slash-and-burn is associated with raising field crops, while nomadism usually involves herding livestock.

Slash-and-Burn Agriculture

Farmers have practiced slash-and-burn agriculture, which is also referred to as shifting cultivation or swidden agriculture, in almost every region of the world where farming is possible.

Although at the end of the twentieth century slash-and-burn agriculture was most commonly found in tropical areas such as the Amazon River basin in South America, swidden agriculture once dominated agriculture in more temperate regions, such as northern Europe. Swidden agriculture was, in fact, common in Finland and northern Russia well into the early decades of the twentieth century.

Agriculture: World Food Supplies

World Food Supplies

Soil types, topography, climate, socioeconomics, dietary preferences, stages in agricultural development, and governmental policies combine to give a distinctive personality to regional agricultural characteristics and, hence, food supplies in various areas of the world.

All living things need food to live, grow, work, and survive. Almost all foods that humans consume come from plants and animals. Not all of earth’s people eat the same foods, however. The types, combinations, and amounts of food consumed by different peoples depend upon historic, socioeconomic, and environmental factors.

History of Food Consumption

Early in human history, people ate what they could gather or scavenge. Later, people ate what they could plant and harvest and the products of animals they could domesticate. Modern people eat what they can grow, raise, or purchase.

Agronomy

Agronomy

Agronomy is a group of applied science disciplines concerned with land and soil management and crop production. Agronomists’ areas of interest range from soil chemistry to soil-plant relationships to land reclamation.

The word "agronomy" derives from the ancient Greek agros (field) and nemein (manage) and therefore literally means "field management". The American Society of Agronomy defines agronomy as "the theory and practice of crop production and soil management". There are many specialties within the study of agronomy.

Agronomic Specialties

Agronomy is the family of disciplines investigating the production of crops supplying food, forage, and fiber for human and animal use. It studies the stewardship of the soil upon which those crops are grown. Agronomy covers all aspects of the agricultural environment, from agroclimatology to soil-plant relationships.

Alternative Grains

Alternative Grains

Alternative grains refers to alternatives to high-yield grain crops, the harvest of which has led to severe soil erosion and increased use of fertilizers and pesticides.

More than one-half of the calories consumed daily by humans comes from grains. Most of these grains are produced by plants of the grass family, Poaceae. Major cereal plants domesticated centuries ago include rice (Oryza sativa), wheat (Triticum aestivum), and corn (Zea mays). Other important grain crops, also plants of the grass family, include barley (originating in Asia), millet and sorghum (originating in Africa), and oats and rye (originating in Europe).

Grain Genetics

Since the early twentieth century, the scientific principles of genetics have been applied to improvements of crop plants. Some notable improvements occurred between 1940 and 1970. As a result of irrigation, improved genetic varieties, and the use of large amounts of fertilizers and pesticides, yields of major crops greatly increased.

Asian Agriculture

Asian agriculture

Land constraints and growing population and urbanization throughout Asia underscore the need for environmentally sound technologies to sustain agricultural growth.

The first agricultural revolution occurred in Asia and involved the domestication of plants and animals. It is believed that vegeculture first developed in Southeast Asia more than eleven thousand years ago. In vegeculture, a part of a plant—other than the seed—is planted for reproduction.

The first plants domesticated in Southeast Asia were taro, yam, banana, and palm. Seed agriculture, now the most common type of agriculture, uses seeds for plant reproduction. It originated in the Middle East about nine thousand years ago, in the basins of the two major rivers of present-day Iraq, the Tigris and the Euphrates.

Australian Agriculture

Australian Agriculture

Agriculture is an important part of Australia’s economy. Australia’s exports were overwhelmingly agricultural products until the 1960’s, when mining and manufacturing grew in importance.

Agriculture occupies 60 percent of the land area of Australia, but much of this is used for open-range cattle grazing, especially in huge areas of the states of Queensland and Western Australia. Only 5 percent of Australia’s agricultural land is used for growing crops.

Western Australia and New South Wales have the largest areas of cropland. The limited area suitable for growing commercial crops is limited mainly by climate, because Australia is the world’s driest continent.

Annual rainfall of about 20 inches (500 millimeters) is necessary to grow crops successfully without irrigation; less than half of Australia receives this amount, and the rainfall is often variable or unreliable.

Biofertilizers

Biofertilizers

The use of biofertilizers, biological systems that supply plant nutrients such as nitrogen to agricultural crops, could reduce agriculture’s dependency on chemical fertilizers, which are often detrimental to the environment.

Plants require an adequate supply of the thirteen mineral nutrients necessary for normal growth and reproduction. These nutrients, which must be supplied by the soil, include both macronutrients (nutrients required in large quantities) and micronutrients (nutrients required in smaller quantities). As plants grow and develop, they remove these essential mineral nutrients from the soil.

Because normal crop production usually requires the removal of plants or plant parts, the nutrients are continuously removed from the soil. Therefore, the long-term agricultural utilization of any soil requires periodic fertilization to replace lost nutrients.

Nitrogen is the plant nutrient that is most often depleted in agricultural soils, and most crops respond to the addition of nitrogen fertilizer by increasing their growth and yield. Therefore, more nitrogen is applied to cropland than any other fertilizer component.

Biopesticides

Biopesticides

Biopesticides are biological agents, such as viruses, bacteria, fungi, mites, and other organisms used to control insect and weed pests in an environmentally and ecologically friendly manner.

Biopesticides allow biologically based, rather than chemically based, control of pests. A pest is any unwanted animal, plant, or microorganism. When the environment provides no natural resistance to a pest and when no natural antagonists are present, pests can run rampant.

For example, spread of the fungus Endothia parasitica, which entered New York in 1904, caused the nearly complete destruction of the American chestnut tree because no natural control was present. Viruses, bacteria, fungi, protozoa, mites, insects, and flowers have all been used as biopesticides.

Advantages of Biopesticides

Many plants and animals are protected from pests by passive means. For example, plant rotation is a traditional method of insect and disease protection that is achieved by removing the host plant long enough to reduce a region’s pathogen and pest populations.

Biotechnology

Biotechnology

Biotechnology is the use of living organisms, or substances obtained from those organisms, to produce processes or products of value to humanity, such as foods, high-yield crops, and medicines.

Modern biotechnological advances have provided the ability to tap into a natural resource, the world gene pool, with such great potential that its full magnitude is only beginning to be appreciated.

Theoretically, it should be possible to transfer one or more genes from any organism in the world into any other organism. Because genes ultimately control how any organism functions, gene transfer can have a dramatic impact on agricultural resources and human health in the future.

Caribbean Agriculture

Caribbean Agriculture

Agriculture in the Caribbean islands, from the Bahamas to Trinidad, is concentrated in sugarcane, bananas, coffee, tobacco, and some citrus and cacao.

The Caribbean Sea is an extension of the western Atlantic Ocean that is bounded by Central and South America to the west and south and the islands of the Antilles chain on the north and east. At the end of the twentieth century, agriculture was basic to the economies of nearly every island.

Two fundamentally different types of agriculture dominate: large-scale commercial, or plantation, agriculture and small-scale semisubsistence, or peasant, farming. Plantation farming provides the most exports, by value, whereas peasant farming involves far more human labor.

Caribbean agriculture operates under various natural and cultural restraints. Most of the islands have rugged terrain, restricting productive agriculture to river valleys and coastal plains. Typically, less than one-third of an island’s land area is suitable for crops.

Central America Agriculture

Central America Agriculture

Agriculture is generally understood to be concerned with the production of food; however, in Central America, ornamental plants and flowers, forest products, and fibers are also important agricultural commodities.

The nations of Central America are generally considered to be Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama. At the end of the twentieth century, the agricultural sector employed about 46 percent of the available labor force in Central America, most of which was engaged in subsistence agriculture. This percentage is higher than that of the neighboring developing countries of Mexico (28 percent) and Colombia (30 percent).

The Central American percentage is higher than those in more developed countries, such as the United States and Canada, each of which is below 4 percent. The percentage of suitable land in Central America is about equal to that in Mexico (12 percent) but significantly more than in Colombia (4 percent). Arable land in the United States is about 19 percent.

Composting

Composting

Compost is a mixture of organic ingredients used for fertilizing or enriching land. Composting is the practice of making and using compost.

Composting is a way for gardeners and farmers to enrich and otherwise improve the soil while reducing the flow of household waste to landfills. Essentially the slow, natural decay of dead plants and animals, composting is a natural form of recycling in which living organisms decompose organic matter.

The decay of dead plants and animals starts when microorganisms in soil feed on dead matter, breaking it down into smaller compounds usable by plants.

Corn

Cornfield

The most important cereal in the Western Hemisphere, corn is used as human food (ranking third in the world), as live-stock feed, and for industrial purposes.

Corn (Zea mays) is a coarse, annual plant of the grass (Gramineae) family. It ranges in height from 3 to 15 feet and has a solid, jointed stalk, and long, narrow leaves. A stalk usually bears one to three cobs, which develop kernels of corn when fertilized. Corn no longer grows in the wild; it requires human help in removing and planting the kernels to ensure reproduction.

In the United States and Canada, “corn” is the common name for this cereal, but in Europe, “corn” refers to any of the small-seeded cereals, such as barley, wheat, and rye. “Maize” (or its translation) is the term used for Zea mays in Europe and Latin America.

Drought

Drought in Bangladesh

Drought is a shortage of precipitation that results in a water deficit for some activity. Droughts occur in both arid and humid regions.

One problem in analyzing and assessing the impacts of drought, as well as in delimiting drought areas, is simply defining “drought” itself. Conditions considered a drought by a farmer whose crops have withered during the summer may not be seen as a drought by a city planner.

There are many types of drought: agricultural, hydrological, economic, and meteorological. The Palmer Drought Severity Index is the best known of a number of indexes that attempt to standardize the measurement of drought magnitude. Nevertheless, there still is much confusion and uncertainty on what defines a drought.

European Agriculture

Yellow rapeseed field

European agricultural practices are affected by the policies of the European Union, in addition to global conditions which influence farming everywhere.

Agriculture in Europe goes back to classical times. The development first of the Greek city states, then of the Roman Empire, created urban centers that required substantial amounts of food to be imported from as far away as Egypt. In the year 2000 European agriculture was dominated by two major groups: the European Union (EU), with fifteen member states, and those European states outside the EU.

The EU, which began with the Common Market created by the Treaty of Rome, signed in 1957, initially comprised France, West Germany, Italy, Belgium, the Netherlands, and Luxembourg. By the year 2000 it had expanded to include Great Britain, Ireland, Denmark, Greece, Spain, Portugal, Finland, Sweden, and Austria.