Agriculture
Agriculture is the growing of crops or rearing of livestock by people for food and raw materials.
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2 Food 3 Crops 4 See also |
Agriculture includes subsistence agriculture, which is producing enough food to meet the needs of the farmer and family, and also the production of financial income from cultivation of the land or commercial raising of animals (animal husbandry). Agriculture is the practice -- the study of these disciplines is called agricultural science.
Agriculture produces food for humans and for animals. Agriculture also produces other goods, such as cut flowers, ornamental and nursery plants, fertilizers, animal hides, leather, industrial chemicals (starch, ethanol, and plastics), fibers (cotton, wool, hemp, and flax), fuels (methane, biodiesel, biomass), and both legal and illegal drugs (biopharmaceuticals, marijuana, opium, cocaine). Genetically engineered plants and animals produce specialty drugs.
The origin of agriculture may be more than 10 000 years old. But some people think it is only 7 000 years old. The practice of agriculture is often used to distinguish the neolithic period from the stone age. The first domestic crops included wheat and barley. Agriculture started in the Fertile Crescent, in East Asia, and also in Central America. There was probably a gradual transition from a hunter-gatherer economy to an agricultural economy. During a certain period of time, some crops were deliberately planted, and other foods were gathered from the wild. The reasons for the earliest introduction of farming may have included climate change. Farming allows a much greater density of population than can be supported by hunting and gathering.
In the Western world, the efficiency of agriculture has greatly improved over the last decades. This improvement is due to cultivation of better varieties, better management of the soil, and better weed control. At the same time, use of mechanization has decreased labor requirements. For these reasons, farmers are less and less numerous in developed countries.
In poor countries, the yields are often low. There are many reasons for this. farmers are less educated, and they have less money to buy modern equipment. When yields are low, forests are sometimes cut to provide new lands to grow food. This is good in the short term, but can be bad for the country and the land in the long term.
In developed countries, there are more and more problems because of intensive agriculture. Farmers use a lot of chemical nutrients or chemical pesticides. This sometimes pollute the soil or the water (for example, the nitrogen surplus in rivers and lakes). The insects become resistant to some insecticides. The soil is sometimes damaged (by erosion).
There are many techniques to cultivate crops. Some of them are :
Some companies have been searching for new plants in poor countries, and genetically modify these plants. They try to patent the seeds, and can sell them back in the poor countries.
New plants were created with genetic engineering. They are modified to resist to an herbicide for example.
It is necessary that there is enough food for everyone. The food must also be safe and of good quality. Some people say the food is not always good. They say it is sometimes no safe, because it contains some chemicals. Other people say intensive agriculture is damaging the environment. For this reason, there are several types of agriculture.
Traditional agriculture is mostly done in poor countries.
Intensive agriculture is mostly done in western countries. It uses pesticides, machinery, chemical fertilizers. Organic farming is using only natural products. Integrated farming is using local resources, and trying to use the waste produce in one processus as a resource of another processus.
Agricultural policy focuses on the goals and methods of agricultural production. At the policy level, common goals of agriculture include:
The major crops produced in the world in 2002, are maize, wheat, rice and cotton.
Aquaculture, the farming of fish, shrimp, and algae, is closely associated with agriculture.
Apiculture, the culture of bees, traditionally for honey, increasingly for crop pollination.
Animal husbandry means breeding and raising animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis.
Overview
Agriculture techniques
Farmers selected plants with better yield, more resistance to disease, more tolerance to drought, easier to harvest, with better taste, and better nutritional value. Centuries of careful selection and breeding have had enormous effects on the characteristics of crop plants. The crops give better yield with other techniques (use of fertilizers, chemical pest control, irrigation). For example, the yields of wheat in France are over 90 qx/ha. In South America, the yields are 20 qx/ha. In Africa, the yields are less than 10 qx/ha. Food
Crops
See also : List of domesticated plants, List of vegetables, List of herbs, List of fruit, List of domesticated animalsSee also
There are specialty producers who raise less common types of livestock or plants.