Agriculture
Agriculture is the process of producing food and other raw materials by cultivation of certain plants and the raising of domesticated animals. Agriculture is also known as farming. It includes both subsistence agriculture, which is producing enough food to meet the needs of the farmer and family, but no more) and also (almost universally in the "developed" nations and increasingly so in other areas) 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.
Increasingly, besides food for humans and animal feeds, agriculture produces 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), and fuels (ethanol, methane, biodiesel). Electricity can be generated from methane gas of animal waste or from burning field waste and specially grown crops (biomass. Plants and animals are genetically altered to produce medicines.
In the Western world, greater use of advanced techniques, complex, expensive machinery, and both conventional breeding and genetic engineering has greatly increased yields, releasing most of the populace from intense agricultural labor. The developing world is behind by Western measures of productivity, because of "geographic distance" (What does this mean?) , climates and soils commonly viewed as unsuitable (but see arid-zone agriculture), and lack of capital.
Animal husbandry means raising animals for slaughter or to harvest animal products on a continual basis.
In recent years, industrial agriculture has been the subject of increasing discussion. Patenting of seeds, the leaching of nitrogen and pesticides into the ground water and runoff, pesticide use, soil erosion, habitat destruction, genetic manipulation of crops and animals, and concerns about animal welfare have raised public awareness of alternative farming methods such as organic farming and permaculture.
History
Farming is known to have taken place for at least 10,000 years. Its introduction is often used to distinguish the neolithic period from earlier parts of the stone age. The first crops that humans domesticated included wheat and barley. The history of farming is obscure because it pre-dates writing, but it is clear that farming was invented at least twice, probably more often: once in the Fertile Crescent (possibly by the Natufian culture), once in Central America, and probably once in east Asia. Most likely, there was a gradual transition from a hunter-gatherer economy to an agricultural one, via a lengthy period when 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.
Methods
- Tillage by plough
- Irrigation
- Fertilizers
- Crop rotation
- Weed removal
- Breeding
- Fencing
- "Slash and burn"
Domesticated plants
Domestication of plants is made in order to increase yield and improve the taste and nutritional value. In recent times, genetic engineering has begun to be employed to enhance certain aspects of the natural plants. Some major crops are wheat, maize, rice, yam, sorghum, millet, soybean
See also : List of domesticated plants, List of vegetables, List of herbs, List of fruit
Domesticated animals
Common farm animals or animal products include cattle, dairy products, chicken, eggs, turkeys, emus, horses, rabbits, sheep, goats, pigs, honey, and silkworms (sericulture). Fish, shrimp, and algae can also be farmed (aquaculture)and also it is closely associated with the agriculture.
See also : List of domesticated animals
Environmental problems
- Nitrogen surplus in rivers and lakes.
- Detrimental effects of herbicides, fungicides, pesticides and biocides.
- Conversion of natural ecosystems of all types into arable land.
- Erosion
See also: