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, use of improved genetics, better management of soil nutrients, and improved weed control have greatly increased yields per acre. At the same time, use of mechanization has decreased labor requirements, releasing most of the populace from intense agricultural labor. The developing world is behind by Western measures of productivity, because of unavailability of the education, capital and technology base needed to sustain these advances, and usually ecoregion with less optimal climates and soils.
Animal husbandry means breeding and raising animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis.
In recent years, some aspects of industrial intensive agriculture have been the subject of increasing discussion. The widening sphere of influence held by large seed and chemical companies and meat packers has been a source of concern both within the farming community and for the general public. The patent protection given to companies that develop new types of seed using genetic engineering has allowed seed to be licensed to farmers in much the same way that computer software is licensed to users. This has changed the balance of power in favor of the seed companies allowing them to dictate terms and conditions previously unheard of. Some argue theses companies are guilty of biopiracy.
Increasing consumer awareness of agricultural issues has led to the rise of community supported agriculture, food movement">local food movement, Slow food, and commercial organic farming, though these yet remain fledgling industries.
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.
Agricultural policy focuses on the goals and methods of agricultural production. At the policy level, common goals of agriculture include:
In millions of metric tons:
Note: There are two units of measure used for rice. Paddy rice is a measure of the tonnage of rice in its as-harvested state. Milled rice is a measure of the tonnage of rice after it is processed to remove the husk and, sometimes, polish the kernel.
Domestication of plants is made in order to increase yield, disease resistance, drought tolerance, ease of harvest, and to improve the taste and nutritional value and many other characteristics. Centuries of careful selection and breeding have had enormous effects on the characteristics of crop plants. Plant breeders use greenhouses and other techniques to get as many as three generations of plants per year, so that they can make improvements all the more quickly.
For example, average yields of corn (maize) in the USA have increased from around 40 bushels per acre (2.5 t/ha) in 1900 to about 150 bushels per acre (9.4 t/ha) in 2001, primarily due to improvements in genetics. Similarly, worldwide wheat yields have increased from less than 10 q/ha (=1 t/ha) in 1900 to more than 25 in 1990. South American average yields are around 20 q/ha, African under 10 q/ha, Egypt and Arabia up to 35 to 40 q/ha with irrigation. In contrast, the average in countries such as France is over 80 q/ha. Higher yields are due to improvements in genetics, as well as use of intensive farming techniques (use of fertilizers, chemical pest control, growth control to avoid lodging).
[Conversion note: 1 quintal (q) of wheat = 60 pounds (lb) ≈ 27.215 kg. 1 quintal of corn = 56 pounds ≈ 25.401 kg]
Very recently, genetic engineering has begun to be employed to speed up the selection and breeding process. The most widely used modification is a herbicide resistance gene that allows plants to tolerate exposure to glyphosate. A less frequently used but more controversial modification causes the plant to produce a toxin to reduce damage from insects (c.f. Starlink).
There are specialty producers who raise less common types of livestock or plants.
Fish, shrimp, and algae can also be farmed (aquaculture)and also it is closely associated with the agriculture.
See also : List of domesticated animals