Agriculture

300px|thumbnail|right|Fields in Poland Welcome to the Agriculture wikibook! Agriculture (a term which encompasses farming and ranching) is the process of producing food, feed, fiber, fuel, and other goods by the systematic raising of plants and animals. "Agri" is from Latin ager, meaning "a field", and culture is from Latin cultura, meaning "cultivation" in the strict sense of tillage of the soil. Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, fiber, forest products, horticultural crops, and their related services". A literal reading of the English word yields: tillage of the soil of a field. In modern usage, the word agriculture covers all activities essential to food/feed/fiber production, including all techniques for raising and processing livestock. Agriculture is also short for the study of the practice of agriculture—more formally known as agricultural science. The history of agriculture is a major element of human history; agricultural progress has been a crucial factor in worldwide social change, including the specialization of human activity: when farmers became capable of producing food beyond the needs of their own families, others in the tribe or nation or empire were freed to devote themselves to tasks other than food acquisition. About 42% of the world's laborers are employed in agriculture, making it by far the most common occupation. Agriculture may often cause environmental problems because it changes natural environments and produces harmful byproducts. Some of the negative effects are: Surplus of nitrogen and phosphorus in rivers and lakes Detrimental effects of herbicides, fungicides, insecticides, and other biocides Conversion of natural ecosystems of all types into arable land Consolidation of diverse biomass into a few species Soil erosion Depletion of minerals in the soil Particulate matter, including ammonia and ammonium off-gassing from animal waste contributing to air pollution Release of feral plants and animals Odor from agricultural waste Soil salination Agriculture is cited as a significant adverse impact to biodiversity in many nations' Biodiversity Action Plans, due to reduction of forests and other habitats when new lands are converted to farming. Some critics also include agriculture as a cause of current global climate change. According to the United Nations, the livestock sector (primarily cattle, chickens, and pigs) emerges as one of the top two or three most significant contributors to our most serious environmental problems, at every scale from local to global. It is one of the largest sources of greenhouse gases - responsible for 18% of the world’s greenhouse gas emissions as measured in CO2 equivalents. By comparison, all transportation emits 13.5% of the CO2. It produces 65% of human-related nitrous oxide (which has 296 times the global warming potential of CO2) and 37% of all human-induced methane (which is 23 times as warming as CO2). Agricultural policy focuses on the goals and methods of agricultural production. At the policy level, common goals of agriculture include: Food safety: Ensuring that the food supply is free of contamination Food security: Ensuring that the food supply meets the population's needs Food quality: Ensuring that the food supply is of a consistent and known quality Conservation Environmental impact Economic stability Chapters /History of farming/ /Farming mammals/ /Farming game/ /Farming plants/ /Tillage/ Benefits Effects /No-Tilling/zero tillage/ Benefits Effects /Industrial chemicals/ /Pesticides/ /Herbicides/ /Soil conditioning/ /Natural chemicals/ /Manure/ /Earthworms/ /Microbes/ /Organic farming/ Vegetables /Perma culture/ Subsidies /Policy/ Contributors http://www.agclassroom.org/gan/ http://www.fao.org/ag/agl/agll/wrb/images/image002.jpg Agriculture and husbandry A 25%