page_title: Agriculture
section_title: Land and water issues
hierarchical_section_title: Agriculture / Environmental impact / Land and water issues
caption_attribution_description: English: Satellite image of crops growing in Kansas, United States. Healthy, growing crops are green. Corn would be growing into leafy stalks by late June (when this photo was taken). Sorghum, which resembles corn, grows more slowly and would be much smaller and therefore, possibly paler. Wheat is a brilliant gold as harvest occurs in June. Fields of brown have been recently harvested and plowed under or lie fallow for the year. The circular crop fields are a characteristic of center pivot irrigation. The fields shown here are 800 and 1,600 meters (0.5 and 1 mile) in diameter. The image is centered near 37.4 degrees north latitude, 100.9 degrees west longitude, and covers an area of 37.2 x 38.8 km. The 'grid' in which the fields are laid out runs north-south/west-east and the dark angled line is U.S. Route 56. The image is aligned with the satellite orbital track, which is in a 98 degrees tilted orbit. North is about 10 degrees counter-clockwise from up. The image is a false-color presentation made to simulate natural color. The 3 bands that were used are in the green, red, and near infrared parts of the spectrum. ASTER does not have a blue channel, so any blue that can be seen was created from the other bands. Français&#160;: Image satellitaire de cultures poussant au Kansas (Etats Unis) à la fin du mois de juin. Les cultures en pleines croissance comme le maïs sont représentées en vert. Le Sorgho, moins avancé en cette saison, est plus pâle. Le blé est déjà doré et sera bientôt récolté. Les parcelles brunes ont déjà été moissonnées ou sont en jachère. La forme circulaire des champs est typique de l'irrigation à pivot central. Le diamètre de ces champs est souvent de 800 ou 1600 mètres, ils sont inscrits dans les "sections" de 1 mile américain de côté héritées du Public Land Survey System (article en Anglais). La ligne oblique qui traverse l'image est la Route Fédérale 56. L'image est alignée sur l'orbite du satellite ASTER de la NASA qui a pris la photo. Cette orbite est inclinée de 98 degrés par rapport à l'axe des pôles. Le nord est vers le haut, mais il fait un angle de 10 degrés dans le sens inverse des aiguilles d'une montre. L'image est en fausse couleurs, simulant les couleurs naturelles. Les trois longueurs d'ondes observées correspondent au vert, au rouge, et au proche infrarouge. Deutsch: Ein Satellitenbild von Anbaufeldern in Kansas, Vereinigte Staaten. Gesunde und wachsende Pflanzen sind grün. Mais bildet Ende Juni (als dieses Foto aufgenommen wurde) belaubte Stängel aus. Hirse sieht Mais ähnlich, wächst langsamer, ist viel kleiner und daher möglicherweise blasser. Weizen ist leuchtend gold, wenn im Juni die Ernte beginnt. Braune Felder wurden vor kurzem abgeerntet und umgegraben oder liegen in diesem Jahr brach. Die kreisrunden Felder sind charakteristisch für eine Bewässerung durch Kreisberegnung. Die gezeigten Felder besitzen einen Durchmesser von 800 und 1,600 Metern (1/2 und 1 Meile). Das Bild ist bei etwa 37,4 Grad nördlicher Breite und 100,9 Grad westlicher Länge zentriert und deckt ein Gebiet von 37,2 x 38,8 km ab. Das 'Gitter', in dem die Felder angelegt sind, verläuft in Nord/Süd- und West/Ost-Richtung. Die schräge dunkle Linie ist die U.S Route 56. Das Bild ist an die Satellitenbahn ausrichtet, die einen Winkel von 98 Grad aufweist. Norden befindet sich etwa 10 Grad gegen den Uhrzeigersinn gedreht. Das Bild zeigt eine Falschfarbendarstellung, die natürliche Farben simulieren soll. Die drei verwendeten Bänder befinden sich im Grün-, im Rot- und nahe des Infrarotbereichs des Spektrums. Das Radiometer ASTER besitzt keinen Blaukanal, und daher wurde die sichtbare blaue Farbe von den anderen Bändern erzeugt. Česky: Satelitní snímek zemědělské krajiny v Kansasu v USA. Zdravé, rostoucí plodiny jsou zelené. Snímek byl pořízen koncem června, kdy kukuřice už je zelená, ale čirok, který roste pomaleji a je mnohem menší, je bledší. Pšenice je zářivě zlatá, protože je právě před její sklizní. Hnědá pole jsou už sklizená a zaoraná, případně byla ponechána ladem. Kruhová pole jsou charakteristická pro závlažování s pivotem. Zobrazená pole mají 800 a 1600 m v průměru. Střed obrázku zachycuje oblast okolo 37,4° severní šířky a 100,9° západní délky. Fotografie pokrývá oblast 37,2 × 38,8 km. Mřížka polí je orientována severojižně/západovýchodně. Tmavá šikmá čára je U.S. Route 56. Fotografie je natočená podél oběžné dráhy satelitu, která má sklon 98°. Sever je asi 10° proti směru chodu hodinových ručiček od směru nahoru. Obrázek je ve falešných barvách simulujících přirozené zabarvení. Byl pořízen ve třech kanálech: zeleném červeném a blízkém infračerveném. ASTER nemá modrý kanál, proto cokoli modrého je na této fotografii složeno z ostatních kanálů.
context_page_description: Agriculture is the science and art of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities. The history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs, sheep and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture into the twenty-first.
  Modern agronomy, plant breeding, agrochemicals such as pesticides and fertilizers, and technological developments have sharply increased yields, while causing widespread ecological and environmental damage. Selective breeding and modern practices in animal husbandry have similarly increased the output of meat, but have raised concerns about animal welfare and environmental damage.
context_section_description: Land transformation, the use of land to yield goods and services, is the most substantial way humans alter the Earth's ecosystems, and is considered the driving force in the loss of biodiversity. Estimates of the amount of land transformed by humans vary from 39 to 50%. Land degradation, the long-term decline in ecosystem function and productivity, is estimated to be occurring on 24% of land worldwide, with cropland overrepresented. The UN-FAO report cites land management as the driving factor behind degradation and reports that 1.5 billion people rely upon the degrading land. Degradation can be deforestation, desertification, soil erosion, mineral depletion, or chemical degradation (acidification and salinization).
  Agriculture lead to rise in Zoonotic disease like the Coronavirus disease 2019, by degrading natural buffers between humans and animals, reducing biodiversity and creating big groups of genetically similar animals. 
  Eutrophication, excessive nutrients in aquatic ecosystems resulting in algal bloom and anoxia, leads to fish kills, loss of biodiversity, and renders water unfit for drinking and other industrial uses. Excessive fertilization and manure application to cropland, as well as high livestock stocking densities cause nutrient (mainly nitrogen and phosphorus) runoff and leaching from agricultural land. These nutrients are major nonpoint pollutants contributing to eutrophication of aquatic ecosystems and pollution of groundwater, with harmful effects on human populations. Fertilisers also reduce terrestrial biodiversity by increasing competition for light, favouring those species that are able to benefit from the added nutrients.
  Agriculture accounts for 70 percent of withdrawals of freshwater resources. Agriculture is a major draw on water from aquifers, and currently draws from those underground water sources at an unsustainable rate. It is long known that aquifers in areas as diverse as northern China, the Upper Ganges and the western US are being depleted, and new research extends these problems to aquifers in Iran, Mexico and Saudi Arabia. Increasing pressure is being placed on water resources by industry and urban areas, meaning that water scarcity is increasing and agriculture is facing the challenge of producing more food for the world's growing population with reduced water resources. Agricultural water usage can also cause major environmental problems, including the destruction of natural wetlands, the spread of water-borne diseases, and land degradation through salinization and waterlogging, when irrigation is performed incorrectly.
caption: Circular irrigated crop fields in Kansas. Healthy, growing crops of corn and sorghum are green (sorghum may be slightly paler). Wheat is brilliant gold. Fields of brown have been recently harvested and plowed or have lain in fallow for the year.
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