Irrigation

Irrigation

activity, use

Subclass of	process, transport
Get use	agriculture
Facet give	transport of water
Has effect	runoff
Studied by	irrigation engineering
Class of object(s) of occurrence	water

Irrigation be de practice of applying controlled amounts of water to land to help grow crops, landscape plants, den lawns. Irrigation be a key aspect of agriculture for over 5,000 years wey e be developed by chaw cultures worldwide. Irrigation dey help to grow crops, maintain landscapes, den revegetate disturb soils insyd dry areas den during times of below-average rainfall. In addition to dese uses, irrigation sanso be employed to protect crops from frost, suppress weed growth insyd grain fields, den prevent soil consolidation. E sanso be used to cool livestock, reduce dust, dispose of sewage, den support mining operations. Drainage, wich dey involve de removal of surface den sub-surface water from a given location, often be studied in conjunction plus irrigation.

Several irrigation methods dey differ insyd how water be supplied to plants. Surface irrigation, dem sanso know as gravity irrigation, be de oldest form of irrigation wey e be in use for thousands of years. Insyd sprinkler irrigation, water be piped to one anaa more central locations within de field den distributed by overhead high-pressure water devices. Micro-irrigation be a system wey distribute water under low pressure thru a piped network den dey apply am as a small discharge to each plant. Micro-irrigation dey use less pressure den water flow dan sprinkler irrigation. Drip irrigation dey deliver water directly to de root zone of plants. Subirrigation be used insyd field crops insyd areas plus high water tables for chaw years. E dey involve artificially raising de water table to moisten de soil below de root zone of plants.

Irrigation water fi cam from groundwater (dem extract from springs anaa by using wells), from surface water (dem withdraw from rivers, lakes anaa reservoirs) anaa from non-conventional sources like treated wastewater, desalinated water, drainage water, anaa fog collection. Irrigation fi be supplementary to rainfall, wich be common insyd chaw parts of de world as rainfed agriculture, anaa e fi be full irrigation, wer crops dey rarely rely on any contribution from rainfall. Full irrigation be less common den dey occur only insyd arid landscapes plus very low rainfall anaa wen crops be grown insyd semi-arid areas outsyd de rainy season.

De environmental effects of irrigation dey relate to de changes insyd quantity den quality of soil den water as a result of irrigation den de subsequent effects on natural den social conditions insyd river basins den downstream of an irrigation scheme. De effects stem from altered hydrological conditions wey dey result from de installation den operation of de irrigation scheme. Amongst dese problems be de depletion of underground aquifers thru overdrafting. Soil fi be over-irrigated secof poor distribution uniformity anaa management wastes water, chemicals, wey fi lead to water pollution. Over-irrigation fi cause deep drainage from rising water tables, wich fi lead to irrigation salinity problems, wey dey require watertable control thru sam form of subsurface land drainage.

Extent

Example values for crops

Approximate values of seasonal crop water needs

Crop	Crop water dey hia mm / total growing period
Sugarcane	1500–2500
Banana	1200–2200
Citrus	900–1200
Potato	500–700
Tomato	400–800
Barley/oats/wheat	450–650
Cabbage	350–500
Onions	350–550
Pea	350–500

Gallery

• 
  De hub of a center-pivot irrigation system
• 
  Leaks insyd micro-irrigation drip lines
• 
  Sprinkler irrigation of blueberries insyd Plainville, New York, United States
• 
  Irrigation insyd Tamil Nadu, India
• 
  Irrigation ditch insyd Montour County, Pennsylvania, USA
• 
  Water gardens insyd Sigiriya, Sri Lanka
• 
  Micro-sprinkler

External links

• International Commission on Irrigation and Drainage (ICID)
• Irrigation at the Water Quality Information Center, U.S. Department of Agriculture
• AQUASTAT: FAO's global information system on water and agriculture