Editing Soil salinity (section)

==Salinity due to irrigation==
[[Image:Salinity from irrigation.png|thumb|400px|Rain or irrigation, in the absence of leaching, can bring salts to the surface by capillary action.]]
{{Main article|Environmental impacts of irrigation}}
Salinity from [[irrigation]] can occur over time wherever irrigation occurs, since almost all water (even natural rainfall) contains some dissolved salts.<ref>{{Citation | title = Effectiveness and Social/Environmental Impacts of Irrigation Projects: a Review  | series = Annual Report 1988 of the International Institute for Land Reclamation and Improvement | year = 1989 | pages = 18–34 | location = Wageningen, The Netherlands | url = http://www.waterlog.info/pdf/irreff.pdf |publisher=waterlog.info |url-status=live |archive-url=https://web.archive.org/web/20240216213433/https://www.waterlog.info/pdf/irreff.pdf |archive-date= Feb 16, 2024 }}</ref> When the plants use the water, the salts are left behind in the soil and eventually begin to accumulate. This water in excess of plant needs is called the [[Leaching model|leaching fraction]]. Salinization from irrigation water is also greatly increased by poor [[drainage]] and [[Biosalinity|use of saline water]] for irrigating agricultural crops.

Salinity in urban areas often results from the combination of irrigation and groundwater processes. Irrigation is also now common in cities (gardens and recreation areas).