Editing San Luis Valley (section)

===Agriculture and wildlife===
Much of the land in the San Luis Valley is used for grazing. Farming is generally concentrated around the towns of Alamosa, Monte Vista and Center.{{citation needed|date=August 2021}} Principal crops include [[potato]]es, [[lettuce|head lettuce]], wheat, and [[barley]]. The barley grown here is the main supplier for Coors beer company. In 1982, [[quinoa]] was successfully grown for the first time outside of South America in the San Luis Valley of Colorado,<ref name="Colorado State University - San Luis Valley Research">{{cite web |url=http://www.colostate.edu/depts/SLVRC/slv_research_newcrops.html |publisher=Colorado State University |title=San Luis Valley Research Center}}</ref> and commercial growth has occurred since 1987.<ref name=FieldCrop1990>{{cite book |title=Alternative Field Crops Manual |publisher=University of Wisconsin and Minnesota |date=February 1990}}</ref> Less favored areas with a shorter growing season and less access to water rights tend to be devoted to [[alfalfa]] and [[grazing]]. Broad areas, especially in [[Saguache County, Colorado]] have a high [[water table]] or are even flooded part of the year. Uncultivated land is often covered with "chico", low brush such as [[Chrysothamnus|rabbitbrush]], [[Sarcobatus|greasewood]] and other woody species. Cropland is typically irrigated with large ({{frac|1|4}}&nbsp;mile radius) [[center-pivot irrigation]] systems, and a common feature of the Rio Grande Delta area where the Rio Grande enters the valley are large piles of potato-sized rocks screened from the soil.<ref name=colosun20210829>{{cite news |title=The water supply of the San Luis Valley faces pressure as never before |url=https://coloradosun.com/2021/08/29/san-luis-valley-water-diversion-drought-climate-change/ |last1=Obmascik|first1=Mark |work=[[Colorado Sun]] |date=29 August 2021 |access-date=31 August 2021 }}</ref>

The area supports a wide variety of wildlife. [[Sandhill crane]]s migrate through the valley every spring and fall. The Monte Vista Crane Festival takes place in March, centering on the [[Monte Vista National Wildlife Refuge]] located {{convert|6|mi|km|spell=in}} south of town. The valley is a flyway for many migrating birds including [[avocets]], [[bald eagle]]s, [[American Goldfinch|goldfinch]]es, and a plethora of [[hawk]] species.

Agriculture in the San Luis Valley is enabled by irrigation, since average annual precipitation is just {{convert|7|-|10|in|cm}} whereas most ag crop production requires at least twice that much water. [[Water in Colorado|Surface water rights]] in the Valley began to be allocated in 1852, with the People's Ditch, near San Luis. In the 1870s, some {{cvt|50000|acre|sqmi km2}} of the San Luis Valley were irrigated, which rose to {{cvt|800000|acre|sqmi km2}} in the 1880s.<ref name=colosun20210829/>  By the early 1900s, demand for surface water had outstripped the available supply and farmers began to use subsurface wells to supply water. Over 5,000 groundwater wells existed by the time of [[World War I]]. By the early 1970s, water availability began to be limited, with the [[Government of Colorado|State]] enforcing a moratorium on new wells in much of the valley in 1972, and then completely ending [[Prior-appropriation water rights|new appropriations]] of water throughout the valley in 1981.<ref name=colosun20210829/>  The 1980s and 90s saw relatively bountiful water years in the valley, with drought conditions becoming the norm in the 2010s.<!-- quote from refname colosun20210829: "Ten of the past 11 years have delivered below-average snowpacks for the upper Rio Grande basin, with this year’s snowpack measuring just 58% of normal at the key May 1 measurement. All but one of the main local reservoirs were less than half-filled. --> {{asof|2021}}, water use cutbacks are anticipated due to a court order requiring the restoration of 400,000 acre-feet of water to the groundwater aquifer, as well as the forecast for reduced Rio Grande flows in future years.<ref name=colosun20210829/>