A readily available source of water for irrigation is essential for viable crop production and landscape maintenance in the arid southwest. In San Juan County, New Mexico, the amount of water available for irrigation depends upon the depth of precipitation, particularly winter snowfall that occurs in the San Juan and La Plata Mountains of southwest Colorado. Recurring droughts and ever-increasing demands for this water may decrease the amount available for irrigation in the future. Consequently, it is important that irrigation management plans be developed to mitigate potential adverse effects of reduced water availability on crop production and landscape quality.

Efficient irrigation management requires an accurate estimate of a crop's water requirements or evapotranspiration (ET) during the plant's life cycle so that irrigations can be scheduled accordingly. While under-irrigation may reduce crop production and/or plant quality, over-irrigation wastes water, energy (due to excessive pumping), fertilizers and chemicals (due to increased weed and disease pressure and excessive leaching or runoff). As a result, production costs are increased, economic returns are potentially decreased, and environmental quality is degraded.

Since its conception more than 30 years ago, New Mexico State University's Agricultural Science Center at Farmington has evaluated relationships between irrigation (or ET) and crop production or quality. These studies have identified the ET requirements of various agricultural crops and landscape plants, including turfgrass.


Serving the agricultural needs for the San Juan River basin of northwest New Mexico and the Four Corners region since 1966. The Agricultural Science Center at Farmington consists of 254 acres leased from the Navajo Nation. It is the only agricultural research facility, in the state of New Mexico, that is on the western side of the Continental Divide. The Center is located approximately seven miles southwest of Farmington, (36 degrees 4' N by 108 degrees W) at an elevation of 5,640 ft.

ASC Farmington Map