Soil Moisture Sensors for Precision Irrigation Water Management

The decrease in annual and crop growing season precipitation and the increase in temperatures might be translated into the increase in crop evapotranspiration demand versus reducing available water resources. Long-term average annual precipitation in the Four Corners regions is about 8” while crop water use is about 32” corn and 44” for alfalfa, 26” for potato. Small crop producers in the region are 100% relying on the streamflow of the San Juan, Animas, and LaPlata rivers and the commercial growers such as the Navajo Agricultural Products Industry and contractors use water diversion from the Navajo Lake with other functions. Limited available water resources under a decreasing trend of precipitation under changing climate, there is a call for more efficient and precise use of water in irrigated agriculture in the Four corners region. Field experiments were conducted both at the Agricultural Science Center in Farmington and in the Navajo Mesa Farms commercial potato production fields. Different irrigation rates were applied to corn plots throughout the growing season during the 2018-2020 period and the results showed no yield penalty under 75% of crop evapotranspiration compared to the fully irrigated treatment. The use of soil moisture sensors at the station and in the Navajo Mesa Farms potato fields helps considerably reduce irrigation water input and irrigation frequency with a great saving in irrigation water and electricity costs. Research results and the soil moisture sensors and soil moisture probes were disseminated by presentations to the community grower groups meetings, field day presentations, and exhibitions at different community events within the Four Corners region.