The High Plains Underground Water Conservation District No. 1 conducts an annual pre-plant soil moisture survey to inform producers about general plant-available soil moisture conditions within its 16-county service area. Irrigators can use this information to estimate the amount of water needed (either by precipitation or irrigation) to bring their soil closer to field capacity without wasting water by over-irrigating.
Water is the most limiting factor for crop production on the Southern High Plains. There is a direct correlation between crop yields and the amount of water available for crop water use during the growing season.
Irrigation is used throughout the region to supplement precipitation in order to meet crop water use requirements.
During late summer, many farmers find that the capacity of their irrigation systems is not adequate to meet their crop water needs--especially during the time when the crop is establishing and maturing fruit. Producers have managed to overcome this problem by storing water in the five-foot plant root zone soil profile prior to planting.
The region contains soils ranging from three to seven feet in thickness. These soils have the capacity to store 1.5 to 2.5 inches of water per foot of depth which can be extracted by the crop when needed. The four major field crops grown in the area (cotton, corn, wheat, and grain sorghum) have roots that can extend deep into the soil profile to extract the stored water.
Soil moisture readings are taken by lowering a probe into a permanently-installed aluminum access tube at monitoring sites throughout the District. Each site is chosen based upon soil type, the variations in the saturated thickness of the Ogallala Aquifer which indicated potential water well yields, and typical farming operations in the area.
The results of the annual pre-plant soil moisture survey are published each year in The Cross Section, and distributed to all media organizations in the 16-county water district service area.