Thermocouple hygrometers were used to monitor soil water potential in control and harvested (bare) plots in the Chihuahuan Desert of New Mexico (U.S.A.) from June 1983 and June 1984. Soil water potentials were converted to water contents using the moisture tension release characteristics for each soil horizon. Comparisons of seasonal fluctuations in soil water storage on these plots suggest that 72% of incident precipitation is removed by plant transpiration in this ecosystem. Plant uptake of water from the lower soil profile is an important factor affecting the rate and depth of CaCO3 deposition in desert soils.