Precipitation and Water-Table Effects on Agricultural Production and Economics

Abstract

The sensitivity of irrigated agriculture to water-table fluctuations and agroeconomic parameters was analyzed in the context of long-term climatic variability. Capillary rise was modeled as a function of soil moisture content and depth to the water table. The capillary rise model was used to define the sensitivity of soil moisture depletion, actual evapotranspiration, and agricultural benefits to changes in water-table depth. Water-table fluctuations had a pronounced effect on root-zone soil moisture, irrigation water use requirements, and agricultural benefits. An economic analysis was performed to determine the sensitivity of site-specific irrigated potato production in the San Luis Valley given the potential changes in available irrigation water supply and agroeconomic parameters. Agricultural benefits were found to be highly sensitive to production costs variations, to deviations of crop market prices from their mean values, and to available irrigation water supply.