The agricultural impacts of irrigation induced waterlogging and soil salinity in the Arkansas Basin

Agricultural production along the Lower Arkansas River of Colorado is being negatively affected as a result of irrigation induced waterlogging and soil salinization. This publication presents an estimate of these damages along a study area of approximately 65,000 irrigated acres for 3 different years. Estimates of the damage are generated by linking a detailed hydrologic model, calibrated from extensive field data, to an economic model that evaluates productivity losses within the study region. The hydrologic model provides a detailed estimate of the soil salinity levels and water table depths that occur throughout the region. Using geographic information system (GIS) software, the output from the hydrologic model is converted into field level data which are used to estimate the damages that are occurring upon each irrigated field across the study area. Previously published research that identifies the relationship between crop yield and soil salinization was used to estimate the impact of soil salinity on agricultural production. The relationship between crop yield and waterlogging was estimated econometrically using a synthesis of secondary data sources. The results indicate that the impact of waterlogging and soil salinization within this region is significant. Average annual losses to agricultural production along the study area were estimated to be approximately US$ 68/acre or US$ 4.3 million.