A web application for cotton irrigation management on the U.S. Southern High Plains. Part I: Crop yield modeling and profit analysis

Irrigated cotton (Gossypium Hirsutum L.) production is a central part of west Texas agriculture that depends on the essentially non-renewable water resource of the Ogallala aquifer. Web-based decision support tools that estimate the profit effects of irrigation for cotton under varying lint price, production cost, and well capacity conditions could help to optimize the agricultural value of the Ogallala's water. The crop modeling and profit analysis component of such a support tool is demonstrated here. This web application is based on a database of modeled yields generated from the meteorological records of four weather stations under un-irrigated (dryland) conditions and under center pivot irrigation with 12 total irrigation (TI) levels spanning deficit to full irrigation conditions. The application converts the database's dryland and irrigated yield outcomes into corresponding values of profit per hectare based on user-defined yield values and production costs. Given the resulting values of dryland and irrigated profit per unit area and the additional constraints of a user's well capacity and center pivot area, the application also calculates the profit effects of dividing center pivot area into dryland and irrigated production under the 12 irrigation levels.