Southwest Irrigation Engineering

Dr. Norman Klocke, professor water resources engineering, has led a collaboration of scientists and computer programmer to develop the Crop Water Allocator (CWA).  This program is available for download to individual computers from the Mobile Irrigation Lab (MIL) website.  CWA gives optimal solutions to limited irrigated management questions.  The premise of the program is that the user has a water supply that will not keep up with the water demanded by crop(s).  Solutions may be to grow more than one crop or irrigate one crop with less water.  CWA proposes optimum net returns for single or multiple crops and finds the best land and water allocations for these crops.

He is leading scientists from weed science, animal science, and entomology to gather field data to find grain yields from crops with full irrigation (meeting atmospheric demand) to dryland management.  No-till crop and optimum irrigation management form the foundation of the study. The cropping sequence is corn-corn-wheat-grain sorghum-sunflower.  The relationship of yield and irrigation is fundamental for economic decisions.  The output if the research will provide input information to decision programs like CWA.

Dr. Klocke is completing a study of soil water evaporation in sprinkler irrigation.  Frequent irrigations and soil surface wetting with center pivots causes soil water evaporation to be 25-30% of evapotranspiration (crop water use).  Crop residues from the previous year have the potential for reducing soil water evaporation.  Crop residues reduce the energy reaching the soil surface, which results in less evaporation.  Crop residues that nearly cover the ground can reduce soil water evaporation by half of bare soil evaporation.  This can be a 3-inch water savings during the growing season.