Using the Least Limiting Water Range to Evaluate Water Stress On Crops.

Plant stress caused by adverse soil physical conditions can cause major reductions in plant biomass and grain yield. One way to evaluate adverse soil physical properties is the use of the Least Limiting Water Range (LLWR). This procedure evaluates soil physical conditions based on soil water holding capacity, soil strength, and soil aeration. Using soil bulk density and water content measurements, we determined the time the plant was growing under physically limiting conditions. Plants evaluated included corn, winter wheat, sunflower, spring barley, field pea and red kidney bean. The effects of water stress as indicated by the LLWR on plant development, biomass production and grain yield will be discussed.