KS Water Budget: Educational software for illustration of drainage, ET, and crop yield.

摘要

Water supply for irrigation in western Kansas is dependent on groundwater. Increasing demands on groundwater, declining groundwater supplies, and possible contamination of groundwater due to drainage of water and dissolved chemicals indicate the need for proper management of water in crop production. A knowledge of interrelationships among soil water supply, drainage, evapotranspiration (ET), and crop yield is essential for efficient water management. Simulation models are useful means to observe and understand these interrelationships. The objectives of this study were to develop equations to estimate drainage, and to develop a water balance model and microcomputer software package for illustration of drainage, ET, and crop yield as influenced by water conditions. Drainage equations for Eudora, Keith, Richfield, and Ulysses silt loams were developed by using the Wilcox technique. A model was developed which estimates drainage by using a Wilcox-type drainage equation, ET by using the Jensen-Haise reference ET equation, and crop yield from yield-ET functions. Weather records and field research results from Tribune, KS were used for adaptation of the model for western Kansas. Based on this model, a software package ("KS Water Budget v. T1") was developed. The software provides output for corn (Zea mays L.), grain sorghum (Sorghum bicolor (L.) Moench), sunflower (Helianthus annuus L.), and winter wheat (Triticum aestivum L.). The KS Water Budget v. T1 software allows users to observe the interrelationships among irrigation system efficiency, water application timing and amount, ET, drainage, and crop yield. The software illustrates daily ET, drainage, and available soil water. The software presents total drainage and ET for the crop and non-crop seasons, and estimated seed yield. The KS Water Budget v. T1 software was developed from climate, soil (Ulysses silt loam), and crop yield-water use data collected near Tribune. The software is to be used as an educational tool for illustration of water's influence on crop production in the region of western Kansas - eastern Colorado with the deep silt loam soils developed from loess.