Accuracy Test of the Web-Based Simulation Model CropWaterUse: Comparison of Simulated to Observed Lysimetric Daily Values During the Growing Season

Computer-assisted decision support systems can be useful tools in agricultural research and commercial crop management as they can help dealing with environmental variability and the complex nature of soil-crop-pest-environment interactions. CropWaterUse is an online tool included in the Crop-Weather Program, an evolving Web-based decision support system developed for cotton growers farming in South Texas (http://cwp.tamu.edu). CropWaterUse was developed using a mechanistic modeling approach to simulate the progression of canopy development (height, leaf area index, and ground cover), crop water use (actual soil evaporation and canopy transpiration), soil moisture storage throughout the soil profile, relative plant-available soil water content and cumulative soil water deficit at root depth. This tool was designed to support management decisions in both rain-fed and irrigated cotton crops. A study was conducted to test the accuracy of CropWaterUse by comparing simulated values to continuous actual evapotranspiration and soil moisture profile data collected in cotton-planted monolithic lysimeters and non-destructive weekly growth measurements of the plants growing in the lysimeters. Results from this study are presented and discussed in this presentation.