Analysis of the Accuracy of the Web-Based Simulation Model Cropwateruse.

Computer-assisted decision support systems can be important tools in the decision-making process in farming, as they can assist crop managers deal 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 confirm (validate) 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.