Efficacy of Nonlinear Root Water Uptake Model for a Multilayer Crop Root Zone

A root uptake model developed and validated for a uniform crop root zone in a semiarid agroclimate is tested for its efficacy in predicting moisture depletion in a multilayer crop root zone in a subtemperate, subhumid agroclimate. Evaluation of moisture uptake prediction efficiency of model in uniform, vis-a-vis multilayer crop root zone, done on the basis of secondary experimental data of three crops, indicates significant improvement in predicted moisture uptake when a multilayered crop root zone is considered. To validate the enhanced prediction efficiency of the model, in the case of a multilayer crop root zone, field experiments on two Indian crops, i.e.,Indian mustard (Brassica Juncea) and Wheat (Triticum-aestivum), are conducted in the subtemperate, subhumid agroclimate of Solan, Himachal Pradesh, India. Model performance indicators exhibit good agreement between model-predicted soil-moisture parameters and experimental results. The results demonstrate the utility of the root water uptake model across semiarid, subtemperate, subhumid agroclimates and establish its efficacy for nonuniform soils having variations in soil moisture properties along depth in predicting soil moisture in the crop root zone.