COMPARISON OF SPRING MAIZE ROOT WATER UPTAKE MODELS UNDER WATER AND SALINITY STRESS VALIDATED WITH FIELD EXPERIMENT DATA

Crop root water uptake has strong correlations with transpiration and yield. An accurate prediction of crop root water uptake can benefit understanding of the law of transpiration and soil water movement. Under water and salinity stress, maize root water uptake will decrease because of soil water pressure and osmotic head. Usually such reduction of water uptake can be expressed by models such as the additive model and the multiplicative model. Based on a field irrigation experiment, we calculated spring maize root water uptake in this study by setting different combinations of water amount and saline concentration based on the water balance method. One additive model and four multiplicative models of root water uptake were calibrated and verified in order to simulate the impact of water and salt stress on root water uptake. The result shows that multiplicative models are better than the additive model in simulating the experimental data from different treatments. Therefore, the multiplicative model is recommended as the optimal model of root water uptake of spring maize under water and salinity stress in the arid region of north-west China. Copyright (C) 2015 John Wiley & Sons, Ltd.