Estimation of root water uptake of maize: an ecophysiological perspective

An understanding of movement and distribution of soil water has been long known essential to the optimization of plant biomass productivity. This study provides an ecophysiologically based analytic model for estimating root water uptake rate of maize (Zea mays L.). The model can be run with readily available inputs, such as water potentials of leaf, soil and air, solar radiation, potential evapotranspiration, root length, and some soil physical properties, such as bulk density and particle-size distribution. Comparison with measured data showed that the model described root water extraction with acceptable accuracy. Analysis of the response of the model to changes in the input parameters revealed that the model is most sensitive to leaf water potential and root length. Examination of the model response also showed that the model could be improved with more information about the root hydraulic conductance and effective root length responsible for water extraction. (C) 2001 Elsevier Science B.V. All rights reserved.