Estimating normalized root length density distribution of winter wheat using measured soil water content profiles

It is very difficult, even not impossible, to measure root density timely and accurately, especially in the field. However, it is an essential parameter for root study. In this study, an approach to estimating the normalized root length density distribution was proposed, which was based on two measured soil water content profiles and the inverse method to estimate the average root-water-uptake rate. The approach was also used to estimate the normalized root length density distributions of winter wheat grown in soil columns and in the field. The results showed that the approach was reliable to estimate the normalized distributions of relative root length density, compared with the measured values. Therefore, the estimated effective root density parameter can be provided for root-water-uptake models and soil water flow can be simulated continuously even without any measured root density information.