Simulation of water movement and root water uptake in drip irrigated guava

The study involved field experimentation on guava (Psidium guajava L.) crop under drip irrigation system for two years viz. 2011 and 2012. Field data were collected on spatial and temporal distribution of water in the growing season to calibrate and validate the mathematical model. A two dimensional water movement model HYDRUS- 2D was applied to simulate the water movement in drip irrigated guava. The root water uptake by the plant was also considered in the model. The HYDRUS 2D predictions of the water content were found to be in good agreement with the observed data. Maximum water content after 4h, 8h and 24h was observed for 15–30 cm soil layers as compared to other soil layers for both observed and simulated water contents. Values of simulated and observed water content at the end of 4h, 8h and 24h varied from 8–32% and 10–30%, 8–27% and 11–24%; 8–18% and 7–18%, respectively. The correlation coefficient (R2) and root mean square error (RMSE) between simulated and observed values of water content varied from 0.396–0.978 and 1.46–2.57, respectively.