Validation of Estimating Dual Crop Coefficient Approach in Growing Season for the Community of Leymus Chinensis under Water Stress Conditions
Based on the field experiment data of climate and physiological factors in the growth period of the Community of Leymus Chinensis from 2005 to 2006 to simulate the basic crop coefficient(Kcb),and one for soil evaporation(Ke) of the Community of Leymus Chinensis in the Otindag sandy area in two different hydrological years presented in the FAO irrigation and drainage paper 56(FAO56,1998,crop evapotranspiration,guidelines for computing crop water requirements),and adjust them by climate and leaf resistance.The daily evapotranspiration is simulated with the basic crop coefficient adjusted.The simulation results are assessed by the approach of consisting in presenting a graphical representation of model simulation transpiration and evaporation compared with observed values and by the regression between observed and model simulated values close to the origin The results show that the transpiration and evaporation values calculated by adjusted dual crop coefficient approach are close to that as estimated from experiment data.The basic crop coefficient on the Penman Method need to be updated by climate and leaf resistance under water stress conditions if there are on the spot experiment data available.