Simulation of mulch effect on soil moisture and salinity distribution using HYDRUS-2D and AquaCrop

One of the main objectives of the agricultural sector in arid and semi-arid regions is to improve soil moisture conservation and water productivity. Evaporation from soil surface is non-beneficial losses in irrigation. Mulching is one of the most important agricultural managements in maintaining soil moisture and improving the physical environment of the soil. The use of mulch outside the growing season prevents the salinity of the topsoil. The purpose of this study was to investigate the effect of plant mulch on solute transfer, soil moisture, temperature and salinity outside the growing season, which using two laboratory lysimeters with a length of (1 m), a width of (0.5 m) and a height of (1 m) was investigated. During the 122-day simulation period, moisture and salinity values from 5 depths of soil profiles (50-40-30-20-10 cm) were measured. To compare the means of each treatment with each other, t-test was used in two software models, HYDRUS-2D and AquaCrop. RMSE, MBE, MAE and R2 statistical indexes were used to evaluate each model. The results show that the HYDRUS-2D model has a good ability to model moisture at depths of 10 to 40 cm, but for depths of 0 to 10 and 40 to 50 cm has not performed well in the simulation. Also, the results of AquaCrop model show that this model does not have a good ability to model moisture at depths and HYDRUS-2D model compared to AquaCrop model has the ability to better estimate and more acceptable relative accuracy of moisture at depths of 10 to 40 cm for simulation of solute transportation.This model does not have a good ability to model moisture at depths performed and HYDRUS-2D model compared to AquaCrop model has the ability to better estimate and more acceptable relative accuracy of moisture at depths of 10 to 40 cm for simulation