Evaluation the Potential of LEACHM Model to Predict Soil Moisture, Nitrate Losses and Uptake by Sugarcane

This study fulfilled to assess the moisture in soil profile over the study period with LEACHM model and estimation of leaching، denitrification and nitrogen uptake with sugarcane. Irrigation treatments consisted of full irrigation (I1) and others were 85 (I2) and 70 (I3) percent of I1. Experimental fields irrigated with hydroflumes. Nitrogen application were concluded of 150 (N1)، 250 (N2) and 350 (N3) kg/ha. Moisture measured from Soil samples collected from field plots in 0. 3 m depth increments to 1. 2m on a periodic basis. LEACHM model Efficiency (Willmott''s index) to simulation soil moisture changed from 0. 78 to 0. 95 and best regression coefficient occurred in I2 treatment. Simulation of nitrogen losses and uptake indicated that Mean of highest and lowest of leaching was observed in I1 and I3 with 17 and 8 percent. These results showed with leaching and increase of irrigation had a close relationship. High and low rate of denitrification occurred in I1N3 and I1N1 treatment with 19 and 38 percent. Maximum rate of nitrate uptake with 63 and 56 percent in I2N1 and I1N1 and minimum rate with 35 and 37 percent was observed in I1N3 and I3N3 respectively، full irrigation showed the nitrate leached from root zone and couldn’t uptake by plant and deficit irrigation with composing the stress decreased the root uptake.