Document Type : Research Paper
M.Sc. Student of Irrigation and drainage, Department of Water Sciences and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
Assistant Professor, Department of Water Sciences and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
Professor of Irrigation and Drainage Engineering, Agricultural Engineering Research Institute (AERI), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.
the present study was conducted at a 500-hectare farm of the Seed and Plant Breeding Research Institute located at 50.58° East longitude and 35.56° latitude on two corn cultivars. For double cross 370, two factors include the amount of irrigation water at four levels (W1: 120, W2: 100, WI3: 80 and W4: 60 percent of water requirement) and nitrogen fertilizer at four levels (N1: 100, N2: 80, N3: 60 and N4: zero percent of nitrogen requirement) were considered. For single cross 260 fertilizer levels factor in four levels (N1: 100, N2: 80 and N3: 60 and N4: 50 percent of nitrogen requirement) were studied. The results for both cultivars showed that the CERES-Maize model had a low estimation error (0 ≥ MBE). The error of this model for simulating the yield of double cross cultivar 370 was equal to 1.24 tons per hectare and for single cross cultivar 260 was equal to 0.44 tons per hectare. The accuracy of CERES-Maize model for simulating these two cultivars was in the category of good (NRMSE = 0.13) and excellent (NRMSE = 0.06), respectively. The error of CERES-Maize model for irrigated treatments in double cross cultivar 370 was between 0.89-1.65 t/ha and for fertilizer treatments in this cultivar was between 0.43-9.9 t/ha. No difference was observed between the model errors in two fertilizer applications. Therefore, it was not sensitive to fertilizer installments, while changes in irrigation water and fertilizer amount had a great effect on its accuracy. Based on all the results, the CERES-Maize model is proposed to simulate both corn cultivars, although its accuracy was higher in the single cross 260 cultivar.