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Calibration and Testing of the Aquacrop Model for Rice under Water and Nitrogen Management
- Amiri, Ebrahim
- Communications in soil science and plant analysis 2016 v.47 no.3 pp. 387-403
- biomass, canopy, demonstration farms, field experimentation, grain yield, inflorescences, irrigation management, models, nitrogen, rice, statistical analysis, submergence, Iran
- The objective of this study was to adapt and test the ability of the AquaCrop model under different nitrogen and irrigation management conditions in northern Iran. A three-year field experiment was conducted at the experimental farm of the Iranian Rice Research Institute in Rasht, Iran, from 2005 to 2007. Irrigation treatments comprised continuous submergence, irrigation at 5-day intervals, and irrigation at 8-day intervals. Nitrogen (N) application levels were 0, 45, 60, and 75 kg N ha ⁻¹. The goodness of fit between observed and simulated canopy cover, total and panicle biomass, grain yield, and final biomass was assessed by means of the coefficient of determination (R ²) and the absolute and normalized root mean square errors (RMSE ₙ). Results of the statistical test of the model for total and panicle biomass showed moderately high R ² (≥0.90) and moderate RMSE ₙ (6–36%) values, confirming that the model simulated the total and panicle biomass accurately. The model was simulated for CC with RMSE ₙ and R ² of 28 and 0.82, respectively. The agreement between predicted and observed rice grain yield and final biomass were with R ² of 0.81 and 0.82 and RMSE ₙ of 13 and 10% respectively.