Calibration and Validation of CERES-Wheat (Triticum Aestivum) Model for Simulating Fertilizer Application Rates in Management Zones

H U Farid,N Ahmad,Z Mahmood-Khan,A Bakhsh,A Ahmad

doi:10.5539/jas.v7n7p115

H U Farid, N Ahmad + Show 3 more

Open Access

https://doi.org/10.5539/jas.v7n7p115

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Abstract

Precision agriculture requires precise urea fertilizer application rates for site-specific applications to maximize crop yield across the management zones (MZs). A two years (2010-11 to 2011-12) field experimental study was conducted at Postgraduate Agricultural Research Station, University of Agriculture, Faisalabad, Pakistan to simulate urea fertilizer application rates for four MZs using CERES-Wheat ( Triticum Aestivum ) model. The model was calibrated using grain yield data of urea fertilizer application rate of 247 kg-urea/ha during growing season of 2010-11 in MZ 1. It was validated against two years independent yield data sets for all treatments ranging from no urea application to 247 kg-urea/ha application in each MZ. The model simulations were found to be acceptable for calibration as well as validation period, as the model evaluation indicators showed root mean square error of 314 kg/ha having its range from 77 to 566 kg/ha, model efficiency of 66% ranging from 24 to 98%, mean percent difference of -4.83%, ranging from -9.93 to 3.70%, against all observed grain yield data in four MZs. Scenario simulations revealed that urea fertilizer application rates of 221, 210 , 208 and 197 kg-urea/ha simulated maximum wheat grain yield of 3679, 3582, 3689, 3690 kg/ha, in MZs of 1, 2, 3 and 4, respectively. These simulated urea fertilizer application might be used to maximize wheat grain yield for each MZs within the field. Furthermore, field verification should be required by applying the simulated urea fertilizer application rates in each MZ.

Highlights

The food and fiber requirements of Pakistan are increasing because of its population growth rate of 2.05%, which has increased population to 176 million in 2011, it is likely to be doubled by 2050 (GOP, 2011)
The main objectives of this study were: 1) Calibration and validation of Decision Support Systems for Agrotechnology Transfer (DSSAT) model to predict wheat yield based on field experimental data; 2) To simulate management scenario based on management zones (MZs) for determining urea fertilizer application rates to maximize wheat yield
The CERES-Wheat model was calibrated against the measured data of grain and biological yields in MZ 1 for treatment Treatment 1 (T1) (173 kg-urea/ha) for growing season of 2010-11 and was validated using data of all treatments for growing seasons of 2010-11 and 2011-12

Summary

Introduction

The food and fiber requirements of Pakistan are increasing because of its population growth rate of 2.05%, which has increased population to 176 million in 2011, it is likely to be doubled by 2050 (GOP, 2011). Agricultural production of the major food crops including wheat in Pakistan is lower when compared with other wheat producing countries of the world. The average wheat yield per hectare in Pakistan is 27 % lower than the world’s average wheat yield per hectare (Arifullah et al, 2009). This situation needs attention of the scientist and engineers to find the factors responsible for low wheat productivity in the country. In addition to cultivar potential, several scientists have reported that topography, climatic conditions, management practices and spatial variability effects within the field are considered as the main factors affecting wheat productivity (Bakhsh et al, 2000a; Abbas et al, 2005; Ayoubia et al, 2007; Marques & Silva, 2008; Begue et al, 2010)

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