African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6849

Article in Press

Calibration and Evaluation of the CROPGRO-Chickpea Model in Semi-Arid Environments of North-Eastern Ethiopia

Adem Mohammed

  •  Received: 15 July 2015
  •  Accepted: 10 February 2016
In order to develop basis for strategic decision making towards agricultural productivity improvement in Ethiopia, a new approach in which crop models could be used is required. Biophysical resource managements using crop models for chickpea production in particular and for most crops in general are highly limited in the country. In this perspective, the CROPGRO-chickpea model was calibrated and evaluated at two locations in semi-arid environments of north-eastern Ethiopia to quantify model parameters and use the model as agricultural decision making tool in the region. The most important aspects in evaluating crop models include determination of cultivar-specific parameters or genetic coefficients. Cultivar coefficients for chickpea varieties in north-eastern Ethiopia were not determined. Hence, the CROPGRO-chickpea model was calibrated to predict growth, development and yield of chickpea. Well adapted chickpea cultivar Kutaye was planted at three sowing dates at two different locations in the main crop season. In addition, experimental data sets of 2005and 2006 were obtained from Sirinka Agricultural Research Center to evaluate the model performance. Using the sowing dates experiment data, the cultivar coefficients were adjusted, until flowering date, physiological maturity date, leaf area index, grain yield and above ground biomass were simulated within 10% of the measured values. The RMSE values between observed and predicted values in the calibration phase of the experiment for LAI, grain yield (kg/ha), above ground biomass (kg/ha) and pod weight (kg/ha) were 0.201, 244.9, 335.6 and 235.2, respectively. The d-index value for these parameters was 0.99. Using the estimated cultivar coefficients, the model simulated well the growth and development stages of chickpea. Therefore, it can be concluded that the model calibration and evaluation was satisfactory and that the model fitted with cultivar specific parameters can be used in simulation studies for research, farm management or decision making for chickpea production in North-Eastern Ethiopia.

Keywords: Chickpea, Crop model, Drought, DSSAT, Ethiopia, Semi-arid