The sensitivity of predicted sillage-corn yield using CERES - Maize model to physical soil parameters under two nitrogen fertilizer levels

Useful and extensive use of crop models depends on understanding their behavior in response to probable errors in input parameters. The aim of this study was to assess the sensitivity of the simulated sillage-corn yield by the most commonly used crop model، CERES – Maize، to physical soil parameters under two nitrogen fertilizer levels. In this study، by using one year field data of sillage corn in Varamin، the model-output sensitivity to field capacity، saturated water content، curve number، root growth factor، drainage coefficient and albedo was analyzed for two N-fertilizer levels (0 and 150 kg N/ha). To determine the response of model to changes of input parameters، model was run 80 times. After collecting data، the normalized sensitivity of each parameter was calculated using the program written in MATLAB environment. The results showed that the highest model sensitivity in the simulation of the yield in both treatments was shown to field capacity. But the response of the model to changes in input parameters was strongly influenced by the amount of fertilizer. Finally، by using the calculated relative sensitivity values، the relationship between probable error in estimating yield for both fertilizer treatments and error in estimation input data was presented. Useful and extensive use of crop models depends on understanding their behavior in response to probable errors in input parameters. The aim of this study was to assess the sensitivity of the simulated sillage-corn yield by the most commonly used crop model، CERES – Maize، to physical soil parameters under two nitrogen fertilizer levels. In this study، by using one year field data of sillage corn in Varamin، the model-output sensitivity to field capacity، saturated water content، curve number، root growth factor، drainage coefficient and albedo was analyzed for two N-fertilizer levels (0 and 150 kg N/ha). To determine the response of model to changes of input parameters، model was run 80 times. After collecting data، the normalized sensitivity of each parameter was calculated using the program written in MATLAB environment. The results showed that the highest model sensitivity in the simulation of the yield in both treatments was shown to field capacity. But the response of the model to changes in input parameters was strongly influenced by the amount of fertilizer. Finally، by using the calculated relative sensitivity values، the relationship between probable error in estimating yield for both fertilizer treatments and error in estimation input data was presented. Useful and extensive use of crop models depends on understanding their behavior in response to probable errors in input parameters. The aim of this study was to assess the sensitivity of the simulated sillage-corn yield by the most commonly used crop model، CERES – Maize، to physical soil parameters under two nitrogen fertilizer levels. In this study، by using one year field data of sillage corn in Varamin، the model-output sensitivity to field capacity، saturated water content، curve number، root growth factor، drainage coefficient and albedo was analyzed for two N-fertilizer levels (0 and 150 kg N/ha). To determine the response of model to changes of input parameters، model was run 80 times. After collecting data، the normalized sensitivity of each parameter was calculated using the program written in MATLAB environment. The results showed that the highest model sensitivity in the simulation of the yield in both treatments was shown to field capacity. But the response of the model to changes in input parameters was strongly influenced by the amount of fertilizer. Finally، by using the calculated relative sensitivity values، the relationship between probable error in estimating yield for both fertilizer treatments and error in estimation input data was presented. Useful and extensive use of crop models depends on understanding their behavior in response to probable errors in input parameters. The aim of this study was to assess the sensitivity of the simulated sillage-corn yield by the most commonly used crop model، CERES – Maize، to physical soil parameters under two nitrogen fertilizer levels. In this study، by using one year field data of sillage corn in Varamin، the model-output sensitivity to field capacity، saturated water content، curve number، root growth factor، drainage coefficient and albedo was analyzed for two N-fertilizer levels (0 and 150 kg N/ha). To determine the response of model to changes of input parameters، model was run 80 times. After collecting data، the normalized sensitivity of each parameter was calculated using the program written in MATLAB environment. The results showed that the highest model sensitivity in the simulation of the yield in both treatments was shown to field capacity. But the response of the model to changes in input parameters was strongly influenced by the amount of fertilizer. Finally، by using the calculated relative sensitivity values، the relationship between probable error in estimating yield for both fertilizer treatments and error in estimation input data was presented.