Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6368523 | Agricultural Systems | 2015 | 15 Pages |
Abstract
The aim of this study was to evaluate the potential of the Decision Support System for Agrotechnology Transfer - Cropping System Model (DSSAT-CSM) using the CENTURY-based soil module to simulate long-term trends of grain yield, soil organic C (SOC) and soil organic N (SON) based upon 14-year data from a spring maize (Zea mays L.) and winter wheat (Triticum aestivum L.) cropping system study conducted in the Loess Plateau of Northwestern China. There were four treatments including no fertilizer (N0), 90âkgâNâhaâ1 from urea (N90), 30âkgâNâhaâ1 from straw plus 90âkgâNâhaâ1 from urea (SN90), and 40âkgâNâhaâ1 from cattle manure plus 90âkgâNâhaâ1 from urea (MN90) selected in this study. The DSSAT-CSM showed a good to excellent agreement for simulating maize yields with normalized root mean square error (nRMSE)ââ¤â19%, index of agreement (d)â>â0.91 and modeling efficiency (EF)ââ¥â0.56, and a moderate to good agreement for wheat yields with nRMSEââ¤â22%, dâ>â0.89 and EFâ>â0.46 for N90, SN90 and MN90 treatments. The model simulated SOC in the 0-20âcm depth for both SN90 and MN90 very well with nRMSEâ<â13% and dâ>â0.63 and moderately for N90 and N0. The simulated topsoil SON matched the measured data for N90, SN90 and MN90 very well with nRMSEâ<â7%, dâ>â0.77 and EFâ>â0.15, whereas the simulation for N0 was poor. Both maize wheat yields were found to be more sensitive to the fertilizer N rates in humid than drought soil conditions. The sensitivity of grain yields for either maize or wheat to generated growing season precipitation was affected by fertilizer N rate. The simulated soil nitrate-N (NO3-N) in soil profile and the NO3-N leaching below 150âcm increased with the increased fertilizer N rates as expected. The periods occurring high NO3-N leaching were along with drainage events mainly in the next fallow periods. Therefore, this study found that the DSSAT-CSM has a large potential to assess the impacts of various agricultural practices on crop growth, soil C and N dynamics in the semi-arid to semi-humid region of the Loess Plateau, and could contribute to selecting the optimum management practices.
Keywords
Related Topics
Life Sciences
Agricultural and Biological Sciences
Agricultural and Biological Sciences (General)
Authors
Zhuo Ting Li, J.Y. Yang, C.F. Drury, G. Hoogenboom,