Abstract:

【Objective】 The objective of this study was to quantify the impacts of soil organic carbon (SOC) content on grain yield of crops. 【Method】 A biogeochemical model (DNDC) was used in the study. Data on climate, soil properties, and farming management regimes of cropping systems were collected from six typical agricultural zones (Northeast, North, Northwest, Mid-South, East and Southwest regions of China, respectively) and integrated into a GIS database to support the model runs. 【Result】 According to the model, if the initial SOC content in the cropland was increased by 1 g C?kg-1, the crop yield may be increased by 176 kg?hm-2 for maize in the Northeast region, 454 kg?hm-2 for a maize and wheat rotation in the North region, 328 kg?hm-2 for maize in the Northwest region, 185 kg?hm-2 for single-rice in the Midsouth region, 266 kg?hm-2 for double- rice in East region, and 229 kg?hm-2 for rice and wheat rotation in Southwest region. 【Conclusion】There is a great potential for enhancing the crop yield by improving the SOC content in cropland in each region of China.

Key words: soil organic carbon, grain yield, carbon sequestration, DNDC model