Soil Organic Carbon Dynamics Responses to Soil Fertility in the Agricultural Regions of China
2017
Han, D. L. | Zhu, Xi-Ping | Jia, H. T. | Yu, P. J.
Increasing the soil organic carbon (SOC) content in croplands can not only improve the soil fertility, but also mitigate climate warming. To evaluate the extent of soil organic carbon density (SOCD) and SOC stock, the examination and prediction of the changes in SOC are essential. Using a field denitrification–decomposition model simulates the dynamics of SOC in the cultivated layer (Ap horizon, all soil depths of sites were 0–30 cm) across all croplands in China. The model simulations results showed that the SOCD and stock approach 3.69 ± 1.09 kg C m⁻² and 4.73 ± 1.39 Pg C for the 128.2 M ha croplands in 2040, respectively. Interestingly enough, changes in SOC content (ΔSOC) and soil total nitrogen, soil available phosphorus, and soil available potassium showed negative correlations (P < 0.01), while soil pH value had positive (P < 0.01) correlation with ΔSOC in the cultivated layer. Excess fertilizer can be a disadvantage for SOC accumulation, Chinese croplands have relatively low SOCD and used good amount of fertilizer in comparison with the global average, but the croplands could have great potentials for soil carbon stock under better agricultural “watershed” management practices.
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