Variability of soil organic carbon in plough layers and its impact factors in a coastal reclamation area on south coast of Hangzhou Bay.

作者：Xiaojia Chen, Wanzhu Ma, Wang Fei, Zhouqiao Ren, Fangjin Qin, Xunfei Deng, LU Xiao-nan · 发表于：DOAJ (DOAJ: Directory of Open Access Journals) · 年份：2015 · DOI：10.3785/j.issn.1008-9209.2015.01.281 · 研究领域：Agriculture, Soil, Plant Science、Environmental Changes in China

Soil organic carbon (SOC) has been identified as a key element in the global carbon balance. The studies on spatial distribution and variation of SOC are very helpful for soil monitoring and soil mapping. There are few reports on spatial variability of SOC concentration under different crops in plough layers in coastal reclamation areas. This study is intended to determine spatial distribution of SOC storage and its impact factors in the coastal reclamation area on south coast of Hangzhou Bay.A total of 2 353 soil profiles in plough layer were collected from 2007 to 2009 in coastal reclamation area of Hangzhou Bay. SOC concentrations of soil samples were determined according to the dichromate oxidation method with a factor of 0.58. Geo-statistical methods were used for interpolation and spatial grids of crop fields, and random forest method was employed to estimate explanation capability and eliminate inter-correlations among impact factors.The average contents of SOC in plough layer is 9.78 g/kg, varied from 1.04 g/kg to 38.22 g/kg, indicating a moderate degree of variability (variable coefficient=65.24%). For three different cropping patterns, including Vegetables, Rice-Rice and Orchards, the soil points were 1 858, 327 and 168, respectively. Specifically, Rice-Rice has the highest SOC content (18.13 g/kg), followed by Vegetables (8.44 g/kg) and Orchards (8.30 g/kg). Under different soil types, significant differences were observed among paddy soil, coastal saline and fluvi...