Stability of soil organic matter accumulated under long-term use as a rice paddy

文献类型： 外文期刊

第一作者： Nakahara, Shiko

作者： Nakahara, Shiko;Sugiura, Yuki;Watanabe, Akira;Zou, Ping;Fu, Jianrong;Ando, Ho;Cao, Zhihong;Nakamura, Toshio

作者机构：

关键词： Soil organic carbon/nitrogen in long-term use as an irrigated rice is analyzed;Chemical structure and biodegradability indicate no increase in stability;Enhanced accumulation of recently generated organic matter is suggested

期刊名称：JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES （ 影响因子：3.822； 五年影响因子：4.566 ）

ISSN：

年卷期：

页码：

收录情况： SCI

摘要： To understand the mechanism responsible for the enhanced accumulation of soil organic matter (SOM) under long-term use as a rice paddy, soil samples from the plow layer from 16 fields that have been used for irrigated rice production from5 to 2000 years in the Hangzhou Bay, China, were analyzed. The humin in silt/clay particles was isolated as a representative relatively stable SOMpool, and isotopic signatures (δ13C, δ15N, and 14C concentration), 13C nuclear magnetic resonance (NMR) spectra, and biodegradability in an incubation were examined. The amounts of C and N in the bulk soil, silt/clay, and silt/clay-humin increased with increasing period of use as a rice paddy within the east and west zones, respectively. The degree of humification determined for humic acids indicated that the progression of humification did not contribute to the accumulation of C beyond 100 years. The δ15N of silt/clay-humin suggested an increase in organic N derived from chemical fertilizer or recent biological fixation with increasing amount of this fraction. The 14C concentration showed a negative correlation with the amount of silt/clay-humin C. The structural property with regard to 13C NMR spectra and biodegradability of the silt/clay-humin remained constant with the length of use as a rice paddy or 14C concentration. These results suggest that the larger C or N accumulation in the soils with a longer rice paddy history can be attributed to an enhancement in the accumulation of recently generated SOM rather than the stable accumulation of humus over the years.

分类号： Q15

  • 相关文献
作者其他论文 更多>>

微信小程序