Structural Convergence of Maize and Wheat Straw during Two-Year Decomposition under Different Climate Conditions
Structural Convergence of Maize and Wheat Straw during Two-Year Decomposition under Different Climate Conditions
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DOI：
10.1021/es300522x
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发表时间：
2012-07-03
影响因子：
11.4
通讯作者：
Cao, Xiaoyan
中科院分区：
文献类型：
--
作者：
Wang, Xiaoyue;Sun, Bo;Cao, Xiaoyan
秸秆分解在土壤固碳中起着重要作用。凋落物质量和气候条件是影响秸秆分解的关键因素。研究了小麦和玉米秸秆在冷温带、暖温带和中亚热带气候条件下的腐解特性，并考察了不同气候条件下秸秆腐解过程中化学结构的相似性。将秸秆放入0.074 mm筛目大小的垃圾袋中以排除土壤动物，并将其埋在位于上述气候区域的三个实验站的黑土地块中以排除土壤类型的影响。小麦秸秆和玉米秸秆的腐解速率常数随温度的升高而线性增加，前者对温度的反应更为敏感。气候条件和秸秆品质对秸秆残体结构的影响在前半年显著，后半年则逐渐降低。小麦秸秆和玉米秸秆的降解特征相同，O/N-烷基碳和二-O-烷基碳减少，烷基碳、芳香碳、芳香C-O基团和COO/N-C=O基团增加。结果表明，两种秸秆在不同气候条件下经过2年的腐解后，其化学成分趋于相似。
Straw decomposition plays an important role in soil carbon sequestration. Litter quality and climate condition are considered to be key factors that regulate straw decomposition. This study investigated the decomposition characteristics of wheat and maize straw under cold temperate, warm temperate, and midsubtropic climate conditions, and examined whether the chemical structures of straw residues became similar during decomposition under different climate conditions. Straws were put in 0.074-mm-mesh size litter bags to exclude soil fauna and buried in black soil plots at three experimental stations located in the aforementioned climate regions to rule out the impact of soil type. The decomposition rate constants of wheat straw and maize straw increased linearly with temperature, and the former was more sensitive to temperature. Climate conditions and straw quality had marked effects on the residual material structure in the first half year of decomposition, but then decreased. Wheat and maize straw showed common decomposition characteristics with a decrease of O/N-alkyl carbons and di-O-alkyls, and a simultaneous increase of alkyl carbons, aromatic carbons, aromatic C-O groups, and COO/N-C=O groups. Overall, the results indicated that the chemical compositions of the two types of straw became similar after 2-year decomposition under different climate conditions.