秸秆还田对科尔沁地区农田土壤有机碳组分及其稳定性的影响

Effects of Straw Returning on Soil Organic Carbon Fractions and Stability in the Horchin Region, Inner Mongolia

以休闲草地为对照,采用分层取样法研究了科尔沁地区秸秆还田以及常规耕作对0~30 cm浅剖面土壤有机碳组分及其氧化稳定性的影响.结果表明不同处理下土壤总有机碳、易氧化有机碳含量和有机碳氧化稳定性差异显著.0~30 cm各土层总有机碳平均含量秸秆还田处理最高,其次为休闲草地,常规耕作总有机碳平均含量最低,仅为7.09±0.22 g/kg,显著低于其它处理.秸秆还田处理较常规耕作每年多截获有机碳0.70 g/kg.休闲草地土壤有机碳稳定性最高,常规耕作次之,二者间差异不显著,但是均显著高于秸秆还田处理.

A stratified sampling method was used to study the effects of straw returning and conventional tillage on soil organic carbon fractions and their oxidation stability at 0-30 cm in Horchin Region. Significant differences were found in soil total organic carbon, organic carbon content and organic carbon oxidation stability under different treatments. The average content of total organic carbon in the 0-30 cm soil layer was the highest in straw returning treatment, followed by fallow grassland, and lowest in conventional tillage at 7.09±0.22 g/kg, which was significantly lower than that of other treatments. Compared with conventional tillage, straw returned to field more than 0.70 g/kg of organic carbon. The stability of soil organic carbon was highest in fallow grassland, and the difference between the two groups was not significant but was significantly higher than that of straw returning treatment.