耕作方式对土壤有机碳库的影响

Effects of Different Tillage Methods on Soil Organic Carbon Pool

通过在甘肃中部干旱半干旱农业区进行6a的田间定位试验,探讨了传统耕作(T)、免耕(NT)、免耕+秸秆覆盖(NTS)以及传统耕作+秸秆还田(TS)等处理对土壤有机碳库的影响。结果表明,在0-30cm土层中,NTS、TS、NT处理土壤有机碳含量分别比T处理提高了5.09%、2.64%和4.08%;与T处理相比,NTS、TS、NT处理土壤微生物量碳含量分别增加了69.67%、47.72%和33.22%。NTS、TS、NT处理有利于土壤有机碳的累积。不同处理(NTS、TS、NT、T)条件下土壤有机碳和微生物量碳在土壤剖面分布是随着土层深度的增加而呈现递减趋势。

In order to discuss the soil organic carbon pool under the different tillage methods in loess plateau semiarid area which was established in Dingxi of Gansu, the soil under different tillage conditions for 6 years was analyzed by chemical method. The results showed that notill with straw cover（NTS）, conventional tillage with straw incorporated（TS） and no-till without straw cover（NT） increased soil organic carbon contents compared with conventional tillage without straw（T） by 5.09%42.64% and 4.08% respectively; no-till with straw cover（NTS）, conventional tillage with straw incorporated（TS） and no-till without straw cover（NT） increased contents of microbial biomass carbon of soil compared with conventional tillage without straw（T） by 69.67%, 47.72% and 33.22% respectively. Conventional tillage with straw incorporated （TS）, no-till without straw cover（NT） and conventional tillage with straw incorpomted（TS） to be more advantageous in developing the content of soil carbon. Soil organic carbon and microbial biomass carbon decreased with the increasing depth in soil profiles under different treatments （NTS, TS, NT and T）.