Straw-returning reduces the contribution of microbial anabolism to salt-affected soil organic carbon accumulation over a salinity gradient  

作　　者：Yingdong Huo Guoqing Hu Xu Han Hui Wang Yuping Zhuge 

机构地区：[1]National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources,College of Resources and Environment,Shandong Agricultural University,Taian 271018,China

出　　处：《Soil Ecology Letters》2023年第4期13-18,共6页土壤生态学快报（英文）

基　　金：supported by the National Key Research and Development Program(2021YFD190090101),Natural Science Foundation of Shandong Province(ZR2022MD093),and China Postdoctoral Science Foundation(2018M632702).

摘　　要：●In low-salinity soil,straw-returning did not change necromass contribution to SOC.●In medium-salinity soil,straw-returning reduced necromass contribution to SOC.●Straw-returning reduced POC contribution to SOC in low-salinity soil.●Straw-returning increased POC contribution to SOC in medium-salinity soil.●Salinity affects the contribution of microbial-derived and plant-derived C to SOC.Salinization affects microbial-mediated soil organic carbon(SOC)dynamics.However,the mechanisms of SOC accumulation under agricultural management practices in salt-affected soils remain unclear.We investigated the relative contribution of microbial-derived and plant-derived C to SOC accumulation in coastal salt-affected soils under straw-returning,by determining microbial necromass biomarkers(amino sugars)and particulate organic C(POC).Results showed that,straw-returning increased necromass accumulation in low-salinity soil but did not change its contribution to SOC.In medium-salinity soil,straw-returning did not increase necromass accumulation but decreased its contribution to SOC.In low-and medium-salinity soils,the contribution of POC to SOC showed the opposite direction to that of the necromass.These results suggest that under straw-returning,the relative contribution of microbial-derived C to SOC decreased with increasing salinity,whereas the reverse was true for plant-derived C.Our results highlighted that straw-returning reduces the contribution of microbial anabolism to SOC accumulation in salt-affected soils with increasing salinity.

关 键 词：amino sugars crop straw-returning soil organic carbon particulate organic carbon soil salinization 

分 类 号：S154.3[农业科学—土壤学]