Variation of soil organic carbon and the influencing factors in croplands of Liaoning Province,China
Northeast China is an important grain production base at the national level.The content of soil organic carbon in this area has been decreasing year by year due to the irrational use.In this study,a total of 444 soil sam-ples were collected from maize and rice fields(two typical croplands)in Liaoning Province.The contents of soil or-ganic carbon and its components(microbial biomass carbon,necromass carbon,and dissolved organic carbon)as well as their influencing factors were analyzed.The results showed that the contents of soil organic carbon(SOC),microbial biomass carbon(MBC)and MBC/SOC in rice field were higher than those in maize field,while the con-tents of dissolved organic carbon,bacterial necromass carbon,fungal necromass carbon,and total necromass car-bon in rice field were lower than those in maize field.SOC in maize and rice fields had a significant positive correla-tion with MBC and microbial necromass carbon,while SOC in rice field had a lower slope with MBC and microbial necromass carbon.Results of random forest model analysis showed that soil C/N ratio and fungal necromass carbon were the key factors influencing SOC in maize and rice fields,with higher interpretation for SOC in maize field.There were significant differences in SOC components and key influencing factors between maize and rice fields.Mi-crobial turnover process had stronger influence on SOC in maize field,while soil properties had a dominant influ-ence on SOC content in rice field.This study provides basic data and a theoretical foundation for the scientific regu-lation of soil organic carbon in the croplands of Northeast China.
国家科技期刊平台
NSTL
万方数据
