Effect of Tillage Systems on Glomalin-Related Soil Protein in an Aquic Brown Soil

Conservation agriculture such as no tillage may increase soil carbon sequestration. The main objective of this study was to examine the profile distribution of soil organic carbon (SOC) and glomalin-related soil protein (GRSP) under no-tillage (NT), conventional tillage,(CT, mouldboard ploughing) and fallow (FF, unmanaged field lasting for 6 years grown with weeds) treatments to a 1 m depth based on a 6-year tillage experiment in Northeast China. The results showed that NT enhanced SOC concentration only at the surface depths of 0-5 and 5-15 cm, but not at deeper depths. SOC concentration at the top 0-5 cm depth was significantly higher in FF than in NT treatments, but significantly lower at the 5-15 and 15-30 cm depths. Compared to CT, NT significantly enhanced the concentrations of TG and EEG throughout the soil profile. In addition, SOC was positively correlated with TG and EEG in present study. Our study indicates that GRSP may be a useful indicator for distiguishing tillage systems on soil carbon sequestration across soil horizons.