Soil carbon sequestration and crop yield in response to application of chemical fertilizer combined with cattle manure to an artificially eroded Phaeozem

Organic manure application is a feasible approach to alleviate the deterioration of soil erosion on soil organic carbon (SOC). However, to what extent manure application can restore carbon contents in SOC fractions in the eroded Phaeozems remains unknown. A 5-year field experiment was conducted in an artificially eroded Phaeozem with up to 30cm of topsoil being removed. Chemical fertiliser, or chemical fertiliser plus cattle manure was applied. The contents of SOC were 23.6, 21.6 and 15.1gC kg(-1) soil for non-soil removal control, 10 and 30cm of topsoil removal, respectively. Compared with the chemical fertiliser-only treatment, the chemical fertiliser plus manure application markedly increased SOC contents by 30-45% and C sequestration rates by 7.1-9.0-fold, especially in the fraction of 53-250 m particulate organic carbon. However, with manure applied, SOC content in the fraction of mineral associated organic carbon in the 30cm topsoil-removed soil was 2.9g kg(-1), 14.7% less than control (3.4g kg(-1)). The combination of chemical fertliser and manure application effectively restored SOC in the eroded Phaeozems mainly through increasing the size of 53-250 m particulate organic C fraction, but did not improve the SOC stability in severely eroded Phaeozems.