Impact of Eight‐Year Topsoil Removal and Soil Amendments on Soil Carbon Dioxide Emission in an Eroded Chinese Mollisols

Abstract

Soil erosion is a serious environmental issue. Information in the severity of soil erosion on CO 2 emission is limited. A soil erosion simulation experiment was used to examine the infl uence of topsoil removal and cattle manure amendment on soil CO 2 emission for a cultivated Mollisols in Northeast China. Soil CO 2 fl ux was determined during corn (Zea mays L.) growing season. Our results showed that aft er 8-yr treatment, topsoil removal decreased CO 2 emission in the order of 30 cm < 10 cm < 5 cm < 20 cm < 0 cm under chemical fertilizer treatment alone and 20 cm < 10 cm < 30 cm < 5 cm < 0 cm for cattle manure addition. At the same erosion depth, cattle manure addition increased soil CO 2 emission compared to chemical fertilizer alone treatment. During growing season, the CO 2 fl ux pattern changed from one peak in chemical fertilizer alone treatment to two peaks in cattle manure addition treatments. In the chemical fertilizer alone system, only microbial biomass carbon (MBC) and dissolved organic carbon (DOC) fractions were signifi cantly correlated with total CO 2 emission. However, cattle manure addition changed the relationship between soil C fraction and CO 2 emission. Th e MBC, particulate organic carbon (POC), and light fraction organic carbon (LOC) were signifi cantly positively correlated with total CO 2 emission. Th ough on-site CO 2 emission was signifi cantly reduced aft er the soil was severely eroded, restoration of eroded soil productivity by cattle manure amendments might release more CO 2 emission into the atmosphere. Adoption of cattle manure application to eroded Mollisols needs considering the potential negative impact of more CO 2 emission.

Influence of Eucalyptus Plantation on Soil Organic Carbon and Its Fractions in Severely Degraded Soil in Leizhou Peninsula, China

“…LOC is an unstable organic carbon fraction in soil which is easily lost with soil erosion [14,62]. In the topsoil of the 0-10 cm layer, DOC/SOC, EOC/SOC, and POC/SOC were significantly higher in RE than in RNE.…”