Prof. Shulan Zhang1, Miss Wenjing Yang1
1Northwest A&f University, Yangling, China
Understanding soil carbon dynamics affected by agricultural practices in dryland ecosystems is helpful in mitigating climate change. This study investigated the responses in soil organic carbon (SOC) and inorganic carbon (SIC) distribution and storage in 3 m depth of soil profiles under long-term applications of chemical fertilizers (NPK) and organic manure plus NPK fertilizers (MNPK) in a loess soil in northwest China. The SOC contents decreased with increasing soil depth. The fertilizer treatments significantly enhanced the SOC concentrations at the top 20 cm depth as compared with the control (CK, no nutrient put). The amount of SOC to the depth of 100 cm in the MNPK-treated soil was significantly higher than those in the CK- and NPK-treated soils. The SIC contents showed higher values at deeper layers than at the top layers of the soil profiles. Application of MNPK significantly increased the SIC contents at the 60–140 cm depth but decreased the SIC contents at the 180–300 cm layer. Correspondingly, the SIC storage to the depth of 100 cm was significantly higher under the MNPK treatment than under the CK and NPK treatments. However, the amounts of SIC to the depth of 300 cm were not significantly different among treatments. It is concluded that manure application enhanced both SOC and SIC accumulation at top one-meter depth, but not three-meter depth.
Shulan Zhang, born on the 9th of November 1966 in Inner Mongolia, China. Currently she is a professor at College of Natural Resources and Environment, Northwest A&F University, China. Her research is long-term effects of fertilization on crop productivity, nutrient use efficiency and soil carbon sequestration.