Dr Xinliang Dong1, Prof Hongyong Sun1, Dr Bhupinderpal Singh2
1The Center For Agricultural Resources Research, Institute Of Genetics And Developmental Biology, CAS, Shijiazhuang, China, 2University of New England, Armidale, Australia
Fertilization is the most common way to supply nutrients to the soil and to maintain crop productivity in the agricultural ecosystem, which may further influence soil organic carbon (SOC) accumulation rate. In this study, we set up a long-term fertilization field experiment in the winter wheat-summer maize cropping system. The treatments include no fertilization (Ct), nitrogen (N, 104.5 kg ha-1 N), phosphorous (P, 104.5 kg ha-1 P2O5) and N combined with P (NP, 104.5 kg ha-1 N combined with 104.5 kg ha-1 P2O5) fertilizer application with or without potassium (K, 104.5 kg ha-1 K2O); totally 8 treatments. After 21 years of fertilization, N application did not increase soil total N content, but P application significantly increased soil total P contents by 33.9%. The single application of N or P did not significantly affect SOC content, while the NP combination significantly increased SOC contents by 22.1% and 29.6% compared to Ct in the no K and K treatments, respectively, The natural 13C abundance approach and the SOC contents suggested that the NP combination increased wheat-derived SOC by 37.5% and 49.8% in the no K and K treatments; however, fertilization had no impact on maize-derived SOC content. Wheat-derived SOC was positively correlated to the wheat yield, while maize-derived SOC was not correlated to the maize yield, which indicated that wheat-derived SOC accumulated more than maize-derived SOC in the wheat-maize cropping system. Our results indicate that N combined with P application is more beneficial than N or P alone to enlarge SOC sequestration, especially for the wheat-derived SOC.
Xinliang Dong studied soil science at the China Agriculture University, where he earned his PhD in 2017. Dr. Dong’s research focuses on the dynamics of soil organic matter derived from different plant sources, and biochar effect on soil organic carbon fractionations.