生物质炭基复合肥施用对砂质水稻土NH3挥发和N2O排放的影响OA

This study investigated the effect of substituting commercial compound fertilizers with rice husk biochar-based compound fertilizers on ammonia(NH3)volatilization and nitrous oxide(N2O)emission in sandy paddy,as well as on rice yield and agronomic efficiency of nitrogen fertilizers,to reduce the amounts of fertilizer application and emissions in rice production.This study conducted a soil column experiment throughout the key growth period of rice,with four treatments:CK(no fertilization),compound fertilizer A(N-P2O5-K2O=15-10-10),and compound fertilizer B(N-P2O5-K2O=15-15-15),and biochar-based compound fertilizer(N-P2O5-K2O=15-10-10,with 11％biochar).Soil NH3 volatilization and N2O emissions throughout the key growth period of rice were determined using the continuous flow method and static chamber method.The effects of biochar-based compound fertilizer application on soil NH3 volatilization,N2O emissions,and rice yield under equal nitrogen fertilization conditions,as well as its relationship with changes in key environmental factors were investigated.In comparison with the treatments applying compound fertilizers A and B,the application of biochar-based compound fertilizer resulted in a significant enhancement by 55.72％and 56.85％in NH3 volatilization from paddy soil.Conversely,it led to a substantial decrease in N2O emissions from the soil,achieving reductions of 67.82％and 58.03％relative to the compound fertilizers A and B,respectively.The soil NH3 volatilization was significantly correlated with soil pH and urease activity(P＜0.05),while soil N2O emission was highly significantly correlated with the content of soil NH4+-N and NO3-N,the pH value of water on the soil column surface,and the soil NH4+-N content and yield(P＜0.01).This indicates that under different fertilization conditions,soil pH and urease activity are important factors driving NH3 volatilization,whereas N2O emissions are influenced by the content of soil NH4+-N and NO3-N,the pH value and the NH4+-N concentration of surface water.Nevertheless,no substantial differences were observed in terms of rice yield and agronomic efficiency when comparing the application of biochar-based compound fertilizer with that of conventional compound fertilizer treatments.In rice cultivation,the application of biochar-based fertilizer as a substitute for conventional commercial compound fertilizers can achieve stable rice production while reducing soil N2O emissions but may also increase the risk of NH3 volatilization from paddy soil.