生物炭和有机肥对华北农田盐碱土N_2O排放的影响

Effects of Biochar and Organic Fertilizer on Saline-alkali Soil N_2O Emission in the North China Plain

基于山东滨州地区冬小麦-夏玉米轮作大田试验,探究了施用生物炭和有机肥对夏玉米季土壤氧化亚氮(N_2O)排放的影响,为盐碱土壤N_2O增汇减排提供理论依据.试验按照不同处理氮、磷、钾含量相同原则,设置对照CK[N:0.2t·(hm^2·a)^(-1),P_2O_5:0.12 t·(hm^2·a)^(-1),K_2O:0.2 t·(hm^2·a)^(-1)]、C1[5 t·(hm^2·a)^(-1)生物炭]、C2[10 t·(hm^2·a)^(-1)生物炭]、C3[20 t·(hm^2·a)^(-1)生物炭]、M1[7.5 t·(hm^2·a)^(-1)有机肥]、M2[10 t·(hm^2·a)^(-1)有机肥]这6个处理.结果表明,施加生物炭和有机肥对土壤N_2O排放影响趋势基本一致,排放高峰均出现在施肥(基肥和追肥)后,累积排放量占整个生育期排放量的近一半;与CK相比,C1、C2分别降低N_2O排放的45.3%、31.6%,而C3、M1、M2分别增加了17.3%、37.4%、27.6%.施加生物炭和有机肥均会对土壤N_2O排放产生影响,施加生物炭可以降低N_2O排放,而施加有机肥则促进了N_2O排放.因此,生物炭对减少农田N_2O排放具有巨大潜力.

Based on the winter wheat-summer maize rotation field experiment, the effects of biochar and organic fertilizer on saline-alkali soil N2 O emissions in the summer maize season were studied in Binzhou in the Shandong Province to provide a theoretical basis for reducing N2 O emissions from saline-alkali soil. The experiment includes six treatments with three replications： CK [ N： 0. 2 t·（hm2·a） - 1 , P2 O5： 0. 12 t·（hm2·a） - 1 , K2 O： 0. 2 t·（hm2·a） - 1 ], C1 [ 5 t·（hm2·a） - 1 biochar], C2 [ 10 t·（hm2·a） - 1 biochar], C3 [20 t·（hm2·a） - 1 biochar], M1 [7. 5 t·（hm2·a） - 1 organic fertilizer], and M2 [10 t·（hm2·a） - 1 organic fertilizer]. The same nitrogen, phosphorus, and potassium fertilizer was applied for each treatment. The results showed that the dynamic trend of the soil N2 O fluxes among different treatments were similar. The peak N2 O emissions occurred after fertilization （base fertilizer and topdressing）. The N2 O cumulative emission fluxes accounted for nearly half of the emissions during the whole growth period, and the N2 O emissions of the C1, C2, and C3 treatments were lower than that of CK after fertilization. Compared with CK, the N2 O cumulative emissions from C1 and C2 were reduced by 45. 3% and 31. 6% , respectively, but C3, M1, and M2 increased by 17. 3% , 37. 4% , and 27. 6% , respectively. Biochar and organic fertilizer both affected N2 O emission fluxes. Applying biochar can reduce N2 O emissions, while organic fertilizer can increase N2 O emissions. In summary, biochar has a great advantage in reducing N2 O emissions in the farmland.