施用生物炭和硝化抑制剂对菜地N_2O排放和蔬菜产量的影响

Effects of biochar and nitrification inhibitor amendment on N_2O emissions and vegetable yield under intensive vegetable production

[目的]生物炭或硝化抑制剂已被广泛应用于农田生态系统以增加作物产量、提高氮肥利用率。[方法]采用静态暗箱-气相色谱法,研究了生物炭和硝化抑制剂(DCD)对江苏某地酸性菜地周年氧化亚氮(N_2O)排放和蔬菜产量的综合影响。试验设置4个处理:U(尿素)、UB(尿素配施生物炭)、UD(尿素配施DCD)和UBD(尿素配施生物炭和DCD)。[结果]施用生物炭处理(UB、UBD)的土壤有机碳含量平均显著增加25.7%,施用DCD处理(UD、UBD)的土壤p H值平均显著提高18.1%。与U处理相比,UB、UD和UBD处理的蔬菜总产量分别显著提高103%、129%和134%,同时减少低温阶段(2012年11月至2013年5月)N_2O排放量;虽对N_2O周年总排放量没有影响,但显著降低单位产量N_2O排放量。与UB和UD处理相比,UBD处理对N_2O排放、蔬菜产量和周年单位产量N_2O排放量均没有显著影响。[结论]在常规施肥条件下,施用生物炭或硝化抑制剂均有效增加作物产量,减少单位产量N_2O排放量,但二者联合施用并不优于单施。

[Objectives] Biochar or nitrification inhibitor addition to soils has been frequently proposed as strategies to increase crop yield and nitrogen use efficiency in agriculture.To investigate the overall effects of maize straw biochar and nitrification inhibitor （DCD） incorporation on N2O effluxes and vegetable yields,a 1-yr field experiment was conducted using the static chanber and gas chromatography method in an acidic vegetable farm from Jiangsu,China.[Methods] The experiment included four treatments：U：urea;UB：urea＋biochar（30 t·hm^-2）;UD：urea＋DCD;UBD：urea＋biochar（30 ·hm^-2） ＋DCD.[Results] Results showed that biochar addition（UB and UBD treatments）greatly incrcased soil organic carbon on average by 25.7% compared with treatments without biochar addition.Nitrification inhibitor（UD and UBD treatments） significantly increased soil pH on average by 18.1% （P〈0.05） compared with treatments without nitrification inhibitor addition.Additionally,compared with the U treatment,the UB,UD and UBD treatments significantly increased vegetable yield by 103%,129% and 134%,respectively （P〈 0.05）and significantly reduced seasonal N2O emissions during the cold period（2012-11 to 2013-05）.Although they had no significant influences on the annual N2O emissions,biochar and nitrification inhibitor significantly reduced yield-scaled N2O emissions.Compared with the UB and UD treatments,the UBD treatments had no significant effects on annual N2O emissions,vegetable yield and yield-scaled N2O emissions.[Conclusions] Therefore,under the conditions of conventional fertilization,the application of biochar or nitrification inhibitor is effective in both increasing crop yield and reducing yield-scaled N2O emissions,though the combination of biochar and DCD is not superior to single application in the intensified vegetable field.