生物炭对棕壤NH3挥发、N2O排放及氮肥利用效率的影响

通过田间试验,采用封闭式酸吸收法和静态箱法,研究秸秆生物炭对棕壤玉米旱田NH_3挥发和N_2O排放以及氮肥利用效率的影响。试验设不施氮肥(对照CK)、单施氮肥(NB0)、施氮基础增施20 t·hm~(-2)生物炭(NB20)、施氮基础增施40 t·hm~(-2)生物炭(NB40)4个处理。结果表明,各施肥处理的NH3挥发量差异显著,表现为NB0NB20NB40,NB20和NB40分别比NB0降低24.07%和37.62%。NB20和NB40可显著降低N_2O排放量,分别比NB0降低21.76%和19.57%,而NB20和NB40之间差异不显著。NB20和NB40显著增加了土壤的p H、全氮和有机碳含量,降低了土壤的容重。相关分析表明,NH_3挥发量与土壤容重和铵态氮含量均呈极显著正相关,与土壤有机碳含量呈显著负相关;N_2O排放量与土壤容重呈显著正相关,与土壤硝态氮含量和有机碳含量呈显著负相关。与NB0相比,NB20提高了氮肥利用效率,玉米产量显著提高6.07%,而NB40降低了氮肥利用效率,玉米产量显著降低了13.88%。

Effects of biochar on NH3 volatilization, N2O emission and nitrogen fertilizer use efficiency in brown soil

A field experiment was conducted to investigate the effects of biochar on NH₃ volatilization, N₂O emission, and N fertilizer use efficiency in brown soil by acid absorption and static chamber method. Four treatments, including no N fertilizer(CK), N fertilizer(NB0), N fertilizer with 20 t·hm^-2 biochar(NB20) and N fertilizer with 40 t·hm^-2 biochar(NB40), were designed. Results showed that:Compared with NB0, NH₃ volatilization in NB20 and NB40 decreased by 24.07% and 37.62%, respectively, while N₂O emission in these two treatments reduced by 21.67%and 19.57%, with no significant difference between them; Soil bulk density was decreased, but soil pH, total nitrogen and organic carbon content were increased in NB20 and NB40; A significant positive correlation existed between NH₃ volatilization and soil bulk density or ammonium nitrogen concentration, and between N₂O emission and soil bulk density, whereas a negative correlation between NH₃ volatilization and organic carbon content, and between N₂O emission and nitrate-nitrogen concentration or organic carbon content; NB20 increased N fertilizer use efficiency and maize yield by 6.07%, while NB40 decreased the yield by 13.88%, as compared with NB0.