田间老化生物质炭对潮土氨挥发的影响

Effects of field-aged biochar on NH_(3) emissions under wheat-maize rotation

为了揭示不同用量生物质炭田间老化后对土壤氨挥发的影响,采用密闭通气法监测了小麦-玉米轮作下土壤氨挥发损失。试验设5个处理:不施肥(Control)、常规施氮(CN)以及常规施氮加3、6、12 t·hm^(-2)生物质炭(NB3、NB6、NB12)。结果表明:6 t·hm^(-2)和12 t·hm^(-2)生物质炭施用3 a后降低了小麦产量,但对玉米产量无影响;生物质炭显著降低了小麦籽粒氮吸收量,但3 t·hm^(-2)和6 t·hm^(-2)生物质炭增加了玉米籽粒氮吸收量。田间老化生物质炭显著降低了小麦季NH3挥发,相反增加了玉米季NH3挥发,但是6 t·hm^(-2)和12 t·hm^(-2)生物质炭显著降低了年度NH3挥发累积量。6 t·hm^(-2)生物质炭田间老化3 a后显著降低了单位小麦产量NH3排放量,对单位玉米产量NH3排放量无显著影响,总体降低了年度单位产量NH3排放量。研究表明,田间老化3 a后,6 t·hm^(-2)和12 t·hm^(-2)生物质炭处理显著降低了年度NH3挥发量。

Using a continuous air-flow enclosure method,soil NH3 volatilization under wheat-maize rotation was monitored to explore the effect of different doses of field-aged biochar on NH3 volatilization.The field experiment included five treatments:no fertilization(Control);conventional N application(CN);conventional N fertilizer and 3 t·hm^(-2)(NB3),6 t·hm^(-2)(NB6),and 12 t·hm^(-2)(NB12)biochar.Biochar application after three years reduced wheat yield but had no apparent effect on maize yield.Additionally,biochar reduced the grain N uptake by wheat,while the NB3 and NB6 treatments increased the N uptake.In the fourth year after application,biochar reduced the cumulative NH3 emissions and NH3 emission factor of the applied N during the wheat season but increased these values during the maize season.The NB6 and NB12 treatments reduced the annual NH3 emissions.The NB6 treatment did not affect the yield-scaled NH3 emissions in the maize season but reduced the yield-scaled NH3 emissions in the wheat season,thereby reducing annual yield-scaled NH3 emissions.