不同肥料施用对设施菠菜地NH3挥发和N2O排放的影响

以湖南设施菠菜地为研究对象,采用通气法和静态箱-气相色谱法研究了设施菠菜生长季施用工厂化堆肥(SC)、农民传统堆肥(SS)和单施化肥(FC)对土壤NH_3和N_2O排放的影响.结果表明在同等施氮水平下,与FC相比,SC处理能减少NH_3和N_2O排放量,分别减少52.9%和95.12%(P0.01);SS处理则增加NH_3挥发量24.8%,减少N_2O排放量48.8%.不同处理NH_3损失率分别为SS(10.97%)FC(4.19%)SC(2.74%);N_2O排放系数分别为FC(4.50%)SC(2.21%)SS(0.60%);与FC处理相比,SC处理条件下菠菜产量和作物吸氮量分别降低19.61%和13.20%,差异不显著;SS处理则显著降低27.9%和40.0%(P0.05).在该地区冬季设施菠菜田中,影响NH_3和N_2O排放的主要因素为土壤水分,环境温度不是此研究中影响气体排放的主要因素.因此,畜禽养殖固体废弃物经过不同处理后作为有机肥施入菠菜田,SC处理的菠菜可保证产量的同时,减少NH_3挥发和N_2O排放损失.

Emission of NH3 and N2O from Spinach Field Treated with Different Fertilizers

Agricultural management techniques such as fertilizer or manure application have substantial influence on NH₃ and N₂O emissions and, by understanding this influence, management strategies can be developed to reduce them. An experiment was conducted in a greenhouse at Hunan Agricultural University during 2012 to 2013, to investigate effects of different fertilizers on NH₃ and N₂O emissions. The treatments included control without fertilizer (CK), swine composting fertilizer (SC), stored swine manure fertilizer (SS), and chemical fertilizer (FC). The fluxes of NH₃ and N₂O were collected by venting method and static-chamber method, respectively. The results showed that during the spinach growth season, compared with FC, loss of both NH₃ and N₂O for SC were reduced by 52.9% and 95.12%, respectively(P<0.01). However, loss of NH₃ for SS increased by 24.8%, and loss of N₂O reduced by 48.8% compared with FC. Loss rate of NH₃ were SS (10.97%) > FC (4.19%) > SC(2.74%), and emission coefficient for N₂O were FC(4.50%) > SC(2.21%) > SS(0.60%). Yield and utilization of nitrogen for SC were reduced by 19.61% and 13.20% compared with FC, respectively, but not significantly; and significantly reduced by 27.9% and 40.0% compared with SS, respectively. Loss of gases (NH₃ and N₂O) for SC were 1.83%, which was the lowest, while utilization of nitrogen for SC was 13.20%, similar with FC. Greenhouse temperature was not the critical factor during the spinach planting in winter, but soil water was. Therefore, optimizing manure management could reduce ammonia volatilization and N₂O emission loss without decreasing vegetables production, and the present data indicated that SC would be optimal for better yields with reduced ammonia volatilization and N₂O emission loss.