不同氮素管理模式对黄土旱塬春玉米产量及N2O排放的影响OA北大核心CSTPCD
Effects of Different Nitrogen Application Patterns on Yield and Nitrous Oxide Emission of Spring Maize in Dryland Farming of the Loess Plateau
[目的]探讨不同氮素管理模式对玉米产量、N2O排放的影响,为黄土旱塬区合理施用氮肥和减缓温室气体排放提供理论依据.[方法]依托中国科学院长武黄土高原农业生态试验站,以春玉米先玉 335 为研究对象,开展为期 2 年的田间定位试验.试验共设置 5 种不同氮素管理模式:不施氮(no fertilizer)、传统施氮(Con,250 kg N·hm-2)、减量施氮(Opt,200 kg N·hm-2)、减量施氮+缓控释肥(Opt+SR,200 kg N·hm-2)、减量施氮+硝化抑制剂(Opt+DCD,200 kg N·hm-2).用静态箱-气相色谱法监测N2O排放通量,并计算全球增温潜势和N2O气体排放强度,分析不同氮素管理模式对春玉米产量和N2O排放的影响.[结果](1)氮肥施用后N2O排放迅速升高,在施肥后2 d左右达到峰值,维持10 d后快速下降.减量施氮模式显著降低N2O排放量(P＜0.05).与Con处理相比,Opt、Opt+DCD和Opt+SR处理N2O排放量降低幅度分别为 21.4%、27.6%和 26.0%.Con、Opt、Opt+DCD和Opt+SR处理的N2O增温潜势依次为 425.01、334.01、307.83、314.57 kg CO2-eq·hm-2.与Con处理相比,Opt+DCD显著降低了N2O排放强度,降幅为 30.1%(P＜0.05).(2)N2O排放量与表层土壤NH4+-N含量呈极显著正相关(P＜0.01),而与土壤水分、温度无明显相关性.(3)与Con处理相比,Opt、Opt+DCD和Opt+SR处理能显著提高氮肥农学效率(增幅依次为25.5%、25.7%、22.2%)及氮肥偏生产力(增幅依次为29.9%、28.7%、25.4%)(P＜0.05),但对春玉米的产量无显著影响.[结论]在黄土旱塬地区,适当减量施氮、缓控释肥及添加硝化抑制剂均能取得N2O减排和玉米增产的效果,其中减氮20%并添加硝化抑制剂在保证玉米产量的同时,N2O减排效果最好.
[Objective]Investigating the impacts of different N application regimes on crop(spring maize)yield and nitrous oxide(N2O)emission provided the basis for reasonable N(Nitrogen)application and GHG(Greenhouse Gas)emission mitigation in dryland farming of the Loess Plateau.[Method]In this study,the impacts of five N application regimes on spring maize(Xianyu 335)yield and N2O emission were investigated in a short-term(2 years)experiment in Changwu Agro-Ecological Experimental Station,and the treatments included:no fertilizer;conventional N fertilization(Con,250 kg N⋅hm-2);optimized N fertilization(Opt,200 kg N⋅hm-2);optimized N fertilization with slow-release fertilizer(Opt+SR,200 kg N⋅hm-2);optimized N fertilization with dicyandiamide(Opt+DCD,200 kg N⋅hm-2).The N2O emission fluxes were monitored using sealed static chambers,and the gas chromatograph and the global warming potential(GWP)was calculated.[Result](1)N2O emissions increased rapidly after N application,reaching a peak on the second day,and rapidly decreased after 10 days of maintenance.Optimized N fertilization significantly decreased N2O emissions(P＜0.05).Compared with Con,the reductions in N2O emissions under Opt,Opt+DCD,and Opt+SR were 21.4%,27.6%,and 26.0%,respectively.The GWP of N2O emissions under Con,Opt,Opt+DCD,and Opt+SR were 425.01,334.01,307.83,and 314.57 kgCO2-eq⋅hm-2,respectively.Opt+DCD significantly reduced N2O emission intensity by 27.8%than that under Con(P＜0.05).(2)N2O emissions were highly correlated with surface soil NH4+-N content(P＜0.01),but showed no significant correlation with soil moisture and temperature.(3)Compared with Con,Opt,Opt+DCD,and Opt+SR significantly improved N fertilizer agronomic efficiency(with increases of 25.5%,25.7%,and 22.2%,respectively)and nitrogen fertilizer partial factor productivity(with increases of 29.9%,28.7%,and 25.4%,respectively)(P＜0.05),whereas they had no significant impact on spring maize yield.[Conclusion]In dryland farming of the Loess Plateau,reducing N fertilizer application,applying slow-release fertilizer,and adding nitrification inhibitors properly could promote N2O emission reduction and increase spring maize yield.Notably,reducing N fertilizer application by 20%and adding nitrification inhibitors not only ensured spring maize yield but also had the best effect on N2O emission reduction.
鲁科丹;路远;王蕊;党廷辉
中国科学院教育部水土保持与生态环境研究中心,陕西杨凌 712100||中国科学院水利部水土保持研究所,陕西杨凌 712100||中国科学院大学,北京 100049西北农林科技大学资源环境学院,陕西杨凌 712100中国科学院教育部水土保持与生态环境研究中心,陕西杨凌 712100||西北农林科技大学水土保持研究所,陕西杨凌 712100
减量施氮缓控释肥硝化抑制剂春玉米产量N2O排放黄土旱塬
reduced nitrogen applicationlow-release fertilizerdicyandiamidespring maizeyieldnitrous oxide emissiondryland farming of the Loess Plateau
《中国农业科学》 2024 (018)
3642-3653 / 12
国家自然科学基金重点项目(41830751)
评论