摘要
【目的】瘠薄型农田玉米生产严重依赖施肥。研究长期施用有机肥对土壤N_(2)O排放和维持玉米产量的影响,为瘠薄型农田氮素高效管理提供理论依据。【方法】长期定位试验始于2008年,试验设计包括4个处理:不施肥对照处理(CK)、当地常规施肥处理(NPK)、增施有机肥处理(MNPK)、50%有机肥替代化肥处理(RMN)。2023年5月至10月,采用静态箱―气相色谱法监测土壤N_(2)O排放通量,计算施用有机肥对土壤N_(2)O累积排放以及产量的影响,并探明影响土壤N_(2)O排放的主要因素。【结果】与CK相比,施用有机肥(MNPK、RMN)显著提高玉米产量,增幅在95%~103%(P<0.05)。在整个监测周期内,3个施肥处理促进土壤N_(2)O排放,整体呈现出“脉冲式”排放规律。N_(2)O最大排放峰值由高到低依次为MNPK、NPK、RMN处理,分别达到4.71±0.68、3.29±0.62、1.71±0.15μg/(m^(2)·min),MNPK处理土壤N_(2)O最大排放峰值和累积排放量分别显著高于NPK处理43.00%、64.65%,而RMN处理比NPK处理分别降低了48%、26.22%。土壤N_(2)O排放通量与土壤铵态氮(NH_(4)^(+)-N)、全氮(TN)含量以及体积含水率(VWC)呈极显著正相关关系(P<0.01),与有机碳(SOC)、地温(GT)呈显著正相关关系(P<0.05)。NPK处理平均温室气体净排放量为CO_(2)-eq 361 kg/(hm^(2)·a),净温室效应为“源”,MNPK和RMN处理净温室气体排放强度(GHGI)较NPK处理分别降低了572%和655%,玉米种植所产生的净温室气体排放量分别减少了668%和737%,两个有机肥处理之间的温室气体排放强度和净排放量无显著差异。【结论】施用有机肥可有效减少瘠薄农田土壤N_(2)O排放,降低净温室效应并显著提高玉米产量。综合减排和产量因素,在本试验条件下,有机肥替代50%的常规化肥养分量可在有效降低温室气体排放的同时,降低氮肥损失,提高玉米生产效益。
【Objectives】Maize production heavily relies on fertilization in infertile farmland.We explored the effects of organic fertilization methods on reducing N_(2)O emissions and maintaining crop yield,with a view to provide a theoretical basis for optimizing nitrogen management in infertile farmland.【Methods】The study was carried on the field of a 15-year-long localization experiment,which included a total of four treatments:no fertilization control(CK);conventional chemical fertilization(NPK);organic fertilizer plus NPK(MNPK),and 50% chemical fertilizer+ 50% organic fertilizer(RMN).The cumulative soil N_(2)O emission fluxes were monitored from May to October 2023 using static chamber-gas chromatography,and the maize yields were recorded at harvest.【Results】The organic fertilizer treatments MNPK and RMN increased maize yield by 95% to 103%,compared to CK(P<0.05).Throughout the monitoring cycle,the soil N_(2)O emissions in all the three fertilizer treatments turned in an overall “pulsed” patterns.The maximum emission peaks in treatment MNPK,NPK,and RMN were 4.71±0.68,3.29±0.62,and 1.71±0.15 μg/(m^(2)·min),respectively.The soil maximum emission peak and cumulative N_(2)O emission in MNPK treatment were 43.00% and 64.65% higher than in NPK treatment,while those in RMN treatment were 48% and 26.22% lower(P<0.05).Soil N_(2)O emission fluxes showed extremely significant and positive correlations with soil NH_(4)^(+)-N,total N,and volumetric water content(P<0.01),and significant and positive correlation with soil organic carbon and soil temperature(P<0.05).The average net greenhouse effect(GHG) emissions under the NPK treatment were CO_(2)-eq 361 kg/(hm^(2)·a),showing a net GHG“source”.Compared to NPK treatment,MNPK and RMN treatment decreased the greenhouse gas emission intensity(GHGI) by 572% and 655%,and reduced the net GHG emissions by 668% and 737%,showing a net GHG “sink”.And MNPK and RMN treatments were calculated similar GHGI and net GHG.【Conclusions】The use of organic fertilizer can effectively reduce soil N_(2)O emissions in infertile farmland,lower the net GHG,and increase maize yield significantly.Under the experimental condition,replacing 50% chemical fertilizer with organic fertilizer is recommended as the more satisfactory reduction effect of N_(2)O emission and increase maize yield.
作者
魏禾雅
王立刚
周颖
蔡育蓉
杨万青
杨建君
WEI He-ya;WANG Li-gang;ZHOU Ying;CAI Yu-rong;YANG Wan-qing;YANG Jian-jun(State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2024年第10期2032-2040,共9页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(32171564)
国家重点研发计划项目(2021YFD1901002,2022YFD1901605)。
