首页|大气CO2浓度升高背景下优化施氮对淹水稻田CH4排放的影响

大气CO2浓度升高背景下优化施氮对淹水稻田CH4排放的影响

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为探讨未来气候变化条件下,合理管理氮肥以充分协调水稻产量与温室气体排放量之间的矛盾,实现低碳排放并保持水稻产量,本研究探讨了大气CO2浓度升高120 μmol·mol-1与氮肥减施40%对淹水稻田水稻生产及CH4排放的影响及机理。利用开顶式气室(OTC)组成的CO2 浓度自动调控平台设置4个处理,即环境CO2 浓度+施氮250 kg·hm-2(CK)、大气CO2 浓度升高120 μmol·mol-1+施氮250 kg·hm-2(C+)、环境CO2 浓度+施氮150 kg·hm-2(N-)、大气CO2 浓度升高120 μmol·mol-1+施氮150 kg·hm-2(C+N-),分析了稻田CH4累积排放量(CAC)、水稻生物量及产量、土壤理化性质及酶活性等指标。结果表明:与CK处理相比,C+处理使CAC/产量显著提高了16。93%,N-处理使CAC/产量显著降低了13。33%,C+N-处理使CAC/产量降低了7。89%,但不显著;N-处理在一定程度上削弱了C+处理对CAC、CAC/产量、水稻生物量、土壤可溶性有机碳含量的促进作用;逐步回归分析表明,基于可溶性有机碳和硝态氮含量及土壤脲酶活性的线性模型,可解释稻田CH4累积排放64%的变异。综上,在大气CO2浓度升高条件下,氮肥减施可通过影响土壤碳、氮基质及土壤脲酶活性来调节稻田CH4排放。
Effects of optimized nitrogen application on CH4 emissions from flooded paddy fields under elevated atmospheric CO2 concentrations
The aim of this study was to explore the rational management of nitrogen fertilizer under future climate change condition,achieve low-carbon emissions,and maintain rice yield.The effects and mechanisms of elevated atmospheric CO2 concentration(120 μmol·mol-1)and reduced nitrogen application rate(40%)on rice production and CH4 emissions in flooded paddy fields were investigated in this study.Four treatments were set up using open-top chambers(OTCs)to automatically control the CO2 concentration:ambient CO2 concentration+nitrogen application by 250 kg·hm-2(CK),elevated atmospheric CO2 concentration by 120 μmol·mol-1+nitrogen application by 250 kg·hm-2(C+),ambient CO2concentration+nitrogen application by 150 kg·hm-2(N-),elevated atmospheric CO2 concentration by 120 μmol·mol-1+nitrogen application by 150 kg·hm-2(C+N-).The cumulative amount of CH4 emissions(CAC),rice biomass and yield,soil physicochemical properties,and enzyme activities were analyzed.The results showed that compared with CK treatment,the C+treatment significantly increased CAC/yield by 16.93%,N-treatment significantly decreased CAC/yield by 13.33%,and C+N-treatment decreased CAC/yield by 7.89%,but this was not significantly.N-treatment weakened the promoting effect of C+on CAC,CAC/yield,rice biomass,and soil-soluble organic carbon concentration to a certain extent.Stepwise regression analysis showed that the linear model based on dissolved organic carbon and nitrate nitrogen content and soil urease activity could explain 64%of the variation in cumulative CH4 emissions from paddy fields.In summary,nitrogen fertilizer reduction can regulate CH4 emissions from paddy fields under elevated atmospheric CO2 concentrations by affecting soil carbon,nitrogen substrates,and urease activity.

elevated atmospheric CO2 concentrationnitrogen fertilizer reductionCH4 emissionsrice production

黄薇、王圆媛、刘超、伍翥嵘、李琪、胡正华

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南京信息工程大学气象灾害预报预警与评估协同创新中心/生态与应用气象学院,南京 210044

淮阴师范学院生命科学学院,江苏 淮安 223300

南京科技职业学院环境工程学院,南京 210048

大气CO2浓度升高 氮肥减施 CH4排放 水稻生产

国家自然科学基金项目国家自然科学基金项目国家自然科学基金项目江苏省高等学校自然科学研究项目江苏省研究生科研与实践创新计划项目

42375114422051744207102322KJB180010KYCX23_1337

2024

农业环境科学学报
农业部环境保护科研监测所 中国农业生态环境保护协会

农业环境科学学报

CSTPCD北大核心
影响因子:1.52
ISSN:1672-2043
年,卷(期):2024.43(7)