秸秆还田下大气CO_(2)浓度升高对水稻生长和CH4排放的影响  

Effect of Elevated CO_(2) Concentration on Rice Growth and CH4 Emission from Paddy Fields Under Straw Incorporation

作　　者：曾文静 邱岚英 陈俊杰[1] 钱浩宇 张楠[1] 丁艳锋[1] 江瑜 ZENG Wenjing;QIU Lanying;CHEN Junjie;QIAN Haoyu;ZHANG Nan;DING Yanfeng;JIANG Yu(Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学,南京210095

出　　处：《中国水稻科学》2022年第5期543-550,共8页Chinese Journal of Rice Science

基　　金：国家自然科学基金资助项目(32022061);中央高校基本科研业务费资助项目(KJYQ202101)。

摘　　要：【目的】明确秸秆还田下大气CO_(2)浓度升高对水稻生长和稻田CH_(4)排放的影响,为气候变化下温室气体排放评估和丰产低碳的稻作技术创新提供理论参考和科学依据。【方法】利用开顶式气室(Open top chamber,OTC)进行田间试验,设置两个CO_(2)浓度处理,分别为正常大气CO_(2)浓度处理(简称aCO_(2),CO_(2)浓度约为0.04%)和大气CO_(2)浓度升高处理(简称eCO_(2),CO_(2)浓度约为0.055%),每个处理的田块混入等量的前茬小麦秸秆,探明秸秆还田下大气CO_(2)浓度升高对水稻产量等生长特性、稻田CH_(4)排放及微生物丰度的影响,揭示秸秆还田下大气CO_(2)浓度升高对CH_(4)排放的影响机制。【结果】大气CO_(2)浓度升高显著促进水稻的生长,使剑叶叶面积增加25.0%,地上生物量增加22.0%,产量提高29.0%。大气CO_(2)浓度升高显著增加了穗数、结实率和千粒重,但对穗粒数影响不显著。秸秆还田下,大气CO_(2)浓度升高有降低稻田CH_(4)排放的趋势,使单位产量CH_(4)排放量降低了39.4%。大气CO_(2)浓度升高使土壤甲烷氧化关键基因pmoA的拷贝数增加了20.0%,但对甲烷产生关键基因mcrA的拷贝数影响较小。【结论】秸秆还田条件下,未来大气CO_(2)浓度升高不仅提高了水稻产量,而且有利于减少稻田温室气体CH_(4)的排放。【Objective】The aim of this study is to clarify the effects of increased atmospheric CO_(2) concentration on rice growth and CH_(4) emission under straw incorporation,so as to provide theoretical reference and lay a scientific basis for greenhouse gas emission assessment for rice production technology innovation concerning high yield and low carbon emission under climate change.【Method】Field experiments were conducted in Open Top Chambers(OTC).Two CO_(2) concentrations were designed,namely,ambient atmospheric CO_(2) concentration(0.04%,aCO_(2))and elevated atmospheric CO_(2) concentration(0.055%,eCO_(2))with an equal amount of previous wheat straw incorporation.We analyzed the effects of eCO_(2) concentration on rice yield and growth,CH_(4) emission and the abundance of related microorganisms from paddy fields under straw incorporation,which could illustrate the influence mechanism of eCO_(2) on CH_(4) emission under that conditions.【Result】The results showed that eCO_(2) significantly promoted rice growth,i.e.,eCO_(2) increased flag leaf area,aboveground biomass and rice yield by 25.0%,22.0%,and 29.0%,respectively.Elevated atmospheric CO_(2) concentration significantly increased the number of panicles,seed setting rate and 1000-grain weight,but eCO_(2) have no effect on the number of grains per panicle.Under straw incorporation,eCO_(2) trended to mitigate the CH_(4) emission from rice paddies and reduced the yield-scared CH_(4) emission by 39.4%.Elevated atmospheric CO_(2) concentration increased the copy numbers of pmoA,a key gene for methane oxidation in soil,by 20%,but had little effect on the copy number of mcrA,a key gene for methane production.【Conclusion】Under the straw incorporation,eCO_(2) not only improves rice yield but also reduces CH_(4) emission from rice paddies.

关 键 词：大气CO_(2)升高 秸秆还田 温室气体 水稻产量 甲烷排放 

分 类 号：S511[农业科学—作物学] X71[环境科学与工程—环境工程]