秸秆与生物炭对棉田碱性土壤NH_(3)挥发与N_(2)O排放的影响  

Effects of straw and biochar on NH_(3) volatilization and N_(2)O emission from alkaline soils planted with cotton

作　　者：郭儆瑜 金文 刘志涛 程照瑞 赵文青 孟亚利[1] GUO Jingyu;JIN Wen;LIU Zhitao;CHENG Zhaorui;ZHAO Wenqing;MENG Yali(College of Agriculture,Nanjing Agricultural University/Key Laboratory of Crop Ecophysiology and Management,Ministry of Agriculture and Rural Affairs/Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP),Nanjing 210095,China)

机构地区：[1]南京农业大学农学院/农业农村部作物生理生态与生产管理重点实验室/江苏省现代作物生产协同创新中心,南京210095

出　　处：《农业环境科学学报》2024年第2期442-451,共10页Journal of Agro-Environment Science

基　　金：国家重点研发计划项目(2020YFD1001004)。

摘　　要：为探究秸秆和秸秆生物炭连续添加5 a后对土壤氨(NH_(3))挥发和氧化亚氮(N_(2)O)排放的影响,并确定合理的秸秆还田措施,以降低碱性棉田氮损失。本研究基于等碳量输入,设置秸秆翻埋、秸秆催腐+覆盖还田、秸秆生物炭翻埋和不还田对照共4个处理,氮磷钾肥统一施用。结果表明:秸秆生物炭翻埋下土壤NH_(3)挥发和N_(2)O排放分别较不还田对照显著降低27.3%和56.7%,主要归因于生物炭显著抑制土壤羟胺还原酶与硝酸还原酶活性,增加棉花氮吸收量,也与生物炭自身的强吸附能力有关。而秸秆翻埋、秸秆催腐+覆盖还田分别较对照增加NH3挥发37.2%和21.2%,但减少N2O排放17.1%和38.3%,这两种秸秆还田方式均显著促进土壤有机氮矿化和羟胺还原酶活性,抑制硝酸还原酶活性。冗余分析(RDA)结果表明羟胺还原酶和棉花氮吸收是土壤NH3挥发和N_(2)O排放的主要影响因子,解释率分别为64.8%和20.1%。研究表明,秸秆生物炭翻埋对NH_(3)和N_(2)O减排的综合效果优于秸秆,是碱性棉田土壤值得推荐的氮减排措施。The main objectives of this study were to investigate how straw and straw biochar influence soil ammonia(NH_(3))volatilization and nitrous oxide(N_(2)O)emission after continuous addition for 5 years,and to ascertain a practical straw return practice for reducing N loss in alkaline cotton fields.On the basis of the equivalent carbon input,we established four treatments(straw incorporation,straw decomposition plus mulching,straw biochar incorporation,and a control treatment without straw or biochar),all of which involved application of the same amount of NPK fertilizers.The results revealed that compared with the control,straw biochar incorporation promoted a significant reduction in NH_(3) volatilization by 27.3% and N_(2)O emission by 56.7%.These effects were mainly attributed to the significant inhibition of soil hydroxylamine reductase and nitrate reductase activities,and an increase in N uptake by cotton,as well as the strong adsorption capacity of biochar per se.Furthermore,compared with the control treatment,straw incorporation and straw decomposition plus mulching increased NH_(3) volatilization by 37.2% and 21.2%,respectively,but reduced N_(2)O emissions by 17.1% and 38.3%,respectively.These contrasting effects can be ascribed to the fact that that these two straw returning practices promote a significant enhancement of soil organic N mineralization and hydroxylamine reductase activity,while inhibiting nitrate reductase activity.Redundancy analysis provided evidence to indicate that hydroxylamine reductase activity and N uptake by cotton were the main factors influencing the observed effects,explaining 64.8% and 20.1% of the variances in NH_(3) volatilization and N_(2)O emission,respectively.On the basis of these findings,it appears that straw biochar incorporation has the best synthetic benefits in the reducing NH_(3) volatilization and N_(2)O emission and is accordingly recommended as a practice for reducing N loss in alkaline soil planted with cotton.

关 键 词：秸秆 生物炭 NH_(3) N_(2)O 氮循环酶 碱性土壤 

分 类 号：S156[农业科学—土壤学]