长期连续秸秆还田和生物质炭施用对稻田N_(2)O排放的影响  

Effects of Long-term Continuous Straw Incorporation and Biochar Application on N_(2)O Emission from Paddy Field

作　　者：靳鹏辉 陈哲 王慧 徐乔 胡天龙 周蓉 蔺兴武[1] 刘琦 谢祖彬[1] JING Penghui;CHEN Zhe;WANG Hui;XU Qiao;HU Tianlong;ZHOU Rong;LIN Xingwu;LIU Qi;XIE Zubin(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Forestry,Nanjing Forestry University,Nanjing 210037,China;College of Environmental Science and Engeneering,Yangzhou University,Yangzhou,Jiangsu 225009,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049 [3]南京林业大学林学院,南京210037 [4]扬州大学环境科学与工程学院,江苏扬州225009

出　　处：《土壤》2023年第5期964-973,共10页Soils

基　　金：国家自然科学基金项目(31870500,42177333);江苏省农业科技自主创新资金项目(CX(20)2003)资助。

摘　　要：为了评估麦季多年连续秸秆还田和生物质炭施用对稻麦轮作系统下稻田N_(2)O排放的影响,于2010年麦季开始开展了为期11 a的麦季秸秆还田和生物质炭施用定位试验。试验共包括5个处理:无玉米秸秆还田和生物质炭施用(CK);6 t/(hm^(2)·a)玉米秸秆还田(CS);2.4 t/(hm^(2)·a)生物质炭施用(BC1);6 t/(hm^(2)·a)生物质炭施用(BC2)和12 t/(hm^(2)·a)生物质炭施用(BC3)。结果表明,BC2和BC3处理较CK均显著提高了土壤碱解氮、有效磷、速效钾、易氧化碳、可溶性有机氮和土壤微生物生物量氮含量。CS、BC1和BC2处理水稻生长季N_(2)O总排放量与CK没有显著差异,但是BC3处理的N_(2)O总排放量比CK提高了245.31%,并显著高于其他处理。BC3处理的N_(2)O总排放量和施氮肥后N_(2)O排放高峰期的累积排放量分别比CK提高了3.84 kg/hm^(2)和3.36 kg/hm^(2)(以N_(2)O-N计),BC3处理对土壤N_(2)O排放的刺激作用主要体现在施氮肥后的N_(2)O排放高峰期内。与CK相比,BC3处理显著提高了土壤阳离子交换量(20.35%),同时分别增加了土壤微生物生物量碳和生物量氮含量(26.13%和49.96%)。不同处理在复水并施用穗肥后引起的N_(2)O排放高峰期的累积排放量占总排放量的27.66%~32.83%,其中BC3处理的排放占比最高。研究结果说明生物质炭长期连续施用下土壤阳离子交换量的增加,提高了土壤NH_(4)^(+)的持留,进而促进了土壤硝化过程,同时延长穗肥施用和复水间隔时间可有效减少N_(2)O排放量。A 11-year experiment was conducted in 2010 in order to evaluate the effects of long-term continuous straw incorporation and biochar application in wheat season on N_(2)O emission from a paddy field under rice-wheat rotation system,in which five treatments were setup:no maize straw incorporation and biochar application(CK);6 t/(hm^(2)·a)maize straw incorporation(CS);2.4 t/(hm^(2)·a)biochar application(BC1);6 t/(hm^(2)·a)biochar application(BC2)and 12 t/(hm^(2)·a)biochar application(BC3).The results showed that BC2 and BC3 significantly improved soil properties such as alkaline hydrolysis nitrogen(AN),available phosphorus(AP),available potassium(AK),readily oxidizable carbon(ROC),dissolvable organic nitrogen(DON)and soil microbial biomass nitrogen(SMBN).CS,BC1 and BC2 had no significant effect on seasonal cumulative N_(2)O emission from paddy soil,while seasonal cumulative N_(2)O emission increased by 245.31%under BC3 compared to CK.Seasonal cumulative N_(2)O-N emission and the peak period cumulative emission after nitrogen application of BC3 were increased by 3.84 kg/hm^(2)and 3.36 kg/hm^(2),respectively,compared to CK.The promoting effect of BC3 on soil N_(2)O emission was mainly in the peak period of N_(2)O emission after nitrogen fertilizer application.Compared to CK,BC3 significantly increased soil cation exchange capacity(CEC),microbial biomass carbon(SMBC)and SMBN by 20.35%,26.13%and 49.96%,respectively.Cumulative emissions at the peak period of N_(2)O emissions caused by re-flooding and panicle fertilizer application accounted for 27.66%–32.83%of seasonal cumulative emissions,of which BC3 having the highest proportion.In conclusion,long-term continuous application of biochar can increase soil CEC and the retention of soil NH_(4)^(+),thus can promote soil nitrification process,and interval prolongation between panicle fertilizer and re-flooding may effectively reduce N_(2)O emission from paddy fields.

关 键 词：N_(2)O 生物质炭 秸秆还田 长期连续 稻田 

分 类 号：S51[农业科学—作物学] S-3