两种水分含量下生物质炭对黑土N_(2)O排放及硝化反硝化基因丰度的影响  

Effects of Biochar on N_(2)O Emission and Nitrification-denitrification Gene Abundances Under Two Water Status in Black Soils

作　　者：苏星源 吴世杰 高威 马君玲[1] 解宏图[3] 鲍雪莲[3] 王连峰[1] SU Xingyuan;WU Shijie;GAO Wei;MA Junling;XIE Hongtu;BAO Xuelian;WANG Lianfeng(School of Environment and Chemical Engineering,Dalian Jiaotong University,Dalian,Liaoning 116028,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]大连交通大学环境与化学工程学院,辽宁大连116028 [2]中国科学院南京土壤研究所,南京210008 [3]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《土壤》2022年第5期928-935,共8页Soils

基　　金：国家自然科学基金项目(41471205,41977048);辽宁省百千万人才工程项目(2019B39)资助。

摘　　要：以吉林省梨树县典型黑土为研究对象,通过培养实验,研究了不同土壤水分含量(40%WHC和100%WHC)下,生物质炭种类(玉米秸秆生物质炭和稻壳生物质炭)和施加量(0%、1%、4%,m/m)对黑土N_(2)O排放及硝化反硝化功能基因丰度的影响。结果表明:随着秸秆生物质炭施加量的增加,土壤N_(2)O排放呈下降趋势,4%高量秸秆生物质炭添加下,土壤N_(2)O排放量仅为1%低量添加下的33.9%。同时土壤NO^(-)_(3-)N含量也表现出一致性规律,4%高量生物质炭添加下土壤NO^(-)_(3-)N含量显著低于1%低量生物质炭添加。在100%WHC土壤水分状况下,玉米秸秆生物质炭显著增加了土壤N_(2)O排放,而稻壳生物质炭则显著降低了土壤N_(2)O排放。高土壤水分显著促进了土壤N_(2)O排放,进一步为实时荧光定量PCR结果所证实,高土壤水分通过增加nir S基因丰度进而促进了土壤反硝化作用过程,而4%高量稻壳生物质炭添加下nos Z基因丰度显著高于玉米秸秆生物质炭添加,表现出更强的N_(2)O还原潜力。尽管amoA-AOA基因丰度在不同生物质炭添加量下并未发生显著变化,但amoA-AOB基因丰度在高量玉米秸秆生物质炭添加下显著下降。土壤水分含量和生物质炭种类及其添加量通过影响土壤硝化反硝化微生物,进而影响土壤N_(2)O排放。In the laboratory incubation,the effects of different biochars(maize straw biochar,rice husk biochar)and application rates(0%,1%and 4%,m/m)on N_(2)O emissions and nitrification-denitrification functional gene abundances under different soil moistures(40%WHC and 100%WHC)were investigated by soil microcosm experiment in a typical black soil region in Lishu County,Jilin Province.The results show that soil N_(2)O emissions tends to decrease with increasing straw biochar.4%straw biochar addition results in only 33.9%of soil N_(2)O emissions as compared to 1%biochar addition.Soil NO^(-)_(3-)N also shows a similar pattern,significantly lower at 4%biochar addition than at 1%biochar addition.Under 100%WHC,maize straw biochar significantly increases soil N_(2)O emissions,while rice husk biochar significantly reduces soil N_(2)O emissions.Real-time fluorescence quantitative PCR further confirms that high soil moisture promotes soil denitrification by increasing nirS gene abundance,while nosZ gene abundance is significantly higher under 4%rice husk biochar addition than maize straw biochar addition,showing greater N_(2)O reduction capacity.Although the amoA-AOA genes are insignificantly different at different biochar additions,the amoA-AOB gene is significantly decreased at high maize straw biochar addition.Soil moisture content,biomass char species and their addition amount affect soil N_(2)O emissions by affecting soil nitrification and denitrification microorganisms.

关 键 词：东北黑土 土壤水分 生物质炭 N_(2)O排放 硝化反硝化基因 

分 类 号：S19[农业科学—农业基础科学]