生物炭对退化蔬菜地土壤及其修复过程中N2O产排的影响  

Effects of Biochar Application on N_2O Emission in Degraded Vegetable Soil and in Remediation Process of the Soil

作　　者：王军[1,2] 施雨[1] 李子媛 韩成[1] 谢祖彬[3] 钟文辉[1] 

机构地区：[1]南京师范大学,江苏省物质循环与污染控制重点实验室,南京210023 [2]山东省水土保持与环境保育重点实验室,山东临沂276000 [3]中国科学院南京土壤研究所,南京210008

出　　处：《土壤学报》2016年第3期713-723,共11页Acta Pedologica Sinica

基　　金：国家科技支撑计划项目(2013BAD11B01);江苏省高校优秀科技创新团队项目(CXLX13-385)资助~~

摘　　要：高氮投入的设施蔬菜地土壤易发生次生盐渍化、酸化、板结化等土壤退化现象,也会引起地下水污染、N_2O大量排放等环境后果,严重影响了蔬菜农业的可持续发展。强还原土壤灭菌(reductive soil disinfestation,RSD)作为新兴的退化设施蔬菜地土壤修复方法,能够有效缓解土壤退化,但也导致N_2O大量排放。本研究选用生物炭作为调节剂,评估不同生物炭施加量对退化设施蔬菜地土壤及其强还原修复过程中N_2O排放的影响,并测定反硝化功能基因(一氧化氮还原酶基因nor B和氧化亚氮还原酶基因nos Z)丰度来反映反硝化微生物活性。结果显示:RSD法显著降低了土壤硝酸盐含量、提高了土壤p H,缓解了土壤退化,但其N_2O累计排放量是非修复土壤的950倍以上;施加生物炭具有减排效果,其中施加5%的生物炭显著降低了退化设施蔬菜地土壤及其强还原修复过程中的N_2O排放,其减排量分别为68.7%和16.0%;Pearson相关分析显示,非强还原修复过程和强还原修复过程中土壤N_2O排放速率均与p H显著负相关,而在强还原修复过程中土壤N_2O排放速率还与NO_3^--N含量显著正相关;施加生物炭显著改变了土壤nor B和nos Z基因,线性回归分析表明,非强还原修复过程和强还原修复过程中土壤N_2O排放的微生物机理不同,前者显著受nos Z基因丰度影响,而后者显著受nor B基因丰度影响。在退化设施蔬菜地土壤中施加5%生物炭可有效减低退化设施蔬菜地土壤及其强还原修复过程中的N_2O排放。Excessive application of nitrogen fertilizers in facilitated vegetable fields may easily lead to soil degradation（such as soil salinization,acidification,hardening,etc.）,and even further to some serious environmental consequences like pollution of groundwater and emission of large volumes of N2 O,thus seriously affecting sustainable development of the vegetable industry. Recently,a novel soil remediation technology,called RSD（reductive soil disinfestation）has been developed of adding organic substances（e.g.,crop straw,molasses,manure,etc.）in flooding water. The RSD method can effectively alleviate the risk of soil degradation,such as removing the nitrate accumulated in the soil,increasing p H,lowering soil electrical conductivity and improving soil structure. However,in strong reducing environments the high amount of nitrate accumulated in the degraded facilitated vegetable fields was rapidly reduced by denitrification,and high nitrous oxide（N2O）emission was observed in RSD process. N2 O is the third major greenhouse gas,and is 296～310 times as high as CO2 in global warming potential. It is estimated that N2 O emitted from agricultural soil accounts for 60% of the annual anthropogenic emission into the atmosphere,and the facilitated vegetable soil with high N input is one of the most important agricultural N2 O sources,contributing about 20% to the emission from agricultural soil. Therefore,it is essential to investigate how to mitigate N2 O emission from degraded facilitated vegetable soil,especially in its strong reductive remediation process. In this study,Biochar was selected as soil regulator in evaluating effects of the use of biochar on N2 O emission in degraded vegetable soil and its RSD process relative to rate of its use. Six treatments were designed and conducted,Treatment CK（16% in soil moisture content and no biochar used）,Treatment 1% BC（16% in soil moisture content and 1% biochar applied,w/w）,Treatment 5% BC（16% in soil moisture content and 5% biochar applied）,Treatmen

关 键 词：N2O排放 生物炭 退化设施蔬菜地 土壤修复 环境效应 反硝化微生物 

分 类 号：S154[农业科学—土壤学]