耕作与秸秆还田方式对不同深度土层团聚体有机碳分布特征的影响  

Effects of tillage and straw returning methods on distribution characteristics of soil aggregate organic carbon in different soil layers

作　　者：陈佳琦 郭炜 王楠楠 李玉梅 王伟 高中超 孙冬梅[1] CHEN Jiaqi;GUO Wei;WANG Nannan;LI Yumei;WANG Wei;GAO Zhongchao;SUN Dongmei(College of Agriculture,Heilongjiang Bayi Agricultural University,Daqing Heilongjiang 163000,China;Heilongjiang Black Soil Conservation and Utilization Research Institute,Harbin 150086,China;Quality and Safety Institute of Agricultural Products,Heilongjiang Academy of Agricultural Sciences,Harbin 150086,China)

机构地区：[1]黑龙江八一农垦大学农学院,黑龙江·大庆163000 [2]黑龙江省黑土保护利用研究院,哈尔滨150086 [3]黑龙江省农业科学院农产品质量安全研究所,哈尔滨150086

出　　处：《东北农业大学学报》2024年第8期100-110,共11页Journal of Northeast Agricultural University

基　　金：国家重点研发计划项目(2022YFD1500305,2022YFD1500704)。

摘　　要：为研究秸秆还田措施对东北草甸土团聚体尺度土壤有机碳(SOC)形态分布特征对的影响,利用已进行5a的包括免耕(NT)、浅翻20 cm(ST)、深翻35 cm(DT)和免耕秸秆覆盖(NTS)、秸秆浅翻还田20 cm(STS)、秸秆深翻还田35 cm(DTS)田间定位试验,采用湿筛分级及SOC密度分组法分析土壤团聚体SOC对土壤碳的贡献。结果表明:3种耕作及其秸秆还田方式均以250~2 000μm粒级水稳性团聚体SOC贡献率最高,平均为62.31%。无论是否秸秆还田,>250μm粒级团聚体SOC贡献率由大到小均为NT、ST、DT和NTS、STS、DTS;连续翻耕提高250~2 000μm大团聚体中矿物质结合态SOC(MOC)质量分数,ST与DT较NT分别增加27.92%、20.56%,粗颗粒态SOC(cPOC)较NT分别降低43.90%和31.23%,20~40 cm土层<53μm黏粉粒MOC质量分数较NT平均增加25.20%、40.92%,差异显著;秸秆翻耕还田增加了<53μm的MOC质量分数,STS与DTS较NTS平均增加30.58%,20~40 cm土层增幅高于0~20 cm土层。连续秸秆覆盖免耕可促进草甸土良好团聚结构形成及SOC积累,避免大团聚体破碎形成微小团聚体,提高大粒径团聚体SOC贡献率。秸秆连续翻耕还田可降低大粒径团聚体SOC贡献率,增加黏粉粒SOC贡献率。To study the effects of straw returning methods on distribution characteristics of soil organic carbon(SOC)forms in Northeast meadow soil,field positioning experiments were conducted for five years including no tillage(NT),shallow tillage 20 cm(ST),deep tillage 35 cm(DT),no tillage straw cover(NTS),shallow tillage 20 cm(STS)and deep tillage 35 cm(DTS).The contribution of soil aggregate SOC to soil C was analyzed by using wet sieve classification and density grouping methods of SOC.The results showed that the contribution rate of SOC in water stable aggregates with a particle size of 250-2000μm was the highest among three tillage and straw return methods,with an average of 62.31%.Regardless of whether straw was returned or not,the contribution rate of SOC in aggregates with a particle size greater than 250μm was NT>ST>DT and NTS>STS>DTS.Continuous tillage increased the mass fraction of mineral bound SOC(MOC)in the 250-2000μm aggregates,with treatments of ST and DT increasing by 27.92%and 20.56%respectively compared with NT,while coarse particle SOC(cPOC)decreased by 43.90%and 31.23%respectively compared with NT.Mass fraction of MOC in clay particles<53μm in soil layer of 20-40 cm increased significantly by 25.20%and 40.92%on average compared with NT.Mass fraction of MOC in<53μm were also increased under straw plowing and returning to the field,STS and DTS were increased by an average of 30.58%compared with NTS,with a higher increase in 20-40 cm than in 0-20 cm soil layer.Continuous no tillage with straw mulching could promote the formation of a good aggregation structure and accumulation of SOC in meadow soil,avoiding the fragmentation of large aggregates to formate small aggregates,and improving the contribution rate of large particle size aggregates to SOC.Continuous tillage and returning of straw to the field could reduce the SOC contribution rate of large particle aggregates and increase the SOC contribution rate of clay particles.

关 键 词：团聚体稳定性 有机碳形态 闭蓄态 矿物结合态 

分 类 号：S154[农业科学—土壤学]