保护性耕作对土壤微团聚体碳、氮分布的影响  

Effects of conservational tillage measures on distributions of organic carbon and nitrogen in soil microaggregates

作　　者：王彩霞[1] 岳西杰[1] 葛玺祖[1] 黄婷[1] 王勇[1] 王旭东[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《植物营养与肥料学报》2010年第3期642-649,共8页Journal of Plant Nutrition and Fertilizers

基　　金：国家科技支撑项目(2007BAD89B16);中国科学院知识创新工程项目(KSCX1-YW-09-07)资助

摘　　要：以7年不同耕作的定位试验为研究对象,研究了深松、旋耕、免耕等保护性耕作对关中土小麦-玉米轮作条件下微团聚体分布以及微团聚体中有机碳和全氮含量的影响。结果表明,秸秆粉碎旋耕、秸秆覆盖深松处理提高了特征微团聚体的组成比例,而秸秆还田＋传统耕作和免耕处理对特征微团聚组成比例的影响较小。与传统耕作比较,旋耕、深松处理均能提高较大粒级微团聚体中（0.050-0.25 mm和0.010-0.05 mm）有机碳及全氮含量,而免耕使0.010-0.05 mm微团聚体中的有机碳和全氮含量有所降低;旋耕、深松和免耕对小粒级微团聚体（〈0.01 mm）中的有机碳和全氮含量影响较小。相关分析表明,土壤有机碳与0.050-0.25 mm和0.010-0.05 mm粒级微团聚体中的有机碳、全氮之间均显著正相关,而与〈0.01 mm粒级微团聚体的有机碳、全氮含量不相关;土壤全氮与0.05-0.25 mm粒级的全氮、有机碳显著相关。0.010-0.05 mm粒级微团聚体的碳、氮与0.050-0.25 mm粒级微团聚体的碳、氮间显著正相关,而〈0.01 mm粒级微团聚体的碳、氮与其它粒级的碳、氮间不相关。从土壤微团聚体中碳、氮的分布考虑,旋耕、深松是当地较理想的耕作方式。A seven year location experiment in the condition of wheat-corn rotation of Lou soil in Guanzhong plain was conducted.The effects of the subsoiling,rotary tillage and no-tillage on the distributions of micro-aggregates and the contents of organic carbon and nitrogen in soil micro-aggregates were studied.The results show that the compositional proportions of soil characteristic microaggregates are increased under the rotary tillage with straw pulverizing and the subsoiling with straw mulching,while there are little effects on the proportion under the conventional tillage（plow and rotary tillage） with straw incorporated and no-tillage.Compared with the conventional tillage,the subsoiling and rotary tillage could increase the contents of organic carbon and nitrogen in 0.05-0.25 mm and 0.01-0.05 mm micro-aggregates,and the no-tillage could decrease the contents of organic carbon and nitrogeni in 0.01-0.05 mm micro-aggregates.The rotary tillage,subsoiling and no-tillage have little effects on the contents of organic carbon and nitrogen in 〈0.01 mm micro-aggregates.The correlation analysis demonstrates that the total soil organic carbon is related to the contents of organic carbon and nitrogen in 0.05-0.25 mm and 0.01-0.05 mm micro-aggregates and is not related to the contents of organic carbon and nitrogen in 〈0.01 mm micro-aggregates.Total nitrogen in soil is significantly correlated to the contents of organic carbon and nitrogen in 0.05-0.25 mm micro-aggregates.The contents of organic carbon and nitrogen in 0.01-0.05 mm micro-aggregates are significantly correlated to soil total nitrogen.The contents of organic carbon and nitrogen in 〈0.01 mm micro-aggregate are not correlated to those of the other sized micro-aggregates.Considering the distributions of organic carbon and nitrogen in soil micro-aggregates,the rotary tillage and subsoiling are the recommended tillage measures in Guanzhong plain.

关 键 词：保护性耕作 微团聚体 碳、氮分布 

分 类 号：S153.61[农业科学—土壤学] S343[农业科学—农业基础科学]