不同休闲期农田管理措施下季节性冻融对土壤团聚体的影响  

Change in Soil Aggregation During the Freezing-thawing Fallow Season was Affected by Agronomical Management

作　　者：张新民[1] 高雅玉 李泽霞 张丽萍 祁怀平 ZHANG Xinmin;GAO Yayu;LI Zexia;ZHANG Liping;QI Huaiping(Gansu Research Institute for Water Conservancy,Lanzhou 730000,China;College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Gansu Institute of Soil&Water Conservation Sciences,Lanzhou 730000,China)

机构地区：[1]甘肃省水利科学研究院,兰州730000 [2]兰州理工大学,兰州730050 [3]甘肃省水土保持科学研究所,兰州730021

出　　处：《灌溉排水学报》2022年第12期65-74,共10页Journal of Irrigation and Drainage

基　　金：甘肃省重点研发计划项目(18YF1NA031);甘肃省重点人才计划项目(甘组通字[2019]39号);甘肃省省级水资源费项目(甘水资源发[2021]105号)。

摘　　要：【目的】评价我国西北地区季节性冻融对农田土壤物理性质的影响。【方法】在甘肃省石羊河流域民勤红崖山灌区,以小麦地、玉米地为代表,设计不同休闲期耕作措施和有无冬季储水灌溉处理,开展了冬季季节性冻融过程对土壤团粒结构影响研究,观测了冻融前后不同土层深度土壤机械稳定性团聚体、水稳性团聚体的粒径分配,分析了冻融过程中土壤机械稳定性大团聚体量、水稳性大团聚体量和平均重量直径(MWD)的变化。【结果】由于团聚体形成机制及影响因素的复杂性,冻融对耕层土壤机械稳定性大团聚体量及MWD的作用尚不确定,但可使水稳性大团聚体量显著降低,MWD变小;秋耕能增大土壤机械稳定性大团聚体量及其MWD、水稳性大团聚体量和MWD,但影响在土壤冻结前基本消除,对土壤冻融过程不产生显著影响;冬灌对机械稳定性大团聚体量及其MWD的影响无规律可循,但可增大水稳性大团聚体量及其MWD的降幅。【结论】冬季季节性冻融对试验区土壤大团聚体有破碎作用,显著降低了水稳性大团聚体量,灌水使这种破碎作用加剧,秋耕有增加大团聚体量和增大粒径的作用,但影响随着冻融期结束而消失。【Objective】Soil aggregate is a functional unit used to describe the effect of management practices on soil physical properties and soil functions.It is dynamic and varies with various factors.In this paper,we studied its variation in response to different managements during the freezing-thawing fallow season【.Method】The experiment was conducted in a wheat-corn field at an irrigation area at Hongyashan in Minqin County in Shiyang River Basin.The treatments we compared were winter irrigation(for water storage)and pro-harvest tillage in autumn.In each treatment,we measured the size distribution of mechanically stable aggregates and water stable aggregates at different soil depths before and after the freezing-thawing season,respectively.【Result】The freezing-thawing did not show noticeable influence on macro-aggregate content and mean weight-diameter of the mechanically stable aggregates,but significantly reduced the content of water stable macro-aggregates and their mean weight diameter.The autumn tillage temporally increased large mechanically stable aggregate content and water stable aggregate content,as well as their average weight diameter,but the effect waned before the soil was frozen.The winter irrigation did not show an identifiable impact on mechanically stable large aggregates,but increased the large water-stable aggregate content and their average weight diameter.【Conclusion】Freezing-thawing crushed large soil large aggregates,significantly reducing the content of water-stable aggregates as a result.Winter irrigation aggravated this effect.Autumn plough increased the content of large aggregates and aggregates diameter temporally,and the effect waned and completely vanished before the soil was frozen.

关 键 词：农田休闲期 田间管理措施 机械稳定性团聚体 水稳性团聚体 季节性冻融 

分 类 号：S125.7[农业科学—农业基础科学]