季节性冻融对绿洲灌区农田休闲期土壤水稳性团聚体的影响  

Effect of seasonal freezing-thawing on soil water-stable aggregates of fallow farmland in Oasis Irrigational Area

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 Engi-neering,Lanzhou University of Technology,Lanzhou 730050,China;Gansu Institute of Soil&Water Conserva-tion Sciences,Lanzhou 730020,China)

机构地区：[1]甘肃省水利科学研究院,甘肃兰州730000 [2]兰州理工大学能源与动力工程学院,甘肃兰州730050 [3]甘肃省水土保持科学研究所,甘肃兰州730020

出　　处：《甘肃农业大学学报》2023年第6期169-179,188,共12页Journal of Gansu Agricultural University

基　　金：甘肃省重点研发计划“干旱绿洲区农田储水灌溉作用机理评价与节水型储水灌溉技术研究”(18YF1NA031);甘肃省重点人才计划(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】评价季节性冻融对休闲期农田土壤团聚体性质的影响。【方法】在甘肃省石羊河流域民勤地区,以常规田间管理措施和冬灌制度为代表设计不同试验处理,开展了冬季季节性冻融对土壤水稳性团聚体含量及特性指标的影响研究,观测了冻融前后不同土层深度土壤水稳性团聚体的粒径组成,分析了不同田间管理措施及灌溉条件下冻融前后不同粒径大团聚体含量和特性指标变化。【结果】冬季季节性冻融可使耕层土壤水稳性大团聚体各粒径含量显著降低,降幅与冻结前该粒径含量呈显著线性相关,含量越高,降幅越大;各土层平均质量直径MWD、几何质量直径GMD变小,分形维数D变大,变幅与冻结前各粒径含量呈显著线性相关,平均质量直径MWD、几何质量直径GMD受10~5mm粒径团聚体含量影响较大,分形维数D受2~0.25mm粒径团聚体含量影响明显。【结论】冬季季节性冻融对土壤大团聚体有破碎作用,显著降低了水稳性大团聚体含量;秋耕能增大水稳性团聚体的含量,但影响在土壤冻结前基本消除;冬灌可促进表层土壤大粒径团聚体的形成。【Objective】The study was conducted to evaluate the effect of seasonal freezing-thawing on the characteristics of soil aggregates in fallow farmland.【Method】Different experimental treatments were designed with conventional field management measures and winter irrigation scheme as representatives in Minqin Area of Shiyang River Basin of Gansu Province.The effects of winter freezing-thawing on soil water-stable aggregate content and characteristics were determined.The particle size composition of water-stable aggregates at different soil depths before and after freezing-thawing was observed.The content of ag-gregates with different size and its characteristic indexs were analyzed under different field management and irrigation measures.【Result】The seasonal freezing-thawing in winter could significantly reduce the con-tents of water-stable aggregates in different size.There was a significant linear correlation between the con-tent decrease of aggregates in different size and its content.The higher this content,the greater was the de-crease.The mean weight diameter MWD and geometric weight diameter GMD of soil aggregates in each layer declined,while the fractal dimension D got big.The variation amplitude is significantly linearly corre-lated with the particle content before freezing.The mean weight diameter MWD and geometric weight diam-eter GMD were significantly affected by the content of 10~5 mm aggregates,and the fractal dimension D was significantly affected by the content of 2~0.25 mm aggregates.【Conclusion】The seasonal freezing-thawing in winter had a role in crushing soil macro-aggregates and could significantly reduce the content of water-stable macro-aggregates.Autumn tillage could increase the content of water-stable aggregates,but the effect almost disappeared before soil freezing.Winter irrigation could contribute to the formation of macro-aggregates in surface soil.

关 键 词：季节性冻融 农田休闲期 水稳性团聚体 绿洲灌区 

分 类 号：S152.7[农业科学—土壤学]