| Cite this article: | 孙召军,李金山,贾艳辉,等.干湿交替次数对土壤干密度和饱和导水率的影响[J].灌溉排水学报,0,():-. |
| Sun Zhaojun,Li Jinshan,Jia Yanhui,et al.干湿交替次数对土壤干密度和饱和导水率的影响[J].灌溉排水学报,0,():-. |
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| DOI： |
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| Effects of alternate times of dry and wet on soil dry density and saturated hydraulic conductivity |
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Sun Zhaojun1,2,3,2, Li Jinshan1, Jia Yanhui1, li hao1
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1.Farmland Irrigation Research Institute of Chinese Academy of Agricultural Sciences,Henan Key Laboratory of Water-Saving Agriculture;2.China;3.Graduate School of Chinese Academy of Agricultural Sciences
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| Abstract: |
| Soil water movement characteristics are important parameters that affect soil water and salt transport and crop quality and high yield. 【Objective】By studying the influence characteristics of alternating wet and dry on soil dry density (DD) and saturation conductivity (KS) of undisturbed soil and disturbed soil, it is of great significance to understand the change law of soil water movement and the change of field soil physical properties during crop growth period. 【Method】In this paper, the dry density and hydraulic conductivity of undisturbed soil and disturbed soil under different dry-wet alternation conditions were measured through laboratory tests, and the effects of different dry-wet alternation processes on the variation characteristics and laws of soil dry density and hydraulic conductivity were analyzed. 【Result】The results showed that the dry density of undisturbed soil fluctuated between 1.41～1.89 g/cm3, and that of disturbed soil fluctuated between 1.47～1.85 g/cm3. The dry density of undisturbed soil after the first dry-wet alternation increased significantly compared with the original dry density, and gradually fluctuated in a small range with the increase of dry-wet alternation times, with an average coefficient of variation of 8%. The disturbed soil was in an upward trend, and the average coefficient of variation was 5%; The change range of dry density of undisturbed soil was significantly greater than that of disturbed soil (P < 0.05). The hydraulic conductivity of undisturbed soil fluctuated between 0.29 ~ 1.07 cm/h, and that of disturbed soil fluctuated between 0.07 ~ 0.57 cm/h. Undisturbed soil showed an upward trend after different dry-wet alternation times, and the average coefficient of variation was 39%. The hydraulic conductivity of disturbed soil decreased first and then increased after different dry-wet alternation times, and the average coefficient of variation was 94%. The change range of hydraulic conductivity of undisturbed soil was significantly less than that of disturbed soil (P < 0.05). 【Conclusion】Under the experimental conditions, more water channels were formed after the soil experienced the alternation of dry and wet, and the soil permeability was enhanced. After field tillage, the surface soil is in a disturbed and loose state, with small dry density and large hydraulic conductivity. After the first irrigation, the dry density increases and the hydraulic conductivity decreases, and the dry density and hydraulic conductivity tend to be stable in the subsequent production process. |
| Key words: Dry wet alternation; Soil dry density oil dry density; Saturated hydraulic conductivity; Soil moisture characteristics |
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