| 引用本文: | 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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| 摘要: |
| 土壤水分运动特性是影响土壤水盐运移和作物优质高产的重要参数。【目的】通过研究干湿交替对原状土和扰动土土壤干密度(DD)和饱和导水率(Ks)的影响特征,对于认识土壤水分运动的变化规律以及作物生育期内大田土壤物理性状的变化有重要的意义。【方法】本文通过室内试验对不同干湿交替条件下原状土和扰动土的干密度和导水率进行测定,分析不同干湿交替过程对土壤干密度和导水率的变化特征及规律的影响。【结果】原状土干密度在1.41～1.89 g/cm3之间波动,扰动土干密度在1.47～1.85 g/cm3之间波动；原状土在第一次干湿交替后的干密度较原始干密度有大幅上升,随着干湿交替次数的增加逐渐趋于小范围波动,平均变异系数为8%；扰动土总体处于上升趋势,平均变异系数为5%；原状土干密度变化幅度显著大于扰动土(P＜0.05)。原状土导水率在0.29～1.07 cm/h之间波动,扰动土导水率在0.07～0.57 cm/h之间波动；原状土在经历不同干湿交替次数后呈现上升的趋势,平均变异系数为39%；扰动土在经历不同干湿交替次数后导水率呈现先下降后上升的趋势,平均变异系数为94%；原状土导水率变化幅度显著小于扰动土(P＜0.05)。【结论】本实验条件下,土壤经历干湿交替后形成了较多水道,土壤透水性增强；大田翻耕后,表层土壤处于扰动松散状态,干密度较小,导水率较大,而第一次灌水以后,干密度变大,导水率降低,且干密度和导水率在后续的生产过程中趋于稳定状态。 |
| 关键词: 干湿交替;土壤干密度;饱和导水率;土壤水分特性 |
| DOI： |
| 分类号:S275.3 |
| 基金项目:中国农业科学院基本科研业务费专项,农村应急性防洪排涝技术和装备研发。 |
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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 |
