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为研究滨海盐渍土滴灌原土水盐调控不同处理对土壤导水率(K)、土壤孔隙大小分布常数(Gardnerα)、土壤孔隙对水流贡献率等水力性质的影响,在滨海盐渍土上进行滤层及基质势(-5、-10、-15、-20、-25kPa)处理的原土水盐调控试验。用圆盘入渗仪在-15、-6、-3、0cm4个连续增大的负压下进行入渗测定,并计算不同负压下导水率、土壤孔隙大小分布常数、孔隙级别对水流的贡献率。结果表明:经原土水盐调控后,各处理的饱和导水率、土壤孔隙大小分布常数较对照增大,在-6和-15cm水头下的导水率较对照减少,在-3cm水头下的导水率无明显变化规律。滤层处理下土壤的饱和导水率、-6cm水头下的导水率、土壤孔隙大小分布常数较无滤层处理有显著提高;各处理土壤大孔隙对水流的贡献率大于对照处理,中等孔隙2及小孔隙对水流的贡献率小于对照处理。滤层处理是不同级别土壤孔隙对水流贡献率大小的主要影响因素,其中滤层的土壤大孔隙、中等孔隙1对水流的贡献率显著高于无滤层。可见,经原土水盐调控后,土壤饱和导水率、-6cm水头下的导水率、土壤孔隙大小分布常数明显增加,土壤大孔隙增加,小孔隙减少,土壤结构得到改善。
In order to study the effects of different treatments on soil water conductivity (K), Gardnerα (soil pore size distribution constant) and contribution rate of soil porosity to water flow in coastal saline soil, The original soil water and salt control experiments were carried out for the treatment of filter layer and matrix potential (-5, -10, -15, -20, -25kPa). The infiltration was measured at -15, -6, -3, and 0 cm under negative pressure increasing continuously with a disc infiltration meter. The water conductivity under different negative pressures, the distribution of soil pore size distribution, The contribution rate. The results showed that the saturated hydraulic conductivity and soil pore size distribution constant increased with the control of original soil water and salt, and the hydraulic conductivity decreased under the water head of -6 and -15cm compared with the control. Under the water head of -3cm No significant change in the water conductivity. The saturated hydraulic conductivity of soil, the hydraulic conductivity under -6cm water head and the distribution constant of soil pore size were significantly higher than those without filtration treatment. The contribution of macropores to water flow was larger than that of control treatment, 2 and small pores on the water contribution rate is less than the control treatment. Filter layer treatment is the main influencing factor on the contribution rate of soil porosity to different water levels. The contribution of soil macropores and medium pores 1 to water flow is significantly higher than that of non-filter layers. It can be seen that the soil saturated hydraulic conductivity, the hydraulic conductivity under the water head of -6cm, the pore size distribution constant of soil increased obviously after the control of original soil salt and water, the soil macropores increased, the small pores decreased and the soil structure improved.