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土壤水分特征曲线是研究土壤水分运动与调控等方面的重要科学依据。以往土壤水分特性曲线的研究关注土壤孔隙特性的影响,而对土壤液体的影响关注较少。为此,本研究以甘肃省秦安县果园黑麻土为研究对象,采用室内模拟的方法,研究了不同矿化度(0、1、3、5、10 g L-1)的NaCl和Na2SO4溶液对土壤脱水曲线及拟合参数的影响。结果表明:水质的矿化度对土壤饱和含水量有一定的影响,低矿化度(<3 g L-1)仅对低吸力段(pF<2.5)水分特征曲线有影响,高矿化度(≥3 g L-1)对整个吸力段(pF在0~4.2)水分特征曲线有影响,其中矿化度为5 g L-1的NaCl和Na2SO4处理土壤容积含水量最小,且较对照差异最大。相同矿化度的NaCl和Na2SO4溶液对土壤水分特征曲线参数变化率的影响程度不同,对α的影响最为显著,其次为θs,再次为n。NaCl对参数α和n变化率的影响均随矿化度的增大呈先增加后降低趋势,而Na2SO4对参数α和n变化率的影响随矿化度的增大呈先降低后增大的趋势,且NaCl对土壤持水特性的影响大于Na2SO4。
Soil water characteristic curve is an important scientific basis for studying soil moisture movement and regulation. Previous studies of soil water characteristics have focused on the effects of soil pore properties, while less attention has been paid to soil fluids. Therefore, in this study, the black mahogany orchard in Qinan County, Gansu Province was used as the research object to study the effects of NaCl and Na2SO4 solutions with different salinities (0, 1, 3, 5 and 10 g L-1) Effect on Soil Dehydration Curve and Fitting Parameters. The results show that the salinity of water has a certain influence on the saturated water content of the soil. Low salinity (<3 g L-1) only affects the water characteristic curve of low-suction section (pF <2.5) (≥3 g L-1) had an influence on the water characteristic curve of the whole suction section (pF at 0 ~ 4.2). The soil water content of NaCl and Na2SO4 with the salinity of 5 g L-1 was the lowest, maximum. The same degree of salinity of NaCl and Na2SO4 solution on soil moisture characteristic curve parameters of the rate of change of different degrees, the most significant impact on α, followed by θs, again n. The effects of NaCl on the parameters α and n changed first and then decreased with the increase of salinity, while the influence of Na2SO4 on the parameters α and n decreased first and then increased with the increase of salinity Trend, and the effect of NaCl on soil water retention is greater than that of Na2SO4.