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对土娄土不同层次的几个水分物理常数及持水曲线进行了测定 ,依据其在不同层次的垂直变化 ,对其相互之间的相关性进行了分析。结果表明 :①田间持水量在 2 10 .5～ 2 2 6 .9g·kg- 1之间 ,近似一个常数。田间持水量与无效水含量 (萎焉系数 )成显著正相关 ,与物理性粘粒含量之间并无明显相关 ;②容重除表层 (0～ 10cm)为 1.0 1g·cm- 3外 ,其余各层在 1.30～ 1.4 9g·cm- 3之间 ,各层次有较大偏差。容重与重力水、全有效水、速效水、迟效水含量以及低吸力段 (小于 10 0kPa)下的比水容量值之间成显著或极显著负相关。③物理粘粒含量在 4 30 .0～ 586 .6 g·kg- 1之间 ,各层次差异较大。物理粘粒含量与重力水、全有效水含量成显著负相关、与无效水含量 (萎焉系数 )成显著正相关 ,与容重之间并无明显相关。④水分特征曲线以经验方程θ=AS-B 拟合效果最佳 ;土壤各层次水分特征曲线、比水容量曲线差别不大。⑤无效水含量 (萎焉系数 )以 150 0kPa吸力下的含水量来等效 ,略有偏高 ,以 180 0kPa为宜
The physical constants and water retention curves of several soil moisture at different levels of soil were determined, and their correlations with each other were analyzed based on their vertical variations at different levels. The results showed that: ① The field water holding capacity was between 210.5-262.99g · kg-1, which was approximately a constant. There was a significant positive correlation between field water holding capacity and invalid water content (wilting coefficient), but no significant correlation with physical clay content. (2) Bulk density was 1.01 g · cm-3 except surface layer (0-10 cm) The layers are between 1.30 ~ 1.4 9g · cm-3, and there are large deviations in all levels. There was a significant or a significant negative correlation between the weight and the specific water capacity of gravity water, total effective water, available water, delayed water content and specific water capacity at low suction section (less than 100 kPa). ③ physical clay content of 4 30 .0 ~ 586. 6 g · kg-1 between the different levels. There is a significant negative correlation between the physical clay content and the gravity water and the total effective water content, and positively correlated with the invalid water content (wilting coefficient), but no significant correlation with the bulk density. ④ The water characteristic curve is best fitted by the empirical equation θ = AS-B. The soil water characteristic curves at different levels have little difference from the water capacity curve. ⑤ invalid water content (wilting coefficient) at 150 0kPa water content under the suction to the equivalent, slightly high, with 180 0kPa appropriate