Changing Characteristics of Salt Accumulation Patterns in the Soil Surface

通过对饱和NaCl溶液的土样在炒制过程中盐分积累规律的研究，发现在各分层上，代表土壤表面蒸发量与土壤悬浮液浓度关系的盐分积累曲线存在显著的拐点，即A点。为了解释这一现象，在不同的干燥条件下进行了盐积累的附加实验。并进行了与盐分积累有关的土壤溶液干燥速率曲线和土壤溶液运动特性的试验研究，得到以下结果.在拐点A处，蒸发量随干燥温度的升高而减小。土壤溶液浓度的差异对蒸发量的影响不大.利用土柱试验研究了土壤种类和土壤溶液浓度对土壤积盐干燥特性的影响。结果表明，土壤干燥特性曲线的形状随这些参数的不同而变化.通过不同分层含水率分布、不同干燥程度含水率分布、分层累积干燥速度与干燥程度的关系、各分层干燥速度与干燥程度的关系等4种曲线，研究了土壤溶液的运动规律。认为这些曲线是研究土壤盐分积累的有效方法，但需要进一步提高实验精度。

It was recognized that salt accumulation curves represented relation between evaporation from soil surface and concentration of soil suspension at each divided layers have the remarkable inflection point named point of A by the study which was performed to determine the salt accumulationpatterns in the frying process of soil specimens saturated with NaCl solution. In order to explain this phenomenon additional experiments for salt accumulation were performed at the different drying conditions. And some kinds of experiments related with salt accumulation were tried; i.e. patterns of drying rate curves to soil solution and movement characteristics of soil solution.The following results were obtained.1. Volume of evaporation decreased in the increase of drying temperature at the inflection point of A. But, the difference of concentration of soil solution did not have an effect on the volume of evaporation.2. The effect of differnces in the kinds of soils and concentration of soil solution on the drying characteristics of soil s during the process of salt accumulation was studied experimentally using soil columns. It was recognized that the configuration of curves of the drying characteristics of soils varied with the differnce in these parameters.3. The movement of soil solution was studied by four kinds of curves; i.e. water content distribution at the different divided layers and at the different drying levels, and relation between accumulated drying velocity of divided layers and drying level, and relation between drying velocity at each divided layer and drying level. It was recognized that these curves were effective to study the salt accumulation and that experimental accuracy is need to increase.