土壤水吸力

结果表明，灌水时供水压力大于15kPa、控制灌水下限土壤水吸力设定为30kPa，该PVC管滴灌系统出水均匀度可达到既定标准。

The results show that the uniformity of irrigation with PVC tube can meet the designed standard , using 15 kPa as irrigation pressure and 30 kPa soil water suction as the lower limit of irrigation .

无论在隔绝蒸发还是在自然蒸发条件下，短期内土壤水吸力有随土层深度的增加呈先下降后升高的趋势，而同一深度土层水吸力则随时间的推移而升高；

Regardless of preventing evaporation or not , soil water suction decreased firstly and then increased with the increase of soil depth , and soil water suction at the same depth increased with time .

PDV土壤水吸力的时间稳定性只在一个灌溉周期内存在，而FQS的时间稳定性可在整个灌溉周期、不同作物条件下持续。

For PDV , temporal stability persists in an irrigation cycle , while for FQS , temporal stability was persists in the whole measuring period and different types of crops .

有作物条件下潜水蒸发与作物根系层下的土壤水吸力关系较好，提出了利用土壤水吸力计算有作物条件下潜水蒸发的方法。

The relationship between evaporation from groundwater and soil moisture suction beneath root zone is very well .

大棚土壤水吸力研究

They always connected water with their attitude . The study on Moisture Suction in Soil under Shed Protection

当土壤水吸力较低时，表土层土壤非饱和导水率大于底层土和中间土层的土壤非饱和导水率；

When the soil water suctions were low , the unsaturated hydraulic conductivities in topsoil layers were higher than those in middle soil layers .

当土壤水吸力增大到一定值时，中间土层的土壤非饱和导水率反而大于底土层和表土层。

While the soil water suctions increased to some values , the unsaturated hydraulic conductivities in middle soil layers were higher than those in topsoil layers .

各土层的水分特征曲线总的趋势是一致的，即随土壤水吸力的增加土壤体积含水量逐渐下降；

Tendencies of the soil water retention curves of all soil layers in three kinds of soil were similar , the soil volumetric water content decreased with the soil water suctions .

结果表明，肥料施用数量和灌溉控制下限土壤水吸力值的大小对番茄的产量及其果实的品质影响显著，且两因素的交互作用也达到了1%的显著水平；

The results indicated that the fertilizer application rate and the soil water suction related to the lower limit of irrigation affected the yield of tomato and fruit quality significantly , and the interaction of these two factors reached 1 % significant level .