【摘要】 本文研究了东北5种耕作土壤<1巴的低吸力段持水性能,包括影响低吸力段持水量的因素、所吸持水分对植物的有效程度、比水容量及脱水速度等。根据东北地区春旱尽管程度不同,但发生较为普遍的这一特点,分析、比较各种土壤基质本身存在的差异,并就它们对早期土壤干旱的抗逆能力作出评价。结果表明,熟化程度较高的草甸棕壤最优,而砂壤质冲积性草甸土最差。更多还原

【Abstract】 It is generally considered that tensiometer is only suitable for investigation of water-retention characters in low suction range on irrigated soils. But, it may also be adaptable for studying the dry cultivated (non-irrigated) soils in Northeast China, because in the presence of seasonal frozen layer the moisture content in upper soil layersis higher in early spring. The present paper deals mainly with the resistance of soil matrix in the early stage of soil drought.The soil factors influencing the water-retention characters in low suction range are primarily the texture, secondly the organic matter. Besides, temperature is one of the most important environmental factors.Specific water capacity (SWC) may be used to correctly evaluate the soil water-retention characters and the availability of soil moisture. In addition, the daily changes in soil suction from 0.1 bar to 0.8 bar indicated the differences of dewater rate between 5 cultivated soils.Based on the studies of SWC and the dewater rate of soils, the results of primary investigation showed that the evaluation of drought resistance of soil matrix per se follows the order: meadow burozem>cultivated burozem and ameliorated soda saline soil>thick black soil>alluvial meadow soil.更多还原