荒山植树造林离不开雨水、植树造林中,土壤水分含量的多少对苗木、种子成活率的影响很大。植物根系对土壤水分的吸收是由植物根系与土壤之间的水势梯度引起的,而土壤水势的大小,与土壤含水量的多少密切相关。土壤本身对水分有吸力,有一定的能态。当土壤含水量较小时,水膜薄,受土粒吸力的影响大,水 Afforestation in barren hills is inseparable from the rain, afforestation, the amount of soil moisture content of seedlings, seeds have a significant impact on the survival rate. Plant roots to soil moisture absorption by the plant roots and soil water potential gradient between the caused, and the size of the soil water potential, and soil moisture content is closely related. Soil itself has a suction of water, there is a certain energy state. When the soil moisture content is small, the water film is thin, influenced by the soil suction, water