盐碱地滴灌春小麦土壤水盐运动特点

Characteristics of Soil Water and Salt Movement under Drip Irrigation for Spring Wheat

通过测坑试验,测定水平和垂直方向距滴灌带不同位置土壤含水率和含盐量。结果表明,小麦滴灌条件下土壤水盐分布受滴灌影响深度主要在0～60cm土层,0～20cm土层水盐变化最剧烈。小麦主根系层土壤在垂直和水平方向一定范围内(垂直20cm、水平25cm)形成一个盐分淡化区,在0～100cm土壤剖面内,土壤含水率随土层深度呈先升后降变化。土壤盐分在0～40cm处于脱盐状态,60～100cm积盐。上层土壤水盐受灌水和蒸发的影响随时间均升降交替变化,土壤盐分在非灌水期间呈表层和深层双聚、耕层脱盐特点。

Test-pit experiments in wheat at various growth stages were carried out to measure soil moisture and salt content in different positions of drip irrigation belt from the horizontal and the vertical directions. The results showed that soil water and salt distributions were influenced by drip irrigation in 0--60 em in depth, and water and salt changed most severely in 0-20 cm in depth. Wheat main root layer soil in a cer- tain range （20 cm in vertical, 25 cm in horizontal） formed a salt dilution zone, and soil moisture content in 100 cm increased with soil depth, then decreased. Soil salinity in 0-40 cm was desalted, and was accumu- lated in 60-100 cm. Soil water and salt upper changed irregularly over time by evaporation and irrigation with soil salinity in surface and deep gathering and the arable layer desalting in the non-irrigation period.