苗木移栽条件下的滨海盐渍土水盐动态变化

在河北唐山南堡开发区,结合穴状衬膜改土整地,移栽了绒毛白蜡、国槐、桧柏、柳树等研究用苗木,以土钻取土法进行两年土壤水盐动态定期监测,研究了移栽苗木对滨海盐渍土水盐动态规律的影响,以期为滨海泥质盐碱地造林绿化的树种选择提供理论依据。结果表明,与未移栽苗木的处理(对照组)相比,移栽苗木会降低土壤含水量和电导率,并增大二者的月际变化幅度,但对土壤含水量和电导率的总体变化趋势影响不大。苗木的生长季、树冠结构和根系吸水是移栽苗木后影响土壤水盐动态变化的主要因素,其中苗木的生长季影响主要表现为同一时期,各种苗木所在土壤含水量差异较大;苗木的冠型结构主要影响表层土的土壤含水量;根系吸水作用则是改变了土壤含水量和盐分的垂直分布。4种苗木间对比,土壤含水量动态变化无明显差异;土壤电导率动态变化呈显著差异,其中以桧柏对土壤电导率动态变化影响较为显著、脱盐降盐效果最好。

Water and salt dynamics of coastal saline soil after seedling transplantation

Soil preparation with cave padded plastic film was implemented to ameliorate saline soil in Nanpu economic development area in Tangshan, Hebei province. In order to provide a theoretical basis for afforestation tree species selection in the coastal saline soil, the objective seedlings including Fraxinus chinensis (Fraxinus velutina Torr), Sophora japonica (Sophora japonica Linn), sabina chinensis (Sabina chinensis) and willow (Salix babylonica) were transplanted and the soil water and salt dynamic changes were continuously monitored for two years to study the effects of seedling transplantation with earth boring auger on the water and salt dynamics of coastal saline soil. It was shown that compared with the control group without transplantation, the soil moisture and electrical conductivity were reduced after seedling transplantation while the range of variation increased and the effect on the trend of soil moisture content and conductivity was not significant; the growing season and crown structure and water uptake by plant roots were the main reasons for changes of water and salt dynamics after seedling transportation, specifically, the effect of the growing season manifested that the differences of soil moisture contents of the seedlings were significant, the crown structure of seedling mainly influenced the soil moisture content of topsoil, and the water uptake by plant roots transformed the vertical distribution of the soil moisture and salic horizon. Among the four seedling species, there was no significant difference in terms of dynamics of soil moisture content, while the soil conductivities varied remarkably. The impact on soil electrical dynamics and salt rejection of sabina chinensis was the largest in the four species.