Study On The Afforestation Model And Wet And Salt Movement In Coastal Saline-alkaline Soil

The paper sets the eco.& tech. development zone of Cangzhou Hebei as the experiment plots. At treatment of different salt isolated layer, surface coverage and rainfall harvest planting, soil wet and salt are observed, and the laws of their movement in the depth of 60cm.The results show that (1)In those factors which impact the coastal afforstation in saline-alkaline soil, B1(plant selection) takes nearly 50% of the total weight ratio, in which the largest contribution to B1 is the survival rate (20%), and fallowed by B3(maintenance and management)24% to overall target, the last one is B2(construction level),accounted for nearly 21%. (2) The groundwater response characteristics of the rainfall is that, when short-term cumulative rainfall reaches above 80 mm, the groundwater level elevates rapidly, which means 80mm is the upper limit of the regional drainage, when the precipitation excess 80mm, the groundwater table raises fast and depth water stagnant happening in the ragion. (3)Under the treatment of slag and sand salt isolated layers, after the period of rain leaching , because of the tension of water at the interface, there is a " wet cumulative" phenomenon at the bottom of the soil profile, while the " salt leaking" at the isolated layer interface, which mean that the role of salt isolated layers are notable. After comparatively analyzing the role of salt isolative and the wet rising, we find that the role of sand isolated layer is more significant compare to slag. (4) In the film, stalk and sand surface cover material treatment, the soil wet or moisture has enhanced significantly compared to those of control in both surface (0-5 cm) and root growth layers (20-40 cm) ,while salt reduced significantly, which means that the role of surface coverage treatment in inhibiting soil salt is notable. In those three coverage material treatment, the role of mulching is the most significant. (5) We find that the role of water keeping and salt leaching is more significant in the treatment of rainwater harvesting forestry compared to those single salt isolated layer treatments. There is no phenomenon of "accumulation" at the bottom of the rainfall harvesting profile, which shows that when soil water reaches or surpasses the interface, there will be a thoroughly salt leaching. (6)After a growing season's observation, by evaluating different ways of afforestation, we propose three constructive modal, which are afforestation by treatment of salt isolated layer, by surface coverage, and by rainwater harvest.