Coastal saline-alkaline soil greening structure and method utilizing local topography to control salt return

Abstract

The invention relates to a coastal saline-alkaline soil greening structure and method utilizing local topography to control salt return; the structure comprises heap terrain arranged on the surface ofan original saline-alkaline soil layer; rainwater collecting ditches are arranged on the cross section of the heap terrain at intervals; trees and shrubs are planted on the heap terrain, and ground cover plants are planted in the rainwater collection ditches; a gravel isolation layer is laid on the surface of the original saline-alkaline soil layer; a geotextile layer is laid on the gravel isolation layer, and a transverse pipe network and salt control columns are arranged at the bottom of the original saline-alkaline soil layer below the heap terrain; and the salt control columns are communicated with the transverse pipe network. According to the invention, a comprehensive supporting system is established by locally raising the terrain away from underground water and adopting the measures of collecting rainwater or irrigation water to slowly permeate and wash salt, centrally discharging salt, providing salt isolation layers and salt-discharging hidden pipes, improving soil and the like, so that the possibility of returning salt is broken, and the effect of inhibiting salt accumulation on the surface layer of soil is achieved.

Description

technical field [0001] The invention relates to the technical field of saline-alkali land greening, in particular to a coastal saline-alkali land greening structure and method that utilizes local topography to control salt return, and is especially suitable for greening moderately and above moderately salinized soil in coastal areas. Background technique [0002] The main characteristics of saline-alkali land in coastal areas are heavy compaction, poor permeability, and high salt content, mainly composed of sodium chloride salt, which is difficult to achieve by washing salt with fresh water. In addition, due to the large amount of evaporation, high groundwater salinity and high groundwater table are the root causes of coastal saline-alkali land, which eventually lead to high soil salinity, poor soil structure and fertility. Therefore, in order to afforest in saline-alkali land, it is necessary to make full use of the law of water and salt movement and control salt return. T...

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Problems solved by technology

[0003] At present, there are mainly the following methods for controlling saline-alkali land: the use of chemical modifiers can achieve a temporary improvement effect, especially in the season of returning to salt, but it often treats the symptoms but not the root cause; and the technology of laying salt barriers Measures to interrupt the upward migration of soil capillary water are considered from the law of water and salt movement, but the structure is too simple and the effect of long-term salt control is limited

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