A three-dimensional structure of rapid desalination and improvement of soil profile in saline-alkali land in tidal flat reclamation area

Abstract

The invention provides a sectional three-dimensional structure for the fast desalting and soil improvement of saline-alkali soil of a new tidal marsh reclamation area. According to the sectional three-dimensional structure, a soil layer of the saline-alkali soil to be desalted is subjected to ditching at the depth of 90-100 cm, and underground pipes are buried in a manner that the burying spacing is 20-30 m and the inclination angle is 1-3 DEG, so as to form an underground-pipe drainage layer; soil of a sectional surface layer of the soil layer is grooved at the depth of 40-45 cm and is stacked in an open space aside, and straws are laid uniformly after the surface of soil is leveled, so as to form a straw isolating layer with the thickness of 5-8 cm; and chopped straws and desulfation gypsum are added into the soil of the surface layer, which is stacked aside, the chopped straws, the desulfation gypsum and the soil of the surface layer are mixed uniformly, composite soil with the thickness of 10-15 cm is laid on the straw isolating layer, infiltrating irrigation capillaries are laid in the spacing of 0.8-2 m, and rest composite soil is then laid and is leveled, so as to form a straw and gypsum mixed cultivation layer. The sectional three-dimensional structure has the advantages that the sectional three-dimensional structure is organically combined into a whole up and down, the effects on the fast desalting and soil improvement and effective salinization process inhibition of the new tidal marsh reclamation area are remarkable, and the improvement cycle for the saline-alkali soil of the new reclamation area can be shortened effectively.

Description

technical field [0001] The invention belongs to the technical field of saline-alkali land improvement engineering, and in particular relates to a three-dimensional structure for fast desalination and soil improvement of saline-alkali land in a new sea reclamation area. Background technique [0002] The tidal flats in the coastal areas are rich in resources, which are rare land reserve resources in our country. The implementation of scientific reclamation and development of tidal flats plays an irreplaceable role in supplementing the shortage of cultivated land resources in my country, ensuring national food security, and expanding coastal development space. However, the newly reclamation area of ​​the tidal flat has the characteristics of high salt content, shallow groundwater depth, high mineralization, poor soil texture and structure, and low natural fertility level of the soil due to the short time of soaking away from seawater and soil formation. These barrier factors h...

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Problems solved by technology

On the one hand, the soil in the newly reclamation area of ​​the tidal flat is mostly high-sodium-salt muddy marine extremely fine-grained clay, and the soil permeability is poor, and the permeability coefficient is (0.4~6)×10 -5 cm / s, and the surface soil is quickly compacted after being soaked by precipitation or irrigation water, and the soil infiltration capacity is further reduced. Under the condition of heavy rain or heavy rain, the water is easy to form surface runoff and discharge, and the water infiltrates into the soil to wash the salt and pass through The proportion of discharge from underground pipes is low, and the rapid desalination effect of underground pipes is not obvious; on the other hand, through on-site investigations in newly reclaimed tidal flats in counties such as Rudong, Dafeng, and Dongtai, it was found that there are generally A dense layer of silt and silt with a thickness of 5~8cm and a permeability coefficient lower than 0.4×10 -5 cm / s, becoming a water movement barrier layer, reducing the rate of drainage and desalination of underground pipes

Thirdly, the special hydrogeological conditions of the new tidal reclamation area determine that the soil profile is poorly ventilated, which is not conducive to the growth of plant roots and the absorption and desalination of salt by plants. Difficulty in desalination and alkali treatment of saline-alkali land in new reclamation areas

This method is conducive to the rapid leaching of soluble salt ions in the soil below the plow layer, but at the same time it fails to take into account the special soil profile structure and hydrogeological conditions of the new tidal reclamation area, and its promotion effect in the new reclamation area is limited. constraints

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