RU2147165C1 - Method for desalinization of saline soil - Google Patents

Abstract

FIELD: agriculture, in particular, desalinization of saline soils in regions with snowy winters and marked freezing of ground. SUBSTANCE: method involves strip cultivation of perennial grasses-halophytes in the field with following harvesting. Width of strips is 10-20 m and width of strip spacing is 3-8 m. Method allows soil desalinization process to be intensified. EFFECT: increased efficiency and improved quality of desalinized soil. 2 ex

Description

 The invention relates to the field of agriculture and can be used to saline saline soils in areas with snowy winters and their pronounced freezing.

 A known method of salinization of saline soils, including cultivating halophyte plants on them (RF Patent N 2109425, A 01 B 79/00). The disadvantage of this method is the low degree of desalinization caused by the short duration of their impact on the soil due to the use of annual plants as halophytes.

 The closest in its technical essence is the method of salinization of saline soils, including cultivation of perennial halophyte herbs on them with their subsequent harvesting (RU N 2108016, 04/10/98, A 01 B 79/00).

 The disadvantage of this method is the low desalination rate. This is due to the fact that during the frosty period, moisture from the lower layers of the soil along the capillaries due to the temperature gradient and pressure difference rises to the upper colder layers of the soil, where it freezes. During the thawing period of the soil, moisture migrates back to the deep layers due to the vacuum formed under the permafrost crust during the winter. As a result, it becomes scarce in the most developed part of the root system, which does not allow the full use of the potential of halophyte plants.

 The objective of the present invention is to increase the rate of desalinization of saline soils using low-cost technologies by fixing moisture in the zone of the root system of salt-tolerant perennial grasses.

 The present problem is solved by the fact that in the method of salinization of saline soils, including cultivating halophytes on the field of perennial grasses with their subsequent harvesting, cultivating halophytes perennial grasses is carried out in a strip, with a strip width of 10-20 m and an interband space of 3-8 m.

 The novelty of the proposed solution lies in the application for the purpose of desalination of perennial halophyte herbs according to a specific cultivation scheme, taking into account the observance of certain sizes of strips and inter-strip space.

 The method is as follows. On soils intended for salinization, perennial halophytes are sown in spring in strips of 10 - 20 m wide, with an inter-strip space of 3 - 8 m wide. During the growing season, grasses absorb some of the salts from the soil horizon equal to the depth of the root system. As a result of this, the soil sections under perennial grasses and the inter-strip space will have differences in the concentration of salts in the root layer of the soil by autumn. In winter, due to the difference in salt concentration, the soil in areas under perennial grass freezes faster, and in the inter-strip space the freezing process will be less intensive, as the soil will be more saline.

 In the spring time, the process of thawing more saline sections of the soil will be faster, as a result of which through these sections more melt water with a low salt concentration gets into the soil, and this, in turn, will cause the inter-strip spaces to pass in the first year of the crop rotation partial desalination by melt water.

 At the same time as melt water, atmospheric air penetrates into the soil through the inter-strip space, which falls under the permafrost crust of undecreased bands with perennial grasses and relieves under-pressure formed during the winter as a result of the temperature gradient and vapor and moisture transfer. As a result, the capillary moisture that is pulled into the upper layers and frozen during thawing of these sections of soil in larger quantities than usual will linger in the root layer of the soil, which will allow perennial grasses to use it more productively at the beginning of the growing season, thereby performing effective desalination. The repetition of this process for 2 to 4 years can significantly increase the rate of desalinization of saline soils.

 Example 1. Salinization of saline soils was carried out by strip cultivation of perennial grasses on the field surface.

 As a perennial crop, the Sitnikovy saplings, seeded with strips 10 m wide, were used. Inter-strip space 3 m wide was left under steam. Perennial grasses in this field were cultivated for 4 years. Reducing the size of the strips of perennial grasses and the inter-strip space leads to a complication of the technology for processing the field, and also does not allow atmospheric air to penetrate under the permafrost crust of the strips of perennial grasses during thawing of the soil. After 4 years of growing perennial grasses, the concentration of salts in soil moisture was 20-30% lower than with continuous cultivation.

 Example 2. Salinization of saline soils was carried out by strip cultivation of perennial grasses. Yellow clover sown with strips of 20 m wide was used as a perennial culture; an inter-strip space of 8 m wide was seeded with spring barley. An increase in the width of strips of perennial grasses and the width of the inter-strip space leads to a decrease in the rate of desalinization, since atmospheric air does not have time to penetrate the entire width of the strips of perennial grasses and remove the vacuum formed under it during the period between the complete thawing of the soil strips, thereby preserving part of the tightened in the root layer of soil moisture from its reverse migration. After 2 years of growing perennial grasses, the amount of salt in the soil in the experimental field was 17-20% less than in the field of continuous sowing of perennial grasses.

Claims (1)

 The method of salinization of saline soils, including cultivating perennial halophyte herbs on them, followed by their harvesting, characterized in that the cultivation of perennial halophyte herbs is carried out in a strip, with a strip width of 10 - 20 m and an inter-strip width of 3 - 8 m.