CN106576486A - Method of converting severely lost soil on a surface layer of a mudflat into a forest land in a quick and highly efficient manner - Google Patents

Abstract

The invention discloses a fast and efficient ecological engineering method for recovering heavily missing soil in tidal flat topsoil into forest land. The steps are: 1) high-intensity and high-frequency plowing, irrigation to accelerate the alternation of dryness and wetness; 2) ridge formation, and salt washing ; 3) Apply organic materials, cover the film, remove the film, and plow; 4) Apply organic fertilizer, biochar, superphosphate; The present invention is based on the artificial acceleration of the natural ecological process. By making the raw soil layer undergo high-intensity and high-frequency natural ecological processes such as dryness and humidity, anaerobic/aerobic, etc., and supplemented by artificially adding organic matter to ferment and heat-producing ripening, the soil structure can be improved. Rapid improvement; salt washing on the basis of in-situ ridging, through the addition of biochar, organic fertilizer and superphosphate, etc., to improve soil nutrients and their retention and buffer capacity, and reduce pH and salt content, which can be fast and efficient Restoration of forest land is also applicable to the improvement and greening of the destroyed soil or contaminated soil surface in the coastal zone.

Description

A method for quickly and efficiently restoring the severely missing soil in tidal flat topsoil to forest land method

technical field

The invention belongs to the technical field of soil improvement and ecological engineering restoration, and specifically relates to a method for quickly and efficiently restoring the heavily missing soil in the surface soil layer of tidal flats into forest land.

technical background

Under the national strategic deployment of coastal development, coastal tidal flats, as a backup base for food security, are gradually improving qualified tidal flats into farmland as planned. At the same time, in order to reduce and control wind damage, the construction of windbreak forest belts is also implemented simultaneously. Windbreak forest belts often need to be ridden about 1.5 m to prevent saline-alkali stress on tree growth. Due to the lack of overall planning in the early stage and unreasonable soil borrowing and ridging engineering, the topsoil layer of some farmland soil was seriously missing, and the thickness of the missing soil layer was as high as 1.0-1.5 m. These missing soil surface zones have been idle for a long time because they are difficult to use, which not only tends to aggravate the unstable evolution of the local landscape structure, but also is a serious waste of soil resources.

At present, most of the technologies and researches on the repair of surface missing soil are through deep plowing, fertilization, or adding organic materials and microbial fertilizers to fertilize the soil, and then plant crops. However, the restoration objects of existing technologies mainly focus on the restoration of the surface soil layer with a thickness of <20 cm, and there are almost no reports on the restoration of severely missing soil in the thickness of >1.0 m. After the severe loss of soil layer, not only the soil fertility and organic matter are deficient, but more importantly, the structure of the raw soil layer is poor, the particle composition is homogeneous, the water retention and fertilizer retention are low, and the function of supporting plant growth is seriously defective. Even with a large amount of fertilization and addition of organic matter, it is difficult for the soil to maintain the normal growth and corresponding yield of food crops. In addition, the missing zone is irregular and fragmented, and it is difficult to restore it as farmland in a unified manner. Especially in coastal tidal flat areas, the underlying soil has high salt content and high pH, and the existing fertilization restoration and improvement technologies face the limitations of long time and poor effect. If you choose to add chemical materials to speed up the remediation process, there may be a potential risk of soil and groundwater contamination. Therefore, it is generally more appropriate and feasible to choose forest-shrub for restoration. However, how to restore the soil with severe topsoil loss to forest land also poses new challenges to previous restoration techniques.

Contents of the invention

The present invention is based on the artificial acceleration of the natural ecological process. By making the raw soil layer undergo high-intensity and high-frequency natural ecological processes such as dryness and humidity, anaerobic/aerobic, etc., and supplemented by artificially adding organic matter to ferment and heat-producing ripening, the soil structure can be improved. Rapid improvement; salt washing on the basis of in-situ ridging, through the addition of biochar, organic fertilizer and superphosphate, etc., to improve soil nutrients and their retention and buffer capacity, reduce pH and salt content, and provide a rapid , An ecological engineering technology that efficiently restores the severely missing soil in the topsoil layer of tidal flats to forest land.

The method for recovering the heavily missing soil of tidal flat topsoil layer as forest land according to the present invention comprises the following steps:

1) High-intensity and high-frequency plowing, artificial irrigation to accelerate the alternation of dryness and wetness;

2) ridging and washing salt;

3) After applying organic materials to the ridge belt, turn and mix evenly, water, cover, remove the film, and plow;

4) Apply organic fertilizer, biochar, superphosphate;

5) Plant green manure crops, plant salt-tolerant trees and shrubs with shallow roots after overturning.

The specific methods for restoring the soil with severe lack of topsoil layer in tidal flats to forest land are as follows:

The plowing in step 1) can loosen the raw soil layer and accelerate the redox process at the same time. The plowing depth is 30-50 cm to meet the soil volume required for subsequent ridges. The amount of irrigation water is 2000-3000 m ³ ·hm ^-2 , which can make the soil moisture content of 0-50 cm reach 30%-40%; repeated plowing and irrigation can accelerate the process of dry and wet aerobic/anaerobic processes. Soil maturation, structure improvement; duration is 4-6 months.

Step 2) Ridging is to pile up the soil on both sides of the plowed area towards the middle to form a ridge belt with a height of 40-60 cm and a width of 2.5-3.0 m; digging on both sides of the ridge belt is 40-60 cm deep and 20-30 cm wide for drainage Ditch; salt washing is to repeatedly irrigate and wash the soil in the ridge until the salt content of the soil in the ridge drops to <0.5%.

Step 3) The addition of organic materials such as rice husks and straws can quickly increase the soil fertility of the raw soil layer, improve the soil structure, and can be obtained locally with low cost. First, grind or pulverize organic materials such as rice husks and straws to a particle size of 2-10 mm, then spread 10-15 cm thick on the soil surface, and mix evenly; after filling the soil with water, cover the ridges with agricultural film, After 30-50 days, the film was removed, plowed again, and covered with film. Thereafter, plow once every 20-30 days until the maturity of the added organic material is >80%.

Step 4) The organic fertilizer applied in the step is pig, cattle, horse, chicken, duck, goose and other livestock and poultry manure; spread 10-15cm thick on the soil surface, then spread 1-2cm thick biochar, and apply superphosphate 400- 500 kg·hm ^-2 , tilled and mixed evenly. Applying a large amount of organic fertilizer can further increase soil organic matter and mineral nutrients, form an interactive stimulation effect with the previous organic materials, and significantly increase the number of soil microorganisms. Biochar has strong adsorption, anti-oxidation, can reduce soil bulk density, retain water and fertilizer, and provide attachment sites for soil microorganisms to further improve the nutrient conversion efficiency of organic materials and organic fertilizers. Applying superphosphate can not only increase the content of phosphorus and calcium in the soil, and adjust the ratio of nutrients, but superphosphate is acidic, which can significantly reduce the pH value of such soil.

The 5th step green manure crop selects mung bean, soybean etc. with short growth cycle. Cooperating with the applied organic fertilizer, it can maximize the soil fertility and improve the nutrient use efficiency of crops. Green manure crops are managed according to conventional methods and overturned on the spot in a suitable growth period; after two seasons of planting, you can choose trees and shrubs with shallow root systems and certain salt tolerance, such as seaside hibiscus, black locust, poplar, crape myrtle, and North American crabapple. Planting not only has certain ecological and landscape benefits, but also has certain economic benefits.

Positive beneficial effect of the present invention:

1) The present invention mainly accelerates the natural ecological process artificially, and combines the input of rice husk, straw organic material, film covering, organic fertilizer, biochar, superphosphate, etc., and the method is environmentally friendly.

2) The present invention uses high-intensity and high-frequency plowing, alternation between dryness and wetness and oxidation-reduction, covering/removing the film, organic matter decomposing and fermenting to generate heat, biochar adsorption to maintain nutrients, in-situ ridging to reduce salt, and superphosphate to reduce pH, green manure crop planting and other measures, the repair speed is fast and the effect is good.

3) The present invention is especially suitable for the improvement and greening after soil destruction or removal of polluted soil surface in the coastal zone. In a short period of 18-24 months, the target soil structure and fertility can be significantly improved, and vegetation can be restored efficiently.

In a word, the present invention makes the raw soil soil loose, air-permeable, water-permeable and heat-conductive by high-frequency intensive plowing and alternation of dry and wet; the plowed soil is piled up from both sides to the middle to form ridges and wash salt; Apply ground organic materials and cover them with film to decompose, plow tillage, release a large amount of heat through organic matter fermentation, anaerobic/aerobic alternation, etc., artificially accelerate soil maturation; apply organic fertilizer, biochar and superphosphate to further improve soil fertility, Improved structure, lowered pH; finally planted with green manure crops and planted with shallow-rooted salt-tolerant trees. The invention can quickly and efficiently restore the soil with severe lack of topsoil in tidal flats to forestry land, and is also suitable for improvement and greening after the surface layer of destroyed soil or polluted soil is removed in the coastal zone.

detailed description

The ecological engineering method for recovering the severely missing soil in the tidal flat topsoil with a thickness of 1.2-1.3 m as high as 1.2-1.3 m is explained below in detail. Proceed as follows:

1) Plow 30-50 cm;

2) Irrigate 2000-3000 m ³ hm ^-2 ;

3) After the water dries up naturally, repeat 1) and 2) for 4-6 months;

4) Pile the soil on both sides of the plowing area toward the middle to form a ridge belt with a ridge height of 50 cm and a width of 2.5-3.0 m;

5) Dig drainage ditches with a depth of 50 cm and a width of 20-30 cm on both sides of the plowing area;

6) Repeatedly irrigate and wash the soil in the ridge until the salt content of the 0-50 cm soil reaches 0.3-0.5%;

7) Crush rice husks and straws to a particle size of 2-10 mm;

8) Spread 10-15 cm of crushed rice husk and straw on the soil surface;

9) Plow 50 cm, mix rice husk, straw and soil evenly;

10) Irrigate 2000-3000 m ³ hm ^-2 ;

11) Cover the ridge with plastic film for 30-50 days;

12) Remove the film, plow 50 cm, and cover the film; repeat the process of removing the film, plowing 50 cm, and covering the film every 20-30 days until the organic material is more than 80% decomposed;

13) Spread 10-15 cm thick pig and chicken manure thicker than the soil surface;

14) Spread 1-2 cm thick biochar;

15) Apply superphosphate 400-500 kg·hm ^-2 ;

16) Plow and mix the manure, biochar and superphosphate with 0-50 cm soil;

17) Plant green manure crops such as mung beans and soybeans, and manage them according to conventional methods; and in a suitable growth period, carry out on-site plowing and plowing into the soil for 20-30 cm; plant two seasons;

18) Plant trees and shrubs with shallow roots and salt-alkali tolerance, such as seaside hibiscus, black locust, poplar, crape myrtle, and North American crabapple.

Through the above method, the target soil structure and fertility can be significantly improved within 18-22 months, and the vegetation can be restored efficiently.

The present invention is based on the artificial acceleration of the natural ecological process. By making the raw soil layer undergo high-intensity and high-frequency natural ecological processes such as dryness and humidity, anaerobic/aerobic, etc., and supplemented by artificially adding organic matter to ferment and heat-producing ripening, the soil structure can be improved. Rapid improvement; salt washing on the basis of in-situ ridging, through the addition of biochar, organic fertilizer and superphosphate, etc., to improve soil nutrients and their retention and buffer capacity, and reduce pH and salt content, which can be fast and efficient Restoring the heavily missing soil in the tidal flat topsoil as forest land.

Claims (7)

1. A kind of fast, highly efficient restoration tidal flat topsoil heavily lacks soil is the method for forest land, it is characterized in that comprising the following steps: 1) High-intensity and high-frequency plowing, artificial irrigation to accelerate the alternation of dryness and wetness; 2) ridging and washing salt; 3) After applying organic materials to the ridge belt, turn and mix evenly, water, cover, remove the film, and plow; 4) Apply organic fertilizer, biochar, superphosphate; 5) Plant green manure crops, plant salt-tolerant trees and shrubs with shallow roots after overturning. 2. A kind of method according to claim 1 fast, highly efficient restoration tidal flat topsoil serious lack soil is forest land, it is characterized in that: in the 1st) step, plowing depth is 30-50 cm, and irrigation after plowing , the irrigation volume is 2000-3000m ³ ·hm ^-2 ; after the soil becomes dry, repeat the plowing and irrigation process for 4-6 months. 3. A kind of method according to claim 1 fast, highly efficient recovery tidal flat topsoil serious lack soil is forest land, it is characterized in that: in the 2nd) step, ridging is to pile up the soil on both sides of the plowing area to the middle , forming a ridge belt with a height of 40-60cm and a width of 2.5-3.0 m; digging a drainage ditch with a depth of 40-60 cm and a width of 20-30 cm on both sides of the ridge belt; washing salt is to repeatedly pour water into the ridge belt to wash the soil until the ridge belt Soil salinity drops to <0.5%. 4. according to claim 1, a kind of fast, highly efficient restoration of tidal flat topsoil heavily lacking soil is the method for forest land, it is characterized in that: in the 3rd) step, the organic material that applies is rice husk, straw, and particle diameter is 2-10 mm, spread 10-15 cm thick on the soil surface of the ridge belt, turn and mix evenly, irrigate until the soil is saturated, cover the ridge belt with agricultural film, remove the film after 30-50 days, and plow; thereafter, every 20 days Plow once every -30 d until the maturity of the added organic material is >80%. 5. a kind of fast, highly efficient restoration tidal flat topsoil layer serious lack soil according to claim 1 is the method for forest land, it is characterized in that: in the 4th) step, the organic fertilizer that applies is pig, ox, horse, chicken, Duck, goose, livestock and poultry manure, spread 10-15cm thick on the soil surface, then spread 1-2 cm thick biochar, apply superphosphate 400-500 kg·hm ^-2 , till and mix evenly. 6. A kind of method according to claim 1 fast, highly efficient recovery tidal flat topsoil serious lack soil is forest land, it is characterized in that: described green manure crop selects crop with short growth cycle, manages by conventional method and grows in suitable Overturn and press on the spot in the early stage; plant salt-tolerant trees and shrubs with shallow root system after two seasons of planting. 7. according to claim 6, a kind of fast, high-efficiency method of recovering heavily missing soil in tidal flat topsoil layer is the method for forest land, it is characterized in that: described green manure crop is mung bean, soybean, shallow root system salt-tolerant tree, shrub are seaside hibiscus , locust, poplar, crape myrtle, North American crabapple.