NL2033429B1

NL2033429B1 - Method for improving soil porosity

Info

Publication number: NL2033429B1
Application number: NL2033429A
Authority: NL
Inventors: Fan Leilei; Yan Xiong; Li Huazhang; Jin Xing; Xiong Bailian; Li Wenzhao
Original assignee: Univ Zunyi Normal
Priority date: 2021-11-16
Filing date: 2022-10-31
Publication date: 2023-06-30
Also published as: CN114051786A; NL2033429A; CN114051786B

Abstract

The present disclosure discloses a method for improving soil porosity in the technical field of soil improvement, comprising the following steps: uniformly spreading a soil conditioner on the soil surface according to the amount of 300—800 kg/mu, and deeply ploughing to obtain a plough layer, wherein the ploughing depth is greater than or equal to 40 cm; after flattening the soil surface, thoroughly watering; and planting plants after 5—15 days; wherein the soil conditioner is of a three—dimensional form prepared by mixing phosphogypsum, bentonite and vermiculite, the three— dimensional form comprises a cylinder, a sphere, a square, a cone or a cube, and the size is 3—7 cm.

Description

METHOD FOR IMPROVING SOIL POROSITY

TECHNICAL FIELD

The present disclosure belongs to the technical field of soil improvement, particularly to a method for improving soil porosity.

BACKGROUND

Soil is a porous body. There are pores between soil parti- cles, soil aggregates and inside the aggregates. The soil porosity is the percentage of soil pores per unit volume.

Presently, the improvement of soil porosity is mainly based on the application of scil conditioners. Many types of soil condi- tioners are available, including natural soil conditioners such as zeolite, vermiculite, shale, and weathered coal, as well as vari- ous composite soil conditioners, for example, CN111944531B dis- closes a soil conditioner, comprising the following components in percentage by volume: 40-55% of organic waste compost, 2-43 of woody biochar, 2-4% of rice husk charcoal, 2-4%o0f coconut bran and 0.5-1% of attapulgite powder. These components are made into a conditioner with the green space soil physical properties accord- ing to a scientific ratio. The conditioner together with the mi- crobial agents can effectively improve the problems of degradation of soil physical properties such as the soil bulk density, aera- tion, infiltration rate, aggregate structure, and non-capillary porosity of the green space for different types of green space habitats such as lawns, tree and shrub planting holes, road green belts, which plays a good long-term promoting effect on the growth of green plants and improves the sustainability of the ecological functions of green spaces.

However, the product form of these conditioners is mostly powder, which is not suitable for mechanized construction and can only be applied manually, with uneven dosage.

SUMMARY

The present disclosure designs a three-dimensional soil con-

ditioner, aiming at solving the shortcomings in the prior art. The soil conditioner is mainly prepared from waste phosphogypsum, and can effectively increase the soil porosity.

An object of the present disclosure is to provide a method for improving soil porosity. The method is characterized by com- prising the following steps: uniformly spreading a soil condition- er on the soil surface according to the amount of 300-800 kg/mu, and deeply ploughing to obtain a plough layer, wherein the plough- ing depth is greater than or equal to 40 cm; after flattening the soil surface, thoroughly watering; and planting plants after 30-45 days; wherein the soil conditioner is of a three-dimensional form prepared by mixing phosphogypsum, bentonite and vermiculite, the three-dimensional form comprises a cylinder, a sphere, a square, a cone or a cube, and the size is 3-7 cm. Preferably, the three- dimensional soil conditioner is prepared by using a mold of the cylinder, sphere and square, and the size is preferably 3-5 cm.

The working principle and the beneficial effects of the meth- od are as follows: the method mainly adopts industrial waste phos- phogypsum for preparation, wherein less bentonite and vermiculite are also used; the phosphogypsum is a byproduct in the production process of a phosphorus compound fertilizer, the main component of the phosphogypsum is calcium sulfate dihydrate, and the phos- phogypsum is a renewable resource that is capable of replacing natural gypsum. However, due to relatively high yield and limited comprehensive utilization ways, the comprehensive utilization rate of the phosphogypsum in China is only 20%. Calcium ions rich in the phosphogypsum are used for exchanging sodium ions in soil so as to adjust the pH value of the soil, and meanwhile, the phos- phogypsum has little influence on the chemical properties of sur- face phreatic water, only plays roles in irrigation and drainage, and can be used for desalting the surface phreatic water, thus the mineralization degree of the phreatic water is reduced by 39.62%, and as a result, the porosity of the soil can be effectively im- proved; in addition, by using effective nutrients such as sulfur, phosphorus and magnesium in the phosphogypsum, the physical and chemical properties of the soil can be effectively improved, and the aim of increasing both production and income of crops can be achieved.

The water absorption rate of bentonite is up to 100-240%, and the volume of the bentonite can be increased by 10-30 times along with the absorbed water; the number of soil aggregates can be in- creased when the bentonite is applied to soil, thus the soil bulk density is reduced, and the soil porosity is increased; and the soil aggregates are basic units of a soil structure and influence the porosity and water binding capacity of the soil, and the com- position and stability of the soil aggregates directly influence the soil fertility and crop growth, so the water retention and air permeability of the bentonite to the soil are improved.

Vermiculite can be used as the soil conditioner, and has good cation exchange performance and adsorption performance, therefore, the soil structure can be improved, the water storage and soil moisture preservation effects are achieved, the air permeability and the water retaining performance of the soil are improved, and the acid soil becomes neutral soil; the vermiculite can also achieve a buffering effect, and can block the fast change of the

PH value, thus the fertilizer is slowly released in a crop growth medium; in addition, the fertilizer is allowed to be used in a slightly excessive way, which has no harm on plants; and the ver- miculite can also provide intrinsic elements such as K, Mg, Ca, Fe and trace elements such as Mn, Cu and Zn for crops. Through the water absorption performance, the cation exchange performance and the chemical ingredient characteristics of the vermiculite, the multiple effects of fertilizer preservation, water storage, air permeability, mineral fertilizer and the like are achieved.

According to the present disclosure, the above three compo- nents are mixed to prepare the three-dimensional soil conditioner, and the size of the soil conditioner is ensured to be 3-7 cm, thus the uniformity after ploughing can be ensured, and the defect that the soil conditioner is easily lost along with water and soil loss when being prepared into powder or small particles can be avoided.

Most importantly, modified phosphogypsum is taken as a basic framework, a small amount of bentonite and vermiculite are mixed and distributed on the basic framework and the basic framework is applied to soil, the bentonite and the vermiculite gradually fall off from the basic framework in the process of swelling after con- tinuously absorbing water, wrap part of phosphogypsum and then en- ter the soil, and the bentonite and the vermiculite are gradually dispersed into each soil layer instead of being lost along with water and soil, so that the porosity of the soil is further im- proved and is kept for a long time, and meanwhile, the functions of fertility improvement, fertilizer retention, water retention and air permeability are exerted.

Further, there is a plurality of conical bulges on the sur- face of the three-dimensional soil conditioner, and the bulges are made of mushroom bran. Therefore, the air permeability of soil is improved, and the porosity is improved.

Further, the bulges are adhered to the surface of the soil conditioner through a binder.

Further, the binder is 5-10 parts of attapulgite clay powder.

The binder can be manually processed or processed through a ma- chine.

Further, the soil conditioner comprises the following raw ma- terials in parts by weight: 200-500 parts of modified phosphogyp- sum, 50-100 parts of bentonite, 30-50 parts of vermiculite and 30- 50 parts of mushroom bran.

Further, the method comprises the following specific steps: adding water into the modified phosphogypsum powder, bentonite powder and vermiculite particles, mixing, processing into a three- dimensional shape, adhering the blocky mushroom bran to the three- dimensional surface through the binder to obtain a rough blank, and drying the processed rough blank at a temperature of 90-120°C until the water content is less than 10% to obtain the soil condi- tioner.

Another object of the present disclosure is to provide a soil conditioner prepared by the above method. A method for preparing modified phosphogypsum comprises the following steps: crushing phosphogypsum, removing impurities, and removing organic matters and soluble impurities in the phosphogypsum to obtain modified phosphogypsum powder.

By modifying the phosphogypsum, harmful components such as heavy metals in the phosphogypsum are reduced. The three- dimensional soil conditioner prepared by the method can obviously improve the soil porosity. After application, the total porosity of the soil can be increased from 30-40% to 48-56%, and high po- 5 rosity can be maintained for a long time. The application frequen- cy 1s reduced, and the water absorption capacity of the soil can be improved. The pH value of the soil is improved to 6.5-7.5, which is more beneficial to the plant growth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the shape of the fin- ished product according to Example 4 of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure will be further described in details below with reference to particular embodiments.

Example 1 A method for improving soil porosity comprises the following steps:

Sl; prepare a soil conditioner: prepare 200 parts of phos- phogypsum, 50 parts of bentonite, 30 parts of vermiculite, 40 parts of mushroom bran and 6 parts of attapulgite clay powder; crush the phosphogypsum, remove impurities, and remove organic matters and soluble impurities in the phosphogypsum to obtain mod- ified phosphogypsum powder; crush the mushroom bran into blocks with the size of 1.5 cm or below, and mix the attapulgite clay powder with water to form a binder; add water into the modified phosphogypsum powder, bentonite powder and vermiculite particles, and uniformly mix; fill the mixture into a spherical mold with the size of 3-5 cm; demold and pre-dry; dip the mushroom bran into the binder, and adhere the mushroom bran to a demolded sphere with a binder to form a plurality of bulges on the surface of the sphere so as to obtain a rough blank; and dry the rough blank at 90-120°C until the water content is less than 10% to obtain the soil condi- tioner.

S2, release: uniformly spread 300-800 kg of the soil condi- tioner on the surface of soil per mu, and then deeply plough, wherein the ploughing depth is greater than or equal to 40 cm, and the soil conditioner is ensured to be placed into the soil below 20 cm to obtain a plough layer; level the surface of the soil, and thoroughly water the soil; and plant the plants after 30-45 days.

Example 2 A method for improving soil porosity comprises the following steps:

S1, prepare a soil conditioner: prepare 400 parts of phos- phogypsum, 70 parts of bentonite, 40 parts of vermiculite, 45 parts of mushroom bran and 9 parts of attapulgite clay powder; crush the phosphogypsum, remove impurities, and remove organic matters and soluble impurities in the phosphogypsum to obtain mod- ified phosphogypsum powder; crush the mushroom bran into blocks with the size of 1 cm or below, and mix the attapulgite clay pow- der with water to form a binder; add water into the modified phos- phogypsum powder, bentonite powder and vermiculite particles, and uniformly mix; fill the mixture into a cylindrical mold with the size of 3-5 cm; demold and pre-dry; dip the mushroom bran into the binder, and adhere the mushroom bran to a demolded cylinder with a binder to form a plurality of bulges on the surface of the sphere so as to obtain a rough blank; and dry the rough blank at 90-120°C until the water content is less than 10% to obtain the soil condi- tioner. 32, release: uniformly spread 300-800 kg of the soil condi- tioner on the surface of soil per mu, and then deeply plough, wherein the ploughing depth is greater than or equal to 40 cm, and the soil conditioner is ensured to be placed into the soil below 20 cm to obtain a plough layer; level the surface of the soil, and thoroughly water the soil; and plant the plants after 30-45 days.

Example 3 A method for improving soil porosity comprises the following steps:

Sl, prepare a soil conditioner: prepare 500 parts of phos- phogypsum, 100 parts of bentonite, 50 parts of vermiculite, 50 parts of mushroom bran and 10 parts of attapulgite clay powder; crush the phosphogypsum, remove impurities, and remove organic matters and soluble impurities in the phosphogypsum to obtain mod- ified phosphogypsum powder; crush the mushroom bran into blocks with the size of 1.5 cm or below, and mix the attapulgite clay powder with water to form a binder; add water into the modified phosphogypsum powder, bentonite powder and vermiculite particles, and uniformly mix; fill the mixture into a cubic mold with the size of 3-7 cm; demold and pre-dry; dip the mushroom bran into the binder, and adhere the mushroom bran to a demolded cube with a binder to form a plurality of bulges on the surface of the sphere so as to obtain a rough blank; and dry the rough blank at 90-120°C until the water content is less than 10% to obtain the soil condi- tioner.

Example 4 A method for improving soil porosity comprises the following steps: 31, prepare a soil conditioner: prepare 500 parts of phos- phogypsum, 100 parts of bentonite, 50 parts of vermiculite, 50 parts of mushroom bran and 10 parts of starch; crush the phos- phogypsum, remove impurities, and remove organic matters and solu- ble impurities in the phosphogypsum to obtain modified phosphogyp- sum powder; crush the mushroom bran into blocks with the size of 1.5 cm or below, and mix the starch with water to form a binder; add water into the modified phosphogypsum powder, bentonite powder and vermiculite particles, and uniformly mix; fill the mixture in- to a cylindrical mold with the size of 3-7 cm; demold and pre-dry; dip the mushroom bran into the binder, and adhere the mushroom bran to a demolded cylinder with a binder to form a plurality of bulges on the surface of the sphere so as to obtain a rough blank; and dry the rough blank at 90-120°C until the water content is less than 10% to obtain the soil conditioner. Its shape is shown in

FIG. 1. 32, release: uniformly spread 300-800 kg of the soil condi- tioner on the surface of soil per mu, and then deeply plough, wherein the ploughing depth is greater than or equal to 40 cm, and the soil conditioner is ensured to be placed into the soil below 20 cm to obtain a plough layer; level the surface of the soil, and thoroughly water the soil; and plant the plants after 30-45 days.

Example 5 A method for improving soil porosity comprises the following steps: 31, prepare a soil conditioner: prepare 500 parts of phos- phogypsum, 100 parts of bentonite, 50 parts of vermiculite and 10 parts of starch; crush the phosphogypsum, remove impurities, and remove organic matters and soluble impurities in the phosphogypsum to obtain modified phosphogypsum powder; crush the mushroom bran into blocks with the size of 1.5 cm or below, and mix the starch with water to form a binder; add water into the modified phos- phogypsum powder, bentonite powder and vermiculite particles, and uniformly mix; fill the mixture into a cylindrical mold with the size of 3-7 cm; demold and pre-dry to obtain a rough blank; and dry the rough blank at 90-120°C until the water content is less than 10% to obtain the soil conditioner.

Yellow soil in the Zunyi City, Guizhou Province is selected, and the pH value and porosity of the soil are measured by an in- strument respectively before applying the soil conditioner, 3 months after applying the soil conditioner, and one year after ap- plying the soil conditioner, as shown in the table below.

Table 1 Change of the pH value and porosity of soil before and after applying soil conditioner

Before im- 3 months after Before im- 3 months after 1 year after

According to the change before and after applying the soil conditioner in Examples 1 to 5, the pH value of the soil can meet the growth requirement of plants with adoption of the method of the prevent invention, and meanwhile, the porosity of the soil is greatly improved, and a high porosity can be maintained even after one year; and in Example 5 without mushroom bran bulges on the surface, the change of the pH value after improvement is slightly different from that of other examples, but the increment of the porosity is significantly lower than that of other examples.

The foregoing descriptions are only embodiments of the pre- sent disclosure, and common knowledge such as well-known specific structures and characteristics in the technical solutions are not described in details. It should be noted that for those skilled in the art, several modifications and improvements can be made with- out departing from the structure of the present disclosure, and these modifications and improvements should also be regarded as the protection scope of the present disclosure, which will not af- fect the implementation effect and the practicability of the pa- tent. The scope of protection of the present disclosure should be subjected to the content claimed in the claims, and the descrip- tions of the specific embodiments in the Specification can be used to explain the content of the claims.

Claims

CONCLUSIESCONCLUSIONS

1. Werkwijze voor het verbeteren van de bodemporositeit, omvatten- de de volgende stappen: het gelijkmatig verspreiden van een bodemverbeteraar op het bodem- oppervlak in een hoeveelheid van 300 tot 800 kg/mu, en diep ploe- gen om een ploeglaag te verkrijgen, waarbij de ploegdiepte groter is dan of gelijk aan 40 cm; na het afvlakken van het grondopper- vlak, grondig water geven; en planten na 30 tot 45 dagen; waarbij de bodemverbeteraar een driedimensionale vorm heeft die is bereid door het mengen van fosforgips, bentoniet en vermiculiet, waarbij de driedimensionale vorm een cilinder, een bol, een vier- kant, een kegel of een kubus omvat, en de afmeting 3 tot 7 cm is.A method of improving soil porosity, comprising the steps of: evenly spreading a soil conditioner on the soil surface in an amount of 300 to 800 kg/mu, and deep plowing to obtain a plow layer, where the plowing depth is greater than or equal to 40 cm; after leveling the soil surface, water thoroughly; and plants after 30 to 45 days; wherein the soil conditioner has a three-dimensional shape prepared by mixing phosphogypsum, bentonite and vermiculite, the three-dimensional shape being a cylinder, a sphere, a square, a cone or a cube, and the size is 3 to 7 cm .

2. Werkwijze voor het verbeteren van de bodemporositeit volgens conclusie 1, waarbij er meerdere conische uitstulpingen zijn op het oppervlak van de driedimensionale bodemverbeteraar, en de uit- stulpingen zijn gemaakt van paddenstoelenzemelen.The method of improving soil porosity according to claim 1, wherein there are a plurality of conical protrusions on the surface of the three-dimensional soil improver, and the protrusions are made of mushroom bran.

3. Werkwijze voor het verbeteren van de bodemporositeit volgens conclusie 2, waarbij de uitstulpingen door middel van een bindmid- del aan het oppervlak van de bodemverbeteraar worden gehecht.The method of improving soil porosity according to claim 2, wherein the protuberances are bonded to the surface of the soil conditioner by means of a binder.

4. Werkwijze voor het verbeteren van de bodemporositeit volgens conclusie 3, waarbij het bindmiddel 5 tot 10 delen attapulgiet- kleipoeder is.The method for improving soil porosity according to claim 3, wherein the binder is 5 to 10 parts of attapulgite clay powder.

5. Werkwijze voor het verbeteren van de bodemporositeit volgens conclusie 4, waarbij de bodemverbeteraar in gewichtsdelen de vol- gende grondstoffen omvat: 200 tot 500 delen gemodificeerd fosfor- gips, 50 tot 100 delen bentoniet, 30 tot 50 delen vermiculiet en 30 tot 50 delen champignonzemelen.The method of improving soil porosity according to claim 4, wherein the soil improver comprises in parts by weight the following raw materials: 200 to 500 parts modified phosphorus gypsum, 50 to 100 parts bentonite, 30 to 50 parts vermiculite and 30 to 50 parts mushroom bran.

6. Werkwijze voor het verbeteren van de bodemporositeit volgens conclusie 5, waarbij de werkwijze de volgende specifieke stappen omvat: het toevoegen van water aan het gemodificeerde fosforgips-A method for improving soil porosity according to claim 5, wherein the method comprises the following specific steps: adding water to the modified phosphogypsum

poeder, bentonietpoeder en vermiculietdeeltjes, mengen, verwerken tot een driedimensionale vorm, hechten van de blokvormige padden- stoel zemelen aan het driedimensionale oppervlak door het bindmid- del om een ruwe blanco te verkrijgen, en het drogen van de ver- werkte ruwe blanco bij een temperatuur van 90 tot 120 °C tot het watergehalte minder dan 10% is om de bodemverbeteraar te verkrij-powder, bentonite powder and vermiculite particles, mixing, processing into a three-dimensional shape, bonding the blocky mushroom bran to the three-dimensional surface by the binder to obtain a raw blank, and drying the processed raw blank at a temperature from 90 to 120 °C until the water content is less than 10% to obtain the soil improver

gen.gene.

7. Werkwijze voor het verbeteren van de bodemporositeit volgens een van de conclusies 1 tot 6, waarbij een werkwijze voor het be- reiden van gemodificeerd fosforgips de volgende stappen omvat: het breken van fosforgips, het verwijderen van onzuiverheden en het verwijderen van organische stoffen en oplosbare onzuiverheden in het fosforgips om gemodificeerd fosforgips poeder te verkrijgen.A method for improving soil porosity according to any one of claims 1 to 6, wherein a method of preparing modified phosphogypsum comprises the following steps: crushing phosphogypsum, removing impurities, and removing organics and soluble impurities in the phosphogypsum to obtain modified phosphogypsum powder.