A soil conditioner for improving saline-alkali land and a preparation method thereof

Abstract

The invention discloses a soil improver for improving saline-alkali land. The soil improver comprises a mixture of zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ions. The zeolite molecular sieve is prepared from acid-base modified zeolite, and the microbial fertilizer is prepared from nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria through fermentation culture of a fermentation matrix. The soil is preliminarily neutralized by hydronium ions wrapped in an outer layer. After the outer layer is dissolved, salicylic acid, superphosphate and calcium powder in an inner layer can further neutralize and exchange ions on saline-alkali substances in the soil, greatly reduce the content of saline-alkali substances in the soil, and effectively improve saline-alkali soil. At the same time, superphosphate can provide a certain amount of phosphate fertilizer for the soil. Finally, the adsorption and slow-release functions of bentonite and zeolite molecular sieve can greatly reduce the loss rate of dissolved fertilizer nutrients and water. Microbial decomposition in the microbial fertilizer can fundamentally improve soil quality.

Description

Technical Field

[0001] The invention relates to the technical field of soil conditioners, and in particular to a soil conditioner for improving saline-alkali land and a preparation method thereof. Background Art

[0002] Land salinization refers to the process of land quality degradation caused by soil salinization and alkalinization due to a combination of natural factors such as specific climate, hydrology, geology and soil, as well as improper artificial water diversion and irrigation. It is extremely unfavorable to the growth of crops. The problem of soil salinization is the main factor restricting the sustainable use of agricultural land resources in arid areas, and is also an important factor affecting the stability of the ecological environment.

[0003] At present, the functionality of the improvers for improving saline-alkali soil is single, and most of them rely on acidity and some exchange ions to react with alkaline substances and salts in the saline-alkali soil to reduce the salinity and alkali content of the soil to improve the saline-alkali soil. However, excessive application of acidic substances will leave residues, causing the soil to be acidic, which is also not suitable for crop growth. At the same time, saline-alkali soil is usually accompanied by soil problems such as land impoverishment and rapid loss of nutrient fertilizer. After improvement, crops cannot be planted normally. Therefore, the present invention proposes a soil improver for improving saline-alkali land and a preparation method thereof to solve the problems existing in the prior art. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a soil conditioner for improving saline-alkali land and a preparation method thereof. The soil conditioner for improving saline-alkali land and the preparation method thereof preliminarily neutralize the soil through the hydrated hydrogen ions wrapped in the outer layer. After the outer layer is dissolved, the salicylic acid, superphosphate and calcium powder in the inner layer can further neutralize and exchange ions on the saline-alkali substances in the soil, greatly reducing the content of saline-alkali substances in the soil, effectively improving the saline-alkali soil, and at the same time, superphosphate can provide a certain amount of phosphate fertilizer for the soil. Finally, the microbial fertilizer and potassium chloride in the center are dissolved, and the adsorption and slow-release function of bentonite and zeolite molecular sieves can greatly reduce the loss rate of dissolved fertilizer nutrients and water. Microbial decomposition can fundamentally improve the soil quality and provide a steady supply of trace nutrients to the soil.

[0005] To achieve the purpose of the present invention, the present invention is achieved through the following technical scheme: a soil conditioner for improving saline-alkali land and a preparation method thereof, comprising a mixture of zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ions, wherein the mass ratio of the zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ions is 23-28:6-10:5-10:10-15:6-10:12-15:8-10:15-20:5-8, the zeolite molecular sieve is prepared from acid-base modified zeolite, and the microbial fertilizer is prepared from nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria through fermentation culture of fermentation matrix.

[0006] Further improvements are: the fermentation matrix is ​​straw, livestock excrement and waste pomace, the mixed mass ratio of the straw, livestock excrement and waste pomace is 30:25:24; the inoculation amount of the nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria in the fermentation matrix is ​​3.5%;

[0007] The acid-base modified zeolite molecular sieve is modified using a 0.18 mol / L ethylenediaminetetraacetic acid aqueous solution and a 0.9 mol / L sodium hydroxide aqueous solution in sequence.

[0008] A method for preparing a soil conditioner for improving saline-alkali land comprises the following steps:

[0009] Step 1: Pretreatment of raw materials: using acid and alkali solutions to modify zeolite to obtain zeolite molecular sieve for standby use; then mixing the fermentation substrate with nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria for fermentation to obtain microbial fertilizer for standby use;

[0010] Step 2: Premixing of the core base material: dissolving potassium chloride in water, then placing the zeolite molecular sieve in the potassium chloride aqueous solution for absorption, then taking it out and drying it, and then mixing and granulating the dried zeolite molecular sieve with the microbial fertilizer to obtain the core base material;

[0011] Step 3, preparation of the first outer packaging material: firstly heat the distilled water to 65°C for heat preservation, then dissolve salicylic acid therein to prepare a salicylic acid aqueous solution; then add bentonite, superphosphate and calcium powder to the salicylic acid aqueous solution, mix and stir thoroughly to prepare the first outer packaging material;

[0012] Step 4, preparation of the second outer bag material: preparing hydronium ions by mixing an inorganic acid and diatomaceous earth, and then fully stirring the biochar and the hydronium ions to obtain the second outer bag material;

[0013] Step 5, outer bag wrapping treatment: first wrap a layer of the first outer bag outside the central base material to obtain semi-finished particles, then place the semi-finished particles in the second outer bag, let it stand, take it out and dry it, and repeat 5-6 times to obtain the soil conditioner.

[0014] The further improvement is that: the zeolite modification treatment in step 1 is specifically to first grind the zeolite at the nano level, then place it in a 0.18 mol / L ethylenediaminetetraacetic acid aqueous solution and heat it to 85°C for acid treatment, then take out the nano zeolite, rinse it with distilled water, and then dry it at 120°C to obtain acid-treated nano zeolite; then place the acid-treated nano zeolite in a 0.9 mol / L sodium hydroxide aqueous solution and heat it to 65°C for alkali treatment, then take out the nano zeolite, rinse it with distilled water, and then dry it at 120°C to obtain a zeolite molecular sieve.

[0015] A further improvement is that in the step 1, the preparation of the microbial fertilizer is specifically to first dry the straw, livestock manure and fruit residue and then crush them to obtain matrix residue, and then fully mix the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria with the matrix residue and add water to moisten it, so that the moisture content is maintained at 45%-55% and ferment for 5-10 days to obtain the microbial fertilizer.

[0016] Further improvements are: the concentration of the potassium chloride aqueous solution prepared in step 2 is 3.4 mol / L; the drying temperature is 90-120°C and the drying time is 15-20 min; the zeolite molecular sieve and microbial fertilizer are mixed and granulated and then slowly dried at 70°C for 1-2 hours to obtain the core base material.

[0017] A further improvement is that the preparation process of hydronium ions in step 4 is specifically to heat the inorganic acid aqueous solution to 60-100° C., then add diatomaceous earth to the inorganic acid aqueous solution for heat preservation reaction, then filter the reaction solution, centrifuge the filtrate to retain the supernatant, and finally concentrate and purify the supernatant to obtain hydronium ions.

[0018] Further improvements are: in the step 4, the inorganic acid is one of sulfuric acid or hydrochloric acid, and the ratio of the inorganic acid to diatomaceous earth is 1:2; the biochar is prepared by carbonizing rice husks and plant straws and then grinding them.

[0019] The beneficial effects of the present invention are as follows: the present invention preliminarily neutralizes the soil through the hydronium ions wrapped in the outer layer; after the outer layer is dissolved, the salicylic acid, superphosphate and calcium powder in the inner layer can further neutralize and exchange ions on the saline-alkali substances in the soil, greatly reducing the content of the saline-alkali substances in the soil, and effectively improving the saline-alkali soil; at the same time, the superphosphate can provide a certain amount of phosphate fertilizer for the soil; finally, the microbial fertilizer and potassium chloride in the center are dissolved, and the absorption and slow-release functions of bentonite and zeolite molecular sieve are combined to greatly reduce the loss rate of dissolved fertilizer nutrients and water; microbial decomposition can fundamentally improve the soil quality and continuously provide trace nutrients for the soil, providing an efficient and lasting improver for the saline-alkali soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of the preparation method of the embodiment. DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0022] In the following embodiments, the modification treatment method of zeolite molecular sieve is as follows: first, the zeolite is nano-grinded, and then it is placed in a 0.18 mol / L ethylenediaminetetraacetic acid aqueous solution and heated to 85°C for acid treatment, and then the nano zeolite is taken out, rinsed with distilled water, and dried at 120°C to obtain acid-treated nano zeolite; then the acid-treated nano zeolite is placed in a 0.9 mol / L sodium hydroxide aqueous solution and heated to 65°C for alkali treatment, and then the nano zeolite is taken out, rinsed with distilled water, and dried at 120°C to obtain a zeolite molecular sieve.

[0023] The preparation method of microbial fertilizer is as follows: first, straw, livestock manure and fruit residue are dried and crushed to obtain matrix residue, and then nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria are fully mixed with the matrix residue and moistened with water, and the moisture content is maintained at 45%-55% for 5 days to obtain microbial fertilizer. The fermentation matrix is ​​straw, livestock manure and waste fruit residue, and the mixing mass ratio of straw, livestock manure and waste fruit residue is 30:25:24. The inoculation amount of nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria in the fermentation matrix is ​​3.5%.

[0024] The specific process of preparing hydronium ions is to dilute sulfuric acid with water to obtain a 0.102 mol / L sulfuric acid solution, then heat the sulfuric acid solution to 80°C, then add diatomaceous earth to the solution at a reaction ratio of 1:2 between sulfuric acid and diatomaceous earth, and keep the temperature for 2 hours, then filter the reaction solution, centrifuge the filtrate to retain the supernatant, and finally concentrate and purify the supernatant to obtain hydronium ions.

[0025] Unless otherwise specified, the raw materials used in the following examples of the present invention are all obtained through conventional commercial channels; the technical contents not shown in the examples can be achieved by conventional technical means, which are not the key points of the present invention and will not be elaborated.

[0026] Example 1

[0027] according to Figure 1 As shown, this embodiment provides a soil conditioner for improving saline-alkali land, which is prepared by mixing zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ion in a mass ratio of 23:6:10:12:6:12:8:15:8.

[0028] A method for preparing a soil conditioner for improving saline-alkali land comprises the following steps:

[0029] Step 1, raw material pretreatment: using acid and alkali solutions to modify zeolite to obtain zeolite molecular sieve for standby use, and then mixing the fermentation substrate with nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria for fermentation to obtain microbial fertilizer for standby use;

[0030] Step 2: Premixing of the central base material: dissolving potassium chloride in water to obtain a 3.4 mol / L potassium chloride aqueous solution, then placing the zeolite molecular sieve in the potassium chloride aqueous solution for absorption, then taking it out and drying it at 120°C for 15 minutes, then mixing and granulating the dried zeolite molecular sieve with the microbial fertilizer, and slowly drying it at 70°C for 1.5 hours to obtain the central base material;

[0031] Step 3, preparation of the first outer coating material: first heat the distilled water to 65°C to keep it warm, then dissolve salicylic acid therein to prepare a salicylic acid aqueous solution, then fully stir and mix the bentonite, superphosphate and calcium powder, then add the salicylic acid solution and mix and stir thoroughly to prepare the first outer coating material.

[0032] Step 4, preparation of the second outer bag material: preparing hydronium ions by mixing an inorganic acid and diatomaceous earth, and then fully stirring the biochar and the hydronium ions to prepare the second outer bag material, wherein the biochar is prepared by carbonizing rice husks and plant straws and then grinding them;

[0033] Step 5: Wrapping with outer packaging material: First, wrap a layer of the first outer packaging material around the central base material to obtain semi-finished particles, then place the semi-finished particles in the second outer packaging material, let it stand, and then take it out to dry. Repeat this 5-6 times to obtain the finished improver.

[0034] Example 2

[0035] according to Figure 1 As shown, this embodiment provides a soil conditioner for improving saline-alkali land, which is prepared by mixing zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ion in a mass ratio of 25:6:8:10:6:12:8:20:5.

[0036] A method for preparing a soil conditioner for improving saline-alkali land comprises the following steps:

[0037] Step 1: pre-treating the raw materials, using acid and alkali solutions to modify the zeolite to obtain a zeolite molecular sieve for standby use, and then mixing the fermentation substrate with nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria for fermentation to obtain a microbial fertilizer for standby use;

[0038] Step 2: Premixing the central base material: dissolving potassium chloride in water to obtain a 3.4 mol / L potassium chloride aqueous solution, then placing the zeolite molecular sieve in the potassium chloride aqueous solution for absorption, then taking it out and drying it at 90°C for 20 minutes, then mixing and granulating the dried zeolite molecular sieve with the microbial fertilizer, and slowly drying it at 70°C for 2 hours to obtain the central base material;

[0039] Step 3, preparation of the first outer coating material, first heat the distilled water to 65°C to keep it warm, then dissolve salicylic acid therein to prepare a salicylic acid aqueous solution, then fully stir and mix the bentonite, superphosphate and calcium powder, then add the salicylic acid solution and mix and stir thoroughly to prepare the first outer coating material.

[0040] Step 4: preparing a second outer bag material, preparing hydronium ions by mixing an inorganic acid and diatomaceous earth, and then fully stirring the biochar and the hydronium ions to prepare the second outer bag material, wherein the biochar is prepared by carbonizing rice husks and plant straws and then grinding them;

[0041] Step 5: Wrapping with outer packaging materials: first wrap a layer of the first outer packaging material around the central base material to obtain semi-finished particles; then place the semi-finished particles in the second outer packaging material, let it stand, and then fish it out to dry; repeat 5-6 times to obtain the finished improver.

[0042] Application Examples

[0043] In order to verify the effect of the saline-alkali soil conditioner prepared in this application, the soil conditioners prepared in Example 1 and Example 2 and the commercially available Kangdibao brand saline-alkali soil conditioner were applied and then a 25-day crop planting experiment was carried out, wherein the initial pH of the saline-alkali soil was 8.6, and the application amount was 100 kg / hm 2 Usage: Spread the amendment on the soil when tilling the soil before planting, till the soil to a depth of less than 30 cm, plant the lettuce crop (planting cycle 40 days), sample the soil on the 5th day, 10th day, 15th day, 20th day and 40th day (after harvesting the lettuce), and test the salt content and organic matter content in the soil samples. The test results are shown in Table 1.

[0044] Saline-alkali soil improvement substance content test table

[0045]

[0046] Note: “ / ” in the table means not measured; soil organic matter content was determined by potassium dichromate oxidation-external heating method; soil pH was determined by pH meter method, and the water-soil mass ratio during the measurement process was 2.5:1.

[0047] It can be seen from the above table that although the treatment effects of the improvers of Example 1 and Example 2 on saline-alkali substances are not as good as those of the traditional improvers in the early stage, the salt content reduction and pH effect in the soil are better than those of the traditional improvers in the later stage. This is because in the early stage, the examples only rely on the outer dissolved substances with hydronium ions to neutralize the alkaline substances, while in the later stage, a large amount of neutralized acidic substances and ion exchange substances are dissolved inside, which increases the rate of decrease of the salt content and pH in the soil, and finally the effect is better than that of the traditional improvers.

[0048] However, traditional amendments do not have the effect of absorbing and slowly releasing nutrients in the soil. Therefore, the nutrients in traditional amendments are lost quickly and the nutrient content is low. However, the present application can not only increase the nutrient (organic matter) content in the soil after all substances are dissolved, but the zeolite molecular sieve, bentonite and biochar after the outer layer releases hydrated hydrogen ions can absorb nutrients and water, which can have a good slow-release effect. Combined with microbial fertilizers, the soil improvement effect is greatly improved.

[0049] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a soil conditioner for improving saline-alkali land, characterized in that: The following steps are involved: Step 1: using acid and alkali solutions to modify zeolite to obtain zeolite molecular sieve for standby use; then mixing the fermentation substrate with nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria for fermentation to obtain microbial fertilizer for standby use; Step 2, dissolving potassium chloride in water, then placing the zeolite molecular sieve in the potassium chloride aqueous solution for absorption, then taking it out and drying it, and then mixing and granulating the dried zeolite molecular sieve with the microbial fertilizer to obtain a core base material; Step 3, first heat distilled water to 65°C and keep it warm, then dissolve salicylic acid in it to prepare a salicylic acid aqueous solution; then add bentonite, superphosphate and calcium powder to the salicylic acid aqueous solution, mix and stir thoroughly, and prepare a first outer packaging material; Step 4: preparing hydronium ions by mixing an inorganic acid and diatomaceous earth, and then fully stirring the biochar and the hydronium ions to prepare a second outer bag material; Step 5: first wrap a layer of the first outer packaging material outside the central base material to obtain semi-finished particles, then place the semi-finished particles in the second outer packaging material, let it stand, take it out and dry it, and repeat 5-6 times to obtain the soil conditioner; The mass ratio of the zeolite molecular sieve, potassium chloride, microbial fertilizer, bentonite, superphosphate, salicylic acid, calcium powder, biochar and hydronium ion is 23-28:6-10:5-10:10-15:6-10:12-15:8-10:15-20:5-8; The zeolite molecular sieve is prepared from acid-base modified zeolite; The microbial fertilizer is prepared by fermenting and culturing nitrogen-fixing bacteria, phosphate-dissolving bacteria and potassium-dissolving bacteria through a fermentation matrix.

2. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The fermentation matrix is ​​straw, livestock excrement and waste pomace, and the mixing mass ratio of the straw, livestock excrement and waste pomace is 30:25:24; the inoculation amount of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria in the fermentation matrix is ​​3.5%; The acid-base modified zeolite is modified by sequentially using a 0.18 mol / L ethylenediaminetetraacetic acid aqueous solution and a 0.9 mol / L sodium hydroxide aqueous solution.

3. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The zeolite modification treatment in step 1 specifically comprises firstly grinding the zeolite at nanometer level, then placing it in a 0.18 mol / L ethylenediaminetetraacetic acid aqueous solution and heating it to 85°C for acid treatment, then taking out the nano zeolite, rinsing it with distilled water, and then drying it at 120°C to obtain the acid-treated nano zeolite; then placing the acid-treated nano zeolite in a 0.9 mol / L sodium hydroxide aqueous solution and heating it to 65°C for alkali treatment, then taking out the nano zeolite, rinsing it with distilled water, and then drying it at 120°C to obtain the zeolite molecular sieve.

4. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The preparation of the microbial fertilizer in step 1 is specifically as follows: firstly, the straw, livestock manure and fruit residue are dried and then crushed to obtain matrix residue; then, nitrogen-fixing bacteria, phosphate-solubilizing bacteria and potassium-solubilizing bacteria are fully mixed with the matrix residue and then moistened with water to keep the moisture content at 45%-55% and ferment for 5-10 days to obtain the microbial fertilizer.

5. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The concentration of the potassium chloride aqueous solution prepared in step 2 is 3.4 mol / L; the drying temperature is 90-120° C. and the drying time is 15-20 min; the zeolite molecular sieve and the microbial fertilizer are mixed and granulated and then slowly dried at 70° C. for 1-2 h to obtain the core base material.

6. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The specific process for preparing hydronium ions in step 4 is to heat the inorganic acid aqueous solution to 60-100° C., then add diatomaceous earth to the inorganic acid aqueous solution for heat preservation reaction, then filter the reaction solution, centrifuge the filtrate to retain the supernatant, and finally concentrate and purify the supernatant to obtain hydronium ions.

7. The method for preparing a soil conditioner for improving saline-alkali land according to claim 1, characterized in that: In the step 4, the inorganic acid is one of sulfuric acid and hydrochloric acid, and the ratio of the inorganic acid to diatomaceous earth is 1:2; the biochar is prepared by carbonizing rice husks and plant straws and then grinding them.

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