An amendment suitable for improving the fertility of barren soil

Abstract

This invention relates to the field of soil improvement technology, specifically to a soil conditioner suitable for improving the fertility of infertile soils. The conditioner is obtained by modifying bentonite with vinyltrichlorosilane and dimethylsilanediol, followed by crosslinking with acrylic acid, polyethylene glycol allyl ether, and humic acid. This conditioner can effectively regulate the pH of acidic soils, maintaining them at a neutral level, and can significantly increase field water holding capacity, soil organic matter content, and the content of soil aggregates with a particle size >0.25 mm.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to an amendment suitable for improving the fertility of barren soil. Background Technology

[0002] Soil is the foundation of agricultural production, and its fertility level directly affects crop growth and yield. However, infertile soils, due to their low organic matter content, loose structure, and poor water and fertilizer retention capacity, struggle to meet the needs of crop growth, severely hindering agricultural development. Especially in acidic or alkaline soils, a pH level deviating from the neutral range significantly affects nutrient availability, preventing crops from absorbing nutrients properly and inhibiting growth. Studies show that most crops thrive in near-neutral soil environments, while excessively acidic or alkaline soils are detrimental to normal crop growth. Therefore, regulating soil pH to maintain a neutral level has become an important research direction for improving infertile soils.

[0003] Furthermore, poor soils have low field water holding capacity, leading to easy water loss and causing crop water shortages that negatively impact growth. Improving soil water retention capacity not only reduces irrigation frequency but also provides a continuous water supply to crops, improving their growing environment. Simultaneously, poor soils have low organic matter content and insufficient soil fertility, making it difficult to provide crops with adequate nutrient sources. Therefore, increasing soil organic matter content is a key measure to improve soil fertility and quality. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a soil conditioner suitable for improving the fertility of barren soil, so as to adjust the pH value of barren soil, maintain it at a neutral level, and improve its water retention capacity and organic matter content.

[0005] To achieve the above objectives, the present invention provides a soil conditioner suitable for improving the fertility of infertile soil, which is prepared by the following steps:

[0006] (1) Disperse bentonite in toluene, sonicate for 0.5-2 h, then add vinyltrichlorosilane and dimethylsilanediol, heat to 95-105℃, stir and react for 20-30 h, cool, filter, wash, and dry at 55-65℃ for 20-30 h to obtain vinyl bentonite;

[0007] (2) Add acrylic acid and polyethylene glycol allyl ether to deionized water, stir for 20-40 min, then add vinyl bentonite, sonicate for 20-40 min, add ammonium persulfate aqueous solution dropwise, heat to 65-75℃, stir and react for 4-6 h, cool down, filter, wash with deionized water, and dry at 75-85℃ for 20-30 h to obtain modified bentonite;

[0008] (3) Add modified bentonite and humic acid to N,N-dimethylacetamide, sonicate for 0.5-2h, then add diphenylmethane diisocyanate, heat to 65-75℃, stir and react for 20-30h, filter, wash with deionized water, dry at 75-85℃ for 20-30h, crush, and pass through an 80-120 mesh sieve to obtain an amendment suitable for improving the fertility of barren soil.

[0009] Preferably, the density of the bentonite is 2-3 g / cm³. 3 .

[0010] Preferably, in step (1), the weight ratio of bentonite, toluene, vinyltrichlorosilane and dimethylsilanediol is 8-12:80-120:0.5-1.5:0.2-0.7.

[0011] Preferably, in step (2), the weight ratio of acrylic acid, polyethylene glycol allyl ether, deionized water, vinyl bentonite and ammonium persulfate aqueous solution is 3-8:1-3:50-150:8-12:0.5-2.

[0012] Preferably, the concentration of the ammonium persulfate aqueous solution in step (2) is 3wt%-8wt%.

[0013] Preferably, in step (3), the weight ratio of modified bentonite, humic acid, N,N-dimethylacetamide and diphenylmethane diisocyanate is 8-12:1-3:40-60:0.2-1.

[0014] Preferably, the purity of the humic acid is ≥90%.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a soil conditioner suitable for improving the fertility of infertile soil. It effectively regulates the pH of acidic soil, maintaining it at a neutral level. Soil pH is closely related to the availability of soil nutrients and crop growth. Most crops grow well in near-neutral soil environments, while overly acidic soil is detrimental to normal crop growth. This invention provides a more suitable growing environment for crops by regulating soil pH.

[0017] Secondly, this soil conditioner significantly increased field water holding capacity and soil organic matter content. Increased field water holding capacity helps improve soil water retention, reduces water loss, and provides a continuous water supply for crops; while increased organic matter content improves soil fertility, providing a rich source of nutrients for crop growth. Furthermore, this conditioner effectively increased the content of soil aggregates with a particle size >0.25mm. Aggregates with a particle size greater than 0.25mm are important for soil structure and nutrient storage, not only enhancing soil erosion resistance but also improving soil aeration and stability, thereby further optimizing the soil environment.

[0018] This invention constructs a stable hydrophilic cross-linked network through the synergistic effect of acrylic acid, polyethylene glycol allyl ether, and humic acid. This network enhances the soil's water retention capacity, promotes the adsorption of organic matter and the formation of aggregates, and improves the stability and aeration of the soil structure, providing excellent soil conditions for the healthy growth of crops. It is particularly suitable for the fertilization and improvement of infertile soils. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0020] In the specific embodiment of this invention, the bentonite was purchased from Haoyuan Bentonite Factory in Fangzi District, Weifang City, with specifications of HY-002 and a density of 2.6 g / cm³. 3 Humic acid was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number H108498, with a purity of ≥90%.

[0021] Example 1:

[0022] (1) Disperse 8g of bentonite in 80g of toluene, sonicate for 0.5h, then add 0.5g of vinyltrichlorosilane and 0.2g of dimethylsilanediol, heat to 95℃, stir and react for 20h, cool down, filter, wash with acetone, and dry at 55℃ for 20h to obtain vinyl bentonite;

[0023] (2) Add 3g of acrylic acid and 1g of polyethylene glycol allyl ether to 50g of deionized water, stir for 20min, then add 8g of vinyl bentonite, sonicate for 20min, add 0.5g of 3wt% ammonium persulfate aqueous solution, heat to 65℃, stir for 4h, cool down, filter, wash with deionized water, and dry at 75℃ for 20h to obtain modified bentonite;

[0024] (3) Add 8g of modified bentonite and 1g of humic acid to 40g of N,N-dimethylacetamide, sonicate for 0.5h, then add 0.2g of diphenylmethane diisocyanate, heat to 65℃, stir and react for 20h, filter, wash with deionized water, dry at 75℃ for 20h, crush, and pass through an 80-mesh sieve to obtain an amendment suitable for improving the fertility of barren soil.

[0025] Example 2:

[0026] (1) Disperse 10g of bentonite in 100g of toluene, sonicate for 1h, then add 1g of vinyltrichlorosilane and 0.5g of dimethylsilanediol, heat to 100℃, stir and react for 24h, cool down, filter, wash with acetone, and dry at 60℃ for 24h to obtain vinyl bentonite.

[0027] (2) Add 5g of acrylic acid and 2g of polyethylene glycol allyl ether to 100g of deionized water, stir for 30min, then add 10g of vinyl bentonite, sonicate for 30min, add 1g of 5wt% ammonium persulfate aqueous solution, heat to 70℃, stir for 5h, cool down, filter, wash with deionized water, and dry at 80℃ for 24h to obtain modified bentonite;

[0028] (3) Add 10g of modified bentonite and 2g of humic acid to 50g of N,N-dimethylacetamide, sonicate for 1h, then add 0.5g of diphenylmethane diisocyanate, heat to 70℃, stir and react for 24h, filter, wash with deionized water, dry at 80℃ for 24h, crush, and pass through a 100-mesh sieve to obtain an amendment suitable for improving the fertility of barren soil.

[0029] Example 3:

[0030] (1) Disperse 12g of bentonite in 120g of toluene, sonicate for 2h, then add 1.5g of vinyltrichlorosilane and 0.7g of dimethylsilanediol, heat to 105℃, stir and react for 30h, cool down, filter, wash with acetone, and dry at 65℃ for 30h to obtain vinyl bentonite;

[0031] (2) Add 8g of acrylic acid and 3g of polyethylene glycol allyl ether to 150g of deionized water, stir for 40min, then add 12g of vinyl bentonite, sonicate for 40min, add 2g of 8wt% ammonium persulfate aqueous solution, heat to 75℃, stir for 6h, cool down, filter, wash with deionized water, and dry at 85℃ for 30h to obtain modified bentonite;

[0032] (3) Add 12g of modified bentonite and 3g of humic acid to 60g of N,N-dimethylacetamide, sonicate for 2h, then add 1g of diphenylmethane diisocyanate, heat to 75℃, stir and react for 30h, filter, wash with deionized water, dry at 85℃ for 30h, crush, and pass through a 120-mesh sieve to obtain an amendment suitable for improving the fertility of barren soil.

[0033] Comparative Example 1:

[0034] The difference between Comparative Example 1 and Example 2 is that dimethylsilanediol was not added in step (1);

[0035] The specific steps are as follows:

[0036] (1) Disperse 10g of bentonite in 100g of toluene, sonicate for 1h, then add 1g of vinyltrichlorosilane, heat to 100℃, stir for 24h, cool, filter, wash with acetone, and dry at 60℃ for 24h to obtain vinyl bentonite.

[0037] (2) Add 5g of acrylic acid and 2g of polyethylene glycol allyl ether to 100g of deionized water, stir for 30min, then add 10g of vinyl bentonite, sonicate for 30min, add 1g of 5wt% ammonium persulfate aqueous solution, heat to 70℃, stir for 5h, cool down, filter, wash with deionized water, and dry at 80℃ for 24h to obtain modified bentonite;

[0038] (3) Add 10g of modified bentonite and 2g of humic acid to 50g of N,N-dimethylacetamide, sonicate for 1h, then add 0.5g of diphenylmethane diisocyanate, heat to 70℃, stir and react for 24h, filter, wash with deionized water, dry at 80℃ for 24h, crush, and pass through a 100-mesh sieve to obtain the modifier.

[0039] Comparative Example 2:

[0040] The difference between Comparative Example 2 and Example 2 is that polyethylene glycol allyl ether was not added in step (2);

[0041] The specific steps are as follows:

[0042] (1) Disperse 10g of bentonite in 100g of toluene, sonicate for 1h, then add 1g of vinyltrichlorosilane and 0.5g of dimethylsilanediol, heat to 100℃, stir and react for 24h, cool down, filter, wash with acetone, and dry at 60℃ for 24h to obtain vinyl bentonite.

[0043] (2) Add 5g of acrylic acid to 100g of deionized water, stir for 30min, then add 10g of vinyl bentonite, sonicate for 30min, add 1g of 5wt% ammonium persulfate aqueous solution, heat to 70℃, stir for 5h, cool down, filter, wash with deionized water, and dry at 80℃ for 24h to obtain modified bentonite.

[0044] (3) Add 10g of modified bentonite and 2g of humic acid to 50g of N,N-dimethylacetamide, sonicate for 1h, then add 0.5g of diphenylmethane diisocyanate, heat to 70℃, stir and react for 24h, filter, wash with deionized water, dry at 80℃ for 24h, crush, and pass through a 100-mesh sieve to obtain the modifier.

[0045] Comparative Example 3:

[0046] The difference between Comparative Example 3 and Example 2 is that diphenylmethane diisocyanate was not added in step (3);

[0047] The specific steps are as follows:

[0048] (1) Disperse 10g of bentonite in 100g of toluene, sonicate for 1h, then add 1g of vinyltrichlorosilane and 0.5g of dimethylsilanediol, heat to 100℃, stir and react for 24h, cool down, filter, wash with acetone, and dry at 60℃ for 24h to obtain vinyl bentonite.

[0049] (2) Add 5g of acrylic acid and 2g of polyethylene glycol allyl ether to 100g of deionized water, stir for 30min, then add 10g of vinyl bentonite, sonicate for 30min, add 1g of 5wt% ammonium persulfate aqueous solution, heat to 70℃, stir for 5h, cool down, filter, wash with deionized water, and dry at 80℃ for 24h to obtain modified bentonite;

[0050] (3) Add 10g of modified bentonite and 2g of humic acid to 50g of N,N-dimethylacetamide, sonicate for 1h, heat to 70℃, stir and react for 24h, filter, wash with deionized water, dry at 80℃ for 24h, crush, and pass through a 100-mesh sieve to obtain the modifier.

[0051] Performance testing:

[0052] The tested soil was selected from a certain area in Jiangxi Province. Its basic physicochemical properties are as follows: field water holding capacity 18.45%, organic matter 7.58 g / kg, pH 5.56, soluble salt concentration 2.84 g / kg, total nitrogen 0.54 g / kg, total phosphorus 0.12 g / kg, total potassium 0.38 g / kg, available nitrogen 70.23 mg / kg, available phosphorus 6.59 mg / kg, and available potassium 53.25 mg / kg.

[0053] Pot experiment: Using the test soil without any amendments as a control, three replicates were set up for each formulation. The pot experiment was conducted in plastic paper pots. 30g of the amendments prepared in the examples and comparative examples were applied to the soil for the pot experiment. Each pot contained 1500g of test soil. After being saturated with water, the soil was placed under natural conditions to settle for 120 days. The soil was then removed and its physical and chemical properties were tested. The results are shown in Table 1.

[0054] Table 1 Performance Test Results

[0055]

[0056] Data Analysis:

[0057] As can be seen from the data in Table 1 for Examples 1-3 and the control group, the soil conditioner prepared in this invention can effectively increase soil pH and maintain it at a neutral level. Soil pH is closely related to soil nutrient forms and has a significant impact on soil nutrient availability and crop growth. Most crops can only grow well in near-neutral soil environments. Furthermore, it greatly increases field water holding capacity and organic matter content. Increased field water holding capacity helps improve soil water retention, reduces water loss, and provides a continuous water supply for crops. Increased organic matter content improves soil fertility and provides abundant nutrient sources for crop growth. Simultaneously, the soil conditioner prepared in this invention effectively increases the content of soil aggregates with a particle size >0.25 mm. Aggregates with a particle size >0.25 mm are important for soil structure and soil nutrients, not only enhancing soil erosion resistance but also improving soil aeration and nutrient storage capacity, thereby further optimizing the soil environment.

[0058] As can be seen from the data in Example 2 and Comparative Example 1 in Table 1, the addition of dimethylsilanediol can effectively improve field water holding capacity and increase the content of particles with a diameter >0.25 mm in soil aggregates. This is because dimethylsilanediol can crosslink with vinyltrichlorosilane and intercalate into the interlayer structure of bentonite, which helps acrylic acid, polyethylene glycol allyl ether and humic acid to build a hydrophilic crosslinking network, thereby effectively improving the soil's water retention capacity and enhancing the stability of the aggregate structure.

[0059] As can be seen from the data in Example 2 and Comparative Example 2 in Table 1, the addition of polyethylene glycol allyl ether promotes field water holding capacity, organic matter content, and the content of aggregates >0.25 mm. This is mainly because polyethylene glycol allyl ether provides crosslinking sites to construct a crosslinking network on the one hand, and provides a hydrophilic polyethylene glycol backbone structure on the other hand, increasing the hydrophilicity of the crosslinking network. The improvement of the overall network hydrophilicity not only enhances the soil's water retention capacity, but also promotes the adsorption of organic matter and the formation of aggregates, thereby improving soil structure and nutrient availability, and providing a better soil environment for crop growth.

[0060] Data from Example 2 and Comparative Example 3 show that the addition of diphenylmethane diisocyanate helps improve field water holding capacity and the content of aggregates >0.25 mm. This is because diphenylmethane diisocyanate acts as a bridge, enabling humic acid and modified bentonite to construct a suitable hydrophilic network. This hydrophilic network enhances the soil's water retention capacity, allowing water to be more effectively adsorbed and retained. Furthermore, it promotes soil particle aggregation, increasing the content of aggregates >0.25 mm and improving soil structure stability and aeration. The formation of this network structure not only improves the soil's water-holding capacity but also enhances its erosion resistance and nutrient storage capacity, providing a better soil environment for healthy crop growth.

[0061] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0062] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A soil conditioner suitable for improving the fertility of barren soil, characterized in that, It is prepared by the following steps: (1) Disperse bentonite in toluene, sonicate for 0.5-2 h, then add vinyltrichlorosilane and dimethylsilanediol, heat to 95-105℃, stir and react for 20-30 h, cool, filter, wash, and dry at 55-65℃ for 20-30 h to obtain vinyl bentonite; (2) Add acrylic acid and polyethylene glycol allyl ether to deionized water, stir for 20-40 min, then add vinyl bentonite, sonicate for 20-40 min, add ammonium persulfate aqueous solution dropwise, heat to 65-75℃, stir and react for 4-6 h, cool down, filter, wash with deionized water, and dry at 75-85℃ for 20-30 h to obtain modified bentonite; (3) Add modified bentonite and humic acid to N,N-dimethylacetamide, sonicate for 0.5-2h, then add diphenylmethane diisocyanate, heat to 65-75℃, stir and react for 20-30h, filter, wash with deionized water, dry at 75-85℃ for 20-30h, crush, and pass through an 80-120 mesh sieve to obtain a soil conditioner suitable for improving the fertility of barren soil. In step (1), the weight ratio of bentonite, toluene, vinyltrichlorosilane and dimethylsilanediol is 8-12:80-120:0.5-1.5:0.2-0.

7. In step (2), the weight ratio of acrylic acid, polyethylene glycol allyl ether, deionized water, vinyl bentonite and ammonium persulfate aqueous solution is 3-8:1-3:50-150:8-12:0.5-2. In step (3), the weight ratio of modified bentonite, humic acid, N,N-dimethylacetamide and diphenylmethane diisocyanate is 8-12:1-3:40-60:0.2-1.

2. The soil conditioner for improving fertility in barren soil according to claim 1, characterized in that, The density of the bentonite is 2-3 g / cm³. 3 .

3. The soil conditioner for improving fertility in barren soil according to claim 1, characterized in that, The concentration of the ammonium persulfate aqueous solution in step (2) is 3wt%-8wt%.

4. The soil conditioner for improving fertility in barren soil according to claim 1, characterized in that, The purity of the humic acid is ≥90%.

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