A composite modifier for acid resistance and aluminum control, its preparation method and application

Abstract

This invention provides a composite soil conditioner for acid inhibition and aluminum control, its preparation method, and its application. The conditioner consists of microcrystalline activated minerals, silicon-calcium materials, biomass alkaline materials, and microbial agents, wherein the microbial agents include rhizobia, Trichoderma harzianum, and Pseudomonas fluorescens. The specific raw material ratios can be adjusted according to different needs. Field trials are conducted to study the effects of different material ratios on improving soil acidity and increasing crop yield and quality, thus forming an acid soil conditioner formulation. The preparation method includes ultrafine grinding, microcrystalline activation, hybridization, and mixing steps. Microcrystalline activation is performed using an activator solution, and an organic binder is added during hybridization to form an organic-inorganic hybrid structure. This composite conditioner can effectively improve the physical effects and chemical reaction rates of acid soil conditioners and can be used to improve acidic soils.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a composite soil conditioner for inhibiting acid and controlling aluminum, its preparation method, and its application. Background Technology

[0002] Soil acidification causes a series of changes in the physical, chemical, and biological properties of soil, leading to the evolution and degradation of agricultural productivity and ecosystems. Soil acidification depletes soil nutrients, increases the activity of toxic elements, harms plant growth, and causes a decline in soil biodiversity and ecological function. The soil quality degradation and ecological fragility caused by soil acidification seriously threaten the efficient utilization of red soil resources and the realization of agricultural productivity. Studies have shown that for every 1 unit decrease in soil pH within the range of 4.2–6.4, the average yield of rapeseed, peanut, wheat, corn, and citrus decreases by 51.9%. Soil acidification increases the activity of heavy metals. With soil acidification (decreased pH), the availability of Cd and Pb in the soil increases significantly, especially Cd, whose activity increases at low pH levels. This is one of the main reasons why "Cd rice" is commonly found in acidic paddy fields. After soil acidification, not only does the activity of harmful heavy metals increase, causing excessive heavy metal levels in grains, but the activity of soil Al also increases significantly, causing Al toxicity in crops and thus a substantial reduction in yield. Traditional soil conditioners and existing soil improvement technologies can achieve good results in improving the acidity of farmland soil, but the improvement effect is short-lived and the soil becomes acidic again, resulting in long-term fluctuations in farmland soil pH, which seriously affects the high and stable yield of crops. Summary of the Invention

[0003] Therefore, this invention proposes a composite modifier for acid resistance and aluminum control, its preparation method, and its application to solve the above problems.

[0004] The technical solution of this invention is achieved as follows: A composite modifier for acid inhibition and aluminum control comprises the following raw materials in parts by weight: 30-40 parts of microcrystalline activated minerals, 25-35 parts of silicon-calcium materials, 20-30 parts of biomass alkaline materials, and 5-10 parts of microbial agents; the microbial agents are Rhizobium, Trichoderma harzianum, and Pseudomonas fluorescens in a mass ratio of (12-22):(8-10):(5-7), each with an effective viable count of 1×10⁻⁶. 8 -10 10 cfu / mL.

[0005] Furthermore, the raw materials include the following parts by weight: 35 parts of microcrystalline activated minerals, 30 parts of silicon-calcium materials, 25 parts of biomass alkaline materials, and 8 parts of microbial agents.

[0006] Furthermore, the microcrystalline activated minerals include 15-20 parts of phosphate rock powder and 15-20 parts of limestone.

[0007] Furthermore, the silicon-calcium material comprises 10-15 parts of silicon-calcium fertilizer, 8-10 parts of slag, and 7-10 parts of oyster shell powder.

[0008] Furthermore, the slag is selected from steel slag, copper slag, lead-zinc slag, nickel slag, manganese slag, or chromium slag.

[0009] Furthermore, the biomass alkaline material includes 12-18 parts of straw biochar and 8-12 parts of tung seed meal.

[0010] Furthermore, a method for preparing a composite modifier for acid inhibition and aluminum control includes the following steps:

[0011] S1. Ultrafine grinding: Microcrystalline activated minerals and silicon-calcium materials are respectively fed into an air jet mill for grinding. The airflow speed is adjusted to 150-300m / s, and the particle size is 1-10μm.

[0012] S2. Microcrystalline activation: The above-mentioned pulverized microcrystalline activated mineral powder is slowly added to the activator solution, with the mass-to-volume ratio (g / mL) controlled at 1:5-10. The reaction is carried out under stirring conditions, with a stirring speed of 100-300 rpm, a reaction temperature controlled at 40-80℃, and a reaction time of 2-6 hours. After the reaction is completed, solid-liquid separation is performed to obtain the activated microcrystalline activated mineral powder. The powder is washed with water until neutral and then dried at 80-120℃ to constant weight for later use.

[0013] S3, Hybridization: The biomass alkaline material is initially mixed with the silicon-calcium material of S1 and the microcrystalline activated mineral powder of S2 for 15-30 minutes at a speed of 50-100 rpm to obtain a preliminary mixture. The organic binder solution is slowly added to the preliminary mixture while stirring at a speed of 100-300 rpm to ensure that the organic binder is evenly coated on the surface of the inorganic raw material particles, forming an organic-inorganic hybrid structure. Stirring and mixing are continued for 30-60 minutes to ensure that the organic binder and inorganic raw materials are fully combined. Granulation is then performed to obtain granular materials with a particle size of 2-5 mm.

[0014] S4. Mixing: Add the microbial agent to the granular material in S3 and mix at a low speed of 30-60 rpm for 10-20 minutes to avoid deactivation of the microbial agent due to excessive shear force. This ensures that the microbial agent is evenly distributed on the surface and inside of the particles. The mixed material is the finished product of the multifunctional composite modifier for acid inhibition and aluminum control, which is then packaged and stored.

[0015] Furthermore, the activator solution of S2 is a dilute sulfuric acid or hydrochloric acid solution with a concentration of 1-5 mol / L.

[0016] Furthermore, the organic binder solution of S3 is selected from guar gum, cellulose or sodium alginate solution with a mass fraction of 5-15%.

[0017] Furthermore, the composite amendment is applied to acidic soil.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention addresses the principle of long-lasting acid suppression technology through the combined application of organic and chemical fertilizers, and develops a multifunctional composite soil conditioner based on a model of the relationship between silicate mineral weathering, proton consumption, and aluminum activation. The core objective is to enhance the physical protection of arable soil by strengthening soil aggregates, thereby increasing soil organic matter content and biological functions, achieving an acid-suppressing, aluminum-controlling, and fertilization effect through the interactive coupling of "aggregates – organic matter – biological functions." Attached Figure Description

[0020] Figure 1 The process flow diagram shows the preparation method of the composite modifier for acid inhibition and aluminum control. Detailed Implementation

[0021] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0022] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0023] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0024] Example 1

[0025] A composite modifier for acid inhibition and aluminum control comprises the following raw materials in parts by weight: 30 parts of microcrystalline activated minerals, 25 parts of silicon-calcium materials, 20 parts of biomass alkaline materials, and 5 parts of microbial inoculants; wherein the microcrystalline activated minerals are 15 parts of phosphate rock powder and 15 parts of limestone; the silicon-calcium materials are 10 parts of silicon-calcium fertilizer, 8 parts of copper slag, and 7 parts of oyster shell powder; the biomass alkaline materials are 12 parts of straw biochar and 8 parts of tung seed meal; and the microbial inoculants are Rhizobium, Trichoderma harzianum, and Pseudomonas fluorescens in a mass ratio of 12:8:5, each with an effective viable count of 1×10⁻⁶. 8 cfu / mL.

[0026] Example 2

[0027] A composite modifier for acid inhibition and aluminum control comprises the following raw materials in parts by weight: 40 parts of microcrystalline activated minerals, 35 parts of silicon-calcium materials, 30 parts of biomass alkaline materials, and 10 parts of microbial inoculants; wherein the microcrystalline activated minerals are 20 parts of phosphate rock powder and 20 parts of limestone; the silicon-calcium materials are 15 parts of silicon-calcium fertilizer, 10 parts of steel slag, and 10 parts of oyster shell powder; the biomass alkaline materials are 18 parts of straw biochar and 12 parts of tung seed meal; and the microbial inoculants are Rhizobium, Trichoderma harzianum, and Pseudomonas fluorescens in a mass ratio of 22:10:7, each with an effective viable count of 1×10⁻⁶. 10 cfu / mL.

[0028] Example 3

[0029] A composite modifier for acid inhibition and aluminum control comprises the following raw materials in parts by weight: 35 parts microcrystalline activated minerals, 30 parts silicon-calcium materials, 25 parts biomass alkaline materials, and 8 parts microbial agents; wherein the microcrystalline activated minerals are 15 parts phosphate rock powder and 20 parts limestone, the silicon-calcium materials are 12 parts silicon-calcium fertilizer, 10 parts lead-zinc slag, and 8 parts oyster shell powder, the biomass alkaline materials are 15 parts straw biochar and 10 parts tung seed meal; and the microbial agents are Rhizobium, Trichoderma harzianum, and Pseudomonas fluorescens in a mass ratio of 17:9:6, each with an effective viable count of 1×10⁻⁶. 9 cfu / mL;

[0030] The above Examples 1-3 were prepared using the following methods:

[0031] S1. Ultrafine grinding: Microcrystalline activated minerals and silicon-calcium materials are respectively fed into an air jet mill for grinding. The airflow speed is adjusted to 150-300m / s, and the particle size is 1-10μm.

[0032] S2. Microcrystalline Activation: The above-mentioned pulverized microcrystalline activated mineral powder is slowly added to the activator solution, with the mass-to-volume ratio (g / mL) controlled at 1:5-10. The activator solution is a 1-5 mol / L dilute sulfuric acid or hydrochloric acid solution. The reaction is carried out under stirring conditions, with a stirring speed of 100-300 rpm, a reaction temperature controlled at 40-80℃, and a reaction time of 2-6 hours. After the reaction is completed, solid-liquid separation is performed to obtain the activated microcrystalline activated mineral powder. The powder is washed with water until neutral and then dried at 80-120℃ to constant weight for later use.

[0033] S3, Hybridization: The biomass alkaline material is initially mixed with the silicon-calcium material of S1 and the microcrystalline activated mineral powder of S2 for 15-30 minutes at a speed of 50-100 rpm to obtain a preliminary mixture. The organic binder solution is slowly added to the preliminary mixture while stirring at a speed of 100-300 rpm. The organic binder solution is selected from guar gum, cellulose or sodium alginate solution with a mass fraction of 5-15% to make the organic binder uniformly coat the surface of the inorganic raw material particles to form an organic-inorganic hybrid structure. Continue stirring and mixing for 30-60 minutes, then granulate to obtain granular material with a particle size of 2-5 mm.

[0034] S4. Mixing: Add the microbial agent to the granular material in S3 and mix using a low-speed stirring method. The stirring speed is 30-60 rpm and the mixing time is 10-20 minutes. The mixed material is the finished product of the multifunctional composite modifier for acid inhibition and aluminum control, which is then packaged and stored.

[0035] Comparative Example 1

[0036] The difference between this comparative example and Example 3 is that the composite modifier for acid resistance and aluminum control includes the following raw materials in parts by weight: 15 parts of microcrystalline activated minerals, 40 parts of silicon-calcium materials, 12 parts of biomass alkaline materials, and 18 parts of microbial agents.

[0037] Comparative Example 2

[0038] The difference between this comparative example and Example 3 is that the minerals of the composite modifier for acid resistance and aluminum control were not activated.

[0039] Comparative Example 3

[0040] The difference between this comparative example and Example 3 is that the biomass alkaline material of the composite modifier for acid resistance and aluminum control is not hybridized.

[0041] Comparative Example 4

[0042] The difference between this comparative example and Example 3 is that the composite modifier for acid resistance and aluminum control does not contain microbial agents.

[0043] I. Performance Testing

[0044] 1. Acidity / alkalinity (pH) test

[0045] The above-mentioned compound amendment was added to the soil at a rate of 10 g / kg. The soil pH was measured after 14 days, and the initial soil pH was 4.5.

[0046] 2. Aluminum ion fixation ability test

[0047] Add a modifier to a solution containing 10.0 mg / L aluminum ions, and measure the concentration of the remaining aluminum ions in the solution after 7 days. Calculate the fixation rate of the modifier on aluminum ions.

[0048] Fixed rate (%) = ×100%;

[0049] Where C0 is the initial concentration of aluminum ions in the solution before the reaction.

[0050] C represents the concentration of remaining aluminum ions in the solution after the reaction.

[0051] 3. Test Results

[0052]

[0053] The above results indicate that the composite amendment has a good effect on improving soil pH, effectively alleviating soil acidification, and also has the effect of fixing or converting aluminum ions.

[0054] II. Field Trial Related Tests

[0055] 1. Experimental Field Selection: Red soil with a pH between 4.5 and 5.5, moderate and uniform fertility was selected. The experimental field was divided into 7 treatment plots, each with an area of ​​no less than 30 square meters, and replicated 3-4 times. Before rice planting, the experimental field was deeply plowed and turned over to a depth of 20-25 cm to break up soil clods and make the soil loose and level. Then, basal fertilizer was applied according to conventional rice planting requirements, using 30-40 kg of NPK compound fertilizer (15-15-15) per mu. After fertilization, the land was harrowed to thoroughly mix the fertilizer with the soil.

[0056] 2. Application of soil conditioner: 1-2 days before rice transplanting, apply soil conditioner evenly to the surface of the experimental field at a rate of 10g / kg.

[0057] 3. Soil pH test: Soil samples were collected before rice planting, during the tillering stage, the booting stage, and at harvest for pH measurement.

[0058] 4. Rice Yield Measurement: For early rice, the actual yield was measured from mid to late July, and for late rice, from mid to late October. Three quadrats were randomly selected within each treatment plot, each with an area of ​​1 square meter. All rice plants within the quadrats were harvested, threshed, and weighed. The weight of the rice grains in each quadrat was recorded. The average weight of the rice grains from the three quadrats was then converted to the yield per mu (kg / mu). Simultaneously, the moisture content of the rice was measured, and the measured yield was converted to the yield at the standard moisture content (13.5%). For each quadrat, an area of ​​at least 1 square meter was selected to investigate the number of effective panicles, and three hills were selected from each rice plant to investigate the number of grains per panicle and the seed setting rate.

[0059] 5. Rice quality determination: Brown rice rate, milled rice rate, head rice rate, and amylose content were determined according to the methods in the national standard GB / T5502-2008 "Grain and Oil Inspection - Rice Processing Precision Inspection". The Kjeldahl nitrogen determination method was used according to the national standard GB5009.5-2016 "National Food Safety Standard - Determination of Protein in Food".

[0060] 6. Test Results:

[0061] Table 1: Effects of Soil Acidity / Alkalinity (pH)

[0062]

[0063] Table 2: Impact of Rice Yield (kg / mu)

[0064]

[0065] Table 3: Rice Quality

[0066]

[0067] All soil amendment treatments effectively increased soil pH, and the pH remained stable or continued to rise slightly as rice growth progressed. The amendment treatment raised the soil pH to 6.9 at harvest time, indicating that the amendment has a good effect on improving soil acidity and can maintain a suitable pH environment throughout the rice growth period. After applying the amendment, all yield components were improved. The treatment in Example 3 increased the number of effective panicles to 235,000 panicles / mu and the yield to 560 kg / mu; this shows that the amendment can promote rice growth and development by improving soil conditions, thereby increasing yield. The treatment in Example 3 increased the brown rice rate to 89.6%, and also improved the milled rice rate and head rice rate, while decreasing the amylose content and increasing the protein content; this indicates that the amendment not only increases rice yield but also has a positive effect on improving rice quality.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite modifier for acid inhibition and aluminum control, characterized in that: The raw materials include the following parts by weight: 30-40 parts of microcrystalline activated minerals, 25-35 parts of silicon-calcium materials, 20-30 parts of biomass alkaline materials, and 5-10 parts of microbial agents; The microbial inoculant consists of Rhizobium, Trichoderma harzianum, and Pseudomonas fluorescens in a mass ratio of (12-22):(8-10):(5-7), with an effective viable count of 1×10⁻⁶ for each. 8 -10 10 cfu / mL; The silicon-calcium material comprises 10-15 parts of silicon-calcium fertilizer, 8-10 parts of slag, and 7-10 parts of oyster shell powder; The biomass alkaline material includes 12-18 parts of straw biochar and 8-12 parts of tung seed meal; The microcrystalline activated minerals include 15-20 parts of phosphate rock powder and 15-20 parts of limestone. The preparation method of the composite modifier for acid resistance and aluminum control includes the following steps: S1. Ultrafine grinding: Microcrystalline activated minerals and silicon-calcium materials are respectively fed into an air jet mill for grinding. The airflow speed is adjusted to 150-300m / s, and the particle size is 1-10μm. S2. Microcrystalline activation: The above-mentioned pulverized microcrystalline activated mineral powder is slowly added to the activator solution, with the mass-to-volume ratio (g / mL) controlled at 1:5-10. The reaction is carried out under stirring conditions, with a stirring speed of 100-300 rpm, a reaction temperature controlled at 40-80℃, and a reaction time of 2-6 hours. After the reaction is completed, solid-liquid separation is performed to obtain the activated microcrystalline activated mineral powder. The powder is washed with water until neutral and then dried at 80-120℃ to constant weight for later use. S3, Hybridization: The biomass alkaline material is initially mixed with the silicon-calcium material of S1 and the microcrystalline activated mineral powder of S2 for 15-30 minutes at a speed of 50-100 rpm to obtain a preliminary mixture. The organic binder solution is slowly added to the preliminary mixture while stirring at a speed of 100-300 rpm to make the organic binder uniformly coat the surface of the inorganic raw material particles, forming an organic-inorganic hybrid structure. Continue stirring and mixing for 30-60 minutes, then granulate to obtain granular material with a particle size of 2-5 mm. S4. Mixing: Add the microbial agent to the granular material in S3 and mix using a low-speed stirring method. The stirring speed is 30-60 rpm and the mixing time is 10-20 minutes. The mixed material is the finished product of the multifunctional composite modifier for acid inhibition and aluminum control, which is then packaged and stored. The activator solution of S2 is a dilute sulfuric acid or hydrochloric acid solution with a concentration of 1-5 mol / L.

2. The composite modifier for acid resistance and aluminum control as described in claim 1, characterized in that: The raw materials include the following parts by weight: 35 parts microcrystalline activated minerals, 30 parts silicon-calcium materials, 25 parts biomass alkaline materials, and 8 parts microbial agents.

3. The composite modifier for acid resistance and aluminum control as described in claim 1, characterized in that: The slag is selected from steel slag, copper slag, lead-zinc slag, nickel slag, manganese slag, or chromium slag.

4. The composite modifier for acid resistance and aluminum control as described in claim 1, wherein the preparation method is characterized in that: The organic binder solution of S3 is selected from guar gum, cellulose or sodium alginate solution with a mass fraction of 5-15%.

5. The application of the composite amendment for acid inhibition and aluminum control as described in claim 1 in the improvement of acidic soil, characterized in that, The composite amendment is applied to acidic soil.

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