A fertilizing composition for adapting acidified arable land and a method for preparing and applying the same

Abstract

The application discloses a kind of adaptation acidification cultivated land's fertilizing composition and preparation method, application method thereof.The fertilizing composition includes the following components by weight fraction: functionalized organic carrier 40-60 parts, composite inorganic fertilizer 25-40 parts, soil conditioner 10-20 parts, biological synergist 1-5 parts, sodium silicate 5-15 parts, sodium alginate 1-2 parts, polyaspartic acid 2-4 parts, EDTA chelated calcium 1-4 parts, EDTA chelated magnesium 1-4 parts.The functionalized organic carrier is prepared from alkaline organic material and carbon-rich skeleton material at a ratio of 1-2:1;The composite inorganic fertilizer is composed of urea, resin film urea, activated phosphate rock powder, calcium-magnesium phosphate fertilizer and potassium sulfate at a weight ratio of 1-3:1-2:2-3:2-4:1-2;The soil conditioner is prepared from porous mineral material and nano zero-valent iron biochar at a weight ratio of 1-2:1.The application can effectively solve the problems of low pH value, aluminum and manganese toxicity, phosphorus fixation, poor soil structure and low fertility in acidification cultivated land in the south through the synergistic effect of physical-chemical-biological triple action.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement technology, and in particular relates to a fertilizer composition suitable for acidified farmland and its preparation and application methods. Background Technology

[0002] Existing soil improvement and fertilization techniques for acidified soils have shortcomings: improvement and fertilization are disconnected. Alkaline substances such as quicklime and dolomite powder are often used for chemical acidification, but these substances are usually applied separately or simply mixed with chemical fertilizers and organic fertilizers, failing to form a synergistic effect. Moreover, the acidification effect is not lasting and can easily cause drastic fluctuations in local soil pH.

[0003] Ignoring the accompanying obstacles of soil acidification: Soil acidification not only leads to a decrease in pH, but also brings with it a chain of problems such as active aluminum / manganese toxicity, severe leaching of basic ions such as calcium and magnesium, a sharp decrease in phosphorus availability (phosphorus is fixed), and soil structure degradation. Most existing fertilizer products only focus on supplementing nitrogen, phosphorus, and potassium or adjusting pH, failing to systematically address this series of coupled obstacles.

[0004] Improper selection of organic materials: Blindly applying insufficiently decomposed or highly acidic organic materials to acidified soils may exacerbate soil acidification and aluminum toxicity.

[0005] Patent document CN120329132A discloses an alkaline carbon-based bio-organic fertilizer for acidified dryland in southern China. This fertilizer relies on a single alkaline material for acidification, resulting in weak pH buffering capacity and a tendency for pH rebound. It lacks a long-term calcium and magnesium supply system and cannot address the coupling problem of phosphorus fixation and aluminum-manganese toxicity, making it difficult to achieve long-term stable regulation of soil acidity. Patent document CN121377903A discloses a compound fertilizer for improving acidic soil. This fertilizer cannot target and stratify the soil, only achieving surface acidification and simple nutrient supplementation. It lacks stratified targeted application, nano-biochar remediation, and a functionalized organic carrier framework, resulting in poor soil structure improvement and fertilization effects. In summary, current fertilization compositions for acidified farmland have various shortcomings. Therefore, researching a suitable fertilization composition for acidified farmland, along with its preparation and application methods, is crucial. Summary of the Invention

[0006] One objective of this invention is to address the disconnect between farmland improvement and fertilization, by providing a fertilization composition comprising functionalized organic carriers, compound inorganic fertilizers, soil conditioners, and bio-enhancing agents. Through the synergistic effect of these components, chemical improvement and fertility enhancement of acidified farmland can be achieved simultaneously.

[0007] Another objective of this invention is to combine soil remediation, slow nutrient release, and improvement of soil physical structure. The soil conditioner is composed of porous mineral materials and loaded nano-zero-valent iron biochar, which can improve the redox buffering capacity of the soil and improve the soil physical structure.

[0008] Another objective of this invention is to address the difficulty in integrating physical structural support, chemical regulation, and biological nutritional functions during soil improvement. The functionalized organic carrier is obtained by combining lignin-amino acid alkaline chelating carrier and cellulose aerogel particles, thereby constructing a stable physical framework in both the short and long term, multi-site gradient chemical regulation, and a suitable living environment for microorganisms.

[0009] Another objective of this invention is to provide a simple process for preparing the fertilizer composition suitable for acidified farmland that can be stably produced.

[0010] To achieve the above objectives, this invention discloses a soil conditioning composition suitable for acidified farmland, comprising the following components by weight: 40-60 parts of functionalized organic carrier, 25-40 parts of compound inorganic fertilizer, 10-20 parts of soil conditioner, 1-5 parts of bio-enhancing agent, 5-15 parts of sodium silicate, 1-2 parts of sodium alginate, 2-4 parts of polyaspartic acid, 1-4 parts of EDTA chelated calcium, and 1-4 parts of EDTA chelated magnesium. The synergistic mechanism of the above components is as follows: Both the functionalized organic carrier and the soil conditioner have porous structures, which can improve soil aggregate stability; the compound inorganic fertilizer provides crops with the necessary N, P, K elements, as well as some calcium and magnesium elements, and together with EDTA-chelated calcium / magnesium, improves the calcium and magnesium content in the soil; the bio-synergist can degrade organic matter in the soil, activate phosphate fertilizer, and promote crop growth, further enhancing the fertilization effect; EDTA-chelated calcium and EDTA-chelated magnesium are fast-acting fertilizers that can be directly absorbed by crops; polyaspartic acid can chelate calcium and magnesium ions and maintain their absorbability by crops. In this state, EDTA chelates calcium / magnesium to form a calcium and magnesium supply system of "rapid supplementation - slow supply"; sodium silicate provides active silicate ions in an alkaline environment, and synergistically constructs an organic-inorganic composite coating layer with organic components, significantly extending the fertilizer effect period; EDTA provides strong coordination locking for calcium and magnesium, and polyaspartic acid plays a dynamic coordination compensation and steric hindrance stabilization role, while chelating iron and aluminum ions, blocking the combination of phosphate ions with iron and aluminum, and preventing phosphorus fixation; the above components synergistically construct a calcium, magnesium, and silicon synergistic supply system of "rapid supplementation - slow supply - long-term protection", improving fertilizer utilization.

[0011] Preferably, the functionalized organic carrier is composed of alkaline organic material and carbon-rich skeleton material in a weight ratio of 1-2:1, and the pH value of the functionalized organic carrier is 8.5-9.0; the alkaline organic material is a lignin-amino acid alkaline chelate carrier, and the weight ratio of lignin to amino acids is 1:0.3-0.5; the lignin is a powder with a lignin content of 90%-95% and a particle size of 150-200 mesh; the amino acids are obtained by enzymatic hydrolysis of hair, soybean meal and feathers, and the amino acid content is 35%-40%; the carbon-rich skeleton material is cellulose aerogel particles, and the cellulose aerogel particles are composed of cellulose and sodium alginate in a weight ratio of 1-2:1. Carbon-rich framework materials provide a large-pore structure, improving soil aeration and reducing bulk density, while providing a sustained-release carbon source to ensure the nutrient supply for microorganisms. Cellulose aerogel particles have a porosity of up to 90%, and their specific surface area is much higher than that of commonly used carbon-rich materials such as coconut coir and peat. Sodium alginate in cellulose aerogel can rapidly release carbon, while cellulose slowly releases carbon, achieving a continuous supply of carbon in both the short and long term. Sodium alginate can also help improve soil aggregate structure. Alkaline organic materials regulate soil pH and serve as a habitat for microorganisms, protecting functional bacteria from environmental shocks. Functionalized organic carriers can improve soil physical structure and serve as an important source of organic matter. In lignin-amino acid alkaline chelating carriers, lignin can promote the formation of aggregate structure, and amino acids can be directly absorbed by roots. Its active groups can synergistically work with EDTA in the formula to chelate medium-quantity elements such as calcium and magnesium, preventing them from being fixed and unusable by crops. Its alkalinity can not only immediately reduce soil acidity but also slowly release alkalinity, providing continuous protection for the soil.

[0012] Preferably, the compound inorganic fertilizer is composed of urea, resin-film urea, activated phosphate rock powder, calcium magnesium phosphate fertilizer, and potassium sulfate in a weight ratio of 1-3:1-2:2-3:2-4:1-2. The compound inorganic fertilizer combines the rapid-release and slow-release properties of urea and resin-film urea, ensuring adequate nitrogen supply in the early stages of crop growth while reducing nitrogen loss and extending the fertilizer's effectiveness. Activated phosphate rock powder provides readily available phosphorus; calcium magnesium phosphate fertilizer is alkaline, suitable for acidic soils, and simultaneously provides calcium and magnesium, preventing activated phosphate rock powder from exacerbating soil acidification; potassium sulfate provides the potassium needed by crops.

[0013] Preferably, the soil conditioner is a composite material of porous mineral material and nano-zero-valent iron biochar; the porous mineral material is one or both of bentonite and zeolite powder, wherein the specific surface area of ​​the bentonite is 500-650 m2 / g and the specific surface area of ​​the zeolite powder is 500-650 m2 / g; the biochar of the nano-zero-valent iron biochar is obtained by carbonizing rice husks and / or corn stalks at 400-600℃ in anoxic conditions for 2-4 h, and the iron content of the nano-zero-valent iron biochar is 5%-20%; the weight ratio of the porous mineral material to the nano-zero-valent iron biochar is 1-2:1. Zeolite and bentonite have high cation exchange capacity and can adsorb ions such as ammonium, potassium, calcium, and magnesium, reducing nutrient leaching. In nano-zero-valent iron biochar, zero-valent iron can reduce heavy metal ions and prevent heavy metal pollution, while biochar can adsorb organic pollutants and heavy metals. After zero-valent iron is oxidized to iron oxide, the iron oxide-biochar complex has a better effect on fixing heavy metals. The porous structure of soil conditioner can adsorb free metal ions and improve the soil's fertilizer and water retention capacity.

[0014] Preferably, the biosynthetic agent is a mixed bacterial suspension of *Pseudomonas fluorescens* and *Rhodococcus erythropolis*, with a volume ratio of *Pseudomonas fluorescens* to *Rhodococcus erythropolis* of 1:1.5-2.5, and a viable count of 1.5 × 10⁸-3.5 × 10⁸ CFU / mL. The *Pseudomonas fluorescens* has the accession number CGMCC No. 1.1823, and the *Rhodococcus erythropolis* has the accession number CGMCC No. 1.10292; both are deposited at the China General Microbiological Culture Collection Center. *Pseudomonas fluorescens* produces plant growth hormones, stimulating root elongation and lateral root formation, improving nutrient absorption capacity, and also has phosphorus and potassium solubilizing effects, increasing the available phosphorus and potassium content in the soil. *Rhodococcus erythropolis* can degrade cellulose and lignin, releasing nutrients, and also secretes plant growth hormones, increasing crop yield.

[0015] Preferably, the sodium silicate has a silicon dioxide content of 25%-30%, the EDTA chelated calcium has a calcium content of 10%-13%, and the EDTA chelated magnesium has a magnesium content of 9%-11%.

[0016] The present invention also provides a method for preparing a fertilizer composition, comprising the following steps: S1. Preparation of functionalized organic carriers and supported nano-zero-valent iron biochar; S2. Activated Soil Conditioner: Porous mineral materials and loaded nano-zero ferrous biochar are mixed and placed in ferrous sulfate solution. The pH is adjusted to 7-8 to precipitate the mixture. After drying, the mixture is pulverized to obtain the activated soil conditioner. S3. Mixing: Stir the functionalized organic carrier, compound inorganic fertilizer, activated soil conditioner, bio-enhancing agent, sodium silicate, sodium alginate, polyaspartic acid, EDTA chelated calcium and EDTA chelated magnesium evenly at a stirring speed of 50-300 rpm for 15-30 min to obtain the fertilizer composition.

[0017] Preferably, the preparation of the functionalized organic carrier in S1 includes the following steps: 1) Add lignin to the reaction vessel, add potassium hydroxide to adjust the pH to 10-11, heat to 75-80℃, keep warm while stirring and add amino acid solution, then heat to 80-85℃, react for 2-3 hours, cool down to 25-30℃ to obtain a paste material. 2) Disperse cellulose and sodium alginate with water by stirring, gradually add calcium chloride solution, let stand for 30-60 min, lower the temperature to -20℃, maintain for 12-24 h, set the vacuum degree to 10-20 Pa, cold trap temperature to -50℃, and dry for 48-72 h to obtain powder for later use. 3) Place the powder prepared in step 2) into a vacuum impregnation tank, evacuate to -0.08~-0.095 MPa for 30 min, then add the paste material obtained in step 1), restore normal pressure and maintain for 2-4 h, and dry the loaded particles at 50-60℃ to obtain the functionalized organic carrier.

[0018] Preferably, the preparation of the nano-zero-valent iron biochar in S1 includes the following steps: 1) Immerse the biochar in a ferric chloride solution and stir for 30 min; 2) Add sodium borohydride under nitrogen protection and react for 30-60 min. After the reaction is complete, wash with deoxygenated deionized water 1-2 times and freeze-dry at -25~-35℃ for 12-24 h to obtain the supported nano-zero valent iron biochar.

[0019] The present invention also provides a method for applying the fertilization composition adapted to acidified arable land. This method is applicable to the planting of field crops such as rice, corn, and rapeseed, with an application rate of 100-200 kg per acre, and specifically includes the following steps: S1. Base application: When preparing the land, apply 70%-80% of the total amount of the above-mentioned fertilizer composition as base fertilizer, and till it into the soil layer of 15-20 cm by rotary tillage or plowing. S2. Topdressing: At sowing time, apply the remaining 20%-30% of the fertilizer composition to the side at a depth of 5-8 cm. This application method adopts a "layered-targeted" application strategy.

[0020] The present invention has the following beneficial effects: 1) The fertilization composition of the present invention provides nutrients to the soil through the three-in-one synergistic effect of "soil structure improvement - regulation of soil physicochemical properties - biological regulation". The functional organic carrier and compound inorganic fertilizer provide nutrients to the soil; the alkaline organic materials in the functional organic carrier can improve the soil acidity environment in a lasting and gentle way, and the carbon-rich skeleton can improve soil compaction; together with the soil conditioner, it improves soil structure and increases soil porosity; the bio-synergist promotes crop growth.

[0021] 2) The fertilization composition of the present invention can effectively improve soil aggregate structure. Sodium silicate hydrolyzes to form siliceous cement, and the functionalized organic carrier is distributed in the soil, giving the aggregates water stability and mechanical strength; the combination of the two can increase the content of soil aggregates, reduce soil bulk density, increase porosity, and improve the crop's drought resistance and lodging resistance.

[0022] 3) The fertilization composition of the present invention can effectively and stably regulate soil acidity and avoid drastic pH rebound; it can also reduce the toxicity of heavy metals in the soil to crops.

[0023] 4) The fertilizer composition improves the utilization rate of N, P and K through chemical, physical and biological mechanisms, and increases the soil organic matter content, cation exchange capacity and improves the aggregate structure while supplementing nutrients. Attached Figure Description

[0024] Figure 1 The effects of different fertilization compositions on the pH and exchangeable aluminum content of vineyard soil were investigated. Treatment A was the application of quicklime, treatment B was the application of a silicon-potassium soil conditioner, and treatment C was the application of the fertilization composition of this invention (the same applies below, corresponding to Example 25). Figure 2 The effects of different fertilizer compositions on the exchangeable calcium and exchangeable magnesium content in vineyard soil; Figure 3 The effects of different fertilization compositions on soil acidification in yellow peach orchards were investigated. CK was the conventional fertilization control, NF+QL was conventional fertilization plus quicklime treatment, NF+HA was conventional fertilization plus humic acid-containing soil conditioner treatment, and NF+SiK corresponded to conventional fertilization plus the fertilization composition of this invention (the same applies below, corresponding to treatments 1-4 in Example 26). Figure 4 The effects of different fertilizer compositions on soil nutrient content in yellow peach orchards; Figure 5 The effects of different soil amendment compositions on the cation exchange capacity, exchangeable calcium, and exchangeable magnesium content of yellow peach orchard soil were investigated. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0026] General Example: A soil conditioning composition suitable for acidified farmland, the formula of which is as follows by weight: 40-60 parts of functionalized organic carrier, 25-40 parts of compound inorganic fertilizer, 10-20 parts of soil conditioner, 1-5 parts of bio-enhancing agent, 5-15 parts of sodium silicate, 1-2 parts of sodium alginate, 2-4 parts of polyaspartic acid, 1-4 parts of EDTA chelated calcium, and 1-4 parts of EDTA chelated magnesium.

[0027] The functionalized organic carrier is composed of alkaline organic materials and carbon-rich skeleton materials in a weight ratio of 1-2:1; the alkaline organic material is a lignin-amino acid alkaline chelating carrier, with a weight ratio of lignin to amino acids of 1:0.3-0.5; the carbon-rich skeleton material is cellulose aerogel particles, which are composed of cellulose and sodium alginate in a weight ratio of 1-2:1. The compound inorganic fertilizer is composed of urea, resin-film urea, activated phosphate rock powder, calcium magnesium phosphate fertilizer, and potassium sulfate in a weight ratio of 1-3:1-2:2-3:2-4:1-2. The soil conditioner is composed of porous mineral materials and nano-zero-valent iron biochar in a weight ratio of 1-2:1; the porous mineral materials are one or two of bentonite and zeolite powder; the nano-metal biochar is nano-zero-valent iron biochar. The biosynergist was a mixed bacterial suspension of Pseudomonas fluorescens and Rhodococcus rubrum, with a viable count of 1.5×10⁸-3.5×10⁸ CFU / mL and a volume ratio of Pseudomonas fluorescens to Rhodococcus rubrum of 1:1.5-2.5.

[0028] Unless otherwise specified, the components in the following examples and comparative examples are the same as those in the general examples.

[0029] Preparation method of the general embodiment: S1. Preparation of functionalized organic carriers: (1) Add lignin to the reaction vessel, add potassium hydroxide to adjust the pH to 10-11, raise the temperature to 75-80℃, keep warm and add amino acid solution while stirring, then raise the temperature to 80-85℃ and react for 2-3 h, then lower the temperature to 25-30℃ to obtain a paste material; (2) Add water to cellulose and sodium alginate and stir to disperse, gradually add calcium chloride solution, let stand for 30-60 min, lower the temperature to -20℃ and keep for 12-24 h, then freeze dry under vacuum of 10-20 Pa and cold trap temperature of -50℃ for 48-72 h to obtain powder for later use; (3) Place the powder obtained in step (2) in a vacuum impregnation tank, evacuate to -0.08~-0.095 MPa and keep for 30 min, then add the paste material obtained in step (1), restore normal pressure and keep for 2-4 h, dry the loaded particles at 50-60℃ to obtain functionalized organic carriers; S2. Activated Soil Conditioner: Porous mineral materials and loaded nano-zero ferrous biochar are mixed and placed in ferrous sulfate solution. The pH is adjusted to 7-8 to precipitate the mixture. After drying, the mixture is pulverized to obtain the activated soil conditioner. S3. Mixing: Mix the above-mentioned functionalized organic carrier, compound inorganic fertilizer, activated soil conditioner, bio-enhancing agent, sodium silicate, sodium alginate, polyaspartic acid, EDTA chelated calcium and EDTA chelated magnesium evenly at a stirring speed of 50-300 rpm to obtain the fertilizer composition. Example 1:

[0030] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The composition of the functionalized organic carrier is: alkaline organic material and carbon-rich skeleton material in a ratio of 1.5:1; The compound inorganic fertilizer is composed of urea, resin film urea, activated phosphate rock powder, calcium magnesium phosphate fertilizer, and potassium sulfate in a ratio of 2:1.5:2.5:3:1.5. The soil conditioner consists of porous mineral materials and supported nano-zero-valent iron biochar in a ratio of 1.5:1. Composition of the biosynergist: The biosynergist contains 2.0 × 10⁸ CFU / ml of viable bacteria, and the ratio of Pseudomonas fluorescens to Rhodococcus rubrum is 1:2.

[0031] Preparation method of Example 1: S1. Preparation of functionalized organic carriers: (1) Add lignin to the reaction vessel, add potassium hydroxide to adjust the pH to 11, raise the temperature to 75-80℃, keep warm and add amino acid solution while stirring, then raise the temperature to 80-85℃ and react for 3 h, then lower the temperature to 25-30℃ to obtain a paste material; (2) Add water to cellulose and sodium alginate and stir to disperse, gradually add calcium chloride solution, let stand for 50 min, lower the temperature to -20℃ and keep for 24 h, then freeze dry for 72 h under vacuum of 20 Pa and cold trap temperature of -50℃ to obtain powder for use; (3) Place the powder obtained in step (2) in a vacuum impregnation tank, evacuate to -0.095 MPa and keep for 30 min, then add the paste material obtained in step (1), restore normal pressure and keep for 3 h, dry the loaded particles at 50-60℃ to obtain functionalized organic carriers; S2. Activated Soil Conditioner: Porous mineral materials and loaded nano-zero ferrous biochar are mixed and placed in ferrous sulfate solution. The pH is adjusted to 7 to precipitate the mixture. After drying, the mixture is pulverized to obtain the activated soil conditioner. S3. Mixing: Mix the above-mentioned functionalized organic carrier, compound inorganic fertilizer, activated soil conditioner, bio-enhancing agent, sodium silicate, sodium alginate, polyaspartic acid, EDTA chelated calcium and EDTA chelated magnesium evenly at a stirring speed of 200 rpm to obtain the fertilizer composition.

[0032] Unless otherwise specified, the composition of the functionalized organic carrier, compound inorganic fertilizer, soil conditioner, and bio-synergist in the following embodiments are the same as those in Example 1; Example 2:

[0033] Fertilizer composition formula: 40 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 3:

[0034] Fertilizer composition formula: 55 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 4:

[0035] Fertilizer composition formula: 60 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 5:

[0036] Fertilizer composition formula: 50 parts functionalized organic carrier, 25 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 6:

[0037] Fertilizer composition formula: 50 parts functionalized organic carrier, 31 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 7:

[0038] Fertilizer composition formula: 50 parts functionalized organic carrier, 40 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 8:

[0039] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 10 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 9:

[0040] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 17 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 10:

[0041] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 20 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 11:

[0042] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 25 parts soil conditioner, 1 part bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 12:

[0043] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 5 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 13:

[0044] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 5 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 14:

[0045] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 15 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 15:

[0046] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 2 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 16:

[0047] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 4 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 17:

[0048] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 1 part EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 18:

[0049] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 4 parts EDTA chelated calcium, and 2.5 parts EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 19:

[0050] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 1 part EDTA chelated magnesium. The preparation method is the same as in Example 1. Example 20:

[0051] Fertilizer composition formula: 50 parts functionalized organic carrier, 34 parts compound inorganic fertilizer, 15 parts soil conditioner, 3 parts bio-enhancing agent, 10 parts sodium silicate, 1.5 parts sodium alginate, 3 parts polyaspartic acid, 2.5 parts EDTA chelated calcium, and 4 parts EDTA chelated magnesium. The preparation method is the same as in Example 1.

[0052] The following examples show adjustments to the composition of the functionalized organic carrier, while the composition and other proportions of the fertilizer composition remain the same as in Example 1. Example 21:

[0053] The functionalized organic carrier is composed of alkaline organic material and carbon-rich skeleton material in a 1:1 ratio, and other preparation methods are the same as in Example 1. Example 22:

[0054] The functionalized organic carrier is composed of alkaline organic material and carbon-rich skeleton material in a ratio of 2:1. Other preparation methods are the same as in Example 1.

[0055] The following examples show adjustments to the composition of the soil conditioner, while the composition of the fertilization composition and other proportions are the same as in Example 1. Example 23:

[0056] The weight ratio of porous mineral material and loaded nano-zero-valent iron biochar in the soil conditioner is 1:1, and other aspects are the same as in Example 1. Example 24:

[0057] The soil conditioner consists of a porous mineral material and a nano-metal-loaded biochar in a ratio of 2:1; otherwise, it is the same as in Example 1. Example 25:

[0058] Application test of the fertilization composition of the present invention on acidified cultivated land in vineyards; the formulation and preparation method of the fertilization composition are the same as those in Example 1; The experimental site was located in the grape-growing area of ​​Pujiang County, Zhejiang Province. The grape variety was "Kyoho grape". A large-scale experiment was conducted on mature grape vineyards with relatively uniform soil fertility. The basic soil nutrient conditions before the experiment were as follows: organic matter 29.70±1.8 g / kg, total nitrogen 1.67±0.08 g / kg, available phosphorus 34.1±2.5 mg / kg, available potassium 127±16 mg / kg, pH 5.78±0.23. The experiment was divided into three treatment groups: (1) Treatment A: quicklime was applied at 1500 kg / hm2; (2) Treatment B: commercially available silicon-potassium soil conditioner (K2O ≥ 4.0%, CaO ≥ 32.0%, MgO ≥ 5.0%, SiO2 ≥ 30.0%) was applied at 1500 kg / hm2; (3) Treatment C: the fertilization composition described in Example 1 of this invention was applied at 1500 kg / hm2. Example 26:

[0059] The formulation and preparation method of the fertilizer composition are the same as those in Example 1; The experiment was conducted in the red-yellow soil peach planting area of ​​Zhongyu Township, Pujiang County, Zhejiang Province, and the research subjects were mature peach trees. The basic soil nutrient conditions before the experiment were as follows: organic matter 21.30±1.3 g / kg, total nitrogen 1.57±0.06 g / kg, available phosphorus 31.3±2.3 mg / kg, available potassium 124±16 mg / kg, pH 5.28±0.11. The experiment was divided into 4 treatment groups: (1) Treatment 1 (CK): conventional fertilization (no acidification treatment); (2) Treatment 2 (NF+QL): conventional fertilization + quicklime, 65 kg / mu; (3) Treatment 3 (NF+HA): conventional fertilization + commercially available humic acid soil conditioner, 150 kg / mu; (4) Treatment 4 (corresponding to the attached Figure 3-5 (NF+SiK marker location): Conventional fertilization + the fertilization composition described in Example 1 of this invention, 150 kg / mu. Each treatment plot area was 300 m2, with 3 replicates.

[0060] The preparation methods for the following comparative examples are the same as those in Example 1. Comparative Example 1:

[0061] No functionalized organic carrier was added, and all other components were the same as in Example 1. Comparative Example 2:

[0062] No compound inorganic fertilizer was added, and all other components were the same as in Example 1. Comparative Example 3:

[0063] No biosynergist was added, and all other components were the same as in Example 1. Comparative Example 4:

[0064] Sodium silicate was not added, and all other components were the same as in Example 1. Comparative Example 5:

[0065] No polyaspartic acid was added; all other components were the same as in Example 1. Comparative Example 6:

[0066] No soil conditioner was added; all other ingredients were the same as in Example 1. Comparative Example 7:

[0067] No EDTA was added to chelate calcium and magnesium; all other components were the same as in Example 1.

[0068] For Examples 1-24 above, samples were taken from Comparative Examples 1-7 and applied to acidified farmland soil in Hangzhou City, Zhejiang Province. One plot of land was not treated with this fertilizer technology but was treated with conventional fertilization (treated by local farmers); the other plot was treated according to the following steps: the original soil had a water-stable macroaggregate content of 32%±0.5%, a pH of 4.8-5.2, a soil active manganese content of 20-25 mg / kg, and a soil active aluminum content of 78-85 mg / kg; 150 kg was applied per mu (0.067 hectares), and rice was planted. S1. Base application: When preparing the land, use 70-80% of the total amount of the composition as base fertilizer and till it into the soil layer of 15-20cm by rotary tillage or plowing. S2, Topdressing; Apply the remaining 20-30% of the composition at a depth of 5-8 cm on the side at the time of sowing; After use, tests were conducted on soil aggregate structure, soil pH, crop yield, soil pH after crop harvest, changes in initial phosphorus (P) content, and soil P content before crop harvest. Initial tests were performed first, followed by final tests, and the differences were calculated.

[0069] Table 1. Test results of Examples 1-24.

[0070]

[0071] As shown in Table 1, the soil-enriching composition of the present invention can significantly improve soil structure, enhance soil fertility, stabilize soil pH, reduce soil active aluminum / manganese content, reduce phosphorus fixation, and improve phosphorus utilization, thereby increasing crop yield.

[0072] Examples 1-4 reflect the effect of the amount of functionalized organic carrier added on the effect of the soil fertilization composition. With the increase of the amount of functionalized organic carrier added, the content of water-stable macroaggregates in the soil first increased and then decreased. The alkaline organic materials and carbon-rich skeleton materials in the functionalized organic carrier are rich in lignin and cellulose, providing physical space for the formation of water-stable macroaggregates. Cellulose aerogel particles can bind fine soil particles into microaggregates. Increased addition of functionalized organic carrier leads to an increase in alkaline organic materials, enhancing the improvement effect on acidic soils. The organic functional groups can chelate aluminum ions, decompose slowly, and have the ability to continuously regulate acidity. Crop yield increases accordingly. The functionalized organic carrier can improve the aggregate structure, creating a loose and breathable environment for root development. The functionalized organic carrier can serve as a carbon source and nutrient reservoir, continuously supplying nutrients for the mid-to-late stages of crop growth.

[0073] Examples 1 and 5-7 reflect the effect of the amount of compound inorganic fertilizer added. With increasing amounts of compound inorganic fertilizer, the content of water-stable macroaggregates in the soil first increases and then decreases; the ability to improve soil acidity first increases and then weakens; crop yield increases accordingly; and the initial available phosphorus content in the soil increases with increasing amounts. Compound inorganic fertilizer has a relatively small impact on soil physical structure; excessive inorganic fertilizer can actually lead to soil compaction. Calcium magnesium phosphate fertilizer can neutralize soil acidity and synergistically improve soil acidity with alkaline materials.

[0074] Examples 1 and 8-10 reflect the effect of the amount of soil conditioner added. The porous mineral materials in the soil conditioner have a large specific surface area and pores, which can adsorb small soil particles to form micro-aggregates; the loaded nano-zero-valent iron biochar can improve the physical structure of the soil, provide iron to promote microbial activity and enhance biocementation; the biochar is alkaline and can neutralize soil acidity.

[0075] Examples 11-12 reflect the effects of the amount of biosynergist added, Examples 13-14 reflect the amount of sodium silicate added, Examples 15-16 reflect the amount of polyaspartic acid added, Examples 17-18 reflect the amount of EDTA-chelated calcium added, and Examples 19-20 reflect the effects of the amount of EDTA-chelated magnesium added. The changes in all indicators were gradual, indicating that each component achieved good results within the defined range. From the perspective of overall synergistic effects, the functionalized organic carrier and soil conditioner provide the framework and porosity, promoting the formation of water-stable macroaggregates; alkaline organic materials and sodium silicate cement soil particles and coat microaggregates; polyaspartic acid chelates metal ions to form complexes, further enhancing the water stability of the aggregates; and EDTA-chelated calcium and EDTA-chelated magnesium maintain the stability of the aggregate structure.

[0076] Examples 21-24 reflect the influence of the proportions of functionalized organic carriers and soil conditioners. The test results of the above examples are similar to those of Example 1, indicating that within the defined proportion range, both functionalized organic carriers and soil conditioners can exert good fertilization and improvement effects.

[0077] Table 2. Test results of Example 1 and Comparative Examples 1-7.

[0078]

[0079] Table 2 shows that: (1) Compared with Comparative Examples 1-7 (without single component control), the absence of any key component in Example 1 will lead to a significant decrease in at least one key function. Among them, sodium silicate (Comparative Example 4), functionalized organic carrier (Comparative Example 1) and compound inorganic fertilizer (Comparative Example 2) are the main sources of fixed aluminum. The absence of any one of them will significantly reduce the decrease in active aluminum. After the absence of soil conditioner (Comparative Example 6), the decrease in active manganese in the soil will be significantly reduced. After the absence of compound inorganic fertilizer (Comparative Example 2), the increase in initial available phosphorus content will be significantly reduced, indicating that relying solely on organic carriers cannot meet the crop's demand for phosphorus. After the absence of functionalized organic carrier (Comparative Example 1), the increase in soil water-stable large aggregate content will be significantly reduced, indicating that alkaline organic materials and carbon-rich skeleton materials are the core of aggregate formation. After the absence of polyaspartic acid (Comparative Example 5), all indicators will decrease slightly. After the absence of bio-enhancing agent (Comparative Example 3), crop yield will decrease significantly.

[0080] From the appendix Figure 1-2 It can be seen that, compared with treatments A (quicklime) and B (potassium-silicon soil conditioner), treatment C (the soil enrichment composition of this invention) significantly improved soil acidification, raising the soil pH to 6.55, which was significantly higher than treatment A (5.92) and not significantly different from treatment B (6.37). At the same time, the exchangeable aluminum content in the soil decreased to 2.39 cmol / kg, a decrease of 24.8% relative to treatment A. In terms of replenishing basic ions, treatment C significantly increased the exchangeable calcium (19.7 cmol / kg) and exchangeable magnesium (2.09 cmol / kg) in the soil, increasing by 33.1% and 34.8% respectively relative to treatment A. In terms of soil enrichment, treatment C increased the soil organic matter content to 31.3 g / kg, an increase of 22.7% relative to treatment A (25.5 g / kg) and also higher than treatment B (27.9 g / kg). This indicates that the composition of this invention, containing functionalized organic carriers, bio-enhancing agents, and other enrichment components, can significantly compensate for the deficiencies of quicklime and potassium-silicon soil conditioner in increasing soil organic matter. In summary, treatment C (the fertilization composition of this invention) is significantly superior to existing quicklime and silicon-potassium-containing soil conditioners in many aspects, such as improving soil acidity in acidified vineyards, replenishing basic ions, and increasing soil organic matter, demonstrating the comprehensive advantages of the multi-component synergistic effect of the formulation of this invention.

[0081] From the appendix Figure 3-5 It can be seen that, compared with treatment 1 (CK, conventional fertilization), treatment 2 (quicklime), and treatment 3 (containing humic acid), treatment 4 (the fertilization composition of this invention) improved soil acidification by increasing the soil pH to 5.76 (0.48 units higher than CK) and the soil exchange capacity H₂. + The concentrations of cation exchange capacity (CEC) and exchangeable acid (CA) decreased to 0.18 cmol / kg (a 52.6% reduction relative to the control (CK)). Total exchangeable acid decreased to 0.81 cmol / kg (a 35.2% reduction relative to the CK), and exchangeable aluminum decreased to 0.44 cmol / kg (a 49.4% reduction relative to the CK). The reduction in exchangeable aluminum was significantly better than the 29.9% reduction in treatment 2 (quicklime) and achieved the same effect as the 48.3% reduction in treatment 3 (containing humic acid), indicating that the composition of this invention has a significant effect on acidity regulation and aluminum toxicity mitigation in acidified red and yellow soils. Regarding soil nutrient retention, treatment 4 increased soil CEC to 23.8 cmol / kg, the highest among the four treatments, representing a 36.8% increase relative to the CK, a 28.0% increase relative to treatment 2, and an 11.7% increase relative to treatment 3. Regarding soil nutrient supply, treatment 4 increased available potassium to 190 mg / kg, also the highest among the four treatments, representing a 31.0% increase relative to the CK, while simultaneously increasing soil organic matter (31.5 mg / kg). Both the potassium content (g / kg) and available phosphorus (8.96 mg / kg) were significantly higher than the control (CK), demonstrating that the composition of this invention, containing bio-synergists (phosphate- and potassium-solubilizing bacteria), compound inorganic fertilizers, and functionalized organic carriers, has synergistic advantages in potassium supplementation, improving soil fertility retention capacity, and increasing organic matter. In summary, the fertilization composition of this invention exhibits outstanding performance in multiple aspects, including acidity regulation, aluminum toxicity mitigation, improvement of soil fertility retention capacity, and supply of readily available nutrients in acidified red and yellow soils.

[0082] As can be seen from the above results, the soil improvement composition adapted to acidified farmland of the present invention can solve the problem of disconnect between soil acidification and soil improvement, and effectively stabilize the soil pH within the range suitable for crop planting.

[0083] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

Claims

1. A fertilization composition suitable for acidified arable land, characterized in that, By weight, it includes the following components: 40-60 parts functionalized organic carrier, 25-40 parts compound inorganic fertilizer, 10-20 parts soil conditioner, 1-5 parts bio-enhancing agent, 5-15 parts sodium silicate, 1-2 parts sodium alginate, 2-4 parts polyaspartic acid, 1-4 parts EDTA chelated calcium, and 1-4 parts EDTA chelated magnesium.

2. The fertilization composition adapted for acidified farmland according to claim 1, characterized in that, The functionalized organic carrier is composed of alkaline organic material and carbon-rich skeleton material in a weight ratio of 1-2:1, and the pH value of the functionalized organic carrier is 8.5-9.0; the alkaline organic material is a lignin-amino acid alkaline chelating carrier, and the weight ratio of lignin to amino acids is 1:0.3-0.5; the carbon-rich skeleton material is cellulose aerogel particles, and the cellulose aerogel particles are composed of cellulose and sodium alginate in a weight ratio of 1-2:

1.

3. The fertilization composition adapted for acidified arable land according to claim 1, characterized in that, The compound inorganic fertilizer is composed of urea, resin film urea, activated phosphate rock powder, calcium magnesium phosphate fertilizer, and potassium sulfate in a weight ratio of 1-3:1-2:2-3:2-4:1-2.

4. The fertilization composition adapted for acidified farmland according to claim 1, characterized in that, The soil conditioner is a composite material of porous mineral material and nano-sized zero-valent iron biochar; the porous mineral material is one or both of bentonite and zeolite powder, and the specific surface area of ​​the bentonite is 500-650 m². 2 / g, the specific surface area of ​​the zeolite powder is 500-650 m² / g. 2 / g; the iron content of the supported nano-zero ferrous iron biochar is 5%-20%; the weight ratio of the porous mineral material and the supported nano-zero ferrous iron biochar is 1-2:

1.

5. A soil-fertilizing composition adapted for acidified farmland according to claim 1, characterized in that, The biosynergist is *Pseudomonas fluorescens* (… Pseudomonas fluorescens ) and Rhodococcus rubrum ( Rhodococcus erythropolis The mixed bacterial solution; the viable count of the biosynergist is 1.5 × 10⁻⁶. 8 -3.5×10 8 The volume ratio of CFU / mL to *Pseudomonas fluorescens* to *Rhodococcus rubrum* is 1:1.5-2.5; the sodium silicate has a silica content of 25%-30%, the EDTA-chelated calcium has a calcium content of 10%-13%, and the EDTA-chelated magnesium has a magnesium content of 9%-11%.

6. A method for preparing a soil-fertilizing composition adapted for acidified arable land according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of functionalized organic carriers and supported nano-zero-valent iron biochar; S2. Activated Soil Conditioner: Porous mineral materials and loaded nano-zero ferrous biochar are mixed and placed in ferrous sulfate solution. The pH is adjusted to 7-8 to precipitate the mixture. After drying, the mixture is pulverized to obtain the activated soil conditioner. S3. Mixing: Stir and mix the functionalized organic carrier, compound inorganic fertilizer, activated soil conditioner, bio-enhancing agent, sodium silicate, sodium alginate, polyaspartic acid, EDTA chelated calcium and EDTA chelated magnesium evenly to obtain the fertilizer composition.

7. The preparation method according to claim 6, characterized in that, The preparation of the functionalized organic carrier in S1 includes the following steps: 1) Add lignin to the reaction vessel, add potassium hydroxide to adjust the pH to 10-11, heat to 75-80℃, keep warm and add amino acid solution while stirring, then heat to 80-85℃ and react for 2-3 hours, cool down to 25-30℃ to obtain a paste material. 2) Disperse cellulose and sodium alginate with water by stirring, gradually add calcium chloride solution, let stand for 30-60 min, cool to -20℃ and maintain for 12-24 h, and then freeze dry for 48-72 h under vacuum of 10-20 Pa and cold trap temperature of -50℃ to obtain powder for later use. 3) Place the powder obtained in step 2) in a vacuum impregnation tank, evacuate to -0.08~-0.095 MPa and maintain for 30 min, then add the paste material obtained in step 1), restore normal pressure and maintain for 2-4 h, and dry the loaded particles at 50-60℃ to obtain the functionalized organic carrier.

8. The preparation method according to claim 6, characterized in that, The preparation of the nano-zero-valent iron biochar supported in S1 includes the following steps: 1) Immerse the biochar in a ferric chloride solution and stir for 30 minutes; 2) Add sodium borohydride under nitrogen protection and react for 30-60 min. After the reaction is complete, wash with deoxygenated deionized water 1-2 times and freeze-dry at -25~-35℃ for 12-24 h to obtain the supported nano-zero valent iron biochar.

9. The preparation method according to claim 6, characterized in that, In step S2, the pH is adjusted to 7-8; in step S3, the stirring speed is 50-300 rpm and the stirring time is 15-30 min.

10. A method of applying the fertilization composition adapted for acidified farmland according to any one of claims 1-5, characterized in that, The application method is applicable to the planting of field crops such as rice, corn, and rapeseed, with an application rate of 100-200 kg per mu (approximately 0.067 hectares). The specific steps include: S1. Base application: When preparing the land, apply 70%-80% of the total amount of the above-mentioned fertilizer composition as base fertilizer, and till it into the soil layer of 15-20 cm by rotary tillage or plowing. S2. Topdressing: At the time of sowing, apply the remaining 20%-30% of the fertilizer composition to the side at a depth of 5-8 cm.

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