Method for activating peanut phosphorus and increasing yield by pig bone micro-nano bone charcoal

Abstract

The application relates to the technical field of agricultural fertilizers, and discloses a method for activating peanut phosphorus and increasing yield by pig bone micro-nano bone charcoal, which applies pig bone micro-nano bone charcoal particles made of defatted pig bone source bone charcoal and potassium fulvate dispersion solution. The potassium fulvate on the surface of the particles can construct a negative charge barrier to inhibit the secondary agglomeration of bone charcoal caused by calcium ion bridging. When applied, the above particles are used as base fertilizer, seed coating or combined with fine sand to be applied into selected plots in a positioning hole, the synergistic effect of the potassium fulvate coating layer on the surface of the bone charcoal and the exogenous organic acid is utilized to drive the bone charcoal to occur a heterogeneous acidolysis reaction to activate phosphorus; and water management in the growth period is combined to induce the peanut root system to grow in the bone charcoal fertilization area. The application solves the problems that the bone charcoal is easily agglomerated and passivated in a complex soil environment and internal phosphorus release is slow, improves the absorption and utilization efficiency of phosphorus, and promotes the yield increase of peanuts.

Description

Technical Field

[0001] This invention relates to the field of agricultural fertilizer technology, specifically a method for promoting peanut phosphorus activation and increasing yield using pig bone micro-nano bone char. Background Technology

[0002] Phosphorus is an essential nutrient for peanut growth and development. In traditional agricultural production, soil phosphorus is mainly replenished by applying water-soluble chemical phosphate fertilizers. However, chemical phosphate fertilizers readily react with calcium, iron, aluminum, and other metal ions in the soil after application, forming insoluble salts, resulting in low phosphorus utilization rates during the current season. Long-term excessive application of chemical phosphate fertilizers can also easily lead to non-point source pollution problems such as soil compaction and groundwater eutrophication. To find alternative green phosphate fertilizers, the preparation of bone char from animal bones (such as pig bones) rich in hydroxyapatite through pyrolysis has gradually become a research direction. This method can realize the resource utilization of agricultural solid waste while providing a potential phosphorus source for crops.

[0003] Although conventional bone char offers certain environmental advantages as a phosphate fertilizer, its practical agricultural applications still face significant limitations. The phosphorus within bone char primarily exists in the form of crystalline hydroxyapatite, which has extremely low solubility in conventional soil solutions. Its acidolysis reaction under natural conditions is slow, resulting in a delayed release of available phosphorus, making it difficult to meet the concentrated demand for readily available phosphorus during key growth stages of peanuts, such as jointing and flowering. To improve the phosphorus release rate of bone char, mechanical grinding is commonly used in engineering to refine it to the micro-nano level to increase its specific surface area. However, the surface of micro-nanosized bone char particles exposes a large number of free calcium ions. These calcium ions readily undergo electrostatic bridging in soil solutions with a certain ionic strength, leading to severe secondary aggregation between micro-nano particles. This physical aggregation significantly reduces the effective reaction area of ​​the bone char particles, thus diminishing its activated phosphorus release performance.

[0004] Furthermore, peanut cultivation is geographically widespread, with significant differences in the physicochemical properties of the soils in which they are grown. For example, excessive calcium ions in alkaline calcareous soils easily promote secondary precipitation of phosphate ions; iron and aluminum oxides abundant in acidic red soils strongly and specifically adsorb free phosphorus; while phosphorus-deficient sandy loam has poor fertilizer retention capacity, and phosphorus is easily leached away by irrigation water. Existing bone char phosphate fertilizer application technologies mostly employ a single direct basal application method, lacking both a dispersion and protection mechanism for micro / nano bone char particles and a corresponding release and activation mechanism tailored to the characteristics of different soil microenvironments. Bone char applied to the soil struggles to maintain structural stability in these complex saline environments, and the small amount of phosphate released is easily fixed by the soil matrix. Therefore, developing an application method that overcomes the defects of bone char particle aggregation and passivation, and achieves continuous and efficient activation of phosphorus in complex soil environments, is a pressing technical problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for promoting the activation and yield increase of peanut phosphorus by using pig bone micro-nano bone char. This method solves the problem that existing bone char-based phosphate fertilizers are prone to calcium ion bridging and secondary particle aggregation when applied to complex soil environments, and the release of internal phosphorus is slow, making it difficult to achieve efficient phosphorus activation for different types of soil microenvironments.

[0006] To address the above problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for increasing peanut yield by promoting the activation of phosphorus by using pig bone micro-nano bone char particles, the method comprising the following steps: S1. Site selection and tillage: Select the test site and till or level the land before sowing; S2. Base fertilizer application and sowing: The pig bone micro-nano bone char particles are applied as base fertilizer in strips, as seed coating components on the seed surface, or mixed with fine sand and applied in fixed holes; the potassium humate coating layer on the surface of the bone char and the exogenous organic acid produce a synergistic effect to drive the bone char to produce a heterogeneous acid hydrolysis reaction to activate phosphorus. S3. Field management: Water management is carried out during the peanut's growing season to induce the root system to concentrate its growth in the bone char fertilization area. The pig bone micro / nano bone char particles are prepared from raw materials containing the following mass ratio: 1 part of defatted pig bone char obtained by oxygen-limited pyrolysis, and 3 parts of potassium humate dispersion; the mass fraction of potassium humate in the potassium humate dispersion is 2.0% to 5.0%; in the particles, potassium humate physically coats the surface of the bone char to form a negative charge barrier in the soil solution, thereby inhibiting secondary aggregation of the micro / nano bone char caused by calcium ion bridging.

[0007] By employing the above-mentioned technical solution, the phosphorus source is provided by micro- and nano-sized defatted pig bone char, combined with surface physical coating of potassium humate, overcoming the problems of agglomeration and passivation of bone char particles in complex soil environments. Specifically, the mechanism of this method is reflected in the dispersion and synergistic acidolysis process in the microenvironment: because the molecular structure of potassium humate contains a large number of carboxyl and phenolic hydroxyl groups, after it is coated on the surface of bone char particles, it can promote the micro- and nano-particles to carry a negative charge, thereby constructing a dual barrier of steric hindrance and electrostatic repulsion between adjacent particles, thus maintaining the dispersed state of bone char in such calcium-containing soil solutions and avoiding spatial agglomeration.

[0008] While maintaining a dispersed system, after bone char is applied to the soil, its hydroxyapatite components undergo acid hydrolysis in the soil solution. The specific reaction formula is as follows: Ca 10 (PO4)6(OH)2+14H + →10Ca2+ +6H2PO4 - +2H2O; In this reaction system, exogenous organic acids provide protons to promote the above-mentioned acidolysis reaction; at the same time, the fulvic acid macromolecules on the surface of bone char undergo a chelation reaction with the calcium ions generated in the reaction through their multi-coordination groups to form calcium fulvic acid complexes, thereby continuously consuming the calcium ion products in the reaction system, disrupting the original dissolution equilibrium, and promoting the acidolysis reaction to proceed to the right, so as to realize the gradual activation and release of deposited phosphate ions.

[0009] Furthermore, the combination of water management during the growing season and the formation of localized high-concentration, readily available phosphorus distribution zones can promote chemotaxis and growth, guiding peanut roots to extend directionally towards the bone char fertilization zone, shortening the migration distance of phosphorus from the soil solution to the root surface, and improving the efficiency of phosphorus absorption and utilization by the roots.

[0010] Preferably, in S1, the selected test site is phosphorus-deficient sandy loam with an effective phosphorus content of 10-15 mg / kg; in S2, micro-nano bone char particles with a median particle size D50 of 850 nm are selected as phosphate fertilizer supplements, and are mixed evenly with 200 kg / mu of well-rotted organic fertilizer at a dosage of 30 kg / mu, and applied in strips 12 cm below the center of the ridge in the sowing field, so that the potassium humate layer on the surface of the bone char and the organic acids in the organic fertilizer produce a synergistic activation effect.

[0011] By adopting the above technical solution, and considering the poor fertilizer retention capacity of phosphorus-deficient sandy loam, 850nm bone char granules with a relatively large particle size are applied below the center of the ridge, which helps to slow down the rate of phosphorus leaching away with water. Under the action of soil microorganisms, the decomposed organic fertilizer gradually degrades to produce humic acid and low-molecular-weight organic acids. These acids, together with the fulvic acid molecules on the surface of the bone char, form a synergistic effect of large and small molecular-weight organic acids, thereby maintaining a stable phosphorus supply capacity after a single fertilization.

[0012] Preferably, in step S1, the selected test site is a slightly alkaline calcareous soil with a pH value of 7.5–8.2; in step S2, micro / nano bone char particles with a median particle size D50 of 420 nm are selected and mixed with a starch-based film-forming agent at a ratio of 1:5, and peanut seeds are coated with 1.5% of the seed weight, and 20 kg / mu of the bone char particles are simultaneously applied in the sowing furrow; in step S3, during the branching stage of peanuts, a 5% fulvic acid solution is applied with drip irrigation to maintain the solubility of the micro / nano calcium phosphate components in the alkaline soil through its chelating effect.

[0013] By employing the above technical solution, this method addresses the problem of alkaline calcareous soils easily leading to the binding and fixation of free phosphate ions into insoluble calcium phosphate. It combines seed coating with targeted application. The medium particle size of 420nm balances the material's specific surface area and retention capacity. Seed coating allows phosphorus to adhere directly to the seed, meeting the peanut seedlings' need for readily available phosphorus. Subsequent application of humic acid solution during the branching stage replenishes free chelating sites in the soil solution, captures excess calcium ions, and prevents secondary precipitation and passivation of free phosphate ions.

[0014] Preferably, in S1, the selected test site is an acidic red soil plot. Before sowing, quicklime is applied per acre during land preparation to adjust the local rhizosphere microenvironment pH to around 6.0. In S2, micro-nano bone char particles with a median particle size D50 of 150nm are selected and diluted with fine sand at a ratio of 1:10 at a dosage of 15kg / acre. During sowing, the particles are precisely applied 3cm below the seeds, and phosphate-solubilizing bacteria powder is simultaneously inoculated into the sowing holes. In S2, the phosphate-solubilizing bacteria is Bacillus megaterium, and the inoculation amount is 10g / hole. By inoculating with Bacillus megaterium, the low-molecular-weight organic acids secreted by it react with the high specific surface area of ​​the 150nm micro-nano bone char to activate the deposited phosphorus.

[0015] By employing the above-mentioned technical solution, and considering the material characteristics of iron and aluminum oxides in acidic red soil that readily fix phosphorus, the soil pH is adjusted to slightly acidic by pre-applying quicklime, eliminating aluminum toxicity and improving the living environment for beneficial microorganisms. 150nm bone char particles with the largest specific surface area are selected and applied in conjunction with Bacillus megaterium. After colonization by Bacillus megaterium, it secretes low-molecular-weight organic acids such as oxalic acid and citric acid, which directly erode the lattice surface of the high specific surface area nano-bone char, releasing phosphate ions. Simultaneously, these free low-molecular-weight organic acids competitively occupy the adsorption sites of iron and aluminum oxides in the soil, reducing the non-biological fixation of phosphorus.

[0016] Secondly, the present invention provides porcine bone micro / nano char particles applied to the method described in the first aspect, employing the following technical solution: A type of pig bone micro / nano bone char particles, wherein the median particle size D50 of the solid particles is 150 nm to 850 nm, and the zeta potential of the particles dispersed in an aqueous dispersion is maintained between -29.5 mV and -35.8 mV.

[0017] By employing the above technical solution, the structure and physicochemical properties of the fertilizer granules were defined. The median particle size (D50) of the solid granules was controlled within the range of 150 nm to 850 nm. Compared to conventional micron-sized bone char, its specific surface area was effectively expanded, exposing more surface hydroxyapatite reaction sites to the solution system and enhancing the reactivity of the bone char itself. Simultaneously, the zeta potential of the granule surface was controlled within the range of -29.5 mV to -35.8 mV, indicating the accumulation of a relatively high density of the same negative charge on the granule surface. The electrostatic repulsion generated within this potential range overcomes the van der Waals forces between particles, maintaining the suspension and dispersion stability of the bone char granules in complex salt-phase solution systems and preventing particle aggregation and sedimentation.

[0018] Preferably, in the defatted pig bone char used to prepare the pig bone micro / nano bone char particles, the main inorganic phase component is hydroxyapatite, which has a full width at half maximum (FWHM) Δ2θ of 1.25° to 1.45° at 2θ = 25.9° in X-ray diffraction testing.

[0019] By employing the above technical solution, the full width at half maximum (FWHM) values ​​of Δ2θ ranging from 1.25° to 1.45° indicate that the hydroxyapatite in the bone char is in a low-crystallinity and incomplete lattice state. Compared with highly crystalline bone char, low-crystallinity hydroxyapatite has a lower lattice energy, and its crystal structure contains more point defects and disordered arrangement, making it easier for external hydrogen ions to penetrate into the lattice and trigger framework dissociation. This reduces the activation energy required for dissolution and increases the phosphorus release rate.

[0020] Thirdly, the present invention provides a method for preparing pig bone micro / nano char particles as described in the second aspect, employing the following technical solution: A method for preparing micro / nano bone char particles from pig bone includes the following steps: S11. Material pretreatment: Take defatted pork bone fragments, crush and sieve them for later use; S12, oxygen-limited pyrolysis: The bone blocks obtained in S11 are placed in a carbonization furnace. Under the conditions of passing high-purity nitrogen and exhausting the air so that the oxygen content is ≤0.5 vol%, the temperature is increased in stages to carry out dehydration and isothermal pyrolysis. After cooling to room temperature, the degreased pig bone char is obtained. S13. Preparation of dispersion: Add potassium humate to deionized water and stir to dissolve, prepare a potassium humate dispersion with a mass fraction of 2.0% to 5.0%, and adjust the pH of the system to 7.0 to 8.0 using alkaline solution. S14. Micro-nano grinding: The bone char obtained in S12 and the dispersion obtained in S13 are mixed at a mass ratio of 1:3, and grinding media are added for cyclic grinding micro-nano treatment. The suspension is then collected. S15. Low-temperature spray granulation: The suspension obtained in S14 is fed into a fluidized bed spray granulator for drying and granulation to obtain the pig bone micro-nano bone char particles.

[0021] By employing the above-mentioned technical solution, the porous carbon framework and low-crystallinity hydroxyapatite components within the bone are preserved through oxygen-limited pyrolysis, reducing interference from organic impurities. During the preparation process, potassium humate solution is used as a liquid-phase grinding medium to directly participate in micro-nano grinding. Mechanical grinding promotes the continuous breakage of bone char particles and the generation of new surfaces, allowing potassium humate molecules to be physically adsorbed in situ onto these new surfaces, achieving simultaneous particle crushing and coating. Finally, low-temperature spray granulation is used to convert the liquid suspension into dry, uniform particles, facilitating subsequent agricultural transportation and mechanized application.

[0022] Preferably, in S12, the specific parameters for the stepped heating are as follows: first, the temperature is raised to 150°C at a rate of 5-8°C / min and held at this temperature for 30 min for dehydration; then, the temperature is raised to 420-480°C at a rate of 4-6°C / min and held at this temperature for pyrolysis for 2.0-3.0 h to preserve the internal hydroxyapatite lattice in a low crystallinity state.

[0023] By employing the above technical solution, the initial heating rate of 5 to 8℃ / min combined with isothermal dehydration treatment can remove free and bound water from the aggregate relatively gently, avoiding the collapse of the microporous framework caused by rapid vaporization of internal moisture due to excessively rapid heating. Meanwhile, the pyrolysis temperature range of 420 to 480℃ effectively decomposes and removes organic components such as collagen, solidifying them into a stable porous carbon structure. This also avoids the growth and increased crystallinity of hydroxyapatite crystals caused by high-temperature calcination, thus better preserving the biological activity of the original phosphorus.

[0024] Preferably, in S14, the grinding medium is zirconia beads with a particle size of 0.3-0.5 mm, the mass ratio of grinding medium to material is set to 15:1, and the grinding is carried out in a cycle at a speed of 300-500 rpm for 4.0-6.0 h, and the grinding chamber temperature is controlled to be ≤35℃; in S15, the inlet air temperature of the fluidized bed spray granulator is controlled to be 105-120℃, the outlet air temperature is controlled to be 65-80℃, the bed temperature is maintained at 70-80℃, and the spray pressure is 0.2-0.4 MPa.

[0025] By employing the above technical solution, using 0.3 to 0.5 mm zirconia microspheres with a set filling ratio and operating speed, sufficient shearing and extrusion are applied to the material to break down bone char into target micro-nano particle sizes. The circulating temperature of the grinding chamber is controlled to not exceed 35°C to prevent localized mechanical overheating that could lead to deactivation of the potassium humate structure or changes in the bone char lattice. During the granulation stage, an inlet air temperature of 105 to 120°C, combined with a relatively low bed temperature, allows for rapid flash evaporation to remove moisture within the fluidized bed. This avoids prolonged high-temperature heating that could cause thermal degradation of the potassium humate coating, ensuring the final particles have good water dispersibility and surface charge stability.

[0026] This invention provides a method for promoting peanut phosphorus activation and increasing yield using pig bone micro / nano bone char. It has the following beneficial effects: 1. This invention improves the dispersion stability of bone char particles in soil solution by physically coating the surface of micro / nano pig bone char with potassium humate. Potassium humate molecules construct a negative charge barrier on the bone char surface, and the electrostatic repulsion and steric hindrance they provide effectively inhibit secondary aggregation of bone char particles caused by calcium ion bridging, maintaining the effective specific surface area of ​​micro / nano bone char in complex saline soils and providing basic reaction sites for phosphorus release.

[0027] 2. This invention utilizes the synergistic effect of the potassium humate coating on the surface of bone char and exogenous organic acids to achieve continuous activation of deposited phosphorus. The oxygen-limited pyrolysis process retains the low-crystallinity hydroxyapatite inside the bone char. After application, exogenous organic acids provide protons to promote acidolysis. At the same time, the fulvic acid molecules on the surface continuously chelate calcium ions generated by the reaction through multi-coordination groups, breaking the original dissolution equilibrium of the system and driving the acidolysis reaction to continue towards the generation of phosphate ions, thus improving the defect of slow phosphorus release in conventional bone char phosphate fertilizers.

[0028] 3. This invention sets differentiated bone char particle size and application methods for different types of soil microenvironments, expanding the practical engineering applicability of the method. By adjusting the median particle size of bone char to between 150nm and 850nm, and combining it with specific application methods such as basal fertilizer strip application, seed coating, or targeted hole application, it addresses the technical challenges of easy phosphorus leaching and loss in sandy loam, easy secondary precipitation in alkaline calcareous soil, and easy phosphorus fixation by iron and aluminum oxides in acidic red soil. This reduces the non-biological fixation loss of phosphorus and improves the absorption and utilization rate of available phosphorus by peanut roots. Attached Figure Description

[0029] Figure 1 This is a comparison diagram of the macroscopic growth phenotype and final yield of peanuts in Example 1 and Comparative Example 1 of the present invention; Among them, A is a comparison of the growth of potted plants; B is a comparison of the above-ground parts and root morphology of a single plant; C is a comparison of the pods and shelled kernels at harvest; D is a comparison of the plant height of the two groups of plants; E is a comparison of the root length; F is a comparison of the above-ground fresh weight; G is a comparison of the root fresh weight; H is a comparison of the yield per plant; and I is a bar chart comparing the measured data of the 100-seed weight index. Figure 2 This is a comparison chart of Example 1 and Comparative Example 1 in terms of the physicochemical properties of peanut rhizosphere soil, phosphorus occurrence forms, and key soil enzyme activity indicators. In this diagram, A shows a comparison of available phosphorus in the two matrices; B shows a comparison of cation exchange capacity in the two matrices; C shows a comparison of the distribution of phosphorus content extracted by calcium chloride; D shows a comparison of phosphorus content extracted by citric acid; E shows a comparison of phosphorus content extracted by enzymes; F shows a comparison of phosphorus content extracted by hydrochloric acid; and G, I, J, and K show a comparison of the results of urease, sucrase, acid phosphatase, and catalase activities in the two rhizosphere soils, respectively. Figure 3 This is a bar chart comparing the endogenous hormone levels in peanut plant leaves and root tissues of the embodiments and comparative examples of the present invention. Among them, A is a comparison chart of the distribution and differences of abscisic acid measurement data between the two groups of plants; B is a comparison chart of the distribution and differences of auxin measurement data; C is a comparison chart of the distribution and differences of gibberellin measurement data; D is a comparison chart of the distribution and differences of zeatin nucleoside measurement data; E is a comparison chart of the distribution and differences of gibberellin measurement data; F is a comparison chart of the distribution and differences of isopentenyl adenosine measurement data; G is a comparison chart of the distribution and differences of dihydrozeatin nucleoside measurement data; H is a comparison chart of the distribution and differences of methyl jasmonic acid measurement data; and I is a comparison chart of the distribution and differences of brassinolide content measurement data. Figure 4 This is a comparison diagram of the chlorophyll fluorescence parameters and photosynthetic gas exchange parameters of peanut functional leaves in the embodiments and comparative examples of the present invention. In the figures, A is a comparison of the results of the maximum photochemical efficiency measurement of the leaves of the two groups of plants; B is a comparison of the results of the actual photochemical efficiency measurement; C is a comparison of the distribution of non-photochemical quenching measurement data; D is a comparison of the distribution of fluorescence attenuation rate measurement data; E is a comparison of the results of the net photosynthetic rate measurement of the two groups of plants; F is a comparison of the results of the transpiration rate measurement; G is a comparison of the results of the intercellular carbon dioxide concentration measurement; and H is a comparison of the results of the stomatal conductance measurement. Figure 5 This is a flowchart of the method of the present invention. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. The main raw materials and reagents used in the following embodiments and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher products.

[0031] Pig bones, derived from animal byproducts, are primarily composed of hydroxyapatite, with the molecular formula Ca. 10(PO4)6(OH)2, CAS No. 1306-06-5, before use, it is washed with high pressure water to remove residual meat and free oil on the surface and dried with forced air at 80℃ to 105℃ to constant weight.

[0032] Agricultural loam, taken from topsoil textured soil, has a background pH of 6.0 to 7.5. Its mechanical composition is limited to 15% to 30% by mass of clay particles with a particle size of less than 0.002 mm and 30% to 50% by mass of silt particles with a particle size of 0.002 mm to 0.05 mm, with the balance being sand particles with a particle size of greater than 0.05 mm.

[0033] Siliceous sand, inorganic siliceous mineral particles, with silicon dioxide as the main chemical component, molecular formula SiO2, CAS number 14808-60-7, its silicon dioxide mass fraction is greater than or equal to 90%, and the particle size ranges from 0.2 mm to 2.0 mm.

[0034] Preparation Example 1: This preparation example provides a method for preparing porcine bone-derived micro / nano bone char, including the following steps: (1) The pork bones were washed with 10MPa high pressure water to remove surface grease and residual meat, and then dried in a forced-air drying oven at 100℃ for 24 hours until constant weight. The bones were crushed and sieved using a jaw crusher to collect coarse bone pieces with a particle size of 2mm to 5mm. (2) The coarse bone blocks were loaded into a tubular pyrolysis furnace, and high-purity nitrogen gas with a flow rate of 200 mL / min was introduced to purge and remove free oxygen. Under the condition of continuous introduction of high-purity nitrogen gas, the temperature was increased to 450°C at a heating rate of 10°C / min, and the temperature was kept constant for 2 hours. The heating source was cut off, and the mixture was naturally cooled to room temperature under nitrogen protection to collect primary bone char. (3) Transfer the primary bone char to a planetary high-energy ball mill, add zirconium oxide grinding balls, control the mass ratio of grinding balls to primary bone char to be 5:1, set the spindle speed to 450 r / min, and the total grinding time to 4 h. During operation, execute the intermittent reverse program, that is, automatically stop the machine for 5 min of heat dissipation every 30 min of continuous operation and reverse the rotor rotation direction each time it is restarted. After grinding, discharge the material to obtain micro-nano bone char.

[0035] Preparation Example 2: This preparation example provides a method for preparing porcine bone-derived micro / nano bone char, including the following steps: (1) The pork bones were washed with 5MPa high pressure water to remove surface grease and residual meat, and then dried in a forced-air drying oven at 80℃ for 12 hours until constant weight. The bones were crushed and sieved using a jaw crusher to collect coarse bone pieces with a particle size of 2mm to 5mm. (2) The coarse bone blocks were loaded into a tubular pyrolysis furnace, and high-purity nitrogen gas with a flow rate of 100 mL / min was introduced to purge and remove free oxygen. Under the condition of continuous introduction of high-purity nitrogen gas, the temperature was increased to 400℃ at a heating rate of 5℃ / min, and the temperature was kept constant for 1.5 h. The heating source was cut off, and the mixture was naturally cooled to room temperature under nitrogen protection to collect the primary bone char. (3) Transfer the primary bone char to a planetary high-energy ball mill, add zirconium oxide grinding balls, control the mass ratio of grinding balls to primary bone char to be 3:1, set the spindle speed to 300 r / min, and the total grinding time to 2 h. During the operation, execute the intermittent reverse program, that is, automatically stop the machine for 3 min of heat dissipation every 20 min of continuous operation and reverse the rotor rotation direction each time it is restarted. After the grinding is completed, discharge the material to obtain micro-nano bone char.

[0036] Preparation Example 3: This preparation example provides a method for preparing porcine bone-derived micro / nano bone char, including the following steps: (1) The pork bones were washed with 15MPa high pressure water to remove surface grease and residual meat, and then dried in a forced-air drying oven at 105℃ for 24 hours until constant weight. The bones were crushed and sieved using a jaw crusher to collect coarse bone pieces with a particle size of 2mm to 5mm. (2) The coarse bone blocks were loaded into a tubular pyrolysis furnace, and high-purity nitrogen gas with a flow rate of 300 mL / min was introduced to purge and remove free oxygen. Under the condition of continuous introduction of high-purity nitrogen gas, the temperature was increased to 550℃ at a heating rate of 15℃ / min and kept at a constant temperature for 3 hours. The heating source was cut off and the mixture was naturally cooled to room temperature under nitrogen protection to collect primary bone char. (3) Transfer the primary bone char to a planetary high-energy ball mill, add zirconium oxide grinding balls, control the mass ratio of grinding balls to primary bone char to be 8:1, set the spindle speed to 500 r / min, and the total grinding time to 6 h. During the operation, execute the intermittent reverse program, that is, automatically stop the machine for 8 min of heat dissipation every 40 min of continuous operation and reverse the rotor rotation direction each time it is restarted. After the grinding is completed, discharge the material to obtain micro-nano bone char.

[0037] Preparation Example 4: This preparation example provides a method for preparing porcine bone-derived micro / nano bone char, including the following steps: (1) The pork bones were washed with 12MPa high pressure water to remove surface grease and residual meat, and then dried in a forced-air drying oven at 90℃ for 18h until constant weight. The bones were crushed and sieved using a jaw crusher to collect coarse bone pieces with a particle size of 2mm to 5mm. (2) The coarse bone blocks were loaded into a tubular pyrolysis furnace, and high-purity nitrogen gas with a flow rate of 250 mL / min was introduced to purge and remove free oxygen. Under the condition of continuous introduction of high-purity nitrogen gas, the temperature was increased to 500℃ at a heating rate of 12℃ / min and kept at a constant temperature for 2.5 h. The heating source was then cut off, and the mixture was naturally cooled to room temperature under nitrogen protection to collect primary bone char. (3) Transfer the primary bone char to a planetary high-energy ball mill, add zirconium oxide grinding balls, control the mass ratio of grinding balls to primary bone char to be 6:1, set the spindle speed to 400 r / min, and the total grinding time to 5 h. During operation, execute the intermittent reverse program, that is, automatically stop the machine for 6 min of heat dissipation every 35 min of continuous operation and reverse the rotor rotation direction each time it is restarted. After grinding, discharge the material to obtain micro-nano bone char.

[0038] Example 1: This embodiment provides a method for promoting peanut phosphorus activation and increasing yield using pig bone micro / nano bone char, including the following steps: (1) Take agricultural loam and siliceous sand, put them into the mixing equipment at a mass ratio of 2:1 and dry mix them thoroughly to construct a heterogeneous soil matrix with a multi-level pore network reconstruction; (2) Take the micro-nano bone char obtained in Preparation Example 1 and mix it evenly into the heterogeneous soil matrix according to the total mass of the heterogeneous soil matrix obtained in step (1) at an addition dose of 5.0 g / kg to obtain the accelerated release soil. (3) The soil obtained in step (2) is laid in the cultivation container or field furrow, conventional peanut seeds are sown, conventional agricultural water supply management and natural light cultivation are carried out throughout the entire growth period, and no exogenous chemical phosphate fertilizer is applied throughout the entire growth period.

[0039] Example 2: This embodiment provides a method for promoting peanut phosphorus activation and increasing yield using pig bone micro / nano bone char, including the following steps: (1) Take agricultural loam and siliceous sand, put them into the mixing equipment in a mass ratio of 1:1 and dry mix them thoroughly to construct a heterogeneous soil matrix with a multi-level pore network reconstruction; (2) Take the micro-nano bone char obtained in Preparation Example 2 and mix it evenly into the heterogeneous soil matrix according to the total mass of the heterogeneous soil matrix obtained in step (1) at an addition dose of 2.5 g / kg to obtain the accelerated release soil. (3) The soil obtained in step (2) is laid in the cultivation container or field furrow, conventional peanut seeds are sown, conventional agricultural water supply management and natural light cultivation are carried out throughout the entire growth period, and no exogenous chemical phosphate fertilizer is applied throughout the entire growth period.

[0040] Example 3: This embodiment provides a method for promoting peanut phosphorus activation and increasing yield using pig bone micro / nano bone char, including the following steps: (1) Take agricultural loam and siliceous sand, put them into the mixing equipment at a mass ratio of 4:1 and dry mix them thoroughly to construct a heterogeneous soil matrix with a multi-level pore network reconstruction; (2) Take the micro-nano bone char obtained in Preparation Example 3 and mix it evenly into the heterogeneous soil matrix at an addition dose of 10.0 g / kg (based on the total mass of the heterogeneous soil matrix obtained in step (1)) to obtain the accelerated release soil. (3) The soil obtained in step (2) is laid in the cultivation container or field furrow, conventional peanut seeds are sown, conventional agricultural water supply management and natural light cultivation are carried out throughout the entire growth period, and no exogenous chemical phosphate fertilizer is applied throughout the entire growth period.

[0041] Example 4: This embodiment provides a method for promoting peanut phosphorus activation and increasing yield using pig bone micro / nano bone char, including the following steps: (1) Take agricultural loam and siliceous sand, put them into the mixing equipment in a mass ratio of 3:1 and dry mix them thoroughly to construct a heterogeneous soil matrix with a multi-level pore network reconstruction; (2) Take the micro-nano bone char obtained in Preparation Example 4 and mix it evenly into the heterogeneous soil matrix at an addition dose of 7.5 g / kg (based on the total mass of the heterogeneous soil matrix obtained in step (1)) to obtain the accelerated release soil. (3) The soil obtained in step (2) is laid in the cultivation container or field furrow, conventional peanut seeds are sown, conventional agricultural water supply management and natural light cultivation are carried out throughout the entire growth period, and no exogenous chemical phosphate fertilizer is applied throughout the entire growth period.

[0042] Comparative Example 1: Compared with Example 1, the difference is that no bone char was added in step (2), and the heterogeneous soil matrix obtained in step (1) was directly used as the treatment soil, while the rest were the same.

[0043] Comparative Example 2: Compared with Example 1, the difference is that in step (2) of Preparation Example 1, the target pyrolysis temperature is set to 800°C (i.e., conventional high-temperature pyrolysis is carried out to achieve complete carbonization), while the rest are the same.

[0044] Comparative Example 3: Compared with Example 1, the difference is that the preparation of Example 1 does not include the high-energy shear mechanical chemical activation process of step (3) (i.e., only the primary bone char obtained in step (2) is used), and all other aspects are the same.

[0045] Comparative Example 4: Compared with Example 1, the difference is that in step (1), only pure agricultural soil is used as the matrix, and no siliceous sand is added for multi-level pore network reconstruction. All other aspects are the same.

[0046] Comparative Example 5: Compared with Example 1, the difference is that micro-nano bone char is not added in step (2), but commercially available superphosphate fertilizer is added according to the equivalent phosphorus equivalent ratio, and the rest are the same.

[0047] Test Example 1: This test case primarily evaluates the effects of micro / nano bone char prepared under different parameters and different substrate ratios on the phosphorus speciation kinetics and key biochemical enzyme activities in peanut rhizosphere soil. The experimental subjects were the peanut rhizosphere soil substrates cultivated to the pod-setting stage in Examples 1 to 4 and Comparative Examples 1 to 5. The specific experimental steps are as follows: 1. Select peanut plants in the pod-setting stage, carefully dig them out of the cultivation container or furrow, gently shake off the large clumps of non-rhizosphere soil around the roots, and then use a sterile soft brush to brush off the soil tightly attached to the root surface and collect it as a rhizosphere soil sample.

[0048] 2. Place the collected rhizosphere soil samples in a cool, ventilated place to air dry naturally, remove any visible plant and animal remains and impurities such as sand and gravel, grind them using an agate mortar and pestle and pass them through a 2mm nylon sieve for later use. Some samples need to be further ground and passed through a 0.149mm sieve for total element analysis.

[0049] 3. The cation exchange capacity of each group of samples was determined by the hexaamminecobalt trichloride leaching method. A quantitative amount of sieved soil sample was weighed and placed in a centrifuge tube. The leaching agent was added, the sample was shaken, and the supernatant was collected by centrifugation. The absorbance of the system was measured by colorimetry using a spectrophotometer and the cation exchange capacity was calculated.

[0050] 4. Quantitative extraction and determination of phosphorus speciation at various levels in soil were performed using the Hedley phosphate fractionation method. Water-soluble available phosphorus was extracted sequentially using calcium chloride solution, activated phosphorus using citrate solution, and insoluble occult phosphorus using hydrochloric acid solution. After centrifugation and filtration, the phosphorus concentration in the solutions was determined at specific wavelengths using the molybdenum-antimony colorimetric method.

[0051] 5. Standard soil biochemistry kits were used to determine the activities of key enzymes. Acid phosphatase activity was determined using the disodium phenyl phosphate colorimetric method, and urease activity was determined using the sodium phenolate-sodium hypochlorite colorimetric method.

[0052] Table 1. Results of rhizosphere soil physicochemical properties, phosphorus speciation, and enzyme activity determination in the examples and comparative examples: According to Table 1 and Appendix Figure 1 Data shows that the application of micro / nano bone char significantly interferes with the physicochemical balance of the rhizosphere microenvironment. This intervention is not only reflected in the direct replenishment of basic nutrients, but also in its reshaping of the thermodynamic state of the original solid phase system of the soil. Observing the difference in cation exchange capacity between Example 1 and the blank control example 1, it can be found that the cation exchange capacity of Example 1 reached 27.84 cmol / kg, indicating that the oxygen-containing functional groups retained on the surface of bone char under pyrolysis conditions of 450℃ do indeed provide a high density of negative charge sites at the soil-water interface. In conventional farmland soils, there is a common phenomenon of phosphate being adsorbed and precipitated by free calcium ions and iron and aluminum oxides, while bone char with high cation exchange capacity can competitively adsorb cations such as calcium in the micro-region. This essentially breaks the original closed-state phosphorus dissolution and precipitation balance.

[0053] Further analysis of the graded extraction results of phosphorus speciation revealed that in Comparative Example 5, a conventional fast-acting superphosphate fertilizer was applied, maintaining a water-soluble available phosphorus level of 10.45 mg / kg, but a hydrochloric acid-extractable phosphorus level as high as 310.27 mg / kg. Conventional fertilizers are prone to rapid secondary aging and solidification after being applied to the soil, leading to a significant amount of available phosphorus being converted into an insoluble form that is difficult for plants to utilize. In contrast, in Example 1, the hydrochloric acid-extractable phosphorus level decreased to 172.63 mg / kg, while the calcium chloride-extractable phosphorus and citric acid-extractable phosphorus levels jumped to 18.62 mg / kg and 43.51 mg / kg, respectively. This data differentiation confirms that mechanochemically induced lattice distortion lowers the desorption activation energy, allowing the insoluble substrate to be reverse-converted into the active component. Conversely, in Comparative Example 2, due to the use of 800℃ high-temperature pyrolysis, the hydroxyapatite crystals were fully developed and surface functional groups were lost, resulting in phosphorus speciation indicators almost approaching those of the blank control, completely losing its ability to target and regulate soil phosphorus transformation. Comparative Example 3, which was not subjected to high-energy shear ball milling, also had a limited release effect due to severe soft agglomeration of particles and a lack of amorphous active sites.

[0054] With changes in the physicochemical microenvironment, rhizosphere biochemical metabolism also exhibits corresponding response patterns. Although Comparative Example 4, with its pure loam matrix, added the same bone char as Example 1, its acid phosphatase activity was only 2.56 U / g, far lower than the 4.67 U / g of Example 1. The high viscosity and low porosity of agricultural loam increased the resistance to mass transfer, limiting the penetration of enzyme molecules and substrate binding. The 2:1 loam-siliceous sand ratio in Example 1 reconstructed a multi-level interconnected macroporous network, eliminating the spatial steric hindrance of mass transfer diffusion. This reconstruction of the heterogeneous flow field allows soil microorganisms and root-secreted enzyme proteins to be fully enriched at the defect sites of the bone char, catalyzing enzymatic desorption reactions. Overall, the synergistic effect of solid-phase phase transition cutoff and flow field reconstruction constitutes the physicochemical basis for the continuous stimulation of endogenous phosphorus activity in the soil using this technical solution.

[0055] Test Example 2: This test case was used to determine the intervention effect of specific solid-phase interface reactions on the macroscopic morphological development and internal physiological communication network of plants. The experimental subjects were live peanut plants cultivated to the pegging stage and pod-forming stage in Examples 1 to 4 and Comparative Examples 1 to 5, including their complete underground root network and aboveground functional leaves.

[0056] 1. Take whole samples of the target peanut plants in the field or in the cultivation container. During the operation, dig out the soil around the roots and immerse them in a low-frequency ultrasonic cleaning tank filled with deionized water. Use the ultrasonic cavitation effect to gradually peel off the attached soil, ensuring that the lateral roots and fibrous root system at all levels do not break physically.

[0057] 2. Lay the clean roots flat in a root scanner with a transparent developing tray, add an appropriate amount of water to allow the fine roots to float and spread naturally, start the device to acquire a high-resolution root topology image, and import it into root image analysis software to extract the physical parameters of total root length and root surface area.

[0058] 3. After morphological data collection is completed, the base of the main root is quickly cut off using dissecting scissors pre-cooled with liquid nitrogen to separate the root system from the above-ground parts. Select the root meristem tissue and the third-to-last fully expanded functional leaf from the above-ground part, wrap them in sterile aluminum foil and then freeze them in liquid nitrogen.

[0059] 4. Weigh the frozen plant tissue sample and place it in a pre-cooled mortar. Add the methanol-water extract containing antioxidants and grind it in an ice bath. Centrifuge the homogenate in a low-temperature refrigerated centrifuge and take the supernatant. Let the solution flow through an activated solid-phase extraction column for enrichment and impurity elution. Collect the eluent containing the target hormone and concentrate it to near dryness using a nitrogen blower. After reconstitution, filter it through a microporous membrane.

[0060] 5. The samples were analyzed using a high-performance liquid chromatography-mass spectrometry system in multiple reaction monitoring mode. Specific ion pairs and collision energies were set, and the concentrations of auxin and cytokinin in root tissues, as well as the concentrations of methyl jasmonate and abscisic acid in leaf tissues, were quantitatively determined by isotope internal standard method.

[0061] Table 2. Results of peanut root phenotypic parameters and endogenous hormone concentration measurements in each treatment group: According to Table 2 and Appendix Figure 2The data showed that the physiological metabolism of peanut plants under different substrate microenvironments exhibited a clear network reconstruction trajectory. Conventional phosphorus-deficient or severely phosphorus-fixed soils often force plants to initiate defensive stress metabolism. In Comparative Examples 1 and 2, the concentrations of methyl jasmonate and abscisic acid in the leaves were high, a typical physiological feedback mechanism where plants inhibit vegetative growth after sensing nutrient deficiency signals. In Example 1, a stable supply of available phosphorus in the rhizosphere altered this state, resulting in a significant decrease in the level of defensive hormones in the leaves, and a shift in the plant's carbon and nitrogen metabolism center from stress resistance consumption to vegetative growth.

[0062] This shift in metabolic pathways is particularly evident in the synthesis of growth-promoting hormones. Test results showed that in Example 1, the concentrations of auxin and cytokinin in the roots increased to 87.52 ng / g and 31.64 ng / g, respectively, significantly exceeding those of Comparative Example 5, which only applied conventional fertilizer. Previous field monitoring has frequently observed that while fast-acting water-soluble phosphate fertilizers can temporarily relieve phosphorus deficiency stress in the initial stages of soil application, the rapid capture of free cations in the soil during subsequent developmental cycles leads to a renewed micro-nutrient supply shortage in the plant roots. The limited upregulation of hormones in Comparative Example 5 aligns with this phenomenon; the discontinuous spatiotemporal distribution of exogenous chemical fertilizers in the rhizosphere limits the sustained expression of growth-promoting signals. Micro- and nano-bone char treated with low-temperature phase transition and high-frequency mechanical shearing, leveraging the mass transfer advantages of heterogeneous reconstructed flow fields, maintains a constant phosphorus supply environment with low desorption activation energy on the plant root surface.

[0063] Deep-seated physiological and chemical signals ultimately project onto the expansion of physical morphology. High abundances of auxin and cytokinin synergistically drive the proliferation and elongation of cells in the root meristematic zone; in Example 1, the measured total root length and root surface area expanded to 491.27 cm² and 152.88 cm², respectively. 2 In Comparative Example 3, due to the lack of high-energy shear ball milling activation, the van der Waals forces of the primary bone char particles softly aggregated, reducing effective active sites, and its root development indicators remained in the intermediate range. In Comparative Example 4, the dense structure of the pure agricultural loam increased the resistance to mass transfer, hindering the diffusion flux of phosphate to the root surface, and the total root length of the plant was reduced by about one-quarter compared to Example 1. The reshaping of the physicochemical balance of the rhizosphere solid-liquid interface directly intervenes in the plant's internal hormone communication network, and the fully developed underground absorption channel system provides capacity support for the assimilation of substances throughout the plant's entire growth period.

[0064] Test Example 3: This test case primarily aims to verify the underlying driving effects of rhizosphere solid-phase flow field remodeling and high-flux supply of available phosphorus on energy allocation and carbon assimilation processes in the aboveground photosynthetic system of plants. The experimental subjects were functional leaves of the aboveground parts of living peanut plants in the peak pod-setting stage from Examples 1 to 4 and Comparative Examples 1 to 5.

[0065] 1. Under continuous sunny and cloudless weather conditions, the photosynthetic gas exchange parameters of live plants were collected between 9:00 and 11:30 in the morning to avoid interference from abnormal stomatal closure caused by the midday depression of plants. The third leaf from the bottom of the peanut main stem of each treatment group that was fully expanded and facing the sun was selected as the measurement target.

[0066] 2. A portable photosynthesis measurement system was used to perform live-cell measurements on the target leaves. The carbon dioxide concentration in the transparent leaf chamber was controlled at 400 μmol / mol, and a red and blue LED light source was configured to provide a saturated light intensity of 1200 μmol / (m²). 2 After the gas exchange in the leaf chamber reaches a steady state, the net photosynthetic rate and the absolute value of stomatal conductance are recorded.

[0067] 3. After the gas exchange parameters are measured, the functional leaves at the same leaf position are subjected to dark adaptation leaf clips for more than 30 minutes before sunset or before dawn to ensure that the reaction centers in the chloroplasts are fully open and the electron transport chain is in the ground state.

[0068] 4. Using a modulated chlorophyll fluorometer, apply weak measurement light to the dark-adapted leaves to obtain the initial fluorescence yield. Then apply instantaneous saturated pulse light to measure the maximum fluorescence yield. Introduce photochemical light to bring the leaves into a steady-state photosynthetic state, record the steady-state fluorescence, and apply saturated pulse light again to obtain the maximum fluorescence yield under light adaptation.

[0069] 5. Export the measured original fluorescence signal, perform numerical conversion based on the derivation formula of non-photochemical quenching and actual photochemical efficiency of photosystem II, and evaluate the energy dissipation ratio of the leaf in the process of light energy capture and electron transfer.

[0070] Table 3. Results of photosynthetic gas exchange and chlorophyll fluorescence parameters in peanut functional leaves of each treatment group: According to Table 3 and the appendix Figure 3 The data showed that the expansion of the underground root network and the increase in available phosphorus flux in the rhizosphere microzone were directly correlated with the carbon assimilation process of the aboveground functional leaves. Comparative Example 1 under conventional phosphorus deficiency stress and Comparative Example 2 under high-temperature pyrolysis inactivation exhibited net photosynthetic rates hovering only between 11.24 and 12.58 μmol / m³. -2 s -1In the low-lying region, the corresponding stomatal conductance is also at an extremely low level. This stomatal limitation is usually a passive defense strategy adopted by plants to maintain internal water and ion electrochemical balance when they encounter root nutrient shortage. In previous continuous field observations, plants that were routinely treated with fast-acting water-soluble fertilizers were prone to premature photosynthetic senescence in the middle and late stages of growth, and the data from Comparative Example 5 confirmed this field experience. Because chemical fertilizers are prone to secondary precipitation after entering the soil, resulting in a lack of continuity in phosphorus supply, the net photosynthetic rate of its leaves stagnated at 15.41 μmol / m³. -2 s -1 It did not demonstrate the assimilation capacity to support the high-energy-consuming metabolism during the pod-setting stage.

[0071] In contrast, the phenotypic data of Example 1 showed a significant metabolic spurt, with a net photosynthetic rate reaching 26.43 μmol / m³. -2 s -1 Micro- and nano-bone char maintained a constant phosphorus supply environment with low desorption activation energy in the reconstructed heterogeneous porous matrix. Well-developed underground absorption channels supported efficient transmembrane transport of water and fertilizer at the leaf tip, completely eliminating the physical constraint of stomatal closure. This leap in carbon assimilation efficiency inevitably involves the reorganization of photochemical energy distribution pathways; observing fluorescence parameters characterizing light energy utilization reveals the substrate's response patterns. Comparative Example 1, under nutrient and water transport stress, lacked sufficient inorganic phosphorus for the biochemical synthesis of ATP and NADPH at the basal end. The exciton energy captured by photosystem II could not smoothly flow into the electron transport chain, forcing the plant to release excess light energy by activating heat dissipation mechanisms, resulting in an abnormally high NPQ value of 2.45. This passive defense not only represents a significant waste of available light energy but also often carries the potential risk of tissue damage due to the accumulation of reactive oxygen species on the thylakoid membrane.

[0072] In Example 1, which eliminated steric hindrance in mass transfer, the direct biochemical result of the removal of phosphorus supply constraints was the unimpeded electron transport chain. Its NPQ value dropped significantly to 0.84, while ΦPSII, representing the core capability of photochemical conversion, increased to 0.651. This reversal of the fluorescence energy distribution states indicates that the bone char material, relying on the synergistic treatment of 450℃ thermodynamic phase transition cutoff and high-frequency mechanical shear activation, successfully freed the entire plant from an energy-intensive stress state. The improvement of the rhizosphere microphysical flow field guided the massive photosynthetic energy capture to be targeted and converted into chemical energy driving carbohydrate synthesis, establishing the underlying energy foundation for the efficient source-sink transport of photosynthetic products to underground reproductive organs and the accumulation of dry matter. Comparative Example 3, which did not undergo high-energy shear-induced lattice distortion, and Comparative Example 4, which did not undergo matrix reconstruction, were limited by soft particle aggregation or soil viscosity resistance, and their photosynthetic efficiency was in an intermediate transitional state, indirectly demonstrating the indivisibility of the cross-scale physicochemical regulation process system of this invention.

[0073] Test Example 4: This test case was used to verify whether the physicochemical modification of the rhizosphere microenvironment and the reprogramming of endogenous physiological and biochemical pathways in plants could effectively translate into improvements in macroscopic agronomic traits and a substantial leap in dry matter production. The experimental subjects were whole, living peanut plants that had undergone cultivation throughout the entire growth period and reached physiological maturity, as described in Examples 1 to 4 and Comparative Examples 1 to 5.

[0074] 1. Take samples during the harvest period when most of the peanut pods are mature and plump and the inside of the shells shows a net-like dark pattern. Use an agricultural shovel to dig around the main root of the plant and remove the entire peanut plant and pods from the soil substrate intact. Shake off the soil attached to the roots and the surface of the pods.

[0075] 2. Use a measuring tape to measure the absolute length from the base of the main stem to the top of the highest main branch as the plant height above ground. Then, use pruning shears to separate the above-ground stems and leaves from the underground roots and pods at the cotyledon nodes. Use an electronic balance with an accuracy of 0.01 grams to weigh the above-ground fresh weight and the underground fresh weight parameters respectively.

[0076] 3. Manually pick all plump pods and empty pods attached to the underground root system, record the total number of pods per plant, remove obviously rotten or severely diseased and pest-infested pods, place the valid pods in a forced-air drying oven, and slowly dry them to constant weight under a low-temperature airflow of 35℃ to 40℃ to avoid high temperature damaging the oil and protein structure inside the kernel.

[0077] 4. After the pods are completely dry, remove the shells and collect the peanut kernels inside. Randomly select 100 kernels with intact appearance and weigh them to obtain the weight of 100 kernels. Finally, summarize the weight of all dried kernels of a single plant and record it as the final total yield of a single plant.

[0078] Table 4. Peanut growth phenotypic parameters and final yield measurement results for each treatment group: According to Table 4 and Appendix Figure 4 The data showed that microscopic lattice regulation and interfacial flow field reshaping were amplified step by step during the long growth cycle, ultimately establishing the absolute advantage of the treatment group in the accumulation of reproductive metabolites. Observing the data composition of Comparative Example 1 and Comparative Example 2, the blank control group and the treatment group treated with 800℃ high-temperature pyrolysis bone char both fell to a low point in various agronomic indicators, with single-plant yields stagnating at 7.15 g and 8.32 g, respectively. In routine field observations, plants suffering from long-term phosphorus starvation usually exhibit typical stagnation symptoms such as shortened internodes and dark green to purplish leaves. This limited vegetative growth directly leads to insufficient photosynthetic area, failing to provide sufficient carbohydrate sources for later pod development. High-temperature pyrolysis thoroughly removed the oxygen-containing functional groups of residual skeletal organic matter and induced deep crystallization of hydroxyapatite. The solid particles that lost their cation exchange capacity exhibited chemical inertness at the soil-water interface and failed to interfere with the precipitation-dissolution balance of soil phosphates.

[0079] In Example 1, the number of pods per plant and the yield per plant increased to 34 and 25.63 grams, respectively. Comparative Example 3 omitted the high-energy shear-mechanical-chemical activation step, relying solely on the natural porosity distribution of primary bone char. Due to the lack of exposed amorphous high-energy sites caused by lattice distortion, the reduction in desorption activation energy was limited, resulting in a yield per plant falling back to 14.58 grams. Although Comparative Example 4 applied mechanically activated micro / nano bone char, the strong capillary hindrance of the pure agricultural soil matrix caused steric hindrance in mass transfer, blocking the long-distance diffusion path of available phosphorus to the root surface. Its yield also failed to reach the high range set in the examples. The lack of physicochemical mechanisms in each process step resulted in significant biomass loss at the final harvest.

[0080] The conventional agricultural production model, which relies on readily soluble chemical fertilizers to maintain yield, faces profound thermodynamic challenges. Comparative Example 5, which applied an equivalent amount of superphosphate, only yielded 12.41 grams per plant, far lower than Example 1. The initial free concentration of water-soluble inorganic phosphates after soil entry is extremely high, but with rapid water penetration and the rapid combination with free cations in soil microzones, secondary aging and solidification occur quickly. The pod enlargement stage in the later stages of reproductive growth is the peak period of metabolic energy consumption for the entire plant. The phosphorus supply gap created by conventional chemical fertilizers often forces plants to initiate aging prematurely. The sharp drop in 100-grain weight from 78.5 grams in Example 1 to 58.7 grams in Comparative Example 5 confirms the abnormal closure of the source-sink transport channel. Based on a bone char solid-phase system constructed using low-to-medium temperature thermodynamic cutoff and mechanical shearing, combined with the large-pore seepage channels provided by siliceous sand, a micro-nutrient generator with self-buffering and slow-release capabilities was established in the plant rhizosphere, establishing the material basis for supply and demand matching throughout the entire growth period.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for increasing peanut yield by promoting the activation of phosphorus from pig bone micro / nano bone char, characterized in that, The method utilizes micro / nano bone char particles from pig bones, and includes the following steps: S1. Site selection and tillage: Select the test site and till or level the land before sowing; S2. Base fertilizer application and sowing: The pig bone micro-nano bone char particles are applied as base fertilizer in strips, as seed coating components on the seed surface, or mixed with fine sand and applied in fixed holes; the potassium humate coating layer on the surface of the bone char and the exogenous organic acid produce a synergistic effect to drive the bone char to produce a heterogeneous acid hydrolysis reaction to activate phosphorus. S3. Field management: Water management is carried out during the peanut's growing season to induce the root system to concentrate its growth in the bone char fertilization area. The pig bone micro / nano bone char particles are prepared from raw materials containing the following mass ratio: 1 part of defatted pig bone char obtained by oxygen-limited pyrolysis, and 3 parts of potassium humate dispersion; the mass fraction of potassium humate in the potassium humate dispersion is 2.0% to 5.0%; in the particles, potassium humate physically coats the surface of the bone char to form a negative charge barrier in the soil solution, thereby inhibiting secondary aggregation of the micro / nano bone char caused by calcium ion bridging.

2. The method for promoting peanut phosphorus activation and yield increase using pig bone micro / nano bone char according to claim 1, characterized in that, In S1, the selected test site is phosphorus-deficient sandy loam with an available phosphorus content of 10-15 mg / kg. In S2, micro-nano bone char particles with a median particle size D50 of 850nm are selected as phosphate fertilizer supplements. They are mixed evenly with 200kg / mu of well-rotted organic fertilizer at a dosage of 30kg / mu and applied in strips to a depth of 12cm below the center of the sowing ridge, so that the potassium humate layer on the surface of the bone char and the organic acids in the organic fertilizer can produce a synergistic activation effect.

3. The method for increasing peanut yield by promoting peanut phosphorus activation using pig bone micro / nano bone char according to claim 1, characterized in that, In S1, the selected test site was alkaline calcareous soil with a pH value of 7.5 to 8.2; In S2, micro-nano bone char particles with a median particle size D50 of 420nm are selected and mixed with starch-based film-forming agent at a ratio of 1:

5. Peanut seeds are coated with the mixture at 1.5% of the seed weight, and 20kg / mu of the bone char particles are simultaneously applied in the sowing furrow. In step S3, during the branching stage of peanuts, a 5% fulvic acid solution is applied via drip irrigation to maintain the solubility of micro- and nano-calcium phosphate components in alkaline soil through its chelating effect.

4. The method for increasing peanut yield by promoting peanut phosphorus activation using pig bone micro / nano bone char according to claim 1, characterized in that, In S1, the selected test site was an acidic red soil plot. Before sowing, quicklime was applied per acre in conjunction with land preparation to adjust the local rhizosphere microenvironment pH to about 6.

0. In S2, micro-nano bone char particles with a median particle size D50 of 150nm are selected, diluted with fine sand at a ratio of 1:10 at a dosage of 15kg / mu, and precisely applied 3cm below the seed during sowing, while simultaneously inoculating the sowing hole with phosphate-solubilizing bacteria powder.

5. The method for increasing peanut yield by promoting peanut phosphorus activation using pig bone micro / nano bone char according to claim 4, characterized in that, In S2, the phosphate-solubilizing bacteria is Bacillus megaterium, and the inoculation amount is 10g / hole. By inoculating Bacillus megaterium, the low-molecular-weight organic acids secreted by it react with the high specific surface area of ​​150nm micro-nano bone char to realize the activation of deposited phosphorus.

6. A type of pig bone micro / nano char particles applied to the method according to any one of claims 1-5, characterized in that: The solid particle median particle size D50 of the pig bone micro / nano bone char particles is 150 nm to 850 nm, and the zeta potential of the particles dispersed in the aqueous dispersion is maintained between -29.5 mV and -35.8 mV.

7. The pig bone micro / nano bone char particles according to claim 1, characterized in that, In the defatted pig bone char used to prepare the pig bone micro / nano bone char particles, the main inorganic phase component is hydroxyapatite, which has a full width at half maximum (FWHM) Δ2θ of 1.25° to 1.45° at 2θ = 25.9° in X-ray diffraction testing.

8. A method for preparing pig bone micro / nano char particles as described in claim 6 or 7, characterized in that, Includes the following steps: S11. Material pretreatment: Take defatted pork bone fragments, crush and sieve them for later use; S12, oxygen-limited pyrolysis: The bone blocks obtained in S11 are placed in a carbonization furnace. Under the conditions of passing high-purity nitrogen and exhausting the air so that the oxygen content is ≤0.5 vol%, the temperature is increased in stages to carry out dehydration and isothermal pyrolysis. After cooling to room temperature, the degreased pig bone char is obtained. S13. Preparation of dispersion: Add potassium humate to deionized water and stir to dissolve, prepare a potassium humate dispersion with a mass fraction of 2.0% to 5.0%, and adjust the pH of the system to 7.0 to 8.0 using alkaline solution. S14. Micro-nano grinding: The bone char obtained in S12 and the dispersion obtained in S13 are mixed at a mass ratio of 1:3, and grinding media are added for cyclic grinding micro-nano treatment. The suspension is then collected. S15. Low-temperature spray granulation: The suspension obtained in S14 is fed into a fluidized bed spray granulator for drying and granulation to obtain the pig bone micro-nano bone char particles.

9. The method for preparing pig bone micro / nano bone char particles according to claim 8, characterized in that, In S12, the specific parameters for the stepped heating are as follows: first, the temperature is raised to 150°C at a rate of 5-8°C / min and held at this temperature for 30 min for dehydration; then, the temperature is raised to 420-480°C at a rate of 4-6°C / min and held at this temperature for 2.0-3.0 h for pyrolysis, so as to preserve the internal hydroxyapatite lattice in a low crystallinity state.

10. The method for preparing pig bone micro / nano bone char particles according to claim 8, characterized in that, In S14, the grinding media is zirconia beads with a particle size of 0.3 to 0.5 mm, the mass ratio of grinding media to total material is set to 15:1, and the grinding is carried out in a cycle at a speed of 300 to 500 rpm for 4.0 to 6.0 hours, while controlling the grinding chamber temperature to ≤35℃. In S15, the inlet air temperature of the fluidized bed spray granulator is controlled at 105-120℃, the outlet air temperature at 65-80℃, the bed temperature at 70-80℃, and the spray pressure at 0.2-0.4MPa.

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