Fertilizer capable of conditioning soil and improving crop nutrient utilization rate

Abstract

The invention provides a fertilizer with a soil conditioning effect and a crop nutrient utilization rate increasing function. The fertilizer is prepared from 1wt%-5wt% of a biological surfactant, 3wt%-7wt% of modified zeolite and 86wt%-98wt% of mineral nutrient elements, the biological surfactant is a bacillus subtilis fermentation product, and the modified zeolite is low-temperature oxygen plasma modified zeolite. According to the fertilizer with the soil conditioning effect and the crop nutrient utilization rate increasing function, the fertilizer utilization rate can be increased, nutrient elements can be supplemented, effective components of the fertilizer can be increased, crop growth can be promoted, and meanwhile the fertilizer can have a good improvement effect on soil after being applied.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, in particular to a fertilizer capable of conditioning soil and improving the utilization rate of crop nutrients. Background Art

[0002] The normal growth and development of grain and cash crops depend on a healthy soil environment. Neutral soil conditions are most favorable for most plant growth, while overly acidic or alkaline environments are detrimental. In the early decades of agricultural cultivation in my country, increasing grain production relied primarily on the extensive application of chemical fertilizers. The production and use of chemical fertilizers once played a positive role in their rapid effectiveness, increased crop yields, and ease of use. However, over time, their inherent drawbacks have become increasingly pronounced. Prolonged over-fertilization leads to soil compaction, a decrease in organic matter, a reduction in beneficial microorganisms, and soil acidification. Acidic soils are characterized by the accumulation of iron and aluminum oxides, rapid biomass cycling, and low base saturation. Furthermore, they are susceptible to intense leaching, resulting in low levels of basic nutrients such as potassium, calcium, and magnesium. Acidification also reduces the soil's cation exchange capacity, diminishing its nutrient retention capacity, significantly impacting the sustainable development of ecological agriculture. Therefore, soil conditioning and improvement are often necessary during cultivation.

[0003] Currently, existing soil remediation technologies include chemical, physical, and biological technologies. Among them, microbial soil conditioners are made by using microorganisms and their active ingredients, supplemented by water-retaining agents and natural peat or other organic matter rich in organic matter and humic acid. They have the three major soil conditioning properties of "water retention, fertilization, and air permeability." They solve the problem of soil compaction, loosen the soil, improve soil permeability, reduce soil bulk density, promote soil microbial activity, and enhance the penetration of fertilizers and water into the soil. However, existing microbial soil conditioners simply mix nutrients, active substances, and functional microorganisms, and do not utilize the conversion effect of functional microorganisms to convert additives into active substances, which greatly reduces their effectiveness. Another problem is that the current direct addition of various minerals or residual ash from the combustion of agricultural and forestry waste to provide nutrients for crops cannot ensure a reasonable ratio of various nutrients, and they are not easily absorbed and utilized by crops.

[0004] Therefore, developing a fertilizer that can improve the utilization rate of fertilizer, promote crop growth and improve the soil after application is a topic worth studying. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a fertilizer with the effect of conditioning the soil and improving the nutrient utilization rate of crops. The fertilizer can improve the utilization rate of fertilizer, supplement nutrient elements, increase the effective ingredients of fertilizer, promote crop growth, and at the same time enable the fertilizer to have a good improvement effect on the soil after application.

[0006] The present invention provides a fertilizer having the effect of conditioning soil and improving the nutrient utilization rate of crops, comprising: 1wt%-5wt% of a biosurfactant, 3wt%-7wt% of a modified zeolite, and 86wt%-98wt% of mineral nutrients;

[0007] The biosurfactant is a fermentation product of Bacillus subtilis, and the modified zeolite is a low-temperature oxygen plasma modified zeolite.

[0008] In the present invention, the Bacillus subtilis fermentation product is used as a biosurfactant, which contains a large number of different types of amino acids and surfactant components. It has the characteristics of being non-biotoxic, rapidly degradable, and a direct nitrogen source for plants. It is also a key component for conditioning soil and improving the nutrient utilization rate of crops. The low-temperature oxygen plasma-modified zeolite uses low-temperature oxygen plasma to etch the zeolite surface, thereby increasing the roughness and the number of active groups. When the zeolite is mixed with the Bacillus subtilis fermentation product, it can construct a bio-mineral composite interface with the extracellular polymers contained in the Bacillus subtilis fermentation product, which can improve the microbial attachment rate and enhance the metal chelation ability.

[0009] Preferably, the Bacillus subtilis fermentation product is prepared by the following method:

[0010] The seed liquid of Bacillus subtilis is inoculated into a fermentation medium, and fermented and cultured at 25°C-35°C for 3-5 days. After filtering and separating the bacteria, the pH is adjusted to 1.8-2.3 for precipitation, and after purification, the Bacillus subtilis fermentation product is obtained;

[0011] The fermentation medium comprises: 15-25 g / L glucose, 2-8 g / L sodium glutamate, 1-2 g / L potassium dihydrogen phosphate, 0.1-1 g / L magnesium sulfate, 0.01-0.02 g / L iron sulfate and 0.05-0.2 g / L calcium chloride; and the pH value is 6.5-7.5.

[0012] Preferably, the seed solution of Bacillus subtilis is prepared by the following method:

[0013] The Bacillus subtilis strain is first inoculated into LB solid culture medium, cultured at 25°C-35°C for 12-36 hours, and then inoculated into LB liquid culture medium, and cultured with shaking at 25°C-35°C for 6 hours-24 hours to obtain the Bacillus subtilis seed liquid.

[0014] Preferably, the low-temperature oxygen plasma modified zeolite is prepared by the following method:

[0015] The zeolite is fully ground and placed in an oxygen plasma apparatus. After vacuuming, high-purity oxygen is introduced to treat the zeolite in a low-temperature oxygen plasma atmosphere.

[0016] The vacuum degree of the vacuum pumping is 5-10 Pa; the treatment pressure is 20-100 Pa, the radio frequency power is 100-500 W, and the treatment time is 5-15 min.

[0017] Preferably, the zeolite is at least one of clinoptilolite, mordenite or phillipsite.

[0018] Preferably, the mineral nutrient elements include nitrogen source, phosphorus source and potassium source;

[0019] The nitrogen source is at least one of urea, ammonium bicarbonate, ammonium sulfate or ammonium chloride; the phosphorus source is at least one of monoammonium phosphate, diammonium phosphate, triammonium phosphate, monoammonium phosphate or calcium phosphate; and the potassium source is at least one of potassium chloride, potassium sulfate or potassium dihydrogen phosphate.

[0020] Preferably, the mass ratio of the nitrogen source, phosphorus source and potassium source is 1:1.5-3:1-1.5.

[0021] Preferably, the fertilizer further comprises 0.1 wt% to 1 wt% of a chelating agent;

[0022] The chelating agent is obtained by subjecting chitosan to a condensation reaction with chloroacetic acid and then subjecting the chitosan to an amidation reaction with alendronic acid.

[0023] In the present invention, chitosan is first reacted with chloroacetic acid to graft carboxyl groups onto the chitosan, and then reacted with alendronic acid to graft alendronic acid onto the chitosan. As a result, the chitosan is rich in phosphate groups, which can form a strong chelating effect and form chelates with trace elements, thereby being easily absorbed by crops. In addition, the chitosan can gradually decompose and release nitrogen elements, thereby increasing the effective ingredients of the fertilizer and promoting crop growth.

[0024] Preferably, the fertilizer is prepared by the following method:

[0025] The biosurfactant, modified zeolite and mineral nutrients are crushed and added to a drum granulator for granulation. Water is added as a binder at a rate of 5 wt% to 8 wt% of the total weight of the fertilizer. The particle size is controlled to be 2 to 4 mm. The obtained masterbatch is first dried with hot air, then cooled to room temperature with cold air, and finally sieved to obtain the fertilizer.

[0026] Preferably, the hot air drying comprises: initially drying at 80-90°C for 20-40 minutes, and then drying at 50-60°C for 10-30 minutes.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The present invention utilizes the fermentation product of Bacillus subtilis as a biosurfactant, which contains a large number of different types of amino acids and surfactant components. It has the characteristics of being non-biotoxic, rapidly degradable, and a direct nitrogen source for plants. It is also a key component for conditioning soil and improving crop nutrient utilization.

[0029] (2) The present invention modifies zeolite by increasing the adsorption activity of zeolite and significantly improving the metal chelating ability of the modified zeolite through the influence of plasma surface etching on the physicochemical properties of zeolite (such as specific surface area, surface functional groups, surface charge) and metal ion adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the chelating agent described in Example 2; Figure 2 This is the infrared spectrum of the chelating agent described in Example 2. DETAILED DESCRIPTION

[0031] Hereinafter, the technical solutions of the present invention will be described in detail through specific embodiments. However, it should be clearly stated that these embodiments are provided for illustration only and are not to be construed as limiting the scope of the present invention.

[0032] Example 1

[0033] A fertilizer capable of conditioning soil and improving crop nutrient utilization, comprising: 2 wt% of a biosurfactant, 4 wt% of a modified zeolite, 21 wt% of urea, 26 wt% of monoammonium phosphate, 16 wt% of diammonium phosphate, and 31 wt% of potassium sulfate; The biosurfactant is a fermentation product of Bacillus subtilis, which is prepared by the following method: The Bacillus subtilis CMCC63501 strain was first inoculated into LB solid medium and cultured at 30°C for 24 hours. The obtained culture medium was then inoculated with one loop of slant lawn into LB liquid medium and cultured with shaking at 30°C for 12 hours to obtain the seed liquid of the Bacillus subtilis; The LB solid medium includes: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, 15 g / agar; the pH value is 7.0-7.2; the LB liquid medium includes: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride; the pH value is 7.0; The seed liquid of Bacillus subtilis was inoculated into a fermentation medium at an amount of 5% seed liquid (v / v), and fermented at 30°C for 3 days. After centrifugation (10,000 rpm) to separate the bacteria, the supernatant was adjusted to pH 2.0 with 6M hydrochloric acid and allowed to stand at 4°C for 12 hours. The white precipitate was collected and washed twice with distilled water. The resulting crude product was dissolved in methanol (1:10 w / v), vortexed for 10 minutes, and centrifuged to remove insoluble matter. The supernatant was concentrated by rotary evaporation (40°C) and precipitated with ether to obtain a light yellow powder, which was the Bacillus subtilis fermentation product. The fermentation medium comprises: 20 g / L glucose, 5 g / L sodium glutamate, 1.5 g / L potassium dihydrogen phosphate, 0.5 g / L magnesium sulfate heptahydrate, 0.01 g / L ferric sulfate heptahydrate, and 0.1 g / L calcium chloride; the pH value is 7.0 (adjusted with 1 M sodium hydroxide / hydrochloric acid); The modified zeolite is a low-temperature oxygen plasma modified zeolite, which is prepared by the following method: The clinoptilolite (particle size 100 mesh) was placed in an oxygen plasma apparatus, and high-purity oxygen was introduced after vacuuming, and the zeolite was treated in a low-temperature oxygen plasma atmosphere to obtain the low-temperature oxygen plasma modified zeolite; The vacuum degree of the vacuum pumping is 5 Pa, the treatment pressure is 80 Pa, the radio frequency power is 300 W, and the treatment time is 10 min.

[0034] The preparation method of the above-mentioned fertilizer includes: grinding a biosurfactant, modified zeolite and urea, monoammonium phosphate, diammonium phosphate, and potassium sulfate into 80-mesh fine powder, adding the powder into a rotary drum granulator for granulation, adding 6wt% of water as a binder based on the total weight of the fertilizer, controlling the particle size to 2-4mm, and first drying the obtained masterbatch under 80°C hot air conditions for 30 minutes, then drying under 60°C hot air conditions for another 20 minutes, then cooling to room temperature with cold air, and finally vibrating and screening qualified particles of 2-4mm to obtain the fertilizer.

[0035] Example 2

[0036] A fertilizer capable of conditioning soil and improving crop nutrient utilization, comprising: 2 wt% of a biosurfactant, 4 wt% of a modified zeolite, 0.5 wt% of a chelating agent, 20.5 wt% of urea, 26 wt% of monoammonium phosphate, 16 wt% of diammonium phosphate, and 31 wt% of potassium sulfate; The biosurfactant was prepared by referring to the method described in Example 1, and the modified zeolite was also prepared by referring to the method described in Example 1; The chelating agent is prepared by the following method: Chitosan was dissolved in dilute acetic acid (concentration 2 wt%), and then chloroacetic acid (5 wt% by weight of chitosan) was added, and the mixture was heated to 80°C and stirred for 12 h, centrifuged, washed with water, and dried to obtain an intermediate product; the intermediate product was added to ethyl acetate, and then alendronic acid (6 wt% by weight of chitosan) and dicyclohexylcarbodiimide (1 wt% by weight of chitosan) were added, and the mixture was heated to 50°C and stirred for 12 h, filtered, washed with water, and dried to obtain the chelating agent, whose structural formula and infrared spectrum are shown in FIG. Figure 1 、 2 As shown, refer to Figure 1 、 2 It can be seen that in the chelating agent, the -1 There are absorption peaks corresponding to amino and hydroxyl stretching vibrations at 1627 cm -1 and 1546 cm -1 There are stretching vibration peaks corresponding to C=O and bending vibration peaks of NH at 1243cm -1 and 954cm -1 There are stretching vibration peaks corresponding to P=O and antisymmetric vibration peaks of POP.

[0037] The preparation method of the above fertilizer is as described in Example 1.

[0038] Comparative Example 1 A fertilizer capable of conditioning soil and improving crop nutrient utilization, comprising: 2 wt% of a biosurfactant, 25 wt% of urea, 26 wt% of monoammonium phosphate, 16 wt% of diammonium phosphate, and 31 wt% of potassium sulfate; The biosurfactant was prepared by referring to the method described in Example 1.

[0039] The preparation method of the above fertilizer is as described in Example 1.

[0040] Comparative Example 2 A fertilizer capable of conditioning soil and improving crop nutrient utilization, comprising: 2 wt% of a biosurfactant, 4 wt% of a modified zeolite, 0.5 wt% of a chelating agent, 20.5 wt% of urea, 26 wt% of monoammonium phosphate, 16 wt% of diammonium phosphate, and 31 wt% of potassium sulfate; The biosurfactant was prepared by referring to the method described in Example 1, and the modified zeolite was also prepared by referring to the method described in Example 1; The chelating agent is ethylenediaminetetraacetic acid (a common fertilizer chelating agent).

[0041] The preparation method of the above fertilizer is as described in Example 1.

[0042] Test Example 1 Experimental purpose: To verify the effect of carboxylic acid groups (COOH) in the surfactant components or other amino acid components on ammonium ions ( ) can improve the adsorption capacity of ammonium ions and meet the continuous demand of plants for nitrogen sources, thereby indirectly improving the nutrient utilization rate of plants.

[0043] Experimental principle: The adsorption behavior is indirectly characterized by the change in ion concentration in the solution before and after adsorption. The carboxylic acid group dissociates into COO when pH>pKa - , adsorbing NH4 through electrostatic action + NH4 in the solution after adsorption + The concentration decreases and NH4 can be determined by conductivity decrease and spectrophotometry. + Reduce the amount of indirect verification.

[0044] Materials and equipment: Test solution: test surfactant (biosurfactant), reference surfactant (sodium lauryl sulfate); ammonium salt solution: Solution (concentration gradient: 0.1mmol / L, 0.5mmol / L, 1.0mmol / L); buffer system: acetic acid-sodium acetate buffer (pH: 4.0, 5.5, 7.0); other reagents: Nessler's reagent, potassium sodium tartrate solution (for spectrophotometry); instruments: conductivity meter, spectrophotometer, constant temperature oscillator, centrifuge, pH meter; buffer system: acetic acid-sodium acetate buffer (pH: 4.0, 5.5, 7.0).

[0045] Experimental process: (1) Sample preparation: experimental group: containing 50 mg of biosurfactant (biosurfactant described in Example 1); control group: containing 50 mg of sodium lauryl sulfate; blank group: no surfactant; 10 mL of NH4Cl solution (concentration gradient of 0.1 mmol / L, 0.5 mmol / L, 1.0 mmol / L) and 1 mL of buffer were added to each group, and the mixture was shaken at a constant temperature for 30 min (25°C, 150 rpm), centrifuged (10000 rpm) for 15 min, and the supernatant was taken for testing.

[0046] (2) Determination method: A. Conductivity method Calculate adsorption rate from conductivity: The conductivity of the supernatant of each group was measured using a conductivity meter, and the adsorption rate was calculated according to the following formula:

[0047] Where: κ is the conductivity value; B. Spectrophotometric determination Standard curve drawing: Take 6 25mL colorimetric tubes and add 0-25μg NH4 + For the standard solution, add 1 mL of potassium sodium tartrate and 0.5 mL of Nessler's reagent to each tube, shake well and let it stand for 10 min. Measure the absorbance at a wavelength of 420 nm and draw a standard curve.

[0048]

[0049] Standard curve equation:

[0050] Where: y is absorbance, x is NH4 + Concentration (mg / L); Sample detection: add 1 mL of potassium sodium tartrate and 0.5 mL of Nessler's reagent, shake well and let it stand for 10 minutes, measure the absorbance at a wavelength of 420 nm, and then find the NH4 + The adsorption capacity was calculated according to the following formula:

[0051] Where: Q e is the adsorption capacity (mg / g); C0, C e is the initial / equilibrium concentration (mg / L); V is the volume of the solution (L); and m is the surface active mass (g).

[0052] Test results and data processing:

[0053] pH dependence: The adsorption rate of the experimental group increased significantly (>20%) at pH 5.5 and 7.0, which may be due to the dissociation of carboxyl groups. Enhanced electrostatic adsorption; at pH 4.0, the carboxyl group was not dissociated (COOH), and the adsorption rate was close to that of the control group (<7%).

[0054] Carboxyl specificity: The adsorption rate of the control group was always <6%, indicating that the general surfactant itself did not contain amino acid components. The adsorption contribution is weak.

[0055]

[0056] As shown in Table 3, when pH ≥ 5.5, the carboxylic acid group The adsorption capacity can reach 4.4-6.2 mg / g, which proves that the surface active or amino acids in microbial fermentation products have good Adsorption capacity.

[0057] Test Example 2 Experimental purpose: To verify the improvement of metal ion adsorption capacity of zeolite by different modification methods.

[0058] Experimental principle: The adsorption capacity of zeolites obtained by different modification methods for metal ions is indirectly characterized by the change in Cr(VI) concentration in the solution before and after adsorption.

[0059] Materials and equipment: Core instrument: spectrophotometer; adsorbents: clinoptilolite (particle size 100 mesh), acid-modified zeolite, ammonium-type ion exchange-modified zeolite, low-temperature oxygen plasma-modified zeolite, hydrochloric acid, ammonium nitrate, etc.; adsorbate: ( Solution); Auxiliary reagents: Color developer: diphenylcarbazide (purple-red under acidic conditions, ); Others: pH meter, constant temperature water bath shaker, centrifuge, filter paper, volumetric flask, pipette; The acid-modified zeolite is prepared by adding clinoptilolite (100 mesh particle size) to 0.1 mol / L hydrochloric acid, heating, stirring, and refluxing for 2 hours, filtering, repeatedly washing with deionized water until neutral, and drying at 105°C. The ammonium-type ion-exchange modified zeolite is prepared by immersing clinoptilolite (100 mesh particle size) in a 0.1 mol / L ammonium nitrate solution at room temperature, continuously shaking for 24 hours, filtering to separate the solid, repeatedly washing with deionized water until no ions in the exchange solution are detected, and then calcining in a muffle furnace at 500°C for 4 hours. The low-temperature oxygen plasma-modified zeolite was obtained by referring to the method described in Example 1.

[0060] Experimental process: (1) Sample preparation: Experimental group: Prepare 50 mg / L Solution ( Dissolve and adjust to volume), adjust pH to 4-6, take 100mL Solution, add 0.1g unmodified / modified zeolite, then shake at 25℃ for 30min, centrifuge and separate the supernatant; blank group: without zeolite solution; (2) Determination method: A. Color reaction: Take 5 mL of supernatant and add 1 mL of diphenylcarbazide, let it stand for 10 minutes. Color standard curve: Use standard The absorbance-concentration curve of the solution (0-10 mg / L) was drawn (developer: 0.5% diphenylcarbazide (acidic conditions); wavelength: 540 nm, 1 cm; cuvette linear range:

[0061] B. Calculation of adsorption capacity

[0062] Where: q: adsorption amount (mg / g); C0, C e: initial and equilibrium concentrations (mg / L); V: solution volume (L), m: zeolite mass (g).

[0063] Test results and data processing:

[0064] Fitting equation:

[0065]

[0066] As shown in Table 5, the adsorption capacity of low-temperature plasma-modified zeolite is significantly higher than that of other modification methods. This is because plasma etching increases the specific surface area and introduces oxygen-containing functional groups to enhance electrostatic attraction and reduction. Ion exchange-modified zeolite relies on surface positive charges to adsorb anionic Cr (VI), but the loading capacity is limited. Low-temperature plasma modification breaks through the adsorption limit through physical / chemical synergy.

[0067] Test Example 3 Experimental purpose: To verify whether the fertilizer of the present invention can improve the nutrient utilization rate of crops.

[0068] Experimental principle: Through hydroponic experiments with wheat seeds and nutrient solution containing fertilizer, the relationship between electrical conductivity (EC) and nutrient absorption is studied. Electrical conductivity reflects the total ion concentration (salt) in the solution and is negatively correlated with nutrient absorption: the more nutrients the plant absorbs, the lower the ion concentration in the nutrient solution, and the lower the electrical conductivity value. By monitoring the changes in the EC value of the nutrient solution, the efficiency of wheat's nutrient absorption can be indirectly quantified.

[0069] Materials and Equipment: Wheat seeds: Select uniform, plump varieties and soak for 24 hours after disinfection; Nutrient solution: Control group (conventional fertilizer) and experimental group (fertilizers according to the embodiment of the present invention and the comparative example); Container: Transparent hydroponic pot (500 mL), with 10 wheat seedlings fixed in each pot, protected from light; Instrument: Conductivity meter (accuracy 0.01 mS / cm).

[0070] The ordinary fertilizer is a fertilizer including 22.3 wt % of urea, 27.6 wt % of monoammonium phosphate, 17.1 wt % of diammonium phosphate and 33.0 wt % of potassium sulfate.

[0071] Experimental process: (1) Sample preparation: Control group: nutrient solution of ordinary fertilizer with a concentration of 1.0 g / L; Implementation group 1: nutrient solution of the fertilizer of Example 1 with a concentration of 1.0 g / L; Implementation group 2: nutrient solution of the fertilizer of Example 2 with a concentration of 1.0 g / L; Implementation group 3: nutrient solution of the fertilizer of Comparative Example 1 with a concentration of 1.0 g / L; Implementation group 4: nutrient solution of the fertilizer of Comparative Example 2 with a concentration of 1.0 g / L; (2) Measurement frequency: Measure the EC value of the nutrient solution every 24 hours for 7 consecutive days. Calculate the cumulative nutrient absorption rate on the 7th day and compare the differences among the groups.

[0072] Nutrient absorption rate calculation formula:

[0073] Test results and data processing:

[0074] Calculation results: Absorption rate of the control group: [(2.10-1.30) / 2.10]×100 = 38.1%; absorption rate of implementation group 1: [(2.10-0.75) / 2.10]×100 = 64.3%; absorption rate of implementation group 2: [(2.10-0.31) / 2.10]×100 = 85.2%; absorption rate of implementation group 3: [(2.10-1.08) / 2.10]×100 = 48.6%; absorption rate of implementation group 4: [(2.10-0.63) / 2.10]×100 = 70.0%; the absorption efficiency of implementation group 1 compared with the control group was improved by: (64.3%-38.1%) / 38.1%×100 = 68.8%.

[0075] As shown in Table 6, the fertilizer of the present invention significantly increased the nutrient absorption rate of wheat by 68.6% (p<0.01), the EC value decreased faster and the final residue was lower, proving that it can effectively improve the nutrient utilization efficiency of crops.

[0076] Test Example 4 Experimental purpose: To verify whether the fertilizer of the present invention can improve the soil.

[0077] Experimental principle: By comparing the changes in the content of available trace elements (Fe / Zn) in the soil after being treated with ordinary fertilizers and the fertilizer of the present invention, combined with the differences in plant absorption, the chelation effect is doubly verified.

[0078] Materials and Equipment: Soil sample: farmland soil from the same batch (passed through a 2 mm sieve); common wheat seeds (germinated); fertilizer treatments: control group (common fertilizer), experimental group (fertilizer according to Example 1 of the present invention), blank group (no fertilizer blank); testing instrument: spectrophotometer.

[0079] Experimental process: (1) Soil culture experiment (simulating the chelation process) Six wheat seeds that had been germinated were added to each kilogram of soil with three replicates of each group. The conventional fertilizer consisted of 22.3 wt% urea, 27.6 wt% monoammonium phosphate, 17.1 wt% diammonium phosphate, and 33.0 wt% potassium sulfate.

[0080] Culture conditions: 12 h light (LED supplemental lighting, PAR 300 μmol / m² / s) / 12 h dark; 25 ± 2°C (day), 20 ± 1°C (night); deionized water was added daily to maintain 60% of the field capacity. Soil samples were collected on the 7th day, air-dried, and sieved for later use.

[0081] (2) Extraction of effective elements Use a citric acid-hydrochloric acid mixture as the extraction solution (0.05 M citric acid + 0.1 M HCl). Then add 20 mL of the extraction solution to every 10 g of soil sample and shake for 1 hour. Then filter through a 0.45 μm filter membrane and test using the method in the table below.

[0082]

[0083] Test results and data processing:

[0084] Standard curve equation:

[0085]

[0086] Standard curve equation:

[0087] Experimental results:

[0088] As can be seen from Table 10 above, the stronger the chelating ability, the higher the content of effective metal elements, and the higher the content of metal elements that can be extracted by the extract (the chelating ability of a fertilizer refers to the ability to convert non-chelated metals into chelated metals, which is more conducive to plant absorption and utilization). The ability of the fertilizer group of the present invention to chelate Fe and Zn is significantly higher than that of the control group, indicating that compared with ordinary fertilizers, the soil treated with the fertilizer of the present invention can significantly chelate trace elements (Fe / Zn), which is worthy of the name of green fertilizer.

[0089] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A fertilizer having the effect of conditioning soil and improving the nutrient utilization rate of crops, characterized in that: include: 1wt%-5wt% of a biosurfactant, 3wt%-7wt% of a modified zeolite and 86wt%-98wt% of mineral nutrients; The biosurfactant is a fermentation product of Bacillus subtilis, and the modified zeolite is a low-temperature oxygen plasma modified zeolite.

2. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to claim 1, characterized in that: The Bacillus subtilis fermentation product is prepared by the following method: The seed liquid of Bacillus subtilis is inoculated into a fermentation medium, and fermented and cultured at 25°C-35°C for 3-5 days. After filtering and separating the bacteria, the pH is adjusted to 1.8-2.3 for precipitation, and after purification, the Bacillus subtilis fermentation product is obtained; The fermentation medium comprises: 15-25 g / L glucose, 2-8 g / L sodium glutamate, 1-2 g / L potassium dihydrogen phosphate, 0.1-1 g / L magnesium sulfate, 0.01-0.02 g / L iron sulfate and 0.05-0.2 g / L calcium chloride; and the pH value is 6.5-7.

5.

3. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to claim 2, characterized in that: The seed liquid of Bacillus subtilis is prepared by the following method: The Bacillus subtilis strain is first inoculated into LB solid culture medium, cultured at 25°C-35°C for 12-36 hours, and then inoculated into LB liquid culture medium, and cultured with shaking at 25°C-35°C for 6 hours-24 hours to obtain the Bacillus subtilis seed liquid.

4. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to any one of claims 1 to 3, characterized in that: The low-temperature oxygen plasma modified zeolite is prepared by the following method: The zeolite is fully ground and placed in an oxygen plasma apparatus. After vacuuming, high-purity oxygen is introduced to treat the zeolite in a low-temperature oxygen plasma atmosphere. The vacuum degree of the vacuum pumping is 5-10 Pa; the treatment pressure is 20-100 Pa, the radio frequency power is 100-500 W, and the treatment time is 5-15 min.

5. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to claim 4, characterized in that: The zeolite is at least one of clinoptilolite, mordenite or phillipsite.

6. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to any one of claims 1 to 3, characterized in that: The mineral nutrient elements include nitrogen source, phosphorus source and potassium source; The nitrogen source is at least one of urea, ammonium bicarbonate, ammonium sulfate or ammonium chloride; the phosphorus source is at least one of monoammonium phosphate, diammonium phosphate, triammonium phosphate, monoammonium phosphate or calcium phosphate; and the potassium source is at least one of potassium chloride, potassium sulfate or potassium dihydrogen phosphate.

7. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to claim 6, characterized in that: The mass ratio of the nitrogen source, phosphorus source and potassium source is 1:1.5-3:1-1.

5.

8. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to any one of claims 1 to 3, characterized in that: The fertilizer further comprises 0.1 wt% to 1 wt% of a chelating agent; The chelating agent is obtained by subjecting chitosan to a condensation reaction with chloroacetic acid and then subjecting the chitosan to an amidation reaction with alendronic acid.

9. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to any one of claims 1 to 3, characterized in that: The fertilizer is prepared by the following method: The biosurfactant, modified zeolite and mineral nutrients are crushed and added to a drum granulator for granulation, 5wt%-8wt% of water based on the total weight of the fertilizer is added as a binder, and the particle size is controlled to be 2-4mm. The obtained masterbatch is first dried with hot air, then cooled to room temperature with cold air, and then sieved to obtain the fertilizer.

10. The fertilizer having the effect of conditioning soil and improving crop nutrient utilization according to claim 9, characterized in that: The hot air drying comprises: firstly drying at 80-90° C. for 20-40 minutes, and then drying at 50-60° C. for 10-30 minutes.

Images