Slow-release nano organic trace element fertilizer and production method thereof

Abstract

The invention provides a slow-release nano organic trace element fertilizer, which is a mixture of an organic trace element fertilizer nano suspension and a basic carrier, and the organic trace element fertilizer nano suspension comprises organic trace element fertilizer composite nanoparticles and an organic trace element fertilizer clear liquid, suspending the organic microelement fertilizer composite nanoparticles in the organic microelement fertilizer clear liquid to form an organic microelement fertilizer nano suspension; the nano microelement fertilizer has a huge specific surface area, so that the absorption and utilization efficiency of microelements is improved; the source of the trace element fertilizer is expanded, not only can trace element salt be used, but also trace element oxides and simple substance metals with specific meanings can be converted into the trace element fertilizer; the slow release time is set according to different application scenes, so that the use convenience is improved; the nanoscale microelement fertilizer can be matched with an organic fertilizer, a compound fertilizer, a water flush fertilizer, an insecticide and the like for use, and can also be applied to a water and fertilizer integrated system; the nanoscale trace element fertilizer has water insolubility, reduces the influence of environmental factors such as raining and the like, and has higher utilization efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of planting industry (including soil cultivation, soilless substrate cultivation, hydroponics, aeroponics, etc.), specifically to a slow-release nano-organic trace element fertilizer and its production method. Background Technology

[0002] Micronutrient fertilizers contain trace nutrients such as boron, zinc, molybdenum, iron, manganese, and copper. Crops require small amounts of these nutrients, but they are irreplaceable. Deficiency or excess will affect yield and quality, and severe excess can even endanger human and animal health.

[0003] Micronutrient fertilizers are mainly inorganic salts or oxides. Some mineral and metallurgical by-products or wastes can often be used as raw materials for micronutrient fertilizers. Their production methods are the same as those for inorganic chemical products.

[0004] Most current micronutrient fertilizers are in the form of soluble micronutrient ions (inorganic or organic), which have the advantage of rapid absorption, but are also easily lost and have a relatively short duration of action. Most metallic micronutrients in nature exist in oxidized form (ore), making them difficult for plants to utilize and resulting in poor efficacy. Large quantities of elemental metals (scrap iron, scrap copper, slag, ore) are also difficult to use as fertilizers. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a slow-release nano-organic trace element fertilizer and its production method. The nano-scale trace element fertilizer has a large specific surface area, which can greatly improve the absorption and utilization efficiency of trace elements. It expands the sources of trace element fertilizer, allowing the use not only of trace element salts but also the conversion of oxides (in stone form) and elemental metals (in hard blocks) containing specific trace elements into trace element fertilizer. The slow-release time can be set according to different application scenarios, improving ease of use. The nano-scale trace element fertilizer can be used in conjunction with organic fertilizers, compound fertilizers, fertigation fertilizers, pesticides, etc., and can also be applied in integrated water and fertilizer systems. The nano-scale trace element fertilizer is water-insoluble, reducing the impact of environmental factors such as rain and resulting in higher utilization efficiency.

[0006] To achieve the objective of this invention, the technical solution adopted is as follows: A slow-release nano-organic trace element fertilizer is a mixture of an organic trace element fertilizer nano-suspension and a basic carrier. The organic trace element fertilizer nano-suspension includes organic trace element fertilizer composite nanoparticles and organic trace element fertilizer clear liquid. The organic trace element fertilizer composite nanoparticles are suspended in the organic trace element fertilizer clear liquid to form the organic trace element fertilizer nano-suspension.

[0007] A slow-release nano-organic trace element fertilizer, the organic trace element fertilizer nano-suspension includes the following specific raw materials: 150-5000 g of trace element powder, 50-3000 ml of phytic acid solution; the basic carrier is 300-300000 g of fermented and decomposed organic fertilizer.

[0008] Preferably, the trace element powder is one or a mixture of several of the following: ferric sulfate powder, calcium carbonate powder, Hainan phosphogypsum tailings slag powder, rare earth powder, zinc sulfate heptahydrate powder, ferrous sulfate heptahydrate powder / manganese sulfate monohydrate powder / zinc sulfate heptahydrate powder.

[0009] Preferably, the phytic acid solution is an aqueous solution of phytic acid with a mass concentration of 30-60%, and the fermented and decomposed organic fertilizer is one or a mixture of several of the following: fermented and decomposed chicken manure, fermented and decomposed pig manure, and fermented and decomposed Dalbergia odorifera forest litter compost.

[0010] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 150-5000 g of trace element powder, add it in 2-5 portions to 50-3000 ml of phytic acid aqueous solution with a mass concentration of 30-60%, and stir at 300-800 rpm for 3-35 min after each addition, for a total stirring time of 5-90 min, to obtain an organic trace element fertilizer nano-suspension, mix it into 300-300000 g of fermented and decomposed organic fertilizer, and then stir at 300-1500 rpm until the mixture is uniform.

[0011] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 150 g of analytical grade ferric sulfate powder, add it to 100 ml of 50% phytic acid aqueous solution in three portions, stirring at 300 rpm for 5 min after each addition, for a total of 15 min of stirring, to obtain an organic trace element fertilizer nano-suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 1000 rpm until the mixture is uniform.

[0012] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 3200 g of analytically pure calcium carbonate powder, add it in 3 portions to 2000 ml of 50% phytic acid aqueous solution, and stir at 800 rpm for 8 min after each addition, for a total of 24 min of stirring to obtain an organic trace element fertilizer nano-suspension, mix it into 250000 g of fermented and decomposed chicken manure, and then stir at 1500 rpm until the mixture is uniform.

[0013] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weighing 2000 g of Hainan phosphogypsum tailings slag, crushing it through a 100-mesh sieve to prepare Hainan phosphogypsum tailings slag powder, adding it to 1000 ml of 50% phytic acid aqueous solution in three portions, stirring at 500 rpm for 10 min after each addition, for a total of 30 min of stirring, to obtain an organic trace element fertilizer nano-suspension, mixing it into 25000 g of fermented and decomposed chicken manure, and then stirring at 1500 rpm until the mixture is uniform.

[0014] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 100 g of rare earth powder, add it to 50 ml of 50% phytic acid aqueous solution in 5 portions, and stir at 300 rpm for 10 min after each addition, for a total of 50 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 800 rpm until the mixture is uniform.

[0015] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 120 g of analytically pure zinc sulfate heptahydrate powder, add it in two portions to 80 ml of 60% phytic acid aqueous solution, and stir at 300 rpm for 8 min after each addition, for a total of 16 min of stirring to obtain an organic trace element fertilizer nano-suspension, mix it into 40,000 g of fermented and decomposed pig manure, and then stir at 500 rpm until the mixture is uniform.

[0016] As a preferred embodiment, a method for producing the slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 196 g of analytical grade ferrous sulfate heptahydrate powder, 169 g of analytical grade manganese sulfate monohydrate powder, and 288 g of analytical grade zinc sulfate heptahydrate powder, and add them in three portions to 400 ml of a 50% phytic acid aqueous solution. First, add 196 g of ferrous sulfate heptahydrate powder and stir continuously at 500 rpm for 30 min to generate nano-ferric phytate particles; then add 169 g of manganese sulfate monohydrate powder and stir continuously at 500 rpm for 25 min to generate iron-manganese composite phytate particles; finally, add 288 g of zinc sulfate heptahydrate powder and stir again at 800 rpm for 35 min to obtain an organic trace element fertilizer nano-suspension, mix it into 300 g of fermented and decomposed Dalbergia odorifera forest litter compost, and then stir at 1000 rpm until uniformly mixed.

[0017] Phytic acid molecules contain six hydroxyl groups, which can form stable six-coordinate chelates with metal ions (such as Fe-phytate, Zn-phytate, etc.). Phytates of divalent and higher-valent metals have extremely low solubility (<0.1 mg / L). The nanoparticles (50-300 nm) generated by the reaction have high surface energy and good dispersibility, and can be stably suspended in water for a long time, avoiding direct contact of metal ions with the environment and loss.

[0018] After fertilizer is applied to the soil, natural microorganisms in the environment (or artificially added microorganisms / phytase) secrete phytase, which specifically hydrolyzes the ester bonds of phytates, gradually releasing trace element ions (such as Fe²⁺). + Zn² + ) and phosphate. By adjusting the amount of microbial inoculum or enzyme added, the rate of phytate decomposition can be precisely controlled, achieving a slow-release supply of trace elements (the release period can reach 1-3 months or more).

[0019] Metal oxides (such as iron oxide slag), elemental metals (such as waste copper powder), and metal components in industrial waste can be converted into effective nutrients through reaction with phytic acid; at the same time, phytases naturally present in soil organic matter (such as humic acid-related enzymes) can further assist in controlled release without the need for additional chemical coating processes.

[0020] Compared with the prior art, the beneficial effects of the slow-release nano-organic trace element fertilizer and its production method of the present invention are reflected in: Through a dual mechanism of phytate insolubility and microbial controlled release, it significantly extends the effective supply period of trace elements (3-5 times longer than traditional ionic fertilizers) and reduces the loss rate (more than 60% lower); the nano-sized particles (specific surface area ≥300 m² / g) have a large specific surface area, ensuring sufficient contact with the root system, and combined with controlled release, the absorption efficiency of trace elements is increased by 20-40%; it can convert insoluble metal oxides, elemental metals, and industrial waste into fertilizer, reducing production costs and environmental pollution; it is suitable for various trace elements (Fe, Zn, Mn, Cu, Mo, etc.) and different soil types, and can be used alone or in combination with organic fertilizers and macronutrient fertilizers; Nanoscale micronutrient fertilizers possess a huge specific surface area, which can greatly improve the absorption and utilization efficiency of micronutrients. They also expand the sources of micronutrient fertilizers, allowing the use not only of micronutrient salts but also the conversion of oxides (in stone form) and elemental metals (in hard blocks) containing specific micronutrients into micronutrient fertilizers. Slow-release times can be set according to different application scenarios, improving ease of use. Nanoscale micronutrient fertilizers can be used in conjunction with organic fertilizers, compound fertilizers, fertigation fertilizers, and pesticides, and can also be applied in integrated water and fertilizer systems. Furthermore, nanoscale micronutrient fertilizers are water-insoluble, reducing the impact of environmental factors such as rain and resulting in higher utilization efficiency. Detailed Implementation

[0021] The present invention will be further described and illustrated below with reference to specific embodiments.

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship of the technical solution, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] A slow-release nano-organic trace element fertilizer is a mixture of an organic trace element fertilizer nano-suspension and a basic carrier. The organic trace element fertilizer nano-suspension includes organic trace element fertilizer composite nanoparticles and organic trace element fertilizer clear liquid. The organic trace element fertilizer composite nanoparticles are suspended in the organic trace element fertilizer clear liquid to form the organic trace element fertilizer nano-suspension.

[0025] A slow-release nano-organic trace element fertilizer, the organic trace element fertilizer nano-suspension includes the following specific raw materials: 150-5000 g of trace element powder, 50-3000 ml of phytic acid solution; the basic carrier is 300-300000 g of fermented and decomposed organic fertilizer.

[0026] Furthermore, the trace element powder is one or a mixture of several of the following: ferric sulfate powder, calcium carbonate powder, Hainan phosphogypsum tailings slag powder, rare earth powder, zinc sulfate heptahydrate powder, ferrous sulfate heptahydrate powder / manganese sulfate monohydrate powder / zinc sulfate heptahydrate powder.

[0027] Furthermore, the phytic acid solution is an aqueous solution of phytic acid with a mass concentration of 30-60%, and the fermented and decomposed organic fertilizer is one or a mixture of several of the following: fermented and decomposed chicken manure, fermented and decomposed pig manure, and fermented and decomposed Dalbergia odorifera forest litter compost.

[0028] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 150-5000 g of trace element powder, add it in 2-5 portions to 50-3000 ml of phytic acid aqueous solution with a mass concentration of 30-60%, and stir at 300-800 rpm for 3-35 min after each addition, for a total stirring time of 5-90 min, to obtain an organic trace element fertilizer nano-suspension, mix it into 300-300000 g of fermented and decomposed organic fertilizer, and then stir at 300-1500 rpm until the mixture is uniform. Example 1

[0029] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 150 g of analytical grade ferric sulfate powder, add it in 3 portions to 100 ml of 50% phytic acid aqueous solution, and stir at 300 rpm for 5 min after each addition, for a total of 15 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 1000 rpm until the mixture is uniform.

[0030] The control treatment consisted of the same weight of fermented chicken manure (without added organic trace element fertilizer nano-suspension). Forty mature rock sugar orange trees (variety: 'Jincheng', 5 years old, all exhibiting typical iron deficiency chlorosis symptoms—interveinal yellowing of new leaves while the veins remained green) with similar growth conditions were selected from the same orchard and randomly divided into two groups (20 trees in each group). The experimental group received 5000 g of slow-release nano-organic trace element fertilizer (containing approximately 1.875 g of ferric sulfate per tree) applied to the canopy projection area under each tree. The control group received 5000 g of ordinary fermented chicken manure (without added organic trace element fertilizer nano-suspension) per tree.

[0031] Comparison of effects: Experimental group (slow-release nano-organic trace element fertilizer): On the 3rd day after application, the edges of the yellowed leaves began to recover their green color. On the 5th day, the yellowing between the veins of the new leaves obviously faded, and the leaves turned green as a whole (the leaf color was basically the same as that of healthy plants). Control group (ordinary chicken manure, without added organic trace element fertilizer nano suspension): On the 10th day after application, there was no significant improvement in leaf yellowing; on the 15th day, only a few plants showed slight greening between the veins of new leaves; and on the 20th day, some leaves still remained noticeably yellow. Example 2

[0032] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 3200 g of analytically pure calcium carbonate powder, add it in 3 portions to 2000 ml of 50% phytic acid aqueous solution, and stir at 800 rpm for 8 min after each addition, for a total of 24 min of stirring to obtain an organic trace element fertilizer nano-suspension, mix it into 250000 g of fermented and decomposed chicken manure, and then stir at 1500 rpm until the mixture is uniform. Example 3

[0033] The difference between this embodiment and Embodiment 2 is that: A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 180 g of food-grade calcium carbonate powder or 200 g of eggshell powder, add it in 3 portions to 120 ml of a 50% phytic acid aqueous solution, stirring at 300 rpm for 8 min after each addition, for a total stirring time of 24 min, to obtain an organic trace element fertilizer nano-suspension, then add 50,000 g of molasses alcohol waste fermentation liquid with a COD value of 8000 mg / L and an organic matter content of 15%, adjust the pH to 6.5-7.0, and then stir at 1500 rpm until the mixture is uniform.

[0034] The control treatment consisted of the same volume of ordinary molasses alcohol waste fermentation liquid (without the addition of slow-release nano-organic micronutrient fertilizer). Forty tomato plants (variety: Pink Fruit General, characterized by a dark brown, sunken, and rotten blossom-end rot at the fruit blossom end and yellowing of the leaf margins at the top) that had developed blossom-end rot (a typical symptom of calcium deficiency) after three consecutive cropping seasons were selected and randomly divided into two groups (20 plants in each group). In the experimental group, each tomato plant was irrigated with 2500 g of slow-release nano-organic micronutrient fertilizer (containing approximately 4.5 g of calcium carbonate per plant) at the root zone, while in the control group, each plant was irrigated with 2500 g of ordinary molasses alcohol waste fermentation liquid.

[0035] Test metrics and results: Incidence of umbilical rot: The incidence of umbilical rot in the experimental group was 5%, which was significantly lower than that in the control group (45%) by 40 percentage points; Fruit firmness: The firmness of the tomatoes in the experimental group was 3.2 kg / cm², which was 52.4% higher than that of the control group (2.1 kg / cm²). Calcium content: The calcium content of tomato fruit in the experimental group was 186 mg / 100g FW, which was 90.0% higher than that in the control group (98 mg / 100g FW); Single fruit weight: The average single fruit weight in the experimental group was 186.7 g, which was 22.6% higher than that in the control group (152.3 g).

[0036] Conclusion: This embodiment verifies that the combination of calcium-phytic acid organic trace element fertilizer nano-suspension and organic waste liquid fermentation fertilizer can effectively prevent blossom-end rot in tomatoes, increase fruit calcium content, firmness, and single fruit weight, and the nano-sized phytic acid calcium particles (average particle size 300 nm, specific surface area approximately 290 m²) are effective. 2 The slow-release properties of ( / g) ensure a continuous supply of calcium, making it particularly suitable for vegetable crops prone to calcium deficiency in greenhouse cultivation. Example 4

[0037] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weighing 2000 g of Hainan phosphogypsum tailings slag, crushing it through a 100-mesh sieve to prepare Hainan phosphogypsum tailings slag powder, adding it in 3 portions to 1000 ml of 50% phytic acid aqueous solution, stirring at 500 rpm for 10 min after each addition, for a total of 30 min of stirring, to obtain an organic trace element fertilizer nano-suspension, mixing it into 25000 g of fermented and decomposed chicken manure, and then stirring at 1500 rpm until uniformly mixed.

[0038] Select 100 m of land that has shown sulfur deficiency symptoms (pale green to yellow leaves, slow growth) after 5 consecutive years of planting. 2 Acidic red soil rapeseed field (variety: Zhongyouza 2) was randomly divided into two zones (50 square meters each). The experimental zone received 200,000 g of slow-release nano-organic micronutrient fertilizer per mu (containing approximately 3.6 kg / mu of sulfur) as basal application, while the control group received 200,000 g of ordinary phosphogypsum tailings per mu (containing approximately 3.6 kg / mu of sulfur, without the addition of nano-organic micronutrient fertilizer suspension). Relevant indicators were measured during the rapeseed's full flowering period.

[0039] Test metrics and results: Soil pH value: The soil pH value in the experimental area increased to 5.6, which was 0.7 units higher than that in the control group (4.9).

[0040] Sulfur content: The sulfur content of the aboveground parts of rapeseed in the experimental group was 0.42%, which was 100.0% higher than that in the control group (0.21%).

[0041] Dry matter accumulation: The aboveground dry matter weight of rapeseed in the experimental group was 1286 kg / mu, which was 31.0% higher than that of the control group (982 kg / mu).

[0042] Yield: The rapeseed grain yield in the experimental group was 215 kg / mu, which was 30.3% higher than that in the control group (165 kg / mu).

[0043] Oil content: The oil content of rapeseed in the experimental group was 42.8%, which was 8.4% higher than that in the control group (39.5%).

[0044] Conclusion: This embodiment shows that nano-sized phytic acid calcium / sulfur microparticles (average particle size 380 nm, specific surface area of ​​about 210 m² / g) formed by phytic acid and gypsum tailings can effectively improve acidic soil, increase the availability of sulfur, promote sulfur absorption, dry matter accumulation and yield formation in rapeseed, and improve oil quality, thus achieving the dual goals of industrial solid waste resource utilization and soil improvement. Example 5

[0045] The difference between this embodiment and embodiment 4 is that: A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weighing 100,000 g of Hainan phosphogypsum tailings slag, crushing it through a 100-mesh sieve to prepare Hainan phosphogypsum tailings slag powder, adding it to 600 ml of a 30% phytic acid aqueous solution, stirring at 500 rpm for 30 min after each addition to obtain an organic trace element fertilizer nano-suspension, mixing it into 1,000,000 g of acidic red soil with a pH of 4.8, and then stirring at 1500 rpm until uniformly mixed. Example 6

[0046] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 100 g of rare earth powder, add it to 50 ml of 50% phytic acid aqueous solution in 5 portions, and stir at 300 rpm for 10 min after each addition, for a total of 50 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 800 rpm until the mixture is uniform. Example 7

[0047] The difference between this embodiment and embodiment 6 is that: A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 50 g of mixed rare earth oxide powder (calculated as REO, containing light rare earth elements such as La, Ce, Pr, and Nd, with a purity ≥99%), add it to 150 ml of 50% phytic acid aqueous solution in 5 portions, stirring at 250 rpm for 10 min after each addition, for a total stirring time of 50 min, to obtain an organic trace element fertilizer nano-suspension, add 50 g of potassium humate as a dispersing stabilizer, mix it into 2000 g of conventional tea garden organic fertilizer (rapeseed cake fertilizer, containing 7% N), and then stir at 800 rpm until uniformly mixed.

[0048] The control group received the same weight of rapeseed cake fertilizer (without added organic trace element fertilizer nano-suspension). Forty pots of one-year-old tea tree seedlings (variety: Fuding Da Bai Cha) were randomly divided into two groups (20 pots per group). The experimental group received 100 g of phytic acid nano-organic rare earth fertilizer per pot (containing approximately 0.625 g of rare earth oxides per pot), while the control group received 100 g of ordinary rapeseed cake fertilizer per pot.

[0049] Test metrics and results: Rare earth element content: The total rare earth content of the tea shoots in the experimental group was 85.6 mg / kg (calculated as REO), which was significantly enriched compared with the control group (not detected).

[0050] Total amino acid content: The amino acid content of tea in the experimental group was 3.82%, which was 31.3% higher than that in the control group (2.91%).

[0051] Tea polyphenol content: The tea polyphenol content in the experimental group was 22.4%, which was 7.1% lower than that in the control group (24.1%), reaching the appropriate proportion for high-quality green tea.

[0052] Caffeine content: The caffeine content in the experimental group was 3.21%, which was basically the same as that in the control group (3.18%).

[0053] Sensory quality: The experimental group of tea scored 92.5 points (green and lustrous appearance, high and long aroma, fresh, mellow and sweet taste), which was significantly higher than that of the control group (85.3 points), especially the freshness and sweetness.

[0054] Conclusion: This embodiment verifies the formation of nanoscale organic complexes (average particle size 150 nm, specific surface area as high as 510 m²) from phytic acid and rare earth elements. 2 ( / g) can effectively promote the transport and enrichment of rare earth elements in tea plants, optimize the proportion of tea quality components, increase the content of amino acids (fresh and refreshing substances), and coordinate the balance of tea polyphenols and caffeine, significantly improving the sensory quality of green tea, and providing a new way for the safe and efficient utilization of rare earth elements in agricultural production. Example 8

[0055] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 120 g of analytically pure zinc sulfate heptahydrate powder, add it in two portions to 80 ml of a 60% phytic acid aqueous solution, and stir at 300 rpm for 8 min after each addition, for a total of 16 min, to obtain an organic trace element fertilizer nano-suspension, mix it into 40,000 g of fermented and decomposed pig manure, and then stir at 500 rpm until the mixture is uniform.

[0056] The control treatment consisted of the same weight of ordinary fermented pig manure (without added organic micronutrient fertilizer nano-suspension). Forty clumps of zinc-deficient rice (variety: Zhongzheyou 1, exhibiting typical zinc deficiency symptoms—chlorosis at the base of new leaves, leaf tip curling, and stunted growth) with similar growth conditions were selected from the same paddy field and randomly divided into two groups (20 clumps per group). The experimental group received 500g of slow-release nano-organic micronutrient fertilizer (containing approximately 1.5g of zinc sulfate per clump) applied to the rhizosphere of each clump, while the control group received 500g of ordinary fermented pig manure per clump. Relevant indicators were measured during the peak tillering stage of the rice.

[0057] Test metrics and results: Number of tillers: The experimental group had an average of 28.6 tillers per clump, which was 48.2% higher than the control group (19.3 tillers).

[0058] Plant height: The average plant height of rice in the experimental group was 86.3 cm, which was 19.7% higher than that of the control group (72.1 cm).

[0059] Chlorophyll SPAD value: The SPAD value of the functional leaves in the experimental group was 42.6, which was 24.6% higher than that of the control group (34.2).

[0060] Zinc content: The zinc content in the aboveground parts of rice in the experimental group was 28.7 mg / kg, which was 88.8% higher than that in the control group (15.2 mg / kg).

[0061] Conclusion: This embodiment verifies that the zinc phytate nano-suspension prepared by the method of the present invention, when combined with pig manure, can significantly improve zinc deficiency symptoms in rice, increase tiller number, plant height, chlorophyll content, and zinc absorption efficiency. The slow-release characteristics of the nanoparticles ensure a sustained and stable effect. Example 9

[0062] A method for producing a slow-release nano-organic trace element fertilizer as described above includes the following steps: accurately weigh 196 g of analytical grade ferrous sulfate heptahydrate powder, 169 g of analytical grade manganese sulfate monohydrate powder, and 288 g of analytical grade zinc sulfate heptahydrate powder, and add them in three portions to 400 ml of a 50% phytic acid aqueous solution. First, add 196 g of ferrous sulfate heptahydrate powder and stir continuously at 500 rpm for 30 min to generate nano-ferric phytate particles; then add 169 g of manganese sulfate monohydrate powder and stir continuously at 500 rpm for 25 min to generate iron-manganese composite phytate particles; finally, add 288 g of zinc sulfate heptahydrate powder and stir again at 800 rpm for 35 min to obtain an organic trace element fertilizer nano-suspension, mix it into 300 g of fermented and decomposed Dalbergia odorifera forest litter compost, and then stir at 1000 rpm until uniformly mixed.

[0063] Field trial design and effect verification: 1. Experimental Site and Materials: The experiment was conducted at the sandalwood base in Lufeng rare soil forest (pH 4.8-5.2, organic matter content 2.8-3.2%). Sixty 3-year-old Dalbergia odorifera saplings with similar growth vigor (average diameter at breast height 3.2±0.3 cm, average tree height 2.1±0.2 m) were selected and randomly divided into two groups of 30 trees each.

[0064] 2. Processing settings: Experimental group: Each Dalbergia odorifera tree was treated with 200 g of Dalbergia odorifera-specific nano-trace element fertilizer (containing 140 mg iron, 200 mg manganese, and 200 mg zinc). The fertilizer was applied in a shallow circular trench (5-8 cm deep and 10-15 cm wide) at the drip line of the canopy, covered with soil, and thoroughly watered. The fertilizer was applied once each in spring (March-April) and autumn (September-October) for one year.

[0065] Control group: Each plant was treated with 200 g of conventional sulfate micronutrient fertilizer (containing the same amount of ferrous sulfate, manganese sulfate, and zinc sulfate, without phytic acid complexation or nano-treatment), and the application method and timing were the same as the experimental group.

[0066] 3. Test Indicators and Measurement Methods: Growth indicators: Tree height and diameter at breast height were measured before and after the experiment, and annual growth was calculated.

[0067] Leaf nutrition diagnosis: Collect current year functional leaves (mature leaves in the middle and upper part of the canopy) and measure the contents of iron, manganese, and zinc (ICP-OES method) and the chlorophyll SPAD value.

[0068] Physiological activity indicators: The activities of superoxide dismutase (SOD) and peroxidase (POD) in leaves and the content of malondialdehyde (MDA) were measured to evaluate antioxidant capacity and membrane lipid peroxidation level.

[0069] Morphological observation: Record leaf color changes, yellowing rate, and overall tree vigor.

[0070] 4. Application Effect Growth performance Chest diameter growth: The average annual increase in chest diameter in the experimental group was 0.82±0.12 cm, which was significantly higher than that in the control group (0.41±0.08 cm) by 99.8% (p<0.01).

[0071] Tree height growth: The average annual tree height growth in the experimental group was 68.6±8.2 cm, which was significantly higher than that in the control group (42.3±6.7 cm) by 62.2% (p<0.01).

[0072] New shoot growth: The average annual new shoot length per plant in the experimental group was 98.6±12.3 cm, which was 50.8% higher than that in the control group (65.4±9.8 cm); the new shoot thickness was 4.2±0.5 mm, which was 35.5% higher than that in the control group (3.1±0.4 mm).

[0073] Leaf nutrition and health status: Leaf color: The leaves of the experimental group turned from light green to dark green 20-25 days after application. By the end of the experiment (12 months later), all the plants had dark green and glossy leaves without yellowing. The leaves of the control group generally showed interveinal yellowing in the early stage of the experiment (within 3 months) (yellowing rate 83.3%). By the end of the experiment, 40.0% of the plants still had varying degrees of yellowing.

[0074] Trace element content: The iron content in the leaves of the experimental group was 89.6±6.8 mg / kg (dry weight), which was significantly higher than that of the control group (42.3±5.1 mg / kg) by 111.8%; the manganese content was 41.2±3.9 mg / kg, which was significantly higher than that of the control group (21.5±2.8 mg / kg) by 91.6%; and the zinc content was 38.7±3.2 mg / kg, which was significantly higher than that of the control group (19.4±2.1 mg / kg) by 99.5%.

[0075] Chlorophyll content: The SPAD value of the leaves in the experimental group was 52.8±3.1, which was significantly higher than that in the control group (38.6±2.9) by 36.8%, indicating that the photosynthetic capacity was significantly enhanced.

[0076] Physiological activity and stress resistance: Antioxidant enzyme activity: The SOD activity in the leaves of the experimental group was 412.6±35.8 U / g FW, which was 38.3% higher than that of the control group (298.4±28.3 U / g FW); the POD activity was 526.7±42.1 U / g FW, which was 44.2% higher than that of the control group (365.2±31.7 U / g FW); and the MDA content was 8.2±1.1 μmol / g FW, which was significantly lower than that of the control group (14.6±1.8 μmol / g FW) by 43.8%, indicating that the degree of cell membrane lipid peroxidation was low and the stress resistance was enhanced.

[0077] Overall tree vigor: The experimental group plants showed vigorous growth with many branches and thick, glossy leaves; the control group plants showed weak growth with few branches, and some plants showed signs of terminal shoot withering.

[0078] 5. Microstructure Verification: Transmission electron microscopy revealed that the phytic acid-iron-manganese-zinc composite microparticles in the Dalbergia odorifera-specific nano-trace element fertilizer are mainly distributed in the range of 120-300 nm (average approximately 210 nm), with a large specific surface area. This facilitates interaction with rhizosphere exudates (such as organic acids and sugars) of Dalbergia odorifera, promoting root contact and absorption of the nanoparticles. The stable chelate structure formed by the six hydroxyl groups of phytic acid molecules with iron, manganese, and zinc ions ensures the stability of trace elements in the soil, reducing the risk of fixation or leaching by soil colloids.

[0079] Conclusion: This embodiment verifies that a special nano-micronutrient fertilizer for Dalbergia odorifera (based on phytic acid-chelated iron, manganese, and zinc and utilizing the slow-release properties of nanoparticles) can significantly promote the growth of Dalbergia odorifera (increasing diameter at breast height by nearly 100% and tree height by over 60%), effectively prevent and improve leaf yellowing symptoms, increase the content of trace elements such as iron, manganese, and zinc in leaves and photosynthetic efficiency, enhance antioxidant capacity and stress resistance, and solve the problems of easy loss and low absorption efficiency of traditional sulfate trace element fertilizers. This special fertilizer is particularly suitable for the artificial cultivation and quality improvement of rare and precious tree species such as Dalbergia odorifera, providing an innovative solution for the nutritional management of precious tree species, and has significant promotional value and application prospects.

[0080] This invention significantly extends the effective supply period of micronutrients (3-5 times longer than traditional ionic fertilizers) and reduces the loss rate (more than 60% lower) through a dual mechanism of phytate insolubility and microbial controlled release. The large surface area of ​​the nano-sized particles (specific surface area ≥300 m² / g) ensures sufficient contact with roots, and combined with controlled release, increases micronutrient absorption efficiency by 20-40%. It can convert insoluble metal oxides, elemental metals, and industrial waste into fertilizer, reducing production costs and environmental pollution. It is suitable for various micronutrients (Fe, Zn, Mn, Cu, Mo, etc.) and different soil types, and can be used alone or in combination with organic fertilizers and macronutrient fertilizers. Nanoscale micronutrient fertilizers possess a huge specific surface area, which can greatly improve the absorption and utilization efficiency of micronutrients. They also expand the sources of micronutrient fertilizers, allowing the use not only of micronutrient salts but also the conversion of oxides (in stone form) and elemental metals (in hard blocks) containing specific micronutrients into micronutrient fertilizers. Slow-release times can be set according to different application scenarios, improving ease of use. Nanoscale micronutrient fertilizers can be used in conjunction with organic fertilizers, compound fertilizers, fertigation fertilizers, and pesticides, and can also be applied in integrated water and fertilizer systems. Furthermore, nanoscale micronutrient fertilizers are water-insoluble, reducing the impact of environmental factors such as rain and resulting in higher utilization efficiency.

[0081] The technical solutions disclosed in the embodiments of the present invention have been described in detail above. Specific embodiments have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A slow-release nano-organic trace element fertilizer, characterized in that, The slow-release nano-organic trace element fertilizer is a mixture of organic trace element fertilizer nano-suspension and basic carrier. The organic trace element fertilizer nano-suspension includes organic trace element fertilizer composite nanoparticles and organic trace element fertilizer clear liquid. The organic trace element fertilizer composite nanoparticles are suspended in the organic trace element fertilizer clear liquid to form the organic trace element fertilizer nano-suspension. The organic trace element fertilizer nano-suspension comprises the following specific raw materials: 150-5000g of trace element powder, 50-3000ml of phytic acid solution; and 300-300000g of fermented and decomposed organic fertilizer as the basic carrier.

2. The slow-release nano-organic trace element fertilizer according to claim 1, characterized in that, The trace element powder is one or a mixture of several of the following: ferric sulfate powder, calcium carbonate powder, Hainan phosphogypsum tailings slag powder, rare earth powder, zinc sulfate heptahydrate powder, ferrous sulfate heptahydrate powder / manganese sulfate monohydrate powder / zinc sulfate heptahydrate powder.

3. The slow-release nano-organic trace element fertilizer according to claim 1, characterized in that, The phytic acid solution is a phytic acid aqueous solution with a mass concentration of 30-60%, and the fermented and decomposed organic fertilizer is one or a mixture of several of the following: fermented and decomposed chicken manure, fermented and decomposed pig manure, and fermented and decomposed Dalbergia odorifera forest litter compost.

4. A method for producing a slow-release nano-organic trace element fertilizer as described in any one of claims 1-3, characterized in that, The production method includes the following steps: accurately weigh 150-5000 g of trace element powder, add it in 2-5 portions to 50-3000 ml of phytic acid aqueous solution with a mass concentration of 30-60%, and stir at 300-800 rpm for 3-35 min after each addition, for a total stirring time of 5-90 min to obtain an organic trace element fertilizer nano suspension, mix it into 300-300000 g of fermented and decomposed organic fertilizer, and then stir at 300-1500 rpm until the mixture is uniform.

5. The method for producing slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 150 g of analytical grade ferric sulfate powder, add it to 100 ml of 50% phytic acid aqueous solution in 3 portions, and stir at 300 rpm for 5 min after each addition, for a total of 15 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 1000 rpm until it is evenly mixed.

6. The method for producing the slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 3200 g of analytical grade calcium carbonate powder, add it to 2000 ml of 50% phytic acid aqueous solution in 3 portions, and stir at 800 rpm for 8 min after each addition, for a total of 24 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 250000 g of fermented and decomposed chicken manure, and then stir at 1500 rpm until it is evenly mixed.

7. The method for producing slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 2000 g of Hainan phosphogypsum tailings slag, crush it through a 100-mesh sieve to prepare Hainan phosphogypsum tailings slag powder, add it to 1000 ml of 50% phytic acid aqueous solution in 3 portions, and stir at 500 rpm for 10 min after each addition, for a total of 30 min of stirring to obtain organic trace element fertilizer nano suspension, mix it into 25000 g of fermented and decomposed chicken manure, and then stir at 1500 rpm until it is evenly mixed.

8. The method for producing slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 100 g of rare earth powder, add it to 50 ml of 50% phytic acid aqueous solution in 5 portions, and stir at 300 rpm for 10 min after each addition, for a total of 50 min of stirring to obtain an organic trace element fertilizer nano suspension, mix it into 50,000 g of fermented and decomposed chicken manure, and then stir at 800 rpm until it is evenly mixed.

9. The method for producing the slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 120 g of analytically pure zinc sulfate heptahydrate powder, add it in 80 ml of 60% phytic acid aqueous solution in two portions, and stir at 300 rpm for 8 min after each addition, for a total of 16 min, to obtain an organic trace element fertilizer nano suspension, mix it into 40,000 g of fermented and decomposed pig manure, and then stir at 500 rpm until it is evenly mixed.

10. The method for producing the slow-release nano-organic trace element fertilizer according to claim 4, characterized in that, The production method includes the following steps: accurately weigh 196 g of analytical grade ferrous sulfate heptahydrate powder, 169 g of analytical grade manganese sulfate monohydrate powder, and 288 g of analytical grade zinc sulfate heptahydrate powder, and add them in three portions to 400 ml of 50% phytic acid aqueous solution. First, add 196 g of ferrous sulfate heptahydrate powder and stir continuously at 500 rpm for 30 min to generate nano-ferrous phytic acid particles. Then, add 169 g of manganese sulfate monohydrate powder and stir continuously at 500 rpm for 25 min to generate iron-manganese composite phytate particles. Finally, add 288 g of zinc sulfate heptahydrate powder and stir again at 800 rpm for 35 min to obtain an organic trace element fertilizer nano-suspension. Mix this with 300 g of fermented and decomposed Dalbergia odorifera forest litter compost and stir at 1000 rpm until evenly mixed.