Preparation method and application of nano organic fertilizer
By using raw material classification pretreatment and nanoscale wet shear-collision grinding technology, the problems of equipment blockage and uneven particle size in organic fertilizer production have been solved, and nano-organic fertilizer has been prepared, which has improved production stability and product quality consistency, and enhanced the specific surface area and application effect of fertilizer.
Patent Information
- Application Number
- CN202511318340.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2026-01-09
Smart Images
Figure CN121293067A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic fertilizer processing technology, specifically to a method for preparing nano-organic fertilizer and its application. Background Technology
[0002] Organic fertilizer, made from composted organic waste, is a widely used soil conditioner and nutrient source in agricultural production. Conventional organic fertilizer products are usually used directly or after preliminary crushing. However, current technologies still present several technical challenges in the process of further processing composted products to enhance their application effectiveness.
[0003] First, as a biological fermentation product, compost naturally exhibits heterogeneity in its physical properties, containing organic components of varying sizes and incompletely decomposed clumps. When such raw materials are directly fed into subsequent fine grinding or processing equipment, this heterogeneity leads to unstable feed and uneven stress on the grinding media, causing drastic fluctuations in equipment load, and even blockages, thereby interrupting the production process and affecting the overall operational stability of the process.
[0004] Secondly, existing methods for increasing the specific surface area of fertilizers mostly employ conventional dry or wet mechanical pulverization. These methods have limitations in their ability to reduce particle size to the nanoscale, making it difficult to accurately and stably obtain products with a particle size distribution below 1000 nm. Furthermore, these conventional pulverization processes primarily break particles through physical impact and friction, typically without significantly altering the microstructure of the particle surface. Therefore, they cannot simultaneously reduce particle size and create a microporous surface, limiting further improvements in specific surface area and surface reactivity.
[0005] Finally, considering the aforementioned heterogeneity of raw materials and limitations in processing technology, existing processes struggle to achieve strict process control when producing high-value-added organic fertilizers. Differences between batches of raw materials and uncontrollable factors in the grinding process result in significant batch-to-batch variations in the physical properties of the final product (such as particle size distribution and specific surface area). This inconsistency in product quality constitutes a technical obstacle to achieving stable, large-scale production, limiting its application in scenarios requiring precise application and efficient absorption. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing nano-organic fertilizer and its application, solving the problems of uneven particle size, small specific surface area, and unstable production process in existing organic fertilizer products.
[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing nano-organic fertilizer, comprising the following steps:
[0008] Step 1, Raw Material Grading Pretreatment: The mature compost product is screened to separate coarse organic components and collect fine powder components. This step removes heterogeneous coarse particles in advance through physical separation, ensuring the uniformity of feed in subsequent grinding processes, thereby improving the stability of the process and the uniformity of the final product.
[0009] Step 2, preparation of homogeneous slurry: The fine powder components are mixed with deionized water at a predetermined solid-liquid ratio to form a homogeneous slurry.
[0010] Step 3, Nanoscale Wet Shear-Collision Grinding: The homogeneous slurry is placed in a sand mill, and the grinding media driven by a high-speed rotating disperser grinds the homogeneous slurry to obtain liquid nano-organic fertilizer. In this step, high-frequency shearing, collision, and friction act on the organic fertilizer particles, reducing their particle size to the nanoscale.
[0011] Step 4, Post-processing of the product: The liquid nano-organic fertilizer is subjected to solid-liquid separation and drying to obtain nano-organic fertilizer powder.
[0012] Furthermore, the raw material grading pretreatment in step one specifically involves screening the mature compost product using a 200-mesh sieve.
[0013] Furthermore, the predetermined solid-liquid ratio (mass:volume) in step two is in the range of 1:20 to 1:40.
[0014] Furthermore, the shearing and stirring speed in step three is 1500 r / min to 2000 r / min, and the grinding time is 10 min to 30 min.
[0015] Furthermore, the solid-liquid separation in step four is centrifugation, and the drying process is freeze-drying.
[0016] Furthermore, the seed germination index of the decomposed compost product is not less than 70%.
[0017] A second aspect of this invention provides a nano-organic fertilizer powder, which is prepared by the method described in the first aspect of this invention. The high-energy physical processes in this preparation method not only reduce the size of the particles but also alter their original physical structure.
[0018] Furthermore, the particle size range of the nano-organic fertilizer powder is 122.42 nm to 824.99 nm.
[0019] Furthermore, the nano-organic fertilizer powder has a microporous structure.
[0020] A third aspect of the present invention provides the application of the nano-organic fertilizer powder in improving crop yield and quality or improving soil properties.
[0021] This invention provides a method for preparing nano-organic fertilizer and its application. It has the following beneficial effects:
[0022] 1. This invention incorporates a raw material grading pretreatment step before nano-grinding. By using sieving to physically remove coarse organic components and lumps from the mature compost, it ensures high uniformity of the material entering the subsequent grinding process. This step avoids clogging or excessive wear of the grinding equipment due to material inhomogeneity, thereby significantly improving the operational stability of the entire preparation process.
[0023] 2. The nanoscale wet shear-impact grinding process employed in this invention, through precise control of shearing and stirring speed and grinding time, not only effectively reduces the particle size of mature compost particles to the nanoscale, but also alters the original surface morphology of the particles through this high-energy physical action. This structural change creates a microporous structure, increasing the specific surface area of the particles, a physical property that is difficult to obtain using traditional preparation methods.
[0024] 3. The raw material for the nano-organic fertilizer of this invention is a well-rotted compost product of livestock and poultry manure, which is widely available and inexpensive, and can realize the resource utilization and high-value utilization of organic waste. Attached Figure Description
[0025] Figure 1 Scanning electron microscope (SEM) images of ordinary organic fertilizer (a) and prepared nano-organic fertilizer (b);
[0026] Figure 2 The particle size distribution of ordinary organic fertilizer (a) and prepared nano-organic fertilizer (b) is shown.
[0027] Figure 3 Changes in surface functional groups between ordinary organic fertilizer and prepared nano-organic fertilizer;
[0028] Figure 4 Thermogravimetric analysis of ordinary organic fertilizer (a) and prepared nano-organic fertilizer (b). Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Example 1:
[0031] A method for preparing a nano-organic fertilizer, the specific steps of which are as follows:
[0032] Step 1: Raw material grading and pretreatment: Take the chicken manure compost product that has undergone high-temperature aerobic fermentation treatment, whose seed germination index is 75%. Place the compost product on a 200-mesh standard vibrating screen for sieving, and collect the fine powder components that pass through the screen.
[0033] Step 2: Preparation of homogeneous slurry: Weigh 100g of the fine powder component obtained in Step 1 and add it to 2000mL of deionized water, with a solid-liquid ratio (mass:volume) of 1:20. At room temperature, mechanically stir at 600r / min for 15 minutes to form a homogeneous slurry.
[0034] Step 3: Nanoscale wet shear-impact grinding: The homogeneous slurry prepared in Step 2 is pumped into a horizontal rod-pin mill using a peristaltic pump. The spindle speed of the mill is set to 1500 r / min, and the mill is circulated and ground for 30 minutes to obtain liquid nano-organic fertilizer.
[0035] Step 4, Product Post-processing: The liquid nano-organic fertilizer obtained in Step 4 is centrifuged at 10000g for 20 minutes, the supernatant is discarded, and the solid precipitate is collected. The solid precipitate is freeze-dried at -50℃ and a vacuum degree below 10Pa for 48 hours to obtain nano-organic fertilizer powder.
[0036] Example 2:
[0037] A method for preparing a nano-organic fertilizer, the specific steps of which are as follows:
[0038] Step 1: Raw material grading and pretreatment: Take the cow manure compost product that has undergone high-temperature aerobic fermentation treatment, whose seed germination index is 80%. Place the compost product on a 200-mesh standard vibrating screen for sieving, and collect the fine powder components that pass through the screen.
[0039] Step 2: Preparation of homogeneous slurry: Weigh 50g of the fine powder component obtained in Step 1 and add it to 2000mL of deionized water, with a solid-liquid ratio (mass:volume) of 1:40. Stir mechanically at 800r / min for 20 minutes at room temperature to form a homogeneous slurry.
[0040] Step 3: Nanoscale wet shear-impact grinding: The homogeneous slurry prepared in Step 2 is pumped into a horizontal rod-pin mill using a peristaltic pump. The spindle speed of the mill is set to 2000 r / min, and the mill is circulated and ground for 10 minutes to obtain liquid nano-organic fertilizer.
[0041] Step 4, Product Post-processing: The liquid nano-organic fertilizer obtained in Step 3 is centrifuged at 10000g for 20 minutes, the supernatant is discarded, and the solid precipitate is collected. The solid precipitate is freeze-dried at -50℃ and a vacuum degree below 10Pa for 48 hours to obtain nano-organic fertilizer powder.
[0042] Example 3:
[0043] A method for preparing a nano-organic fertilizer, the specific steps of which are as follows:
[0044] Step 1: Raw material grading and pretreatment: Take the pig manure compost product that has undergone high-temperature aerobic fermentation treatment, with a seed germination index (GI) of 72%. Place the compost product on a 200-mesh standard vibrating screen for sieving, and collect the fine powder components that pass through the screen.
[0045] Step 2: Preparation of homogeneous slurry: Weigh 200g of the fine powder component obtained in Step 1 and add it to 2000mL of deionized water, with a solid-liquid ratio (mass:volume) of 1:10. Stir mechanically at 500r / min for 20 minutes at room temperature to form a homogeneous slurry.
[0046] Step 3: Nanoscale wet shear-impact grinding: The homogeneous slurry prepared in step 2 is pumped into a horizontal rod-pin mill via a peristaltic pump. The spindle speed of the mill is set to 1000 r / min, and the mill is circulated and ground for 50 minutes to obtain liquid nano-organic fertilizer.
[0047] Step 4, Product Post-processing: The liquid nano-organic fertilizer obtained in Step 3 is centrifuged at 10000g for 20 minutes, the supernatant is discarded, and the solid precipitate is collected. The solid precipitate is freeze-dried at -50℃ and a vacuum degree below 10Pa for 48 hours to obtain nano-organic fertilizer powder, denoted as S3.
[0048] Example 4:
[0049] A method for preparing a nano-organic fertilizer, the specific steps of which are as follows:
[0050] Step 1: Raw material grading and pretreatment: Take sheep manure compost that has undergone high-temperature aerobic fermentation, with a seed germination index of 85%. Place the compost product on a 200-mesh standard vibrating screen for sieving, and collect the fine powder components that pass through the screen.
[0051] Step 2: Preparation of homogeneous slurry: Weigh 40g of the fine powder component obtained in Step 1 and add it to 2000mL of deionized water, with a solid-liquid ratio (mass:volume) of 1:50. Stir mechanically at 700r / min for 15 minutes at room temperature to form a homogeneous slurry.
[0052] Step 3: Nanoscale wet shear-impact grinding: The homogeneous slurry prepared in Step 2 is pumped into a horizontal rod-pin mill using a peristaltic pump. The mill spindle speed is set to 3000 r / min, and the mill is circulated and ground for 20 minutes to obtain liquid nano-organic fertilizer.
[0053] Step 4, Product Post-processing: The liquid nano-organic fertilizer obtained in Step 3 is centrifuged at 10000g for 20 minutes, the supernatant is discarded, and the solid precipitate is collected. The solid precipitate is freeze-dried at -50℃ and a vacuum degree below 10Pa for 48 hours to obtain nano-organic fertilizer powder.
[0054] Comparative Example 1
[0055] Compared with Example 1, the difference is that the raw material grading pretreatment in step one was not performed. Instead, the unscreened chicken manure compost product was directly used for the preparation of homogenized slurry in step two. All other aspects are the same.
[0056] Comparative Example 2
[0057] Compared to Example 1, the difference lies in that step three, nanoscale wet shear-impact grinding, is omitted. Specifically, after preparing the homogeneous slurry, conventional mechanical stirring is continued at room temperature for 30 minutes, without using a sand mill for high-energy grinding; all other steps remain the same.
[0058] Test Example 1: Comparative Test of Preparation Process Stability and Product Physical Properties
[0059] Experimental steps
[0060] Process stability test
[0061] Two sets of experiments were set up according to the preparation methods of Example 1 and Comparative Example 1, respectively.
[0062] In the grinding steps of both sets of experiments, a high-precision power analyzer was connected to the drive motor of the sand mill. Timing was started from the beginning of grinding, and the instantaneous operating current of the motor was recorded every minute for 30 minutes.
[0063] At the same time, record whether the motor stops for protective purposes or requires manual intervention to resume operation during the entire 30-minute grinding process due to excessive equipment load, material blockage, or other reasons. This number is recorded as the number of process interruptions.
[0064] Product physical property testing
[0065] Sample preparation: Take the nano-organic fertilizer powders (S1, S2, S3, S4) prepared in Examples 1-4 and the product prepared in Comparative Example 2 respectively.
[0066] Particle size distribution determination: Weigh 0.1 g of each sample and disperse it in 100 mL of deionized water to prepare a suspension. After dispersing the suspension in an ultrasonic cleaner for 15 minutes, determine the particle size distribution range of each sample using a Zetasizer NanoZS dynamic light scattering particle size analyzer.
[0067] Microscopic morphology observation: A small amount of each dry powder sample (Example 1, Example 2, Example 3, Example 4 and Comparative Example 2) was fixed on the sample stage, sputtered with gold, and the surface morphology of the particles was observed and photographed at 10,000x magnification using a scanning electron microscope.
[0068] The experimental data are shown in Table 1:
[0069] Table 1 Comparison of process stability and product physicochemical properties test results
[0070]
[0071] Analysis of Experimental Results
[0072] Data shows that Comparative Example 1, which did not undergo screening pretreatment, exhibited significant current fluctuations and process interruptions during the grinding step. This is because coarse organic components and agglomerates in the raw material directly entered the sand mill, causing irregular obstruction to the movement of the grinding media and leading to drastic changes in equipment load. In contrast, the raw material classification pretreatment step used in Examples 1-4 removed these heterogeneous components through a 200-mesh sieve, ensuring the uniformity of the material entering the grinding unit and thus achieving stable equipment operating conditions. This is the foundation for achieving subsequent controllable nano-sizing.
[0073] The comparison of the physical properties of the products shows that wet shear-impact grinding at the nanoscale is the decisive step in obtaining nanoscale particles. Comparative Example 2 only uses conventional mechanical stirring, whose energy input is insufficient to overcome the cohesive forces of the particles and induce effective breakage; the final product particle size remains at the micrometer level. In contrast, in Examples 1-4, the material is subjected to high-frequency shearing and impact forces from the grinding media driven by a high-speed rotating disperser within the sand mill. This high-energy physical force effectively reduces the particle size of the fine powder components to below 1000 nm, achieving nanoscale production.
[0074] Further microscopic morphology analysis confirmed that this method not only alters the particle size but also its physical structure. Under stable process conditions ensured by raw material classification pretreatment, the high-energy forces in the nanoscale wet shear-collision grinding step are continuously and uniformly applied to the particle surface. This force, in addition to reducing particle size, also physically etches the particle surface, forming a microporous structure not present in the product of Comparative Example 2. This microporous structure is one of the inherent physical characteristics of the nano-organic fertilizer powder prepared by this method, increasing the specific surface area of the particles.
[0075] Test Example 2: Comparative Test of Impact on Crop Yield and Quality
[0076] Experimental steps
[0077] Pot experiment setup:
[0078] Select plastic pots of uniform size (15cm in diameter), and fill each pot with 2kg of sterilized garden soil and vermiculite mixed substrate (volume ratio 3:1).
[0079] Three treatment groups were set up: the group receiving the product of Example 1 (S1 group), the group receiving the product of Comparative Example 2 (D2 group), and the control group without fertilizer (CK group). Each group had 5 replicate pots.
[0080] Fertilization: For groups S1 and D2, 2.0g of S1 powder and D2 product were mixed with the top 5cm of substrate in each pot. No fertilizer was applied to the control group.
[0081] Sowing and Management: Sow 10 Shanghai bok choy seeds in each pot. Thin the seedlings one week after emergence, leaving 3 evenly growing seedlings. Place all potted plants in a greenhouse, controlling the light intensity to 14 hours / day and the temperature to 25±2℃. Water daily by weighing to maintain soil moisture at around 70%.
[0082] Indicator Measurement:
[0083] Samples were taken and measured on the 35th day after sowing.
[0084] Yield indicators: Harvest the above-ground parts of all plants and immediately weigh their fresh weight using an electronic balance. Then, place the samples in a 105℃ oven for 30 minutes to blanch them, and then transfer them to a 75℃ oven to dry to constant weight, and weigh their dry weight.
[0085] Quality Indicators:
[0086] Chlorophyll content: Using a SPAD-502 portable chlorophyll meter, the SPAD value of the third fully expanded leaf at the top of each plant was measured. Three points were measured for each leaf, and the average value was taken.
[0087] Vitamin C content: Fresh leaf samples were taken and determined according to the Solarbio BC1235 kit instructions.
[0088] Soluble sugar content: Take fresh leaf samples and determine the content according to the Solarbio BC0030 kit instructions.
[0089] The experimental data are shown in Table 2:
[0090] Table 2. Effects of different treatments on the yield and quality of Chinese cabbage.
[0091]
[0092] Analysis of Experimental Results
[0093] Experimental data show that, compared with the unfertilized treatment and the treatment using the product of Comparative Example 2, the treatment using the product of Example 1 significantly improved both the fresh weight and dry weight of the pak choy. This increase in biomass is due to the physical properties of the product of Example 1. Its nanoscale particle size and microporous structure work together to greatly increase the specific surface area of the particles, thereby increasing the effective contact area between the fertilizer particles and the plant roots. This allows nutrients to be released more efficiently from the solid particles and absorbed by the roots, thus providing a more sufficient material basis for plant growth.
[0094] Regarding crop quality, the treatment applying the product of Example 1 also showed advantages, with higher levels of chlorophyll, vitamin C, and soluble sugars compared to the two control treatments. Chlorophyll synthesis is closely related to nitrogen supply, while the synthesis and transport of vitamins and sugars require the synergistic effect of various mineral elements. The high reactivity of the product of Example 1 due to its nanostructure enhances the bioavailability of nutrients, ensuring the smooth operation of key metabolic activities within the plant, ultimately resulting in improved measurable quality indicators.
[0095] In summary, the results of this test case confirm that the unique physical structure imparted to the product by the preparation method is the direct cause of its functionality. The nanoscale particle size and microporous structure obtained through nanoscale wet shear-impact milling are the essential characteristics that distinguish the product of Example 1 from the product of Comparative Example 2. These structural features alter the interaction between fertilizer and the plant-soil system, improve nutrient utilization efficiency, and ultimately achieve a dual improvement in crop yield and quality.
[0096] Test Example 3: Comparative Test on the Impact on Soil Properties
[0097] Experimental steps
[0098] Soil sample collection and preparation:
[0099] After the crops were harvested from the potted experiment in Test Example 2, soil samples were collected from each replicate pot of the product group of Example 1 (S1 group), the product group of Comparative Example 2 (D2 group), and the unfertilized control group (CK group) at a depth of 0-10 cm using a five-point sampling method, and the five replicate samples of the same treatment group were mixed evenly.
[0100] Place the mixed soil sample in a dark and well-ventilated indoor area to air dry naturally, and remove plant roots, gravel, and other debris.
[0101] The air-dried soil sample was ground until it passed through a 2mm sieve and then bagged for later use.
[0102] Soil physicochemical property determination:
[0103] pH and EC: Weigh the sieved soil sample and add deionized water at solid-liquid ratios of 1:2.5 (pH) and 1:5 (EC), respectively. After shaking for 30 minutes and standing, the pH and EC values of the supernatant were measured using a DZS-706-A multi-parameter analyzer.
[0104] Organic matter: determined by potassium dichromate titration method.
[0105] Alkaline nitrogen: determined by alkaline diffusion method.
[0106] Available phosphorus: extracted with 0.5 mol / L sodium bicarbonate solution and determined by molybdenum antimony colorimetric method.
[0107] Available potassium: extracted with 1 mol / L ammonium acetate solution and determined by flame photometry.
[0108] Soil enzyme activity assay:
[0109] Weigh out sieved soil samples and perform the corresponding reagent kit instructions to determine the activities of soil catalase, urease, and sucrase.
[0110] The experimental data are shown in Table 3:
[0111] Table 3 Effects of different treatments on soil properties and enzyme activity
[0112]
[0113] Analysis of Experimental Results
[0114] The experimental data in this test case show that the application of the products of Example 1 and Comparative Example 2 both affected the chemical properties of the soil. Specifically, the available phosphorus and available potassium contents in the soil treated with the product of Example 1 were significantly higher than those in the treatment group treated with the product of Comparative Example 2 and the unfertilized treatment group. This is because the nano-organic fertilizer powder obtained by this preparation method has a large specific surface area due to its nano-sized particle size and microporous structure. This allows the phosphorus and potassium elements in the particles to come into more complete contact with the soil solution, accelerating their dissociation rate from the organic complex, thereby increasing the concentration of available components in the soil nutrient pool.
[0115] The residual amounts of soil organic matter and available nitrogen in the Example 1 treatment group after crop harvest were slightly lower than those in the Comparative Example 2 treatment group. This does not indicate insufficient fertilizer efficiency of the Example 1 product, but rather a direct reflection of its high efficiency. Combined with the significant increase in crop biomass in Test Example 2, it can be inferred that the efficient release of nutrients by the Example 1 product supported stronger plant growth and higher nutrient uptake. Therefore, the lower nutrient residue in the soil after harvest precisely demonstrates the efficient utilization of nutrients by the crop, contrasting with the situation in Comparative Example 2 where the larger particle size and slower nutrient release of the product resulted in more nutrients remaining in the soil.
[0116] Changes in soil enzyme activity reflect the response of soil microbial communities to different material inputs. The soil sucrase activity in the treatment group of Example 1 was significantly higher than that in the unfertilized treatment group, indicating that its application can promote microbial activity related to soil carbon cycling. This increased activity is related to the unique physical structure of the product. Its microporous surface structure not only directly releases nutrients but also provides a new habitat microenvironment for soil microorganisms, altering local material and energy exchange and thus affecting the metabolic functions of specific microbial populations. These combined effects constitute the improvement of soil properties by the product of this method.
[0117] 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 preparing a nano-organic fertilizer, characterized in that, Includes the following steps: Step 1, raw material grading and pretreatment: The mature compost product is screened to separate the coarse organic components and collect the fine powder components; Step 2, preparation of homogeneous slurry: The fine powder components are mixed with deionized water at a predetermined solid-liquid ratio to form a homogeneous slurry; Step 3, Nanoscale wet shear-collision grinding: The homogeneous slurry is placed in a sand mill, and the grinding media driven by a high-speed rotating disperser are used to grind the homogeneous slurry to obtain liquid nano-organic fertilizer; Step 4, Post-processing of the product: The liquid nano-organic fertilizer is subjected to solid-liquid separation and drying to obtain nano-organic fertilizer powder.
2. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The raw material grading pretreatment in step one specifically involves screening the mature compost product using a 200-mesh sieve.
3. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The predetermined solid-liquid ratio (mass:volume) in step two is in the range of 1:20 to 1:
40.
4. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The shearing and stirring speed in step three is 1500 r / min to 2000 r / min, and the grinding time is 10 min to 30 min.
5. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The solid-liquid separation in step four is centrifugation, and the drying process is freeze-drying.
6. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The seed germination index of the well-rotted compost product shall not be less than 70%.
7. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The particle size range of the nano-organic fertilizer powder is 122.42 nm to 824.99 nm.
8. The method for preparing a nano-organic fertilizer according to claim 1, characterized in that, The nano-organic fertilizer powder has a microporous structure.
9. The application of a nano-organic fertilizer prepared by any one of claims 1-8 in improving crop yield, quality, or soil properties.