Controlled-release type high-nitrogen organic water-soluble fertilizer containing humic acid and preparation method of controlled-release type high-nitrogen organic water-soluble fertilizer

Abstract

The invention discloses a controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid and a preparation method of the controlled-release high-nitrogen organic water-soluble fertilizer. The fertilizer is prepared from the following raw materials: a urea ammonium nitrate solution, an organic concentrated solution, a controlled release agent, a trace element bag, a solubilizer, a preservative, water and the like. The organic concentrated solution contains activated humic acid which can be chelated with quick-acting nitrogen, so that the nitrogen loss is reduced; the controlled release agent adjusts the nitrogen release period, shortens the nitrogen release period to 60-90 days, and accords with the growth period of fruit and vegetable crops. The solubilizer improves the solubility of the fertilizer, and the preservative prevents infectious microbe pollution and ensures the stability of the fertilizer. The preparation method comprises the step of sequentially mixing and dissolving the raw materials. The fertilizer improves the nitrogen utilization rate, supplements organic nutrients and trace elements, saves time and labor, conforms to agricultural fertilization habits and has remarkable economic benefits.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water-soluble fertilizer, and particularly relates to a high-nitrogen organic water-soluble fertilizer containing humic acid and a preparation method thereof. BACKGROUND

[0002] In recent years, with the development and popularization of water and fertilizer integration technology, new slow-release high-nitrogen fertilizers represented by urea ammonium nitrate solution (UAN) gradually stand out in the drip irrigation water and fertilizer integration agricultural production. The three nitrogen sources of nitrate nitrogen, ammonium nitrogen and amide nitrogen are concentrated together, the product is neutral, has the advantages of low corrosion, good compounding property, high water solubility and high utilization efficiency. However, the nitrogen release period is relatively fixed, usually 110-130 days, which does not match the growth period (60-90 days) of most economic crops, resulting in low utilization rate of fertilizer in the season or poor nutrient absorption of crops. In addition, urea ammonium nitrate solution is unstable at low temperature and is prone to crystallization, which affects the fertilizer effect, reduces the fertilizer effect, reduces the economic benefit of fertilizer application, and causes the dilemma of increased agricultural cost. Finally, the single application of urea ammonium nitrate solution can only supplement inorganic nutrient elements, which easily causes the plant to be in a latent hunger state of lack of nutrients and quality decline, and causes hidden troubles to the food health and safety of the people. SUMMARY

[0003] The purpose of the present application is to provide a high-nitrogen water-soluble fertilizer containing humic acid, which shortens the nitrogen release period of urea ammonium nitrate solution through a simple and effective compounding process, so that the nitrogen release period is shortened to 60-90 days, which is more suitable for fruit and vegetable economic crops, and expands the application range of urea ammonium nitrate solution.

[0004] To achieve the above technical purpose, the technical scheme adopted by the present application is: A high-nitrogen organic water-soluble fertilizer containing humic acid is prepared from the following raw materials by weight: urea ammonium nitrate solution 55-65 parts, organic concentrate 10-25 parts, controlled release agent 4-8 parts, trace element package 2-3 parts, solubilizing agent 5-10 parts, preservative 0.1-1 part, and water 5-25 parts; the controlled release agent is one or a mixture of two of potassium nitrate, ammonium sulfate, ammonium chloride, polyammonium phosphate and monoammonium phosphate.

[0005] Preferably, the organic concentrate is one or a mixture of two of paper pulp, yeast concentrate, yellow water extract, seaweed extract and straw extract.

[0006] Preferably, the organic matter content is 50-100 g / L, and the total nitrogen content is 230-270 g / L.

[0007] Preferably, the trace element package is composed of the following raw fertilizers by weight: zinc sulfate 0.6-0.8 parts, manganese sulfate 0.2-0.4 parts, copper sulfate 0.2-0.4 parts, borax 0.6-0.8 parts, and ferrous sulfate 0.4-0.6 parts.

[0008] Preferably, the solubilizing agent comprises a surfactant, a cosolvent, and a stabilizer.

[0009] Preferably, the surfactant is one or more of sodium dodecyl benzene sulfonate, polyethylene glycol, betaine, and Tween.

[0010] Preferably, the cosolvent is one or both of ethylene glycol, glycerol, and glycerin.

[0011] Preferably, the stabilizer is one or more of citric acid, cyclodextrin, lignin, and polyvinylpyrrolidone.

[0012] Preferably, the preservative is one or both of benzalkonium bromide, potassium sorbate, casson, and p-chloro-m-dimethylphenol.

[0013] The present application also provides a preparation method of the humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer, which comprises the following steps: S1: heating the urea ammonium nitrate solution to 50-60℃, adding the solubilizing agent into the urea ammonium nitrate solution while hot, and stirring for 1-2h to obtain a first solution; S2: heating the organic concentrate to 60-70℃, adding the trace element package into the organic concentrate while hot, and stirring for 1-2h to obtain a second solution; S3: dissolving the liquid slow-release nitrogen controlled-release agent in water to obtain a third solution; S4: keeping the temperature of the first solution at 50-60℃, adding the third solution, the second solution, and the preservative into the first solution in sequence, and keeping stirring for 1-2h to obtain the humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer.

[0014] The activated humic acid contained in the organic concentrate used in the present application can chelate the readily available nitrogen that is not easily fixed by the soil, so that the crops can absorb the humic acid and supplement the nitrogen required for their own growth at the same time, thereby reducing the loss rate of the readily available nitrogen due to natural factors such as leaching and denitrification; meanwhile, the addition of the controlled-release agent can adjust the ratio of the readily available nitrogen and the slow-release nitrogen in the urea ammonium nitrate solution, break the original ion balance of the UAN solution, create a microenvironment with high ionic strength, and then release the nitrogen efficiently through the synergistic effect with the organic concentrate in the critical period of crop fertilization, so as to realize the precise regulation and effective shortening of the release period, greatly improve the fertilizer utilization rate, shorten the nitrogen release period to 60-90 days, and be more in line with the growth period of fruit and vegetable economic crops.

[0015] The solubilizing agent used in the present application can improve the solubility of each element in the high-nitrogen liquid fertilizer, especially the nitrogen, so that the precipitation and other phenomena affecting the fertilizer effect do not occur under low temperature conditions (-18℃); the preservative can effectively prevent the bacterial pollution of the clear liquid fertilizer containing organic matter, and the two synergistically improve the stability of the controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid.

[0016] Compared with the prior art, the present application has the following advantages: The fertilizer of the present application controls the release period of urea and ammonium nitrate solution by adding organic concentrate containing humic acid and liquid controlled-release nitrogen controlled-release agent, which synergistically controls the release period of urea and ammonium nitrate solution, shortens the release period to 60-90 days, and matches the growth period of most fruit and vegetable economic crops, thereby improving the absorption and utilization efficiency of crops to nitrogen. At the same time, the added organic matter rich in humic acid and trace elements can timely supplement the organic nutrient elements and trace elements required for plant growth, and once application can be used for a lifetime, saving time, effort, labor and resources, which meets the current farmers' fertilization mode and fertilization habit of planting crops. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The static water nitrogen release determination results of different types of fertilizers of the present application; Figure 2 The number of colored fruits of different treatment groups in the greenhouse tomato planting test of the present application; Figure 3 The average weight per fruit of different treatment groups in the greenhouse tomato planting test of the present application; Figure 4 The number of fruits per plant of different treatment groups in the greenhouse tomato planting test of the present application; Figure 5 The yield per mu of tomatoes of different treatment groups in the greenhouse tomato planting test of the present application. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be further described below in conjunction with specific embodiments, but are not limited thereto. Some raw materials used in the present application are purchased from the following sources: paper pulp, Huatai Group, organic matter content 180 g / L; yeast concentrate, Angel Yeast (Binzhou) Co., Ltd., organic matter content 200 g / L; yellow water extract, Chongqing Lanjie Biotechnology Co., Ltd., organic matter content 160 g / L; seaweed extract, Qingdao Haida Biological Group, organic matter content 120 g / L; straw extract, Shandong Xinquanlin Holdings Group Co., Ltd., organic matter content 150 g / L; urea ammonium nitrate solution, total nitrogen content ≥32%, Jinan Feiyue Chemical Co., Ltd.

[0019] Example 1 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer is prepared from the following raw materials by weight: urea nitrate solution 55 kg, organic concentrate 10 kg, controlled-release agent 4 kg, trace element package 3 kg, solubilizing agent 5 kg, potassium sorbate 0.1 kg, and water 5 kg.

[0020] The organic concentrate is paper pulp; the controlled-release agent comprises ammonium polyphosphate 2 kg and potassium nitrate 2 kg; The trace element package is composed of zinc sulfate 0.8 kg, manganese sulfate 0.4 kg, copper sulfate 0.4 kg, borax 0.8 kg, and ferrous sulfate 0.6 kg; The solubilizing agent is composed of sodium dodecylbenzenesulfonate 0.5 kg, polyethylene glycol 0.5 kg, ethylene glycol 3 kg, and polyvinylpyrrolidone 1 kg.

[0021] The preparation method of the above-mentioned humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer comprises the following steps: S1: heating the urea nitrate solution to 50-60℃, adding the solubilizing agent into the urea nitrate solution while hot, and stirring for 1-2 h to obtain a first solution; S2: dissolving the controlled-release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70℃, adding the trace element package into the organic concentrate while hot, and stirring for 1-2 h to obtain a third solution; S4: keeping the first solution at a temperature of 50-60℃, sequentially adding the second solution, the third solution, and the preservative into the first solution, and keeping stirring for 1-2 h to obtain a humic acid-containing controlled-release organic water-soluble fertilizer with an organic matter content of 50 g / L and a total nitrogen content of 230 g / L.

[0022] Example 2 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer is prepared from the following raw materials by weight: urea nitrate solution 57 kg, organic concentrate 15 kg, controlled-release agent 8 kg, trace element package 2.8 kg, solubilizing agent 6.4 kg, benzalkonium bromide 0.3 kg, and water 10 kg.

[0023] The organic concentrate is yeast concentrate; the controlled-release agent comprises ammonium chloride 6 kg and potassium nitrate 2 kg; The trace element package is composed of zinc sulfate 0.8 kg, manganese sulfate 0.4 kg, copper sulfate 0.4 kg, borax 0.8 kg, and ferrous sulfate 0.4 kg; The solubilizing agent is composed of sodium dodecylbenzenesulfonate 0.5 kg, betaine 0.7 kg, glycerol 1 kg, ethylene glycol 3 kg, and cyclodextrin 1.2 kg.

[0024] The preparation method of the above-mentioned humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer comprises the following steps: according to the above weight parts, S1: heating the urea ammonium nitrate solution to 50-60℃, adding the solubilizing agent to the urea ammonium nitrate solution while hot, stirring for 1-2h, to obtain a first solution; S2: dissolving the controlled release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70℃, adding the trace element package to the organic concentrate while hot, stirring for 1-2h, to obtain a third solution; S4: maintaining the temperature of the first solution at 50-60℃, adding the second solution, the third solution and the preservative to the first solution in sequence, maintaining stirring for 1-2h, to obtain a humic acid-containing controlled release type organic water-soluble fertilizer with an organic matter content of 50g / L and a total nitrogen content of 240g / L.

[0025] Example 3 A humic acid-containing controlled release type high-nitrogen organic water-soluble fertilizer, composed of the following weights of raw materials: urea ammonium nitrate solution 59kg, organic concentrate 18kg, controlled release agent 7kg, trace element package 2.6kg, solubilizing agent 6.7kg, kason 0.5kg, water 20kg.

[0026] The organic concentrate is yellow water extract; the controlled release agent is composed of ammonium chloride 6kg and potassium nitrate 2kg; The trace element package is composed of zinc sulfate 0.8kg, manganese sulfate 0.4kg, copper sulfate 0.3kg, borax 0.8kg, ferrous sulfate 0.3kg; The solubilizing agent is composed of sodium dodecyl benzene sulfonate 0.5kg, polyethylene glycol 0.8kg, glycerol 1kg, ethylene glycol 3kg, citric acid 1.4kg.

[0027] The preparation method of the above-mentioned humic acid-containing controlled release type high-nitrogen organic water-soluble fertilizer, comprising the following steps: according to the above weight parts, S1: heating the urea ammonium nitrate solution to 50-60℃, adding the solubilizing agent to the urea ammonium nitrate solution while hot, stirring for 1-2h, to obtain a first solution; S2: dissolving the controlled release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70℃, adding the trace element package to the organic concentrate while hot, stirring for 1-2h, to obtain a third solution; S4: maintaining the temperature of the first solution at 50-60℃, adding the second solution, the third solution and the preservative to the first solution in sequence, maintaining stirring for 1-2h, to obtain a humic acid-containing controlled release type organic water-soluble fertilizer with an organic matter content of 70g / L and a total nitrogen content of 245g / L.

[0028] Example 4 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer is prepared from the following raw materials by weight: urea nitrate solution 61 kg, organic concentrate 20 kg, controlled-release agent 7 kg, trace element package 2.4 kg, solubilizing agent 8.2 kg, kathon 0.5 kg, p-chloro-m-dimethyl phenol 0.2 kg, and water 22 kg.

[0029] The organic concentrate is seaweed extract; the controlled-release agent is composed of 5 kg of ammonium sulfate and 2 kg of potassium nitrate; The trace element package is composed of 0.6 kg of zinc sulfate, 0.3 kg of manganese sulfate, 0.3 kg of copper sulfate, 0.6 kg of borax, and 0.6 kg of ferrous sulfate; The solubilizing agent is composed of 0.5 kg of sodium dodecyl benzene sulfonate, 1.1 kg of Tween, 2 kg of glycerol, 3 kg of ethylene glycol, and 1.6 kg of lignin.

[0030] The preparation method of the above-mentioned humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer comprises the following steps: S1: heating the urea nitrate solution to 50-60℃, adding the solubilizing agent while hot into the urea nitrate solution, and stirring for 1-2 h to obtain a first solution; S2: dissolving the controlled-release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70℃, adding the trace element package while hot into the organic concentrate, and stirring for 1-2 h to obtain a third solution; S4: keeping the first solution at a temperature of 50-60℃, sequentially adding the second solution, the third solution, and the preservative into the first solution, and keeping stirring for 1-2 h to obtain a humic acid-containing controlled-release organic water-soluble fertilizer with an organic matter content of 80 g / L and a total nitrogen content of 255 g / L.

[0031] Example 5 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer is prepared from the following raw materials by weight: urea nitrate solution 63 kg, organic concentrate 23 kg, controlled-release agent 5 kg, trace element package 2.2 kg, solubilizing agent 8.6 kg, benzalkonium bromide 0.3 kg, p-chloro-m-dimethyl phenol 0.6 kg, and water 25 kg.

[0032] The organic concentrate is straw leaching solution; the controlled-release agent is composed of 3 kg of ammonium chloride and 2 kg of potassium nitrate; The trace element package is composed of 0.6 kg of zinc sulfate, 0.3 kg of manganese sulfate, 0.2 kg of copper sulfate, 0.6 kg of borax, and 0.5 kg of ferrous sulfate; The solubilizing agent is composed of 0.5 kg of sodium dodecyl benzene sulfonate, 1.3 kg of Tween, 2 kg of glycerol, 3 kg of ethylene glycol, 1.4 kg of citric acid, and 0.4 kg of cyclodextrin.

[0033] The preparation method of the humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer comprises the following steps: adding the above-mentioned weight parts, S1: heating the urea ammonium nitrate solution to 50-60°C, adding the solubilizing agent to the urea ammonium nitrate solution while hot, and stirring for 1-2 h to obtain a first solution; S2: dissolving the controlled-release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70°C, adding the trace element package to the organic concentrate while hot, and stirring for 1-2 h to obtain a third solution; S4: keeping the first solution at a temperature of 50-60°C, adding the second solution, the third solution and the preservative to the first solution in sequence, and keeping stirring for 1-2 h to obtain a humic acid-containing controlled-release organic water-soluble fertilizer with an organic matter content of 80 g / L and a total nitrogen content of 260 g / L.

[0034] Example 6 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer is composed of the following weights of raw materials: urea ammonium nitrate solution 65 kg, organic concentrate 25 kg, controlled-release agent 4 kg, trace element package 2 kg, solubilizing agent 9.4 kg, p-chloro-m-dimethylphenol 1 kg, and water 25 kg.

[0035] The organic concentrate is composed of paper pulp 10 kg and yeast concentrate 15 kg; the controlled-release agent is composed of monammonium phosphate 2 kg and potassium nitrate 2 kg; The trace element package is composed of zinc sulfate 0.6 kg, manganese sulfate 0.3 kg, copper sulfate 0.2 kg, borax 0.6 kg, and ferrous sulfate 0.3 kg; The solubilizing agent is composed of sodium dodecylbenzenesulfonate 0.5 kg, polyethylene glycol 0.5 kg, betaine 0.5 kg, Tween 0.5 kg, glycerol 2 kg, ethylene glycol 2 kg, citric acid 1.4 kg, cyclodextrin 1 kg, and polyvinylpyrrolidone 1 kg.

[0036] The preparation method of the humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer comprises the following steps: adding the above-mentioned weight parts, S1: heating the urea ammonium nitrate solution to 50-60°C, adding the solubilizing agent to the urea ammonium nitrate solution while hot, and stirring for 1-2 h to obtain a first solution; S2: dissolving the controlled-release agent in an appropriate amount of water to obtain a second solution; S3: heating the organic concentrate to 60-70°C, adding the trace element package to the organic concentrate while hot, and stirring for 1-2 h to obtain a third solution; S4: keeping the first solution at 50-60℃, adding the second solution, the third solution and the preservative into the first solution in sequence, keeping stirring for 1-2h, obtaining the humic acid-containing controlled-release organic water-soluble fertilizer with the organic matter content of 100g / L and the total nitrogen content of 270g / L.

[0037] Comparative Example 1 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer, which is basically the same as Example 1 in raw material composition and preparation method, except that it does not contain the organic concentrate and the controlled-release agent.

[0038] Comparative Example 2 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer, which is basically the same as Example 1 in raw material composition and preparation method, except that it does not contain the organic concentrate.

[0039] Comparative Example 3 A humic acid-containing controlled-release high-nitrogen organic water-soluble fertilizer, which is basically the same as Example 1 in raw material composition and preparation method, except that it does not contain the controlled-release agent.

[0040] Performance test 1. Static water nitrogen release of different kinds of fertilizers in Example 1 and Comparative Examples 1-3 of the present application was determined According to the determination method of the reference controlled-release fertilizer. 10g of the high-nitrogen organic water-soluble fertilizer prepared in Example 1 and Comparative Examples 1-3 and 10g of commercially available urea and ammonium nitrate solution (containing 32% of nitrogen) were respectively placed in 250mL glass bottles, 200mL of deionized water was added, and the bottles were sealed and placed in a constant temperature incubator at 25℃, with 3 replicates for each fertilizer. The sampling time was 1d, 3d, 7d, 10d, 20d, 30d, 40d, 50d, 60d, 70d, 80d, 90d, 100d, 110d and 120d after incubation, and the nitrogen nutrient release amount was measured. The total nitrogen content was determined by alkaline potassium persulfate digestion-ultraviolet spectrophotometry. The specific results are shown in Table 1. Figure 1 .

[0041] As Figure 1As shown, compared with Comparative Examples 1-3, the nitrogen release period of the fertilizer prepared in Example 1 of the present application is obviously shortened to about 90 days, which precisely covers the growth period of 60-90 days of fruit and vegetable economic crops, and there is no nutrient waste caused by excessive release in the later period. However, the release period of Comparative Examples 1-3 and commercially available urea and ammonium nitrate is as long as 100-120 days, which cannot completely match the growth period of 60-90 days of fruit and vegetable crops, resulting in fertilizer waste and reducing the fertilizer utilization rate. The present application precisely shortens the nitrogen release period of UAN solution from 110-130 days to 60-90 days for the first time through the synergistic effect of the organic concentrate and the controlled release agent. The controlled release agent breaks the original ion balance of UAN, regulates the conversion activity of soil microorganisms, and reduces leaching and fixation of available nitrogen through chelation of humic acid, while efficiently releasing nutrients in the key fertilizer demand period of crops (such as the fruit expansion period of tomatoes and the rapid growth period of Chinese cabbage). The two can solve the dual problems of period mismatching and unstable release. However, changing any kind or proportion of the raw materials of the present application cannot achieve the above-mentioned effect.

[0042] 2. Greenhouse tomato planting test Location: a certain agricultural planting greenhouse in Zhuzhou Village, Donghai County, Jiangsu Province. The 0-20 cm soil layer in the greenhouse has the following physicochemical properties: organic matter 18.5 g / kg, alkali-hydrolyzable nitrogen 120 mg / kg, available phosphorus 35 mg / kg, available potassium 150 mg / kg, and pH 6.8. The soil texture is loam, and the previous crop is cucumber with uniform fertility.

[0043] Test crop variety: tomato Fu La 3661.

[0044] Test fertilizers: the organic water-soluble fertilizer prepared in Example 1 of the present application, the organic water-soluble fertilizer obtained in Comparative Example 1-3, and commercially available urea and ammonium nitrate solution (total nitrogen content 320 g / L).

[0045] Test method: random block design was adopted, and there were 5 treatments (Example 1, Comparative Example 1-3, and commercially available control), 3 replicates for each treatment, and the area of each plot was 15 m 2 (length 5 m x width 3 m). A 0.5 m wide isolation row was set between plots to avoid fertilizer flow. Consistent vigorous seedlings were selected for transplanting, and the plant spacing was 0.5 m and the row spacing was 1.1 m at the time of planting, with 27 plants per plot. All treatments were fertilized with equal nitrogen amount (15 kg of pure nitrogen per mu), and the base fertilizer accounted for 40%. The fertilizer was applied twice through the drip irrigation system with water at the flowering stage and the fruit enlargement stage.

[0046] At the mature harvest period of tomatoes, the total number of mature fruits (fruit color turns red, moderate hardness) on each plant in each plot is counted; 10 plants are randomly selected in each plot, the number of fruits is counted, and the average number of fruits per plant is obtained; 5 mature fruits of medium size are randomly selected in each plot, weighed with an electronic balance, and the average weight of single fruit (unit: g / fruit) is calculated; the total weight of all mature fruits in each plot is counted, and the yield per mu is calculated. The specific test results are shown in Figures 2-5 .

[0047] From the results of the above Figures 2-5 , it can be seen that the number of color-changing fruits, the average weight of single fruit, the number of fruits per plant, and the yield per mu of Example 1 are significantly higher than those of Comparative Examples 1-3 and the commercially available control group, which indicates that the fertilizer of the present application can better promote the maturation and color change of tomato fruits, improve the quality and yield of fruits, help the growth and development of tomato fruits, make the fruits more plump, thereby increasing the weight of single fruit, and can also promote the growth and flowering of tomato plants, improve the fruit setting rate of plants, and thus increase the yield of tomatoes, bringing higher economic benefits to agricultural production.

[0048] 3. Potted Pakchoi Test Location: Shidani Demonstration Garden, Linshu County, Shandong Province. Potted substrate: mass ratio of peat soil: vermiculite: perlite = 3:1:1, 1.5 kg of dry substrate per pot, sterilized at 121°C for 30 min, substrate physical and chemical properties: pH 6.5-7.0, organic matter 15.2 g / kg, alkali-hydrolyzable nitrogen 80 mg / kg, available phosphorus 25 mg / kg, available potassium 100 mg / kg.

[0049] Test crop variety: Four-Season Yellow Stem Pakchoi.

[0050] Test fertilizers: organic water-soluble fertilizer prepared in Example 1 of the present application, organic water-soluble fertilizers obtained in Comparative Examples 1-3, and commercially available urea and ammonium nitrate solution (total nitrogen content 320 g / L).

[0051] Test method: complete random design, 5 treatments, 3 replicates for each treatment, 5 pots (1 healthy seedling per pot) for each replicate, a total of 75 pots, placed in a greenhouse with a temperature of 20-25°C, light for 12 h / d, light intensity of 300 μmol / (m 2 s), humidity of 60-70%. All fertilizers were applied at the same nitrogen level, with 0.5 g of pure nitrogen per pot, and all fertilizers were diluted to 200 mL for irrigation, with one-time basal application.

[0052] At the harvest stage of pakchoi, the plant height was collected and measured, the base to the growth point of each plant in each pot was measured, and the average value of each treatment group was taken. After washing and drying the whole plant, the fresh weight of the plant was measured. After cutting the roots, the roots were killed at 105°C for 30 minutes, dried at 80°C to constant weight, and the dry weight of the roots was measured. The chlorophyll content (SPAD value) of the middle part of the 3rd functional leaf was measured, SPAD-502 chlorophyll meter was used, 3 points per leaf were measured, and the average value was taken. The specific results are shown in Table 1.

[0053] Table 1 test results From the data results of the above Table 1, it can also be seen that the pakchoi treated by Example 1 has significantly higher chlorophyll value, plant height, and fresh weight and dry weight of the aboveground part of the plant than Comparative Examples 1-3 and the commercially available control group, which indicates that the fertilizer of the present application can promote the synthesis of chlorophyll in the leaves of pakchoi and enhance the efficiency of photosynthesis, thereby benefiting the growth and development of plants; promote the growth of pakchoi plants, increase the plant height, and thus increase the biomass of the plants, and the fresh weight and dry weight of the aboveground part of the plants are significantly improved. This is because by adding the organic concentrate containing humic acid and the liquid controlled-release nitrogen release agent, the fertilizer of the present application can better meet the demand for nitrogen during the growth of crops, so that the release period of nitrogen is matched with the growth period of crops, thereby improving the yield and quality of crops. The fertilizer of the present application not only contains rich nitrogen, but also adds organic matter and trace elements rich in humic acid, which can timely supplement the organic nutrient elements and trace elements required for plant growth, and once application can be used for a lifetime, saving time, effort, labor and resources, which meets the current farmers' fertilization methods and habits for planting crops. This helps the healthy growth of plants and improves the stress resistance and disease resistance of plants, thereby further improving the yield and quality of crops.

[0054] The present application realizes the precise shortening of the nitrogen release period of UAN solution from 110-130 days to 60-90 days for the first time through the synergistic effect of the organic concentrate and the controlled-release agent. The controlled-release agent breaks the original ion balance of UAN, regulates the conversion activity of soil microorganisms, and the humic acid reduces leaching and fixation of available nitrogen by chelation, while efficiently releasing nutrients during the critical period of crop nutrient demand. This solves the problem of mismatch between the release period of traditional fertilizer nitrogen and the growth period of crops, improves the utilization efficiency of fertilizer, and reduces environmental pollution.

[0055] It should be noted that the above examples are only part of the preferred modes of implementing the present application, not all. Obviously, based on the above examples of the present application, all other examples obtained by those of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.

Claims

1. A controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid, characterized in that, It is made from the following raw materials in parts by weight: 55-65 parts urea ammonium nitrate solution, 10-25 parts organic concentrate, 4-8 parts controlled-release agent, 2-3 parts trace element packet, 5-10 parts solubilizer, 0.1-1 part preservative, and 5-25 parts water; wherein the controlled-release agent is one or a mixture of two of potassium nitrate, ammonium sulfate, ammonium chloride, ammonium polyphosphate, and monoammonium phosphate.

2. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The organic concentrate is one or a mixture of two of the following: pulp, yeast concentrate, yellow water extract, seaweed extract, and straw extract.

3. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 1, characterized in that, Its organic matter content is 50-100g / L and its total nitrogen content is 230-270g / L.

4. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The trace element package is composed of the following parts by weight of raw fertilizer: 0.6-0.8 parts zinc sulfate, 0.2-0.4 parts manganese sulfate, 0.2-0.4 parts copper sulfate, 0.6-0.8 parts borax and 0.4-0.6 parts ferrous sulfate.

5. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The solubilizer includes surfactants, cosolvents, and stabilizers.

6. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 5, characterized in that, The surfactant is one or more of sodium dodecylbenzenesulfonate, polyethylene glycol, betaine, and Tween.

7. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 5, characterized in that, The cosolvent is one or two of ethylene glycol, glycerol, and glycerin.

8. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 5, characterized in that, The stabilizer is one or more of citric acid, cyclodextrin, lignin, and polyvinylpyrrolidone.

9. The controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to claim 1, characterized in that, The preservative is one or two of benzalkonium bromide, potassium sorbate, Kathon, and p-chloro-m-dimethylphenol.

10. A method for preparing a controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid according to any one of claims 1-8, characterized in that, It includes the following steps: S1: Heat the urea ammonium nitrate solution to 50-60℃, add the solubilizer to the urea ammonium nitrate solution while it is hot, stir for 1-2 hours to obtain the first solution; S2: Heat the organic concentrate to 60-70℃, add the trace element packet to the organic concentrate while it is hot, stir for 1-2 hours to obtain the second solution; S3: Add the liquid slow-release nitrogen control agent to water and stir to dissolve, thus obtaining the third solution; S4: Keep the temperature of the first solution at 50-60℃, and add the third solution, the second solution and the preservative to the first solution in sequence, and keep stirring for 1-2 hours to obtain a controlled-release high-nitrogen organic water-soluble fertilizer containing humic acid.

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