Special magnesium-containing water-soluble fertilizer for citrus as well as preparation method and application of special magnesium-containing water-soluble fertilizer

Abstract

The invention provides a special magnesium-containing water-soluble fertilizer for citrus as well as a preparation method and application thereof, and belongs to the technical field of fertilizers. The invention provides a magnesium-containing water-soluble fertilizer special for citrus. The magnesium-containing water-soluble fertilizer is prepared from potassium nitrate, urea, monopotassium phosphate, boric acid, chelated zinc, magnesium sulfate, chelated iron and potassium fulvate. The magnesium-containing water-soluble fertilizer special for citrus provided by the invention aims at citrus soil nutrient supply, effectively provides annual nutritional requirements of citrus and supplements easily-deficient medium trace elements, and meets the requirements of enhancing tree body resistance, accelerating young shoot growth, promoting fruit development and improving fruit quality.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer technology, specifically relating to a magnesium-containing water-soluble fertilizer for citrus, its preparation method, and its application. Background Technology

[0002] Citrus plays a vital role in overall agricultural production. Common problems in fertilization during citrus production include: 1) Over-fertilization, with an average nitrogen fertilizer application of 500 kg N·m·h⁻¹ in the current season. -1 2) The NPK nutrient application ratio is unreasonable at different stages, and the input of micronutrients is neglected, resulting in low root vitality and weak tree vigor; 3) Fertilizers are seriously homogenized and have weak targeting. There are many types of fertilizers in citrus producing areas, and their quality varies. Micronutrients are lacking; 4) Aging and labor shortages have led to a significant increase in the proportion of fertilizer broadcasting. However, the fertilizer type does not match the fertilization method, resulting in large losses and low utilization rate.

[0003] Currently, the market lacks magnesium-containing water-soluble fertilizers specifically designed for citrus orchards in the hot and rainy south, which can effectively meet the nutrient needs of citrus throughout its entire growth cycle, alleviate magnesium deficiency in citrus orchard soils, increase root quantity and activity, enhance tree resistance, promote fruit development, improve fruit quality, and increase citrus yield. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a magnesium-containing water-soluble fertilizer specifically for citrus. This magnesium-containing water-soluble fertilizer is designed to effectively supply nutrients to citrus soil, meet the year-round nutritional needs of citrus, and supplement easily deficient micronutrients. It can also meet the requirements of enhancing tree resistance, accelerating new shoot growth, promoting fruit development, and improving fruit quality.

[0005] The objective of this invention is achieved through the following technical solution: This invention provides a magnesium-containing water-soluble fertilizer specifically for citrus, comprising, by weight: 120-150 parts potassium nitrate, 480-600 parts urea, 160-210 parts potassium dihydrogen phosphate, 1-2 parts boric acid, 1-2 parts chelated zinc, 50-70 parts magnesium sulfate, 1-2 parts chelated iron, and 15-25 parts potassium humate.

[0006] Preferably, the magnesium-containing citrus-specific water-soluble fertilizer further includes 1-5 parts of an anti-caking agent and 8-15 parts of a bio-enhancing agent.

[0007] Preferably, the anti-caking agent comprises modified sodium dodecylbenzenesulfonate and / or sodium dodecyl sulfate.

[0008] Preferably, the bio-synergist includes any one or more of polyglutamic acid, arginine, and phenylalanine.

[0009] Preferably, the magnesium-containing citrus-specific water-soluble fertilizer also includes a nitrification inhibitor.

[0010] Preferably, the nitration inhibitor includes one or more of hydroquinone, dicyandiamide, and 3,4-dimethylpyrazole phosphate.

[0011] This invention provides a method for preparing the magnesium-containing citrus-specific water-soluble fertilizer described in the above technical solution, comprising: After weighing each raw material according to the mass fraction, urea, potassium nitrate and potassium dihydrogen phosphate are crushed and mixed with the remaining raw materials to obtain a magnesium-containing citrus-specific water-soluble fertilizer.

[0012] This invention provides the application of the magnesium-containing citrus-specific water-soluble fertilizer described in the above-described technical solution or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the above-described technical solution in citrus cultivation.

[0013] Preferably, the application includes at least one of the following: (1) Increase citrus yield; (2) Increase the number and activity of roots; (3) Enhance tree resistance; (4) Accelerate the growth of new shoots; (5) Promotes fruit development; (6) Improve fruit quality.

[0014] This invention provides a method for improving the quality of citrus fruits, comprising: During the citrus planting process, apply the magnesium-containing citrus-specific water-soluble fertilizer described in the above technical solution or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the preparation method described in the above technical solution.

[0015] The beneficial effects of this invention are: This invention provides a magnesium-containing water-soluble fertilizer specifically for citrus, comprising, by weight: 120-150 parts potassium nitrate, 480-600 parts urea, 160-210 parts potassium dihydrogen phosphate, 1-2 parts boric acid, 1-2 parts chelated zinc, 50-70 parts magnesium sulfate, 1-2 parts chelated iron, and 15-25 parts potassium humate. The magnesium-containing citrus-specific water-soluble fertilizer provided by this invention supplements nitrogen, phosphorus, and potassium while adding magnesium sulfate, chelated zinc, chelated iron, and boric acid to supplement micronutrients, promote photosynthesis, and enhance the systemic resistance of citrus. Simultaneously, potassium and magnesium synergistically promote the transfer of photosynthetic products to the roots and fruit, promoting fruit enlargement, color change, and quality formation. The chelated zinc and chelated iron are in EDDHA chelated form; the addition of chelated micronutrients facilitates the absorption of micronutrients by citrus, meeting its nutritional needs, strengthening tree vigor, and improving citrus quality. The addition of fully water-soluble potassium humate increases root quantity and activity, enhances tree resistance, accelerates new shoot growth, and promotes fruit development. The magnesium-containing citrus-specific water-soluble fertilizer scientifically proportions micronutrients: based on the annual nutritional needs of citrus, the formula design is optimized and simplified, precisely proportioning magnesium (a micronutrient) and zinc, iron, and boron (micronutrients) to meet the nutritional needs of citrus during its key growth stages. The magnesium-containing citrus-specific water-soluble fertilizer addresses the nutritional needs and stress resistance enhancement requirements of citrus trees. It contains added polyglutamic acid, arginine, phenylalanine, and other nutrient and functional amino acids to enhance tree resistance, accelerate new shoot growth and elongation, promote fruit development, and improve fruit quality. Combined with fully water-soluble potassium humate, it increases root quantity, improves root activity, and enhances nutrient absorption efficiency. This magnesium-containing citrus-specific water-soluble fertilizer effectively provides year-round nutritional needs for citrus and supplements easily deficient micronutrients, meeting the requirements for enhanced tree resistance, accelerated new shoot growth, promoted fruit development, and improved fruit quality. Example results show that the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention can significantly improve citrus quality while increasing citrus yield, increasing fruit diameter, increasing soluble solids content, reducing titratable acid content, and increasing vitamin C content. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 The flowchart illustrates the preparation method of the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention. Detailed Implementation

[0018] This invention provides a magnesium-containing water-soluble fertilizer specifically for citrus, comprising, by weight: 120-150 parts potassium nitrate, 480-600 parts urea, 160-210 parts potassium dihydrogen phosphate, 1-2 parts boric acid, 1-2 parts chelated zinc, 50-70 parts magnesium sulfate, 1-2 parts chelated iron, and 15-25 parts potassium humate.

[0019] Unless otherwise specified, the present invention does not have any special limitations on the source of each raw material in the following technical solutions, and any commercially available products in the field can be used.

[0020] The magnesium-containing citrus-specific water-soluble fertilizer provided by this invention comprises 120-150 parts by weight, specifically 120, 125, 130, 135, 140, 145, or 150 parts. In this invention, the potassium nitrate in the magnesium-containing citrus-specific water-soluble fertilizer primarily provides nitrogen and potassium for citrus growth, promotes the transport of photosynthetic products to the fruit, promotes fruit enlargement, enhances the tree's resistance to adverse conditions, and is beneficial for better citrus growth.

[0021] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention comprises 480-600 parts of urea, which can be 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, or 600 parts. In this invention, the urea mainly provides citrus trees with nitrogen nutrition quickly, promoting branch and leaf growth, strengthening tree vigor, and improving fruit yield and quality.

[0022] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention comprises 160-210 parts of potassium dihydrogen phosphate, which can be 160, 170, 180, 190, 192, 200, or 210 parts. In this invention, the potassium dihydrogen phosphate rapidly replenishes the key phosphorus and potassium nutrients for citrus, promotes fruit enlargement, color change and sweetening, and enhances the plant's resistance to adverse conditions.

[0023] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention includes 1-2 parts of boric acid, which can be 1, 1.5, or 2 parts. In this invention, the boric acid mainly meets the boron requirements of citrus, preventing and treating physiological diseases such as "flowering without fruiting," fruit drop, and fruit corking caused by boron deficiency, thereby ensuring citrus yield and quality.

[0024] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention includes 1-2 parts of chelated zinc, which can be 1, 1.5, or 2 parts. In this invention, the chelated zinc is in EDDHA chelated form. The addition of chelated trace elements can provide the nutrients required by citrus, enhance tree vigor, and improve citrus quality.

[0025] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention comprises 50-70 parts of magnesium sulfate, which can be 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70 parts. As an optional embodiment of this invention, the magnesium sulfate can be anhydrous magnesium sulfate. In this invention, the magnesium sulfate can precisely match the magnesium requirements of citrus, quickly alleviating magnesium deficiency chlorosis and improving fruit quality, while also being suitable for large-scale planting. The magnesium sulfate can significantly improve the quality of mature fruits, increasing single fruit weight, transverse diameter, and longitudinal diameter, increasing the soluble solids content in the fruit, and increasing the vitamin C content, etc. Furthermore, the magnesium sulfate also helps to increase yield and output value.

[0026] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention includes 1-2 parts of chelated iron, which can be 1, 1.5, or 2 parts. The addition of chelated iron to the magnesium-containing citrus-specific water-soluble fertilizer of this invention can prevent iron deficiency chlorosis in citrus, and improve leaf chlorophyll content and fruit quality.

[0027] Based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer provided by this invention comprises 15-25 parts of potassium humate, which can be 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 parts. In this invention, the potassium humate can improve soil structure, promote citrus root growth, increase root quantity and activity, enhance tree resistance, accelerate new shoot growth, and promote fruit development.

[0028] In this invention, based on the mass fraction of potassium nitrate, the magnesium-containing citrus-specific water-soluble fertilizer further includes 1-5 parts of an anti-caking agent and 8-15 parts of a bio-synergist. As an optional embodiment of this invention, the anti-caking agent includes modified sodium dodecylbenzenesulfonate and / or sodium dodecyl sulfate; the bio-synergist includes any one or more of polyglutamic acid, arginine, and phenylalanine. In this invention, the modified sodium dodecylbenzenesulfonate is a compound of sodium dodecylbenzenesulfonate and unsaturated fatty acid ester sulfate. In this invention, the anti-caking agent effectively prevents fertilizer caking and maintains stable physical properties. In this invention, the functional amino acids provided by the bio-synergist enhance tree resistance, accelerate new shoot growth, promote fruit development, and improve fruit quality, thereby increasing yield and output value.

[0029] In this invention, the magnesium-containing citrus-specific water-soluble fertilizer preferably further includes a nitrification inhibitor. As an optional embodiment of this invention, the nitrification inhibitor includes any one or more of hydroquinone, dicyandiamide, and 3,4-dimethylpyrazole phosphate. In this invention, the nitrification inhibitor primarily protects the newly generated ammonium nitrogen after urea hydrolysis, delaying its nitrification, thereby prolonging fertilizer effectiveness and improving nitrogen utilization.

[0030] The magnesium-containing citrus-specific water-soluble fertilizer provided by this invention supplements nitrogen, phosphorus, and potassium while also adding magnesium sulfate, chelated zinc, chelated iron, and boric acid to replenish micronutrients, promote photosynthesis, and enhance the systemic resistance of citrus. Simultaneously, potassium and magnesium synergistically promote the transfer of photosynthetic products to the roots and fruit, promoting fruit enlargement, color change, and quality formation. The chelated zinc and chelated iron are in EDDHA chelated form; the addition of chelated micronutrients facilitates the absorption of micronutrients by citrus, meeting its nutritional needs, strengthening tree vigor, and improving citrus quality. The addition of fully water-soluble potassium humate increases root quantity and activity, enhances tree resistance, accelerates new shoot growth, and promotes fruit development. This magnesium-containing citrus-specific water-soluble fertilizer effectively provides the year-round nutritional needs of citrus and replenishes easily deficient micronutrients, meeting the requirements for enhanced tree resistance, accelerated new shoot growth, promoted fruit development, and improved fruit quality.

[0031] This invention provides a method for preparing the magnesium-containing citrus-specific water-soluble fertilizer described in the above technical solution, comprising: After weighing each raw material according to its mass percentage, urea, potassium nitrate, and potassium dihydrogen phosphate are pulverized and mixed with the remaining raw materials to obtain a magnesium-containing citrus-specific water-soluble fertilizer. As an optional embodiment of this invention, the mass percentage of nitrogen, phosphorus, potassium, and magnesium in the magnesium-containing citrus-specific water-soluble fertilizer can be 28-10-13+2.0Mg-TE, that is, in this magnesium-containing citrus-specific water-soluble fertilizer, nitrogen fertilizer is calculated as N, phosphorus fertilizer as P2O5, potassium fertilizer as K2O, and magnesium fertilizer as MgO, with a nitrogen fertilizer mass percentage of 28%, a phosphorus fertilizer mass percentage of 10%, a potassium fertilizer mass percentage of 13%, and a magnesium fertilizer mass percentage of 2%.

[0032] This invention does not specifically limit the method for pulverizing the urea, potassium nitrate, and potassium dihydrogen phosphate; any conventional pulverizing method in the art can be used. After obtaining the pulverized urea, potassium phosphate, and potassium dihydrogen phosphate, this invention preferably sieves the pulverized urea, potassium phosphate, and potassium dihydrogen phosphate, wherein the sieve aperture can be 20 mesh. This invention preferably collects the undersize material for further processing. This invention does not specifically limit the mixing method; any conventional mixing method in the art can be used.

[0033] This invention provides the application of the magnesium-containing citrus-specific water-soluble fertilizer described in the above-described technical solution or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the above-described technical solution in citrus cultivation. In this invention, the application includes at least one of the following: (1) increasing citrus yield; (2) increasing root quantity and activity; (3) enhancing tree resistance; (4) accelerating new shoot growth; (5) promoting fruit development; and (6) improving fruit quality. As an optional embodiment of this invention, improving fruit quality includes any one or more of the following: increasing the weight of a single citrus fruit, increasing the diameter of the citrus fruit, increasing the soluble solids content of the citrus fruit, decreasing the titratable acid content of the citrus fruit, and increasing the vitamin C content of the citrus fruit.

[0034] This invention provides a method for improving the quality of citrus fruits, comprising: applying the magnesium-containing citrus-specific water-soluble fertilizer described in the above-mentioned technical solution or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the preparation method described in the above-mentioned technical solution during the citrus planting process. This invention does not specifically limit the application method; any conventional application method in the art can be used. As an optional embodiment of this invention, the application rate of the magnesium-containing citrus-specific water-soluble fertilizer can be 0.1~0.4 kg / plant, or 0.4 kg / plant.

[0035] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0036] In the following technical solutions, nitrogen content is expressed as N, phosphorus content as P2O5, and potassium content as K2O.

[0037] Potassium nitrate, white powder (agricultural grade, content ≥99%, NPK ratio: 13.5-0-46, Hangzhou Daosheng Agricultural Technology Co., Ltd.); Urea, white granular form (N content ≥46%; Yunnan Yuntianhua Co., Ltd.); Potassium dihydrogen phosphate, white crystalline powder (content ≥99%, NPK ratio: 0-52-34, Yunnan Yuntianhua Co., Ltd.); Anhydrous magnesium sulfate, colorless crystalline powder (content ≥99%, MgO ≥33.5%; Potash Corporation of Germany); Boric acid, white powder (B content ≥15%); Trace elements zinc and iron in EDDHA chelated form (Zn content ≥15%, Fe content ≥5%); Mineral-derived potassium humate, gray powder (humic acid ≥50%, potassium oxide ≥12%, moisture ≤15%, pH 10.0, Shanghai Haogen Agricultural Technology Development Co., Ltd.); Anti-caking agent is modified sodium dodecylbenzene sulfonate; Biosynergist is polyglutamic acid.

[0038] Example 1 Magnesium-containing water-soluble fertilizer for citrus, by weight, consists of: 120 parts potassium nitrate, 480 parts urea, 160 parts potassium dihydrogen phosphate, 1 part boric acid, 1 part chelated zinc, 50 parts anhydrous magnesium sulfate, 1 part chelated iron, 15 parts potassium humate, 8 parts biosynergist polyglutamic acid, 1 part nitration inhibitor 3,4-dimethylpyrazole phosphate, and 2 parts sodium dodecylbenzenesulfonate.

[0039] The preparation steps of magnesium-containing water-soluble fertilizer specifically for citrus are as follows: S1: Weigh out the following quantities according to the corresponding mass proportions: 120 parts potassium nitrate, 480 parts urea, 160 parts potassium dihydrogen phosphate, 1 part boric acid, 1 part chelated zinc, 50 parts anhydrous magnesium sulfate, 1 part chelated iron, 15 parts potassium humate, 8 parts biosynergist, 1 part nitration inhibitor, and 2 parts sodium dodecylbenzenesulfonate. S2: Crush urea, potassium nitrate and potassium dihydrogen phosphate into powder and pass them through a 20-mesh sieve for later use; S3: Put the sieved potassium nitrate, urea, and potassium dihydrogen phosphate into a mixer and stir. Add anhydrous magnesium sulfate, boric acid, chelated zinc, chelated iron, and potassium humate and stir. Add anti-caking agent, bio-enhancing agent, and nitrification inhibitor, mix well, and prepare a water-soluble fertilizer for citrus.

[0040] Example 2 Magnesium-containing water-soluble fertilizer for citrus, by weight, consists of: 135 parts potassium nitrate, 570 parts urea, 192 parts potassium dihydrogen phosphate, 1 part boric acid, 1 part chelated zinc, 61 parts anhydrous magnesium sulfate, 1 part chelated iron, 20 parts potassium humate, 10 parts biosynergist phenylalanine, 2 parts nitration inhibitor 3,4-dimethylpyrazole phosphate, and 3 parts sodium dodecylbenzenesulfonate.

[0041] The preparation process of magnesium-containing water-soluble fertilizer for citrus is as follows: Figure 1 As shown, the specific steps are as follows: S1: Weigh out the following quantities according to the corresponding mass proportions: 135 parts potassium nitrate, 570 parts urea, 192 parts potassium dihydrogen phosphate, 1 part boric acid, 1 part chelated zinc, 61 parts anhydrous magnesium sulfate, 1 part chelated iron, 20 parts potassium humate, 10 parts biosynergist, 2 parts nitration inhibitor, and 3 parts sodium dodecylbenzenesulfonate. S2: Crush urea, potassium nitrate and potassium dihydrogen phosphate into powder and pass them through a 20-mesh sieve for later use; S3: Put the sieved potassium nitrate, urea, and potassium dihydrogen phosphate into a mixer and stir. Add anhydrous magnesium sulfate, boric acid, chelated zinc, chelated iron, and potassium humate and stir. Add anti-caking agent, bio-enhancing agent, and nitrification inhibitor, mix well, and prepare a water-soluble fertilizer for citrus.

[0042] The mass percentage of nitrogen, phosphorus, potassium, and magnesium in this magnesium-containing citrus-specific water-soluble fertilizer can be 28-10-13+2.0Mg-TE. That is, in this magnesium-containing citrus-specific water-soluble fertilizer, nitrogen fertilizer is calculated as N, phosphorus fertilizer as P2O5, potassium fertilizer as K2O, and magnesium fertilizer as MgO. The mass percentage of nitrogen fertilizer is 28%, the mass percentage of phosphorus fertilizer is 10%, the mass percentage of potassium fertilizer is 13%, and the mass percentage of magnesium fertilizer is 2%.

[0043] Example 3 Magnesium-containing water-soluble fertilizer for citrus, by weight, consists of: 150 parts potassium nitrate, 600 parts urea, 210 parts potassium dihydrogen phosphate, 2 parts boric acid, 1 part chelated zinc, 70 parts anhydrous magnesium sulfate, 1 part chelated iron, 25 parts potassium humate, 15 parts biosynergist phenylalanine, 3 parts nitration inhibitor 3,4-dimethylpyrazole phosphate, and 5 parts sodium dodecylbenzenesulfonate.

[0044] The preparation steps of magnesium-containing water-soluble fertilizer specifically for citrus are as follows: S1: Weigh out the following quantities according to the corresponding mass proportions: 150 parts potassium nitrate, 600 parts urea, 210 parts potassium dihydrogen phosphate, 2 parts boric acid, 1 part chelated zinc, 70 parts anhydrous magnesium sulfate, 1 part chelated iron, 25 parts potassium humate, 15 parts biosynergist, 3 parts nitration inhibitor, and 5 parts sodium dodecylbenzenesulfonate. S2: Crush urea, potassium nitrate and potassium dihydrogen phosphate into powder and pass them through a 20-mesh sieve for later use; S3: Put the sieved potassium nitrate, urea, and potassium dihydrogen phosphate into a stirrer and stir. Add anhydrous magnesium sulfate, boric acid, chelated zinc, chelated iron, and potassium humate and stir. Add anti-caking agent, bio-enhancing agent, and nitrification inhibitor, mix well, and prepare a water-soluble fertilizer for citrus.

[0045] Application Example 1 Field application effect verification of magnesium-containing citrus-specific water-soluble fertilizer Taking the magnesium-containing citrus-specific water-soluble fertilizer of Example 2 as an example, the following effect verification test was conducted.

[0046] The experiment was conducted from January to November 2024 in Hongshi Modern Industrial Park, Danling County, Meishan City (30°41′38′′N, 103°30′71′′E). The experimental site is at an altitude of 665 m and has a subtropical monsoon climate with an average annual temperature of 17.3℃, annual precipitation of about 1000~1450 mm, and a frost-free period of about 301 days per year.

[0047] The orchard soil is classified as yellow soil, with a pH of 3.90 and an organic matter content of 27.22 g / kg. -1 Total nitrogen 1.48 mg·kg -1 Available phosphorus 11.77 mg·kg-1 Available potassium 488.62 mg·kg -1 Exchangeable calcium content: 2022.50 mg / kg -1 Exchangeable magnesium content: 216.50 mg·kg -1 .

[0048] The citrus variety used in the test orchard was the local late-maturing hybrid mandarin orange 'Ai Yuan 38', with trees aged 10 years and a planting density of 825 trees per hectare. Each demonstration site had four treatments, as follows: T1: Apply magnesium-containing citrus-specific water-soluble fertilizer. In this water-soluble fertilizer, nitrogen is calculated as N, phosphorus as P2O5, and potassium as K2O. The nitrogen-phosphorus-potassium ratio is 28:10:13, that is, the nitrogen fertilizer content in this water-soluble fertilizer is 28%, the phosphorus fertilizer content is 10%, and the potassium fertilizer content is 13%. The amount of fertilizer applied each time is 0.1~0.4kg / plant, specifically: once in January-February, 205g / plant; once in March, 164g / plant; once in early April, 205g / plant; and once in late April, 123g / plant.

[0049] T2: Apply conventional water-soluble fertilizer Yuntianhua 17-17-17. In Yuntianhua 17-17-17, nitrogen is calculated as N, phosphorus as P2O5, and potassium as K2O, with a nitrogen-phosphorus-potassium ratio of 17:17:17, meaning the fertilizer contains 17% nitrogen, 17% phosphorus, and 17% potassium. The application rate is 0.1-0.4 kg / plant. Specifically: apply once in January-February (337 g / plant), once in March (270 g / plant), once in early April (337 g / plant), and once in late April (202 g / plant).

[0050] T3: Apply a water-soluble fertilizer 1, the composition of which is the same as in Example 2, the only difference being that anhydrous magnesium sulfate is not added to the water-soluble fertilizer 1; the amount of fertilizer applied each time is 0.1~0.4 kg / plant. The specific timing, method and dosage of fertilization are the same as in T1.

[0051] T4: Apply a water-soluble fertilizer 2, the composition of which is the same as in Example 2, the only difference being that the water-soluble fertilizer 2 does not contain the bio-enhancing agents phenylalanine and arginine; the amount of fertilizer applied each time is 0.1~0.4 kg / plant. The specific timing, method and dosage of fertilization are the same as in T1.

[0052] Each treatment was replicated three times, with 5-6 citrus trees per replicate, for a total of six plots, using a completely randomized block design. Water-soluble fertilizers (T1-T4) were applied concurrently from January to early April, once a month at a rate of 0.1-0.4 kg / tree. The same fruit-enhancing fertilizer was applied from late April to August. Fruits were harvested in November at the ripening stage.

[0053] The yield and output value of the fruit were statistically analyzed, and the single fruit weight, transverse diameter, longitudinal diameter, fruit shape index, soluble solids, titratable acid, solid-acid ratio and VC (vitamin C) content of the fruit were tested. The results are shown in Tables 1 and 2.

[0054] Table 1. Yield and fruit quality at maturity for groups T1 and T2

[0055] Note: The conventional water-soluble fertilizer in the table corresponds to the T2 treatment group; the citrus-specific magnesium-containing water-soluble fertilizer (Example 2) corresponds to the T1 treatment group.

[0056] Table 2. Yield and fruit quality at maturity for groups T3 and T4

[0057] As shown in Table 1, the citrus-specific magnesium-containing water-soluble fertilizer provided by the present invention can significantly increase the yield and output value of citrus; at the same time, it can also significantly improve the quality of citrus fruits, increase the single fruit weight, transverse diameter, longitudinal diameter, soluble solids content, solid acid ratio and vitamin C content.

[0058] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A magnesium-containing water-soluble fertilizer specifically for citrus, characterized in that, By weight, it includes: 120-150 parts potassium nitrate, 480-600 parts urea, 160-210 parts potassium dihydrogen phosphate, 1-2 parts boric acid, 1-2 parts chelated zinc, 50-70 parts magnesium sulfate, 1-2 parts chelated iron, and 15-25 parts potassium humate.

2. The magnesium-containing citrus-specific water-soluble fertilizer according to claim 1, characterized in that, It also includes 1-5 parts of anti-caking agent and 8-15 parts of bio-enhancing agent.

3. The magnesium-containing citrus-specific water-soluble fertilizer according to claim 2, characterized in that, The anti-caking agent includes modified sodium dodecylbenzenesulfonate and / or sodium dodecyl sulfate.

4. The magnesium-containing water-soluble fertilizer for citrus as described in claim 2, characterized in that, The biosynergist includes any one or more of polyglutamic acid, arginine, and phenylalanine.

5. The magnesium-containing citrus-specific water-soluble fertilizer according to any one of claims 1 to 4, characterized in that, The magnesium-containing citrus-specific water-soluble fertilizer also includes nitrification inhibitors.

6. The magnesium-containing citrus-specific water-soluble fertilizer according to claim 5, characterized in that, The nitration inhibitors include one or more of hydroquinone, dicyandiamide, and 3,4-dimethylpyrazole phosphate.

7. The method for preparing the magnesium-containing citrus-specific water-soluble fertilizer according to any one of claims 1 to 6, characterized in that, include: After weighing each raw material according to the mass fraction, urea, potassium nitrate and potassium dihydrogen phosphate are crushed and mixed with the remaining raw materials to obtain a magnesium-containing citrus-specific water-soluble fertilizer.

8. The application of the magnesium-containing citrus-specific water-soluble fertilizer according to any one of claims 1 to 6 or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the preparation method according to claim 7 in citrus cultivation.

9. The application according to claim 8, characterized in that, The application includes at least one of the following: (1) Increase citrus yield; (2) Increase the number and activity of roots; (3) Enhance tree resistance; (4) Accelerate the growth of new shoots; (5) Promotes fruit development; (6) Improve fruit quality.

10. A method for improving the quality of citrus fruits, characterized in that, include: During the citrus planting process, apply the magnesium-containing citrus-specific water-soluble fertilizer as described in any one of claims 1 to 6 or the magnesium-containing citrus-specific water-soluble fertilizer prepared by the preparation method described in claim 7.

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