Calcium-magnesium-sulfur liquid water-soluble fertilizer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of water-soluble fertilizer production, in particular to a calcium-magnesium-sulfur liquid water-soluble fertilizer and a preparation method and application thereof.The calcium-magnesium-sulfur liquid water-soluble fertilizer is prepared from, by weight, 30-40 parts of sugar alcohols, 12-15 parts of catalytic substances, 45-50 parts of calcium nitrate tetrahydrate, 15-16 parts of magnesium nitrate hexahydrate, 5-7 parts of magnesium chloride hexahydrate and 1.5-2.0 parts of microelements, 2-3 parts of a catalytic solubilizing stabilizer, 0.5-0.6 part of a nitrogen transport accelerant and 27-32 parts of water; according to the water-soluble fertilizer, sugar alcohol and calcium are catalyzed and induced by a catalyst to be chelated and then isomerized, and a sulfur element is grafted into a sugar alcohol structure, so that calcium and sulfur coexist in the same structure.

Description

Technical Field

[0001] The invention relates to the technical field of water-soluble fertilizer production, and in particular to a calcium-magnesium-sulfur liquid water-soluble fertilizer and a preparation method and application thereof. Background Art

[0002] The use of basic agricultural fertilizers has saved more than 2 billion people from hunger, but excessive use of fertilizers has also promoted social problems and human concerns about food health. After decades of development, the health and nutrition of agricultural products are gradually becoming one of the important factors affecting human health. In addition to causing serious environmental problems, excessive use of fertilizers also directly determines the health and nutrition of crops in the form and shape of nutrients provided, and also rings the alarm bell for human health.

[0003] Taking the medium elements as an example, the commonly used calcium fertilizers include inorganic or chelated calcium such as calcium nitrate, calcium chloride, calcium EDTA, and calcium citrate; among them, the most widely used inorganic calcium is calcium nitrate or calcium ammonium nitrate. These products have good water solubility, but there is a large amount of loss during foliar spraying. At the same time, they will quickly form precipitation when encountering sulfate, phosphate, carbonate or borate conditions in the environment, making their utilization efficiency very low; in terms of chelated calcium, calcium EDTA is difficult to degrade and there is a trend of being gradually eliminated; calcium citrate has low water solubility and also has the phenomenon of precipitation when encountering the above salts. The situation is slightly better for magnesium fertilizers, mainly due to the slightly higher water solubility of magnesium sulfate, but it will also form precipitation when encountering phosphate, carbonate or borate conditions. This also creates a shortcoming in the application of fertilizers, making it impossible to supplement the nutrient sulfur for crops while supplementing calcium and magnesium. Although crops can obtain sulfur through soil absorption, the lack of nutrients at critical moments is obvious to all. In addition to the lack of sulfur, another troublesome factor is the residual problem of nitrate nitrogen, which is also a health hazard that cannot be ignored.

[0004] The above situation is contradictory to the development of fertilizers. Looking at the development of fertilizers in the world, it can be basically divided into single nutrient stage, mixed fertilizer stage, compound fertilizer stage and water-soluble fertilizer stage in terms of nutrient form. This division is also closely related to the increasing scarcity of water resources faced by mankind. In my country, fertilizers are in the transition period from compound fertilizer stage to water-soluble fertilizer stage. This special period requires nutrients to be as comprehensive and water-soluble as possible. At the same time, there are strict requirements and controls on the secondary salinization of soil caused by water-soluble fertilizers. This has formed a contradiction between the development of water-soluble fertilizers and environmental health. Therefore, how to achieve stability between medium-sized elements, reduce precipitation between nutrients, and reduce secondary salinization caused by water-soluble fertilizers has become extremely important. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a calcium magnesium sulfur liquid water-soluble fertilizer and a preparation method and application thereof.

[0006] To solve the above problems, the technical solution adopted by the present invention is: On the one hand, a calcium magnesium sulfur liquid water-soluble fertilizer is provided, which includes the following components in parts by weight: 30-40 parts of sugar alcohols, 12-15 parts of catalytic substances, 45-50 parts of calcium nitrate tetrahydrate, 15-16 parts of magnesium nitrate hexahydrate, 5-7 parts of magnesium chloride hexahydrate, 1.5-2.0 parts of trace elements, 2-3 parts of catalytic solubilizing stabilizer, 0.5-0.6 parts of nitrogen transport promoter, and 27-32 parts of water.

[0007] As an embodiment of the invention, the water-soluble fertilizer is catalytically induced to isomerize sugar alcohol and calcium after chelation, and sulfur is grafted into the sugar alcohol structure, so that calcium and sulfur can coexist in the same structure.

[0008] As an embodiment of the invention, the catalytic substance is aminosulfonic acid, or a mixture of aminosulfonic acid and ammonium bisulfate in a weight ratio of 4:1-3:1; As an embodiment of the invention, the sugar alcohol is selected from one of sorbitol, erythritol, and xylitol; or, is selected from a combination of sorbitol and erythritol and / or xylitol, in which the proportion of sorbitol is ≥75%.

[0009] As an embodiment of the invention, the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% ammonia water in a mass ratio of 1:1-2:1; its main function is to reduce the reduction in water solubility of sugar alcohols caused by sulfidation, and can provide an appropriate amount of ring-opening effect through ammonia, and sodium hydroxide can provide a certain pH adjustment to promote the ring-opening of ammonia, thereby enhancing the stability of the system.

[0010] As an embodiment of the invention, the nitrogen transport promoter is a polymerized amino acid with a degree of polymerization of 10-20, and the content of free amino acids does not exceed 10% of the total mass; it is selected from one or two of polyaspartic acid and polyglutamic acid.

[0011] As an embodiment of the invention, the liquid water-soluble fertilizer includes medium elements, trace elements, and also contains a large amount of nitrogen. The system is stable and has no precipitation. The content of medium elements calcium and magnesium is ≥100g / L, the content of medium element sulfur is ≥40g / L; nitrogen is ≥60g / L; the trace elements are ≥3g / L; Wherein, the trace element is selected from at least one of zinc, copper, boron and molybdenum; the trace element is selected from one or more of zinc nitrate, zinc chloride, copper nitrate, copper chloride, boric acid, sodium octaborate and ammonium molybdate.

[0012] In a second aspect, a method for preparing a calcium magnesium sulfur liquid water-soluble fertilizer as described in the first aspect is provided, the method comprising: (1) Preparation of chelated calcium-sulfur products Stir sugar alcohols, catalytic substances and water at 1.2-1.8 MPa, 75±5°C and 75-100 r / min for 30-60 min to obtain a liquid calcium stabilizer; Adding calcium nitrate tetrahydrate to the liquid calcium stabilizer, stirring for 1-2 hours at normal pressure, 75±5° C., and 75-100 r / min to obtain a chelated calcium-sulfur product; (2) Preparation of calcium magnesium sulfur liquid water-soluble fertilizer Under the conditions of normal temperature and stirring at 100-150r / min, a nitrogen transport promoter, magnesium nitrate hexahydrate, magnesium chloride hexahydrate and trace elements are sequentially added to the chelated calcium-sulfur product, and after dissolution, a catalytic solubilizing stabilizer is added dropwise at a rate of 1.25g / min; after the addition is completed, stirring is continued for 15-20min to obtain the calcium-magnesium-sulfur liquid water-soluble fertilizer.

[0013] In a third aspect, there is provided an application of the calcium magnesium sulfur liquid water-soluble fertilizer as described in the first aspect in agricultural irrigation, wherein the application is to apply the calcium magnesium sulfur liquid water-soluble fertilizer to spray / drip irrigation fertilization of crops that are sensitive to sulfur requirements, and the crops are preferably Allium of the Amaryllis family.

[0014] In a fourth aspect, a method for using the calcium magnesium sulfur liquid water-soluble fertilizer as described in the first aspect is provided, wherein the water-soluble fertilizer is directly used as a fertilizer alone during the crop nutrition period or the bulking period, with a safe interval of 14 days.

[0015] The beneficial effects of adopting the above technical solution are: The calcium magnesium sulfur liquid water-soluble fertilizer provided by the present invention and the preparation method and application thereof can realize the synergistic solubilization of calcium and sulfur and diversify the nutrients thereof by adding sugar alcohols to the calcium magnesium sulfur liquid water-soluble fertilizer to react with a catalytic substance; then adding calcium nitrate tetrahydrate provides a sufficient and excellent water-soluble calcium source; continuing to add photosynthetic magnesium elements promotes crop photosynthesis; continuing to add trace crops to provide the crops with trace active elements required in a critical period; and finally adding a catalytic solubilization stabilizer promotes the stability and dissolution between substances.

[0016] The calcium magnesium sulfur liquid water-soluble fertilizer provided by the present invention can provide water-soluble liquid calcium magnesium sulfur while also providing trace elements and macro-element nitrogen, and is suitable for use in crops or growth periods that have high demands for medium elements and also have demands for trace elements and macro-element nitrogen; in addition, the present invention adds a variety of functional substances (such as polymerized amino acids and sugar alcohol substances) that can alleviate secondary salinization, which is very helpful for improving the quality of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the infrared spectrum of the calcium magnesium sulfur liquid water-soluble fertilizer obtained in Example 1 of the present invention.

[0018] Figure 2 This is the infrared spectrum of sorbitol.

[0019] Figure 3 This is the appearance of the calcium magnesium sulfur liquid water-soluble fertilizer obtained in Example 1 of the present invention.

[0020] Figure 4 This is the appearance of the calcium magnesium sulfur liquid water-soluble fertilizer obtained in Comparative Example 1. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is clearly and completely described below in conjunction with specific embodiments.

[0022] Example 1 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials include: 26.5g sorbitol, 8.8g xylitol, 11.0g aminosulfonic acid, 3.0g ammonium hydrogen sulfate, 47.5g calcium nitrate tetrahydrate, 15.5g magnesium nitrate hexahydrate, 6g magnesium chloride hexahydrate, 1.75g ​​zinc nitrate, 2.5g catalytic solubilizing stabilizer, 0.5g nitrogen transport promoter, 29g water, the obtained finished product is as follows Figure 1 shown.

[0023] Among them, all raw materials are of industrial grade and meet the relevant standards; the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% liquid ammonia in a mass ratio of 3:2; the nitrogen transport promoter is selected as polyammonium aspartate, wherein the degree of polymerization of polyammonium aspartate is 15 and the content of free ammonia is 7.93%.

[0024] The preparation method comprises: (1) Preparation of chelated calcium-sulfur products Sorbitol, xylitol, aminosulfonic acid, ammonium bisulfate and water were reacted at 1.5 MPa, 78°C and 85 r / min for 45 min to obtain a liquid calcium stabilizer; Calcium nitrate tetrahydrate is added to the above liquid calcium stabilizer, and the reaction is carried out at normal pressure, 78°C, and 85r / min for 1.5h to obtain a chelated calcium-sulfur product; (2) Preparation of calcium magnesium sulfur liquid water-soluble fertilizer Under the conditions of room temperature and stirring at 125 r / min, nitrogen transport promoter, magnesium nitrate hexahydrate, magnesium chloride hexahydrate and zinc nitrate are added to the chelated calcium-sulfur product in sequence, stirred and dissolved, and then a catalytic solubilizing stabilizer is added dropwise at a rate of 1.25 g / min to obtain a calcium-magnesium-sulfur liquid water-soluble fertilizer.

[0025] The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is stable and has no precipitation, and the calcium and magnesium content is 103.5g / L, sulfur is 40.8g / L, nitrogen is 65.80g / L, and zinc is 3.32g / L.

[0026] Example 2 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials comprising: 30.0g of sorbitol, 12.5g of aminosulfonic acid, 47.2g of calcium nitrate tetrahydrate, 15.0g of magnesium nitrate hexahydrate, 5.0g of magnesium chloride hexahydrate, 1.50g of zinc chloride, 2.0g of a catalytic solubilizing stabilizer, 0.5g of a nitrogen transport promoter, and 32g of water.

[0027] Among them, all raw materials are of industrial grade and meet the requirements of relevant standards; the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% liquid ammonia in a mass ratio of 1:1; the nitrogen transport promoters are potassium polyaspartate and polyglutamic acid, among which the degree of polymerization of potassium polyaspartate is 15 and the average degree of polymerization of polyglutamic acid is 19.

[0028] The preparation method comprises: (1) Preparation of chelated calcium-sulfur products Sorbitol, xylitol, aminosulfonic acid, ammonium bisulfate and water were reacted at 1.2 MPa, 70°C and 100 r / min for 60 min to obtain a liquid calcium stabilizer; Calcium nitrate tetrahydrate is added to the above liquid calcium stabilizer, and the reaction is carried out for 2 hours at normal pressure, 70°C and 100r / min to obtain a chelated calcium-sulfur product; (2) Preparation of calcium magnesium sulfur liquid water-soluble fertilizer Under the conditions of room temperature and stirring at 100 r / min, nitrogen transport promoter, magnesium nitrate hexahydrate, magnesium chloride hexahydrate and zinc nitrate are added to the chelated calcium-sulfur product in sequence, stirred and dissolved, and then a catalytic solubilizing stabilizer is added dropwise at a rate of 1.25 g / min to obtain a calcium-magnesium-sulfur liquid water-soluble fertilizer.

[0029] The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is stable and has no precipitation, and the calcium and magnesium content is 100.3g / L, sulfur is 40.1g / L, nitrogen is 72.4g / L, and zinc is 5.0g / L.

[0030] Example 3 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials comprising: 40.0g of xylitol, 12.0g of aminosulfonic acid, 3.0g of ammonium hydrogen sulfate, 50.0g of calcium nitrate tetrahydrate, 16.0g of magnesium nitrate hexahydrate, 7.0g of magnesium chloride hexahydrate, 1.75g ​​of zinc nitrate hexahydrate, 0.25g of boric acid, 3.0g of a catalytic solubilizing stabilizer, 0.6g of a nitrogen transport promoter, and 27g of water.

[0031] Among them, all raw materials are of industrial grade and meet the relevant standards; the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% liquid ammonia in a mass ratio of 2:1; the nitrogen transport promoter is polyglutamic acid, wherein the average degree of polymerization of polyglutamic acid is 19.

[0032] (1) Preparation of chelated calcium-sulfur products Sorbitol, xylitol, aminosulfonic acid, ammonium bisulfate and water were reacted at 1.8 MPa, 80°C and 75 r / min for 30 min to obtain a liquid calcium stabilizer; Calcium nitrate tetrahydrate is added to the above liquid calcium stabilizer, and the reaction is carried out at normal pressure, 80°C, and 75r / min for 1 hour to obtain a chelated calcium-sulfur product; (2) Preparation of calcium magnesium sulfur liquid water-soluble fertilizer Under the condition of room temperature and stirring at 150r / min, nitrogen transport promoter, magnesium nitrate hexahydrate, magnesium chloride hexahydrate and zinc nitrate are added to the chelated calcium-sulfur product in sequence, stirred and dissolved, and then a catalytic solubilizing stabilizer is added dropwise at a rate of 1.25g / min to obtain a calcium-magnesium-sulfur liquid water-soluble fertilizer.

[0033] The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is stable and has no precipitation, and the calcium and magnesium content is 108.0 g / L, sulfur is 47.8 g / L, nitrogen is 78.5 g / L, and zinc is 3.83 g / L.

[0034] Comparative Example 1 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials comprising: 16.5g sorbitol, 8.8g xylitol, 11.0g aminosulfonic acid, 3.0g ammonium hydrogen sulfate, 47.5g calcium nitrate tetrahydrate, 15.5g magnesium nitrate hexahydrate, 6g magnesium chloride hexahydrate, 1.75g ​​zinc nitrate, 2.5g catalytic solubilizing stabilizer, 0.5g nitrogen transport promoter, and 32g water.

[0035] Among them, all raw materials are of industrial grade and meet the relevant standards; the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% liquid ammonia in a mass ratio of 3:2; the nitrogen transport promoter is selected as polyammonium aspartate, wherein the degree of polymerization of polyammonium aspartate is 15 and the content of free ammonia is 7.93%.

[0036] The preparation method and conditions are the same as those in Example 1; the nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is slightly emulsified, with a calcium and magnesium content of 108.0 g / L, sulfur of 47.8 g / L, nitrogen of 78.5 g / L, and zinc of 3.83 g / L.

[0037] Comparative Example 2 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials of which include: 26.5g sorbitol, 8.8g xylitol, 11.0g aminosulfonic acid, 3.0g ammonium hydrogen sulfate, 47.5g calcium nitrate tetrahydrate, 15.5g magnesium nitrate hexahydrate, 6g magnesium chloride hexahydrate, 1.75g ​​zinc nitrate, 0.5g nitrogen transport promoter, and 31.5g water.

[0038] Among them, all raw materials are of industrial grade and meet the relevant standards and regulations; the nitrogen transport promoter is selected as ammonium polyaspartate, wherein the degree of polymerization of ammonium polyaspartate is 15 and the content of free ammonia is 7.93%.

[0039] The preparation method and conditions are the same as those in Example 1, except that the addition of a catalytic solubilizing stabilizer is omitted in step (2); the nutrient content of the calcium magnesium sulfur liquid water-soluble fertilizer produced according to the above process and components is as follows: the system is slightly emulsified, with a calcium magnesium content of 108.0 g / L, a sulfur content of 47.8 g / L, a nitrogen content of 78.5 g / L, and a zinc content of 3.83 g / L.

[0040] Comparative Example 3 A calcium magnesium sulfur liquid water-soluble fertilizer, the raw materials of which include: 26.5g sorbitol, 8.8g xylitol, 11.0g aminosulfonic acid, 3.0g ammonium hydrogen sulfate, 47.5g calcium nitrate tetrahydrate, 15.5g magnesium nitrate hexahydrate, 6g magnesium chloride hexahydrate, 1.75g ​​zinc nitrate, 2.5g catalytic solubilizing stabilizer and 29.5g water.

[0041] Among them, all raw materials are of industrial grade and meet the relevant standards; the catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% liquid ammonia in a mass ratio of 3:2.

[0042] The preparation method and conditions are the same as those in Example 1, except that the addition of nitrogen transport promoter is omitted in step (2). The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is stable and free of precipitation, and the calcium and magnesium contents are 108.0 g / L, sulfur 47.8 g / L, nitrogen 78.5 g / L, and zinc 3.83 g / L.

[0043] Comparative Example 4 A calcium magnesium sulfur liquid water-soluble fertilizer, whose raw material composition, raw material requirements and indicators, and preparation method are the same as those in Example 1.

[0044] The only difference is step (1). Step (1) of this comparative example comprises: Sorbitol, xylitol, aminosulfonic acid, ammonium bisulfate and water were reacted at normal pressure, 78°C and 85r / min for 45 minutes to obtain a liquid calcium stabilizer; Calcium nitrate tetrahydrate was added to the above liquid calcium stabilizer, and the reaction was carried out for 1.5 h at 1.5 MPa, 78° C. and 85 r / min to obtain a chelated calcium-sulfur product.

[0045] The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is slightly emulsified, with a calcium and magnesium content of 103.5 g / L, sulfur of 40.8 g / L, nitrogen of 65.80 g / L, and zinc of 3.32 g / L.

[0046] Comparative Example 5 A calcium magnesium sulfur liquid water-soluble fertilizer, whose raw material composition, raw material requirements and indicators, and preparation method are the same as those in Example 1.

[0047] The only difference is step (1). Step (1) of this comparative example comprises: Sorbitol, xylitol, aminosulfonic acid, ammonium bisulfate and water were reacted at 1.5 MPa, 55°C and 85 r / min for 45 min to obtain a liquid calcium stabilizer; Calcium nitrate tetrahydrate was added to the above liquid calcium stabilizer, and the reaction was carried out for 1.5 hours at normal pressure, 55°C and 85r / min to obtain a chelated calcium-sulfur product.

[0048] The nutrient contents of the calcium, magnesium and sulfur liquid water-soluble fertilizer produced according to the above process and components are as follows: the system is stable and has no precipitation, and the calcium and magnesium content is 103.5g / L, sulfur is 40.8g / L, nitrogen is 65.80g / L, and zinc is 3.32g / L.

[0049] Test case infrared test The calcium magnesium sulfur liquid water-soluble fertilizer obtained in Example 1 was subjected to infrared testing, and the infrared spectrum obtained was as follows: Figure 1 As shown by Figure 1 It can be seen that there are 6 obvious absorption peaks (transmittance 30-100%) in calcium magnesium sulfur liquid water-soluble fertilizer, which are 3353.63, 1638.39, 1328.23, 1064.76, 1045.68, 823.40cm -1 There are other less obvious absorption peaks in the spectrum, which will not be analyzed here; in the characteristic area (3600-1350cm -1 ), 3353.63cm -1 、1638.39cm -1 There are two obvious absorption peaks, representing the existence of OH association and NH, C = O bonds, among which OH association is consistent with the chelation of sorbitol and calcium and magnesium, and NH and C = O bonds are consistent with the basic structure of polyaspartic acid and its derivatives; in the fingerprint region (1350-400cm -1 ), the sample spectrum contains 1328.23, 1064.76, 1045.68 and 823.40cm -1 There are four obvious absorption peaks, among which 1328.23cm -1The absorption peak indicates the presence of S=O bond (note that it is not SO4; the absorption range of SO4 is 1200-1100cm -1 and 650-550cm -1 ), 1064.76 and 1045.68cm -1 The absorption peak characterizes the presence of CN bonds and proves the presence of the characteristics of polyaspartic acid; 823.40cm -1 The absorption peak characterizes the variation of CH bending vibration absorption, which explains the bending of the structure of the substance. Combined with the operation of this scheme, it can be understood that the bending of the CH bond is caused by the occurrence of chelation. The existence of the above characteristic absorption peaks indicates that the sample contains derivatives of polytian and obvious S=O bonds are generated, and chelation also occurs at the same time.

[0050] In addition, the present invention also compares the above infrared spectrum with the infrared spectrum of sorbitol. Figure 2 As shown in the figure, there are 9 obvious absorption peaks in the infrared spectrum of sorbitol (transmittance 0-50%), which are 3404.67, 2937.37, 1637.66, 1408.56, 1082.40, 1045.77, 879.39, 591.72, 518.99 cm -1 ; Since the transmittance of the standard absorption peak is significantly lower than that of the sample, it can be judged that the density of various bonds is significantly lower than that of the sample; at the same time, there are other less obvious absorption peaks in the spectrum, which will not be analyzed here; in the characteristic area (3600-1350cm -1 ), the sample spectrum contains 3404.67, 2937.37, 1637.66, 1408.56cm -1 Four obvious absorption peaks represent the existence of OH association, CH plane stretching bond, OH (bound water) bond and CH plane bending bond, which is consistent with the characteristics of solid sorbitol containing bound water; in the fingerprint region (1350-400cm -1 ), the sample spectrum contains 1082.40, 1045.77, 879.39, 591.72, and 518.99 cm -1 There are five obvious absorption peaks, including 1082.40cm -1 and 1045.77cm -1 The absorption peaks indicate the presence of CH (CH2 group), 879.39 cm -1 The absorption peaks represent the CH bending vibration absorption, 591.72 cm -1 and 518.99cm -1 The absorption peak is relatively rare and is suspected to be the stretching vibration of the CH bond; the existence of the above characteristic absorption peaks explains the characteristic absorption of sorbitol.

[0051] By comparing the two infrared spectra, it can be clearly found that compared with the standard spectrum of sorbitol, the spectrum of the sample has three obvious differences: first, the appearance of the S=O bond proves that a substitution reaction occurred in the reaction, so that the sulfur element was combined into the product, not in the form of SO4 2- form; secondly, the appearance of the structure of the polyaspartic acid derivative proves that polyaspartic acid may also participate in the reaction, and it may also cause the change of the electronic distribution, otherwise the shift of the structural absorption peak cannot be explained; thirdly, the change of the characteristic peak of sorbitol explains the existence of chelation; through the above analysis, we can clearly realize that the implementation method of Example 1 calcium magnesium sulfur water-soluble fertilizer is that with the help of the catalyst, sulfur element appears in the sugar alcohol, which lays a structural foundation for the coexistence of sulfur and calcium elements. At the same time, the subsequent addition of polyaspartic acid causes changes in the product electrons due to electron redistribution or participation in the reaction, which promotes the shift of some bond absorption peaks and makes the structure more stable, thereby realizing the product structure of "catalyst catalyzed induction of sugar alcohol and calcium chelation to undergo isomerization, and sulfur element is grafted into the sugar alcohol structure, so that calcium and sulfur can coexist in the same structure".

[0052] Effect example: Effect Example 1 Stability Comparison The water-soluble fertilizers prepared in the above Examples 1-3 and Comparative Examples 1-5 were subjected to a high temperature storage experiment. Their appearance was observed at 0, 1, 3, 5, 7 and 14 days after sealing in a water bath at 54±2°C to determine their storage stability (if there is no abnormality in the 14-day hot storage, it proves that their room temperature storage stability is greater than 2 years). The specific results are shown in Table 1. The appearance of the water-soluble fertilizer prepared in Example 1 at 0 days and 14 days, and the appearance of the water-soluble fertilizer prepared in Comparative Example 1 at 0 days, are shown in Table 1. Figure 3 and Figure 4 .

[0053] Table 1 Effects of foliar spraying of liquid water-soluble fertilizer on garlic yield and quality Note: - indicates the product is a clear solution, + indicates a slightly emulsified solution, and ++ indicates a turbid solution.

[0054] In the above table, Examples 1-3 and Comparative Example 3 have good stability during the storage period and no abnormal state occurs; Comparative Examples 1-2 and Comparative Example 4 have a significant increase in turbidity with the increase of storage time, proving that agglomeration is gradually occurring inside them and a perfect system has not been formed; Comparative Example 5 has a process in which the turbidity changes from zero to obvious, proving the instability of its system, which indirectly reflects the necessity of reaction temperature. In summary, Examples 1-4 and Comparative Example 3 have qualified thermal storage stability, and the remaining treatment stability needs to be improved, and the comprehensive effect needs to be verified through planting experiments.

[0055] Effect Example 2 Planting Experiment The water-soluble fertilizers prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to a field foliar spraying test. 22.5 T / hm was applied before sowing and plowing. 2 Mature organic fertilizer, combined with ordinary compound fertilizer (nutrient content N-P2O5-K2O is 15%-15%-15%) 750kg / hm 2 As basal fertilizer; during the garlic planting period, topdressing is carried out at the greening stage, garlic stalk extension stage and garlic head growth stage. 225kg / hm2 is applied at the greening stage. 2 Urea and the above water-soluble fertilizers 15kg / hm 2 , long-term topdressing of garlic stalks 300kg / hm 2 Three-element water-soluble fertilizer (N-P2O5-K2O is 25%-10%-12%) and the above water-soluble fertilizers 15kg / hm 2 , 225kg / hm2 of topdressing during the garlic growth period 2 Three-element water-soluble fertilizer (N-P2O5-K2O is 25%-10%-12%) and the above water-soluble fertilizers 15kg / hm 2 , respectively recorded as T1-T3, CK1-CK5; at the same time, a blank treatment without applying the water-soluble fertilizer of the above embodiments and comparative examples was set, and the other treatments were the same, recorded as CK; all the above treatments were recorded as separate test areas, each test area was 300m2, each treatment was repeated 3 times, and all test areas were randomized (randomized block refers to random arrangement, which is used to eliminate experimental errors).

[0056] This experiment was conducted in Congtai District, Handan City, Hebei Province (114°29'35"E, 36°38'11"N) from 2023 to 2024. The climate in the experimental area is warm temperate humid continental monsoon climate. The selected experimental plots are typical brown soil, with soil pH 7.80-7.93, average organic matter content 2.46%, average total nitrogen 1.46g / kg, average available phosphorus 34.69mg / kg, and average available potassium 123.17mg / kg. The fertility is relatively high, and it is a high-yield grain and vegetable field. The experimental time is from the early planting period to the harvest of garlic (September 25, 2023-June 25, 2024). The yield is measured separately for each plot, and the yield indicators in the measured items are designed with reference to the relevant requirements of the general agronomy introduction. The remaining indicators were measured and analyzed in the fresh weight state after harvest: the determination of alliin (the precursor of allicin) was carried out according to the relevant provisions of the HPLC method for determining the content of alliin in garlic extract (Jiang Li, Chang Junmin. Northwest Pharmaceutical Journal, 2009, 24(01): 21-22), the determination of soluble protein content was carried out by anthrone colorimetry, the determination of reducing sugar content was carried out by arsenomolybdic acid colorimetry, and the determination of VC content was carried out by 2,6-dichloroindophenol titration. The comprehensive statistical analysis method was used to verify the effect of foliar spraying of liquid water-soluble fertilizer on garlic yield and quality. SPSS20.0 data analysis system was used for one-way analysis of variance and Dunckan method was used for significant difference test; the comprehensive data results are shown in Table 2.

[0057] Table 2 Effects of foliar spraying of liquid water-soluble fertilizer on garlic yield and quality In the data in the above table, the garlic yield of Example 1 is the highest compared with other treatments. By comparing the key quality indicators such as alliin, soluble protein, reducing sugar and VC, it is found that the corresponding data are also significantly improved. Therefore, it can be judged that the liquid water-soluble fertilizer produced by Example 1 can improve the yield and quality of garlic at the same time. The improvement path is analyzed as follows: ① In the treatment of Example 1, the elements that have a key influence on the growth of garlic, such as calcium, magnesium and sulfur, are effectively supplemented, so that the garlic grows fully and timely in each growth period; although the data in the corresponding Examples 2-3 are slightly worse, they are also better than all the control treatments, proving that although they do not achieve the effect of Example 1, they can still promote the growth of garlic; ② Similarly, in the treatments of Comparative Examples 1 and 2, the chelating ratio is changed (the ratio of sugar alcohol is reduced) and the catalytic solubilizer is missing, so as to obtain a microemulsified Water-soluble fertilizer, but its effect is still better than the other control treatments, which shows that the above treatment will affect the appearance characteristics of the product, thereby affecting the product effect. With the increase of storage time, its turbidity increases, which in turn has a greater impact on the effect; and the data of comparative example 3 proves that nitrogen transport promoter plays an important role in the formula and has a key effect on the application of crop nitrogen; ③ In theory, when the raw materials and their proportions are the same, the product effect should be equivalent; but from the above table, it is found that the various indicators of comparative examples 4 and 5 are still significantly different from those of embodiment 1, proving that although the product indicators and appearance properties of different production processes may be the same, their internal effects will be different, and the main reason for this can be attributed to the fact that the production process causes the product to undergo a chemical reaction at the microscopic level, thus proving that both production pressure and production temperature can affect the product.

[0058] In summary, the water-soluble fertilizer of the present invention can significantly improve nitrogen utilization, achieve simultaneous supplementation of calcium, magnesium and sulfur, and reduce the antagonistic effects between the above elements, thereby significantly increasing the yield of crops that have a significant demand for the above elements.

Claims

1. A calcium magnesium sulfur liquid water-soluble fertilizer, It is characterized in that The invention comprises the following components in parts by weight: 30-40 parts of sugar alcohols, 12-15 parts of catalytic substances, 45-50 parts of calcium nitrate tetrahydrate, 15-16 parts of magnesium nitrate hexahydrate, 5-7 parts of magnesium chloride hexahydrate, 1.5-2.0 parts of trace elements, 2-3 parts of catalytic solubilizing stabilizers, 0.5-0.6 parts of nitrogen transport promoters and 27-32 parts of water.

2. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The water-soluble fertilizer induces isomerization of sugar alcohol and calcium chelation through a catalyst, and grafts sulfur element into the sugar alcohol structure, so that calcium and sulfur can coexist in the same structure.

3. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The catalytic substance is aminosulfonic acid, or a mixture of aminosulfonic acid and ammonium bisulfate in a weight ratio of 4:1-3:

1.

4. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The sugar alcohol is selected from one of sorbitol, erythritol and xylitol; or, is selected from a combination of sorbitol and erythritol and / or xylitol, in which the proportion of sorbitol is ≥75%.

5. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The catalytic solubilizing stabilizer is a mixture of solid sodium hydroxide and 25% ammonia water in a mass ratio of 1:1-2:

1.

6. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The nitrogen transport promoter is a polymerized amino acid with a degree of polymerization of 10-20, and the content of free amino acids does not exceed 10% of the total mass; it is selected from one or both of polyaspartic acid and polyglutamic acid.

7. A calcium magnesium sulfur liquid water-soluble fertilizer according to claim 1, It is characterized in that The liquid water-soluble fertilizer includes medium elements, trace elements, and also contains a large amount of nitrogen. The system is stable and has no precipitation. The content of medium elements calcium and magnesium is ≥100g / L, the content of medium element sulfur is ≥40g / L; the nitrogen element is ≥60g / L; and the trace elements are ≥3g / L. Wherein, the trace element is selected from at least one of zinc, copper, boron and molybdenum; the trace element is selected from one or more of zinc nitrate, zinc chloride, copper nitrate, copper chloride, boric acid, sodium octaborate and ammonium molybdate.

8. A method for preparing a calcium magnesium sulfur liquid water-soluble fertilizer as claimed in any one of claims 1 to 7, It is characterized in that The method comprises: (1) Preparation of chelated calcium-sulfur products Stir sugar alcohols, catalytic substances and water at 1.2-1.8 MPa, 75±5°C and 75-100 r / min for 30-60 min to obtain a liquid calcium stabilizer; Adding calcium nitrate tetrahydrate to the liquid calcium stabilizer, stirring for 1-2 hours at normal pressure, 75±5° C., and 75-100 r / min to obtain a chelated calcium-sulfur product; (2) Preparation of calcium magnesium sulfur liquid water-soluble fertilizer Under the conditions of normal temperature and stirring at 100-150r / min, a nitrogen transport promoter, magnesium nitrate hexahydrate, magnesium chloride hexahydrate and trace elements are sequentially added to the chelated calcium-sulfur product, and after dissolution, a catalytic solubilizing stabilizer is added dropwise at a rate of 1.25g / min; after the addition is completed, stirring is continued for 15-20min to obtain the calcium-magnesium-sulfur liquid water-soluble fertilizer.

9. Application of the calcium magnesium sulfur liquid water-soluble fertilizer according to any one of claims 1 to 7 in agricultural irrigation, It is characterized in that The application is to apply the calcium magnesium sulfur liquid water-soluble fertilizer to the spray / drip irrigation fertilization of crops that are sensitive to sulfur elements, and the crops are preferably Allium of the Amaryllis family.

10. A method for using the calcium magnesium sulfur liquid water-soluble fertilizer according to any one of claims 1 to 7, It is characterized in that During the crop nutrition period or expansion period, the water-soluble fertilizer is directly used as a fertilizer alone, with a safe interval of 14 days.

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