Value-added urea for spring corn base fertilizer and preparation method of value-added urea

Abstract

The invention relates to value-added urea for spring corn base fertilizer and a preparation method thereof. The preparation method comprises the following steps: sequentially and alternately adding the urea long-acting material and the urea conversion-promoting material into urea liquid at the same position according to the interval time of 6-10 minutes, so as to obtain the value-added urea for the spring corn base fertilizer. The invention aims to solve the problem that one-time production of the value-added urea for the spring corn base fertilizer on a urea production device is realized by sequentially and alternately adding a urea long-acting material and a urea conversion promoting material into a urea liquid, and secondary processing is not needed.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to value-added urea for spring corn base fertilizer and a preparation method thereof. Background Art

[0002] In spring corn production, there are two important requirements for nitrogen fertilizer application: first, due to the low temperature in spring, corn grows slowly, and urea products that can quickly promote seedling growth are needed. Urea needs to be converted into mineral nitrogen (ammonium nitrogen and nitrate nitrogen) before it can be absorbed by crops. Therefore, it is necessary to promote urea conversion and ensure the supply of nitrogen in the corn seedling stage. Technology; second, corn has a long growth period of up to 140 days, which requires long-acting urea products. However, there are contradictions between these two aspects, and it is difficult to achieve the functions of urea-promoting conversion and long-acting in the same urea granules at the same time. At present, there is no value-added urea product that is dedicated to spring corn base fertilizer and produced in an integrated manner on large-scale urea plants. Summary of the invention

[0003] In view of this, the main purpose of the present invention is to provide a value-added urea for spring corn base fertilizer and a preparation method thereof. The problem to be solved is to achieve one-time production of value-added urea for spring corn base fertilizer on a urea production device by alternately adding urea long-acting material and urea conversion-promoting material into urea liquid in sequence, without the need for secondary processing.

[0004] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical scheme. The present invention proposes a method for preparing value-added urea for spring corn base fertilizer, comprising the following steps:

[0005] Before granulating the urea liquid, the urea long-acting material and the urea conversion-promoting material are added into the urea liquid alternately at the same position at intervals of 6 to 10 minutes to obtain the value-added urea for spring corn base fertilizer.

[0006] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0007] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, the volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50).

[0008] Preferably, the method for preparing the aforementioned value-added urea for spring corn base fertilizer, wherein the method for preparing the urea long-acting material comprises the following steps:

[0009] 1a) uniformly mixing monosaccharide acid and amino acid to obtain a monosaccharide acid-amino acid mixture;

[0010] 2a) dissolving the monosaccharide acid-amino acid mixture obtained in step 1a) in water at 90-100° C. to obtain a monosaccharide acid-amino acid solution having a mass percentage concentration of 20%-30%;

[0011] 3a) After the monosaccharide acid-amino acid solution obtained in step 2a) is cooled to room temperature, the pH value of the monosaccharide acid-amino acid solution is adjusted to 5.5-7.5 by using a sodium thiosulfate aqueous solution to obtain a urea-promoting conversion material.

[0012] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0013] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, in step 1a), the molar ratio of the monosaccharide acid to the amino acid is 1:0.1-1.

[0014] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, in step 1a), the molecular weight of the amino acid is less than 100 Daltons.

[0015] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, in step 3a), the mass concentration of the sodium thiosulfate aqueous solution is 50% to 70%.

[0016] Preferably, the method for preparing the aforementioned value-added urea for spring corn base fertilizer, wherein the method for preparing the urea conversion-promoting material comprises the following steps:

[0017] 1b) mixing succinic acid, glutaric acid and adipic acid to obtain an organic diacid mixture; dissolving the organic diacid mixture in boiling water at 100° C. to prepare an organic diacid mixed solution having a mass percentage concentration of 15% to 20%;

[0018] 2b) adjusting the pH value of the organic diacid mixed solution obtained in step 1b) to 6.5-7.5 by using an inorganic alkali aqueous solution to obtain the urea conversion-promoting material.

[0019] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, in step 1b), the molar ratio of succinic acid, glutaric acid and adipic acid is 1:1-2:2-3.

[0020] Preferably, in the aforementioned method for preparing value-added urea for spring corn base fertilizer, in step 2b), the mass percentage concentration of the inorganic alkali aqueous solution is 20% to 40%.

[0021] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions. The present invention proposes a value-added urea for spring corn base fertilizer, which includes a urea long-acting material and a urea conversion-promoting material; the volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50).

[0022] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0023] Preferably, the aforementioned value-added urea for spring corn basal fertilizer is prepared by the above-mentioned method.

[0024] By means of the above technical scheme, the present invention provides a value-added urea for spring corn base fertilizer and a preparation method thereof, which has at least the following advantages:

[0025] 1. The present invention realizes the integration of urea's "promoting conversion + long-term effect" functions in the same value-added urea granule during the urea production process; monosaccharide acid-small molecule amino acid can promote the hydrolysis of urea into mineral nitrogen, solving the problem of slow urea conversion and slow growth of corn seedlings under low temperature conditions; organic binary mixed acid can slow down the hydrolysis of urea, thereby prolonging the urea fertilizer effect. The value-added urea product realizes pulsed nitrogen supply for spring corn, further improving the urea application effect.

[0026] 2. The present invention can realize the integrated production of value-added urea for corn and urea device, without the need for secondary processing, thus reducing manpower and production costs.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a characteristic diagram of urea nitrogen residue in soil of the value-added urea (ZU) for spring corn base fertilizer of the present invention;

[0029] Figure 2 This is a graph showing changes in soil ammonium nitrogen content in the value-added urea (ZU) used as a base fertilizer for spring corn according to the present invention. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation, structure, characteristics and effects of a spring corn base fertilizer value-added urea and a preparation method thereof proposed by the present invention in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0031] The following materials or reagents, unless otherwise specified, were commercially available.

[0032] Some embodiments of the present invention provide a method for preparing value-added urea for spring corn base fertilizer, comprising the following steps:

[0033] Before granulating the urea liquid, the urea long-acting material and the urea conversion-promoting material are added to the urea liquid at the same position in turn at intervals of 6 to 10 minutes to obtain the value-added urea for spring corn base fertilizer. The urea long-acting material promotes urea conversion and ensures the supply of mineral nitrogen in the corn seedling stage, including monosaccharide acid, amino acids with a molecular weight of less than 100 Daltons and sodium thiosulfate; the material for extending the urea fertilizer effect includes succinic acid, glutaric acid, adipic acid and inorganic bases. If it is less than 6 minutes, the long-acting material is added for a short time, which affects the fertilizer effect; if it exceeds 10 minutes, the conversion-promoting material is added for a short time, which affects the seedling effect.

[0034] The above-mentioned preparation method can also be called "one-point addition intermittent method", which is to add urea conversion-promoting materials and long-acting materials into the urea solution at the same position and then enter the urea granulation system. The two synergistic materials are added at a certain interval to solve the product demand problem of urea low-temperature seedling promotion and long-acting nitrogen fertilizer in spring corn production, and realize the one-time production of value-added urea for spring corn base fertilizer on the urea production device without secondary processing.

[0035] In some optional embodiments, the volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50). If the volume ratio of the urea long-acting material to the urea conversion-promoting material is lower than the lower limit, it may lead to fertilizer deficiency in the later stage when the fertilizer application amount is not too high; if the volume ratio of the urea long-acting material to the urea conversion-promoting material is higher than the upper limit, it is not conducive to promoting the growth of corn in the seedling stage under low temperature.

[0036] In specific implementation, the preparation method may include:

[0037] (1) Before the urea liquid with a concentration of 95wt% to 97wt% enters the fluidized bed granulation, the first metering pump is used to add urea long-acting material into the urea liquid pipeline at a dosage of 20 to 80L per ton of urea; if it is lower than 95%, the water content is high, it is not easy to granulate, and it also increases the drying energy consumption. The high tower granulation has a two-stage evaporation process, which can concentrate 97% of the urine to 99.7%. The fluidized bed generally does not require a two-stage evaporation process. The reason why the urea addition amount is selected to be 20 to 80L is mainly to take into account the product effect and production feasibility; if the urea addition amount is less than 20L, the effect is poor; if the urea addition amount is greater than 80L, it will affect the nitrogen content and water content of the urea.

[0038] (2) After an interval of 6 to 10 minutes, the first metering pump is stopped and another metering pump is started to add urea conversion promoting material into the urea liquid pipeline at a dosage of 10 to 50 L per ton of urea; the dosage of urea conversion promoting material is selected to be 10 to 50 L mainly to take into account the effect and production feasibility.

[0039] (3) The two synergistic materials are added alternately at intervals of 6 to 10 minutes.

[0040] Since both synergistic materials are liquid, their flow rates need to be calculated based on the capacity of the urea production unit. The hourly urea output is set to Y, in t / h; the amount of synergistic material added is set to A, in L / t urea; the synergistic material addition flow rate is set to F, in L / h; and the concentration of urea liquid is set to C, in %.

[0041] F (long-acting) = A × Y = 20-80 L × Y × 95%-97%;

[0042] F (promote conversion) = A×Y×C = 10~50L×Y×95%~97%.

[0043] For example, if the urea production capacity is 10 t / h, the urea solution concentration is 95%, and the amount of enhancement material added is 20 L / t urea, then F (promoted conversion) = 10 × 20 × 0.95 = 190 L / h.

[0044] In some optional embodiments, the method for preparing the urea long-acting material comprises the following steps:

[0045] 1a) uniformly mixing monosaccharide acid and amino acid to obtain a monosaccharide acid-amino acid mixture;

[0046] 2a) Dissolving the monosaccharide acid-amino acid mixture obtained in step 1a) in water at 90-100°C to obtain a monosaccharide acid-amino acid solution with a concentration of 20%-30%. The water at 90-100°C is selected mainly for two reasons: 1. faster dissolution; 2. no effect on the effect of organic materials. The monosaccharide acid-amino acid solution with a concentration of 20%-30% can take into account both the stability of the solution and the convenience of addition;

[0047] 3a) After the monosaccharide acid-amino acid solution obtained in step 2a) is cooled to room temperature, the pH value of the monosaccharide acid-amino acid solution is adjusted to 5.5-7.5 by sodium thiosulfate aqueous solution to obtain a urea-promoting conversion material. The pH value of the monosaccharide acid-amino acid solution is adjusted to 5.5-7.5 for the purpose of being suitable for addition to the urea device and for the purpose of facilitating microbial reproduction after entering the soil.

[0048] In some optional embodiments, in step 1a), considering the effect of promoting urea conversion and the cost of amino acids, the molar ratio of the monosaccharide acid to the amino acid can be set to 1:0.1-1.

[0049] In some optional embodiments, in step 1a), the molecular weight of the amino acid is less than 100 Daltons. Amino acids with a molecular weight below 100 are more likely to increase soil microbial activity.

[0050] In some optional embodiments, in step 3a), the mass percentage concentration of the sodium thiosulfate aqueous solution can be set to 50-70% in consideration of the solubility of sodium thiosulfate and the convenience during use. If the mass percentage concentration is less than 50%, the mass concentration is too low, and more liquid is added, which increases the difficulty of operation; if the mass percentage concentration is greater than 70%, the concentration is too high, and precipitation may occur in low temperature seasons, affecting the use effect.

[0051] In some optional embodiments, the method for preparing the urea-promoting conversion material comprises the following steps:

[0052] 1b) Succinic acid, glutaric acid and adipic acid are mixed to obtain an organic diacid mixture; the organic diacid mixture is dissolved in boiling water at 100° C. to prepare an organic diacid mixed solution with a concentration of 15 wt % to 20 wt %; if the concentration is lower than 15 wt %, liquid needs to be added, which may cause the urea water content to exceed the standard; if the concentration is higher than 20 wt %, it will not dissolve at low temperature, affecting continuous production;

[0053] 2b) adjusting the pH value of the organic diacid mixed solution obtained in step 1b) to 6.5-7.5 by an inorganic alkali aqueous solution to obtain the urea long-acting material. Adjusting the pH value of the organic diacid mixed solution to 6.5-7.5 is conducive to the combination of organic diacids such as succinic acid, glutaric acid and adipic acid with urea.

[0054] In some optional embodiments, in step 1b), the molar ratio of succinic acid, glutaric acid and adipic acid can be set to 1:1-2:2-3 from the perspective of safety and convenience.

[0055] In some optional embodiments, in step 2b), the mass concentration of the inorganic alkali aqueous solution can be set to 20% to 40% in consideration of the solubility of the inorganic alkali and the convenience during use. If the mass percentage concentration is less than 20%, the mass concentration is too low, and more liquid is added, which increases the difficulty of operation; if the mass percentage concentration is greater than 40%, the concentration is too high, and precipitation may occur in low temperature seasons, affecting the use effect.

[0056] Some embodiments of the present invention also provide a value-added urea for spring corn base fertilizer, which includes a urea long-acting material and a urea conversion-promoting material; the volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50); the value-added urea for spring corn base fertilizer is prepared by the above method.

[0057] In the above technical scheme, the present invention realizes one-time production of value-added urea for spring corn base fertilizer on a urea production device by alternately adding urea long-acting material and urea conversion-promoting material into urea liquid, without the need for secondary processing.

[0058] The specific implementation methods of the present invention are further described in detail below in conjunction with the embodiments, but it should not be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0059] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0060] Example 1

[0061] This embodiment provides a method for preparing value-added urea for spring corn base fertilizer, comprising the following steps:

[0062] 1. Preparation of urea conversion promoting materials

[0063] (1) mixing gluconic acid and glycine in a molar ratio of 1:0.1 to obtain a gluconic acid-glycine mixture. Then dissolving the mixture in 90° C. water to prepare a monosaccharide acid-amino acid solution with a mass percentage concentration of 20%;

[0064] (2) after the solution is cooled to room temperature, the pH value of the gluconic acid-glycine solution is adjusted to 5.5 with a sodium thiosulfate aqueous solution having a mass percentage concentration of 60%, thereby obtaining a urea-promoting conversion material;

[0065] 2. Preparation of materials for extending the urea fertilizer effect

[0066] (1) mixing succinic acid, glutaric acid, and adipic acid in a molar ratio of 1:1:2 to obtain an organic diacid mixture; then dissolving the mixture in boiling water at 100° C. to prepare an organic diacid mixed solution with a mass percent concentration of 15%;

[0067] (2) adjusting the pH value of the organic diacid mixed solution to 6.5 with a KOH aqueous solution having a mass percentage concentration of 30% to obtain a urea long-acting material;

[0068] 3. Value-added urea production

[0069] (1) Before the urea liquid with a mass percentage concentration of 95% enters the fluidized bed granulation, the first metering pump is used to add urea long-acting material into the urea liquid pipeline at a rate of 80 L per ton of urea;

[0070] (2) After an interval of 6 minutes, stop the first metering pump and start another metering pump to add urea conversion promoting material into the urea liquid pipeline at a rate of 50 L per ton of urea;

[0071] (3) The two synergistic materials are added alternately at intervals of 6 minutes; the production of a batch of value-added urea is terminated when the two synergistic materials are added;

[0072] (4) The hourly output of the urea plant is 5 t / h; the addition flow rate of the synergistic material is set to F, in L / h; the mass percentage concentration of the urea solution is 95%. F (promoting conversion) = 50 L × 5 t / h × 0.95 = 237.5 L / h; F (long-term effect) = 80 L × 5 t / h × 0.95 = 380 L / h.

[0073] Example 2

[0074] This embodiment provides a method for preparing value-added urea for spring corn base fertilizer, comprising the following steps:

[0075] 1. Preparation of urea conversion promoting materials

[0076] (1) mixing fructose acid and alanine in a molar ratio of 1:1 to obtain a fructose acid-alanine mixture. Then dissolving the mixture in 100° C. water to prepare a fructose acid-alanine solution with a mass percentage concentration of 30%;

[0077] (2) After the solution is cooled to room temperature, the pH value of the fructose acid-alanine solution is adjusted to 7.5 with a sodium thiosulfate aqueous solution having a mass percentage concentration of 60%, thereby obtaining a urea-promoting conversion material;

[0078] 2. Preparation of materials for extending the urea fertilizer effect

[0079] (1) mixing succinic acid, glutaric acid, and adipic acid in a molar ratio of 1:2:3 to obtain an organic diacid mixture; then dissolving the mixture in boiling water at 100° C. to prepare an organic diacid mixed solution with a mass percentage concentration of 20%;

[0080] (2) adjusting the pH value of the organic diacid mixed solution to 7.5 with a 30% by mass concentration of NaOH aqueous solution to obtain a urea long-acting material;

[0081] 3. Value-added urea production

[0082] (1) Before the urea liquid with a mass percentage concentration of 97% enters the fluidized bed granulation, the first metering pump is used to add urea long-acting material into the urea liquid pipeline at a rate of 20 L per ton of urea;

[0083] (2) After an interval of 10 minutes, stop the first metering pump and start another metering pump to add urea conversion promoting material into the urea liquid pipeline at a rate of 10 L per ton of urea;

[0084] (3) The two synergistic materials are added alternately at intervals of 10 minutes; the production of a batch of value-added urea is terminated when the two synergistic materials are added;

[0085] (4) The hourly output of the urea plant is 3 t / h; the addition flow rate of the synergistic material is set to F, in L / h; the mass percentage concentration of the urea solution is 97%. F (promoting conversion) = 10 L × 3 t / h × 0.97 = 29.1 L / h; F (long-term effect) = 20 L × 3 t / h × 0.97 = 58.2 L / h.

[0086] Example 3

[0087] This embodiment provides a method for preparing value-added urea for spring corn base fertilizer, comprising the following steps:

[0088] 1. Preparation of urea conversion promoting materials

[0089] (1) mixing lactobionic acid and glycine in a molar ratio of 1:0.5 to obtain a lactobionic acid-glycine mixture. Then dissolving the mixture in 100° C. water to prepare a lactobionic acid-glycine solution with a mass percentage concentration of 25%;

[0090] (2) after the solution is cooled to room temperature, the pH value of the lactobionic acid-glycine solution is adjusted to 6.8 with a sodium thiosulfate aqueous solution having a mass percentage concentration of 60%, thereby obtaining a urea-promoting conversion material;

[0091] 2. Preparation of materials for extending the urea fertilizer effect

[0092] (1) mixing succinic acid, glutaric acid, and adipic acid in a molar ratio of 1:1.5:2.5 to obtain an organic diacid mixture; then dissolving the mixture in boiling water at 100° C. to prepare an organic diacid mixed solution with a mass percentage concentration of 18%;

[0093] (2) adjusting the pH value of the organic diacid mixed solution to 7.0 with a sodium carbonate aqueous solution having a mass percentage concentration of 30% to obtain a urea long-acting material;

[0094] 3. Value-added urea production

[0095] (1) Before the urea liquid with a mass percentage concentration of 97% enters the fluidized bed granulation, the first metering pump is used to add urea long-acting material into the urea liquid pipeline at a rate of 50 L per ton of urea;

[0096] (2) After an interval of 8 minutes, stop the first metering pump and start another metering pump to add urea conversion promoting material into the urea liquid pipeline at a rate of 30 L per ton of urea;

[0097] (3) The two synergistic materials are added alternately at intervals of 8 minutes; the production of a batch of value-added urea is terminated when the two synergistic materials are added;

[0098] (4) The hourly output of the urea plant is 10 t / h; the addition flow rate of the synergistic material is set to F, in L / h; the mass percentage concentration of the urea solution is 97%. F (promoting conversion) = 30 L × 10 t / h × 0.97 = 291 L / h; F (long-term effect) = 50 L × 10 t / h = 485 L / h.

[0099] Application Examples

[0100] The value-added urea prepared in the three embodiments of the present invention has similar performances, and the value-added urea for spring corn base fertilizer prepared in Example 3 was used for performance testing.

[0101] 1. Conversion characteristics of value-added urea for spring corn in soil

[0102] (1) Test method:

[0103] The experiment set up three treatments: (11) a control (CK) without nitrogen fertilizer; (12) ordinary urea (U); (13) the value-added urea for spring corn (ZU) described in Example 3. The amount of nitrogen applied in treatments (12) and (13) was 0.3 g / kg dry soil. Each treatment was repeated 3 times. Weigh 100 g of air-dried soil that passed through a 2 mm sieve, put it into a 250 mL plastic culture bottle, adjust the soil moisture content to 18 wt% with pure water, seal it with plastic wrap, and pre-culture it in an incubator at 25°C for 3 days; then mix the test urea with the soil that was pre-cultured for 3 days, and then put it back into the culture bottle, adjust the soil moisture content to 20 wt%, and continue to culture in a culture room at 15°C (simulating the low temperature in spring) to maintain the soil moisture content at 20 wt%. Fresh soil samples were taken on the 0.25, 0.5, 1, 2, 3, 5, 7, 10, 14 and 28 days of cultivation to determine the contents of urea nitrogen and ammonium nitrogen in the soil.

[0104] (2) Test results

[0105] 1) Changes in soil urea residual rate of value-added urea

[0106] The variation characteristics of soil urea residues can reflect the speed of urea transformation in the soil. Figure 1 It can be seen that with the extension of the cultivation time, the urea nitrogen content of the soil in the U and ZU treatments showed a continuous downward trend; the difference between the two is that 1) on the 0.25 to 5th day of cultivation, the urea residue in the ZU treatment was 12.1% lower than that in the U treatment on average, and the conversion rate was faster; especially on the 1st to 3rd day of cultivation, the urea conversion rate in the ZU treatment was 22.0% faster than that in the U treatment. 2) On the 10th day of cultivation in the U treatment, all the urea applied to the soil had been converted into mineral nitrogen, while the urea conversion rate in the ZU treatment slowed down, and on the 28th day of cultivation, the urea nitrogen content in the soil still reached 84.3 mg / kg. This shows that the value-added urea for spring corn described in Example 3 can accelerate urea conversion under low temperature conditions to ensure the supply of mineral nitrogen in the seedling stage, while prolonging the hydrolysis time of urea.

[0107] 2) Changes in soil ammonium nitrogen with added urea

[0108] The change of soil ammonium nitrogen can further directly explain the transformation of urea into mineral nitrogen in the soil. Figure 2 It can be seen that within 28 days of soil cultivation, the ammonium nitrogen content of the soil in the ZU treatment was higher than that in the U treatment, with an average increase of 39.2%; especially in the middle and late stages of cultivation (10th to 28th day), the ammonium nitrogen content of the soil in the ZU treatment was 2.76 times that of the U treatment. It can be seen that the value-added urea for spring corn described in Example 3 can significantly improve the supply capacity of nitrogen fertilizer.

[0109] 2. Effect of using value-added urea as base fertilizer for spring corn on the growth of corn seedlings

[0110] (1) Test method

[0111] Corn indoor pot experiment. Set up three treatments: blank (no fertilizer, CK), ordinary urea (U), and corn value-added urea (ZU). The experimental pot size is 30cm×30cm. Each pot is filled with 30kg of soil. 5 seeds are sown and 1 corn seedling with consistent growth is left. 5 replicates are performed, with a total of 15 pots. Each pot is fertilized with 3g of pure nitrogen (equivalent to 180kgN / hm 2 All tested fertilizers were used as basal fertilizers, and superphosphate (nutrient P 2 O 5 The content is 16wt%), the dosage is 6.602g / potassium sulfate (nutrient K 2 O content is 50wt%) 7.077g / pot, mixed with soil when potting. The temperature of the culture room was controlled at 15°C, and the seedlings were harvested 21 days after emergence, and the aboveground dry weight, root dry weight, and root activity were measured.

[0112] Table 1. Aboveground dry weight, root dry weight and root activity of corn under different treatments

[0113] deal with Aboveground dry weight, g Root dry weight, g Root activity, TTFμg / (g·h) CK 3.62 0.69 1.97 U 4.55 0.96 3.35 ZU 4.92 1.03 3.79

[0114] As can be seen from Table 1, the value-added urea for spring corn described in Example 3 can significantly improve the growth of corn seedlings compared with ordinary urea. The aboveground dry weight of ZU treatment increased by 8.13% compared with U, and the root dry weight and root activity increased by 7.29% and 13.13%, respectively. In addition, the 7th leaf of corn treated with ZU began to unfold, while the 7th leaf of U treatment was still upright. It can be seen that ZU has a good promoting effect on the growth of corn in the seedling stage.

[0115] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

[0116] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0117] The numerical range described in the present invention includes all the numerical values ​​within the range, and includes the range value formed by any two numerical values ​​within the range. Different numerical values ​​of the same indicator appearing in all embodiments of the present invention can be arbitrarily combined to form a range value.

[0118] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0119] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing value-added urea for spring corn base fertilizer, characterized in that: The following steps are involved: Before granulating the urea liquid, the urea long-acting material and the urea conversion-promoting material are added into the urea liquid alternately at the same position at intervals of 6 to 10 minutes to obtain the value-added urea for spring corn base fertilizer.

2. The method for preparing the value-added urea for spring corn base fertilizer according to claim 1, characterized in that: The volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50).

3. The method for preparing the value-added urea for spring corn base fertilizer according to claim 1, characterized in that: The preparation method of the urea long-acting material comprises the following steps: 1a) uniformly mixing monosaccharide acid and amino acid to obtain a monosaccharide acid-amino acid mixture; 2a) dissolving the monosaccharide acid-amino acid mixture obtained in step 1a) in water at 90-100° C. to obtain a monosaccharide acid-amino acid solution having a mass percentage concentration of 20%-30%; 3a) After the monosaccharide acid-amino acid solution obtained in step 2a) is cooled to room temperature, the pH value of the monosaccharide acid-amino acid solution is adjusted to 5.5-7.5 by using a sodium thiosulfate aqueous solution to obtain a urea-promoting conversion material.

4. The method for preparing value-added urea for spring corn base fertilizer as claimed in claim 3, characterized in that: In step 1a), the molar ratio of the monosaccharide acid to the amino acid is 1:0.1-1; and the molecular weight of the amino acid is less than 100 Daltons.

5. The method for preparing value-added urea for spring corn base fertilizer according to claim 3, characterized in that: In step 3a), the mass concentration of the sodium thiosulfate aqueous solution is 50% to 70%.

6. The method for preparing value-added urea for spring corn base fertilizer according to claim 1, characterized in that: The preparation method of the urea-promoting conversion material comprises the following steps: 1b) mixing succinic acid, glutaric acid and adipic acid to obtain an organic diacid mixture; dissolving the organic diacid mixture in boiling water at 100° C. to prepare an organic diacid mixed solution having a mass percentage concentration of 15% to 20%; 2b) adjusting the pH value of the organic diacid mixed solution obtained in step 1b) to 6.5-7.5 by using an inorganic alkali aqueous solution to obtain the urea conversion-promoting material.

7. The method for preparing value-added urea for spring corn base fertilizer according to claim 6, characterized in that: In step 1b), the molar ratio of succinic acid, glutaric acid and adipic acid is 1:1-2:2-3.

8. The method for preparing value-added urea for spring corn base fertilizer according to claim 6, characterized in that: In step 2b), the mass percentage concentration of the inorganic alkali aqueous solution is 20% to 40%.

9. A value-added urea for spring corn base fertilizer, characterized in that: The value-added urea for spring corn base fertilizer comprises a urea long-acting material and a urea conversion-promoting material; the volume ratio of the urea long-acting material to the urea conversion-promoting material is (20-80): (10-50).

10. The value-added urea for spring corn base fertilizer according to claim 9, characterized in that: The value-added urea for spring corn base fertilizer is prepared by the method described in any one of claims 1-8.

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