Seaweed-containing liquid fertilizer and preparation method thereof

Abstract

The invention discloses a seaweed-containing liquid fertilizer and a preparation method thereof. The seaweed-containing liquid fertilizer comprises the following components in parts by mass: 100 parts of seaweed enzymatic hydrolysate, 10-20 parts of a vinasse extract, 6-10 parts of calcium bentonite, 4-6 parts of kelp fucoidin and 0.3-0.7 part of zinc citrate. According to the preparation method of the seaweed-containing liquid fertilizer, the seaweed raw materials are pretreated through the vinasse extract, seaweed cell walls are softened through organic acid and amino acid components of the vinasse extract, and the use amount of compound enzyme can be reduced; calcium bentonite and fucoidin are compounded to form a slow-release carrier, so that heat-sensitive active substances such as gibberellin and brown algae polyphenol are effectively adsorbed, the oxidative degradation loss is reduced, and the field fertilizer efficiency period is prolonged; through the synergistic effect of vinasse extract pretreatment and the bentonite carrier, the industrial problem of low retention rate of active ingredients in an alginic acid extraction process is solved, the retention rate of gibberellin and the dissolution rate of alginic acid in the fertilizer are remarkably improved, and the growth level of crops is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizers, in particular to a liquid fertilizer containing seaweed and a preparation method thereof. Background Art

[0002] Seaweed is rich in amino acids, inorganic salts, vitamins, alginate, enzymes, plant hormones, polyphenols, polysaccharides and other active substances. It is widely used in agriculture in various forms such as feed, liquid fertilizer, and plant nutrients.

[0003] Seaweed liquid fertilizer made from seaweed as raw material is an organic and high-efficiency fertilizer. It is rich in inorganic salts, organic matter, amino acids and other functional substances. It has the full effect of fertilizer, has a regulating effect on the soil, and has a stimulating effect on crops. It can improve the soil, promote plant growth, increase the yield and quality of crops, and enhance crop resistance. It is a green, non-toxic, pollution-free, high-quality agricultural fertilizer.

[0004] However, seaweed fertilizers produced using existing technologies still have much room for improvement. For example, conventional enzyme extraction methods for extracting seaweed active substances can easily reduce the retention rate of substances such as gibberellins and brown algae polyphenols. Another example is the low sustained-release effect of existing brands of seaweed liquid fertilizers. Therefore, there is a need to develop a technologically improved seaweed-containing liquid fertilizer. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A seaweed-containing liquid fertilizer comprises, by mass, 100 parts of seaweed enzymatic hydrolysate, 10-20 parts of distiller's grains extract, 6-10 parts of calcium-based bentonite, 4-6 parts of kelp fucoidan, and 0.3-0.7 parts of zinc citrate; the seaweed enzymatic hydrolysate is obtained by subjecting seaweed powder prepared from a mixture of Spirulina and Ascophyllum nodosum to an enzymatic hydrolysis reaction with a composite enzyme, the composite enzyme comprising alginate lyase and alginate lyase; and the distiller's grains extract consists of distiller's grains and water.

[0006] Preferably, in the mixture of Spirulina and Ascophyllum nodosum, the mixing ratio of Spirulina to Ascophyllum nodosum is 3:2.

[0007] Preferably, the complex enzyme comprises alginate lyase and alginate lyase, the alginate lyase and the alginate lyase are mixed in a mass ratio of 1:1, and the added amount of the complex enzyme is 2.0% of the mass of the seaweed powder.

[0008] The preparation method comprises the following steps: S1. After crushing the vinasse, sieve it, add a certain amount of warm water, ultrasonicate it, centrifuge it, take the supernatant, and concentrate it to obtain the vinasse extract; S2. Mixing Spirulina and Ascophyllum nodosum, drying, crushing, and airflow milling to obtain seaweed powder, adding the vinasse extract prepared in step S1 and water, and heating with stirring; S3, adding enzyme to the reaction system of S2 to hydrolyze the seaweed, and preparing an enzymatic hydrolyzate after concentration; S4. Mix the calcium bentonite and kelp fucoidan, add water to form a slurry, and then shear at high speed. Then mix it with the enzymatic hydrolyzate prepared in S3, add zinc citrate, and homogenize to obtain a liquid fertilizer product containing seaweed.

[0009] Preferably, in step S1, the water content of the vinasse is ≤10%, the vinasse is sieved through a 60-mesh sieve after being crushed, the warm water temperature is 40-60°C, the ultrasonic power is 200W, the ultrasonic time is 10min, and the mass ratio of vinasse to warm water is 1:8.

[0010] Preferably, in step S1, the concentration method is water bath heating, and the concentration temperature is 60°C.

[0011] Preferably, in step S2, the drying temperature is 45-60°C, the crushing passes through a 40-mesh sieve, and the air flow pulverization passes through a 160-mesh sieve.

[0012] Preferably, the heating and stirring temperature in step S2 is 50° C., and the stirring time is 30 min.

[0013] Preferably, in step S3, the enzymatic hydrolysis temperature is 35-45° C., the enzymatic hydrolysis time is 4-6 h, and the concentration method is rotary evaporation.

[0014] Preferably, in step S4, the high-speed shearing speed is 3000 r / min and the shearing time is 15 min.

[0015] The beneficial effects of the present invention are: 1. The method for preparing a seaweed-containing liquid fertilizer provided by the present invention pretreats the seaweed raw material with distiller's grains extract, and utilizes the organic acid and amino acid components contained in the extract to soften the seaweed cell walls. This can significantly reduce the amount of complex enzymes used, thereby ensuring efficient extraction of active ingredients and significantly reducing production costs. 2. The seaweed-containing liquid fertilizer provided by the present invention and its preparation method form a slow-release carrier by compounding calcium-based bentonite with kelp fucoidan, which effectively absorbs heat-sensitive active substances such as gibberellins and brown algae polyphenols, reduces oxidative degradation losses, and prolongs the field fertilizer effect cycle; 3. The seaweed-containing liquid fertilizer and its preparation method provided by the present invention solve the industry problem of low active ingredient retention rate in the alginate extraction process through the synergistic effect of lees extract pretreatment and bentonite carrier, significantly improve the fertilizer gibberellin retention rate and alginate dissolution rate, and thus improve the crop growth level. DETAILED DESCRIPTION

[0016] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0017] Example 1 A seaweed-containing liquid fertilizer comprises, by weight, 100 parts of seaweed enzymatic hydrolysate, 15 parts of vinasse extract, 8 parts of calcium-based bentonite, 5 parts of kelp fucoidan, and 0.5 parts of zinc citrate.

[0018] The seaweed hydrolysate is obtained by enzymatically hydrolyzing seaweed powder obtained from a mixture of Spirulina and Ascophyllum nodosum with a complex enzyme comprising alginate lyase and alginate lyase. The vinasse extract is composed of vinasse and water. The complex enzyme comprises alginate lyase and alginate lyase, mixed in a 1:1 mass ratio, and the added enzyme concentration is 2.0% of the seaweed powder mass.

[0019] The preparation method comprises the following steps: S1. Take 10 g of vinasse with a water content of ≤10%, crush it, pass it through a 60-mesh sieve, add 80 g of 40°C warm water at a mass ratio of 1:8, ultrasonicate it at 200W for 10 min, centrifuge it, take the supernatant, heat it in a water bath at 60°C, and concentrate it to a total weight of 15 g to obtain a vinasse extract; S2. Mix 60 g of Spirulina and 40 g of Ascophyllum nodosum, dry at 50° C., crush through a 40-mesh sieve, and then jet-mill through a 160-mesh sieve to obtain seaweed powder. Add the vinasse extract prepared in step S1 and 1200 g of purified water, and heat with stirring at 50° C. for 30 min. S3. Lower the temperature of the reaction system in S2 to 40°C, mix 1g of alginate lyase and 1g of alginate lyase to prepare a complex enzyme, add the complex enzyme to the reaction system in S2 to hydrolyze the seaweed. After hydrolysis for 5h, concentrate the mixture by rotary evaporation until the total mass of the system reaches 100g to prepare an enzymatic hydrolyzate. S4. Mix 8 g of calcium bentonite with 5 g of kelp fucoidan, add water to form a slurry, and then high-speed shear at 3000 r / min for 15 min. Then mix it with 100 g of the enzymatic hydrolyzate prepared in S3, add 0.5 g of zinc citrate, and homogenize to obtain a liquid fertilizer containing seaweed.

[0020] Example 2 A seaweed-containing liquid fertilizer comprises, by mass, 100 parts of seaweed enzymatic hydrolysate, 10 parts of vinasse extract, 6 parts of calcium-based bentonite, 4 parts of kelp fucoidan, and 0.3 parts of zinc citrate.

[0021] The seaweed hydrolysate is obtained by enzymatically hydrolyzing seaweed powder obtained from a mixture of Spirulina and Ascophyllum nodosum with a complex enzyme comprising alginate lyase and alginate lyase. The vinasse extract is composed of vinasse and water. The complex enzyme comprises alginate lyase and alginate lyase, mixed in a 1:1 mass ratio, and the added enzyme concentration is 2.0% of the seaweed powder mass.

[0022] The preparation method comprises the following steps: S1. Take 10 g of vinasse with a water content of ≤10%, crush it, pass it through a 60-mesh sieve, add 80 g of 40°C warm water at a mass ratio of 1:8, ultrasonicate it at 200W for 10 minutes, centrifuge it, take the supernatant, heat it in a water bath at 60°C, and concentrate it to a total weight of 10 g to obtain a vinasse extract; S2. Mix 60 g of Spirulina and 40 g of Ascophyllum nodosum, dry at 45° C., crush through a 40-mesh sieve, and then jet-mill through a 160-mesh sieve to obtain seaweed powder. Add the vinasse extract prepared in step S1 and 1200 g of purified water, and heat with stirring at 50° C. for 30 min. S3. Lower the temperature of the reaction system in S2 to 35°C, mix 1g of alginate lyase and 1g of alginate lyase to prepare a complex enzyme, add the complex enzyme to the reaction system in S2 to hydrolyze the seaweed. After 4 hours of enzymatic hydrolysis, concentrate the mixture by rotary evaporation until the total mass of the system reaches 100g to prepare an enzymatic hydrolyzate. S4. Mix 6 g of calcium bentonite with 4 g of kelp fucoidan, add water to form a slurry, and then high-speed shear at 3000 r / min for 15 minutes. Then mix it with 100 g of the enzymatic hydrolyzate prepared in S3, add 0.3 g of zinc citrate, and homogenize to obtain a liquid fertilizer containing seaweed.

[0023] Example 3 A seaweed-containing liquid fertilizer comprises, by mass, 100 parts of seaweed enzymatic hydrolysate, 20 parts of vinasse extract, 10 parts of calcium-based bentonite, 6 parts of kelp fucoidan, and 0.7 parts of zinc citrate.

[0024] The seaweed hydrolysate is obtained by enzymatically hydrolyzing seaweed powder obtained from a mixture of Spirulina and Ascophyllum nodosum with a complex enzyme comprising alginate lyase and alginate lyase. The vinasse extract is composed of vinasse and water. The complex enzyme comprises alginate lyase and alginate lyase, mixed in a 1:1 mass ratio, and the added enzyme concentration is 2.0% of the seaweed powder mass.

[0025] The preparation method comprises the following steps: S1. Take 10 g of vinasse with a water content of ≤10%, crush it, pass it through a 60-mesh sieve, add 80 g of 40°C warm water at a mass ratio of 1:8, ultrasonicate it at 200W for 10 min, centrifuge it, collect the supernatant, heat it in a water bath at 60°C, and concentrate it to a total weight of 20 g to obtain a vinasse extract; S2. Mix 60 g of Spirulina and 40 g of Ascophyllum nodosum, dry at 60° C., crush through a 40-mesh sieve, and then jet-mill through a 160-mesh sieve to obtain seaweed powder. Add the vinasse extract prepared in step S1 and 1200 g of purified water, and heat with stirring at 50° C. for 30 min. S3. Lower the temperature of the reaction system in S2 to 45°C, mix 1g of alginate lyase and 1g of alginate lyase to prepare a complex enzyme, add the complex enzyme to the reaction system in S2 to hydrolyze the seaweed. After 6 hours of enzymatic hydrolysis, concentrate the mixture by rotary evaporation until the total mass of the system reaches 100g to prepare an enzymatic hydrolyzate. S4. Mix 10 g of calcium bentonite with 6 g of kelp fucoidan, add water to form a slurry, and then high-speed shear at 3000 r / min for 15 min. Then mix it with 100 g of the enzymatic hydrolyzate prepared in S3, add 0.7 g of zinc citrate, and homogenize to obtain a liquid fertilizer containing seaweed.

[0026] Comparative Example 1 A seaweed-containing liquid fertilizer comprises, by weight, 100 parts of seaweed enzymatic hydrolysate, 8 parts of calcium-based bentonite, 5 parts of kelp fucoidan, and 0.5 parts of zinc citrate.

[0027] The seaweed hydrolysate is obtained by enzymatically hydrolyzing seaweed powder prepared from a mixture of Spirulina and Ascophyllum nodosum using a complex enzyme, which includes alginate lyase and alginate lyase. The complex enzyme contains alginate lyase and alginate lyase in a 1:1 mass ratio, and the added enzyme concentration is 2.0% of the seaweed powder mass.

[0028] The preparation method comprises the following steps: S1. Mix 60 g of Spirulina and 40 g of Ascophyllum nodosum, dry at 50°C, crush through a 40-mesh sieve, and then jet-mill through a 160-mesh sieve to obtain seaweed powder. Add 1215 g of purified water, and heat with stirring at 50°C for 30 min. S2. Lower the temperature of the reaction system in S1 to 40°C, mix 1g of alginate lyase and 1g of alginate lyase to prepare a complex enzyme, add the enzyme to the reaction system in S2 to hydrolyze the seaweed. After 5h of enzymatic hydrolysis, concentrate the solution by rotary evaporation until the total mass of the system reaches 100g, and prepare an enzymatic hydrolyzate. S3. Mix 8 g of calcium bentonite with 5 g of kelp fucoidan, add water to form a slurry, and then high-speed shear at 3000 r / min for 15 min. Then mix with 100 g of the enzymatic hydrolyzate prepared in S3, add 0.5 g of zinc citrate, and homogenize to obtain a liquid fertilizer containing seaweed.

[0029] Comparative Example 2 A seaweed-containing liquid fertilizer comprises, by mass, 100 parts of seaweed enzymatic hydrolysate, 15 parts of vinasse extract, 8 parts of silica sand powder, 5 parts of kelp fucoidan, and 0.5 parts of zinc citrate.

[0030] The seaweed hydrolysate is obtained by enzymatically hydrolyzing seaweed powder obtained from a mixture of Spirulina and Ascophyllum nodosum with a complex enzyme comprising alginate lyase and alginate lyase. The vinasse extract is composed of vinasse and water. The complex enzyme comprises alginate lyase and alginate lyase, mixed in a 1:1 mass ratio, and the added enzyme concentration is 2.0% of the seaweed powder mass.

[0031] The preparation method comprises the following steps: S1. Take 10 g of vinasse with a water content of ≤10%, crush it, pass it through a 60-mesh sieve, add 80 g of 40°C warm water at a mass ratio of 1:8, ultrasonicate it at 200W for 10 min, centrifuge it, take the supernatant, heat it in a water bath at 60°C, and concentrate it to a total weight of 15 g to obtain a vinasse extract; S2. Mix 60 g of Spirulina and 40 g of Ascophyllum nodosum, dry at 50° C., crush through a 40-mesh sieve, and then jet-mill through a 160-mesh sieve to obtain seaweed powder. Add the vinasse extract prepared in step S1 and 1200 g of purified water, and heat with stirring at 50° C. for 30 min. S3. Lower the temperature of the reaction system in S2 to 40°C, mix 1g of alginate lyase and 1g of alginate lyase to prepare a complex enzyme, add the complex enzyme to the reaction system in S2 to hydrolyze the seaweed. After hydrolysis for 5h, concentrate the mixture by rotary evaporation until the total mass of the system reaches 100g to prepare an enzymatic hydrolyzate. S4. Mix 8 g of silica sand powder with 5 g of kelp fucoidan, add water to make a slurry, and then high-speed shear at 3000 r / min for 15 min. Then mix it with 100 g of the enzymatic hydrolyzate prepared in S3, add 0.5 g of zinc citrate, and homogenize to obtain a liquid fertilizer containing seaweed.

[0032] Performance Testing Test Example 1 The reducing sugar content and the brown algae oligosaccharide yield of the finished seaweed liquid fertilizers prepared in Examples 1-3 and Comparative Example 1 were tested. The reducing sugar content was tested using the DNS method, and the brown algae oligosaccharide yield was tested using the TLC-phenol-sulfuric acid method.

[0033] The test results are shown in Table 1.

[0034] Table 1 Comparison of reducing sugar content and brown algae oligosaccharide yield in liquid fertilizer containing seaweed

[0035] As shown in Table 1, the addition of distiller's grains extract to seaweed-containing liquid fertilizer can significantly increase the reducing sugar content and brown algae oligosaccharide yield of the fertilizer, and the greater the proportion of distiller's grains extract, the higher the reducing sugar content and brown algae oligosaccharide yield.

[0036] Test Example 2 The nutrient slow-release cycle test was conducted on the finished liquid fertilizer containing seaweed obtained in Examples 1-3 and Comparative Example 2: 10 g of the finished liquid fertilizer was evenly adsorbed in 50 g of quartz sand and placed in a 5 cm diameter leaching column. 100 mL of deionized water was added daily to simulate daily rainfall for 7 consecutive days. The filtrate was collected and the total nitrogen (TN), total phosphorus (TP), and zinc ion content (Zn) in the filtrate were determined. 2+ ), defined as the nutrient release rate of liquid fertilizer. Total nitrogen was determined using the Kjeldahl method, total phosphorus using ammonium molybdate spectrophotometry, and zinc ion content using atomic absorption spectrometry. On the seventh day, the cumulative nutrient release rate of each of the three nutrients was calculated: Cumulative nutrient release rate = total released amount / total nutrient amount × 100%.

[0037] The test results are shown in Table 2.

[0038] Table 2 Comparison of cumulative nutrient release rate of liquid fertilizer containing seaweed after seven days

[0039] It can be seen from Table 2 that the addition of calcium-based bentonite to the seaweed-containing liquid fertilizer can significantly prolong the slow-release period of the seaweed-containing liquid fertilizer, and the greater the proportion of calcium-based bentonite, the longer the slow-release period of the seaweed-containing liquid fertilizer.

[0040] Test Example 3 The finished seaweed-containing liquid fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 were applied to crops for field trials. The fertilization frequency was once every 7 days at a fertilizer rate of 1.5 kg per mu. The growth rate, stress resistance, and fertilizer durability of the crops were tested.

[0041] Among them, the crop is tomato (variety name "Ruby"), with a total planting area of ​​216m 2 , divided into 3 replicate groups, each replicate group was divided into 6 plots, and each plot had an area of ​​12m 2, 30 plants were planted with a spacing of 40 cm, and the plots within the replicate group were randomly arranged; the growth rate was measured using the average plant height of the crops in the fourth week after fertilization; the stress resistance was measured using the wilting recovery time (the time when more than half of the leaves unfolded after watering for 3 days after drought); the fertilizer effect durability was measured using the yellow leaf rate after the last fertilization (the proportion of yellowing leaves at the bottom 10 days after the last fertilization) as an indicator.

[0042] The test results are shown in Table 3.

[0043] Table 3 Comparison of cumulative nutrient release rate of liquid fertilizer containing seaweed after seven days

[0044] As shown in Table 3, the addition of distiller's grains extract and calcium-based bentonite to the seaweed-containing liquid fertilizer can significantly increase the plant height of crops, shorten the wilting recovery time of crops, and reduce the yellow leaf rate after the last fertilization. It can be seen from Table 3 that Example 1 is a preferred embodiment.

[0045] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A liquid fertilizer containing seaweed, comprising, by weight: 100 parts of seaweed enzymatic hydrolysate, 10-20 parts of vinasse extract, 6-10 parts of calcium bentonite, 4-6 parts of kelp fucoidan, and 0.3-0.7 parts of zinc citrate; The seaweed enzymatic hydrolysate is obtained by subjecting seaweed powder prepared from a mixture of Spirulina and Ascophyllum to an enzymatic hydrolysis reaction with a composite enzyme, wherein the composite enzyme comprises alginate lyase and alginate lyase; The vinasse extract consists of vinasse and water.

2. The seaweed-containing liquid fertilizer according to claim 1, characterized in that In the mixture of spirulina and Ascophyllum nodosum, the mixing ratio of the spirulina to the Ascophyllum nodosum is 3:

2.

3. The seaweed-containing liquid fertilizer according to claim 1, characterized in that: The complex enzyme comprises alginate lyase and alginate lyase, the alginate lyase and the alginate lyase are mixed in a mass ratio of 1:1, and the added amount of the complex enzyme is 2.0% of the mass of the seaweed powder.

4. A method for preparing liquid fertilizer containing seaweed, characterized in that: The preparation of the seaweed-containing liquid fertilizer according to claim 1 comprises the following steps: S1. After crushing the vinasse, sieve it, add a certain amount of warm water, ultrasonicate it, centrifuge it, take the supernatant, and concentrate it to obtain the vinasse extract; S2. Mixing Spirulina and Ascophyllum nodosum, drying, crushing, and airflow milling to obtain seaweed powder, adding the vinasse extract prepared in step S1 and water, and heating with stirring; S3, adding enzyme to the reaction system of S2 to hydrolyze the seaweed, and preparing an enzymatic hydrolyzate after concentration; S4. Mix the calcium bentonite and kelp fucoidan, add water to form a slurry, and then shear at high speed. Then mix it with the enzymatic hydrolyzate prepared in S3, add zinc citrate, and homogenize to obtain a liquid fertilizer product containing seaweed.

5. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In the step S1, the water content of the vinasse is ≤10%, and the vinasse is sieved through a 60-mesh sieve after being crushed; the temperature of the warm water is 40-60° C., the ultrasonic power is 200 W, and the ultrasonic time is 10 min; and the mass ratio of the vinasse to the warm water is 1:

8.

6. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In step S1, the concentration method is water bath heating, and the concentration temperature is 60°C.

7. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In the step S2, the drying temperature is 45-60°C, the crushed product is passed through a 40-mesh sieve, and the air flow milling product is passed through a 160-mesh sieve.

8. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In step S2, the heating and stirring temperature is 50° C., and the stirring time is 30 min.

9. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In step S3, the enzymatic hydrolysis temperature is 35-45° C., and the enzymatic hydrolysis time is 4-6 hours; and the concentration method is rotary evaporation.

10. The method for preparing a liquid fertilizer containing seaweed according to claim 4, characterized in that: In step S4, the high-speed shearing speed is 3000 r / min and the shearing time is 15 min.

Images