Preparation method and application of straw-based biochemical fulvic acid

Abstract

The present invention provides a preparation method and application of straw-based biochemical fulvic acid, the preparation method comprising grinding straw, adding tap water, sodium hydroxide, and hydrogen peroxide to stir, adding deionized water to mix and stir at a mass ratio of 1:10, then centrifugally separating liquid, adjusting pH, etc., belonging to the field of agricultural environmental technology. The present invention can be directly returned to the field as a fertilizer, has significant growth-promoting and soil-improving performance, and simultaneously solves the two major problems of straw resource utilization and soil fertility improvement.

Description

Technical Field

[0001] The invention relates to a preparation method and application of straw-based biochemical fulvic acid, belonging to the technical field of agricultural environment. Background Art

[0002] my country produces approximately 1 billion tons of straw annually. Traditional treatment methods include composting and incineration, but composting takes a long time, produces a strong odor, and requires significant space. Incineration, on the other hand, requires significant investment, causes secondary pollution, and is inconsistent with the dual-carbon policy. Therefore, there is an urgent need to develop green and efficient technologies for the resource utilization of straw.

[0003] Fulvic acid, a naturally occurring organic compound with a relatively low molecular weight and numerous active functional groups, is soluble in both acids and alkalis and is widely found in nature, offering significant potential for development. Fulvic acid has the potential to improve soil quality, increase fertilizer utilization, stimulate crop growth, enhance crop resilience, and improve product quality. Depending on its source, it can be categorized as either mineral-derived or biochemical fulvic acid. Mineral-derived fulvic acid is primarily extracted from lignite, but because the raw material is non-renewable, the industry's sustainability is limited.

[0004] Therefore, there is an urgent need in the art for a method for continuously producing fulvic acid. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem in the prior art that the raw materials for fulvic acid production are non-renewable and the industry sustainability is weak.

[0006] In order to achieve the purpose of solving the above problems, the technical solution adopted by the present invention is to provide a preparation method and application of straw-based biochemical fulvic acid.

[0007] The first aspect of the present invention provides a method for preparing straw-based biochemical fulvic acid, comprising the following steps:

[0008] Step 1: Grind straw (water content 20-30%) to 100-200 mesh to obtain straw powder;

[0009] Step 2: Add tap water, sodium hydroxide, and hydrogen peroxide to 10-20 g of straw powder, stir, irradiate with a high-energy electron beam, and then heat and dry;

[0010] Step 3: Grind the material obtained in step 2 to 100-200 mesh, mix with deionized water at a mass ratio of 1:10 and stir, and then centrifuge to separate the liquid;

[0011] Step 4: Add concentrated hydrochloric acid to the solution obtained in step 3 to adjust the pH to 1-2, and then centrifuge to separate the liquid, which is the straw-based biochemical fulvic acid.

[0012] Preferably, in step 1, the straw is selected from one or more of corn, wheat and rice.

[0013] Preferably, in step 2, 3-6 g of tap water, 0.1-1 g of sodium hydroxide, and 0.01-0.1 g of hydrogen peroxide are added; the stirring speed is 1000-2000 rpm, and the stirring time is 10-30 min; the high-energy electron beam is 5-10 MeV, 10-30 kGy; the irradiation time is 1-2 minutes, the heating time is 0.5-2 hours, and the temperature is 100-160 degrees Celsius.

[0014] Preferably, in step 3, the stirring speed is 1000-2000 rpm, and the time is 10-30 min; the centrifugal speed is 8000-10000 r / min, and the time is 5-10 min.

[0015] Preferably, in step 4, 1-2 ml of concentrated hydrochloric acid is added, and the centrifugation speed is 8000-10000 r / min for 5-10 min.

[0016] The second aspect of the present invention provides an application of the straw-based biochemical fulvic acid prepared by the above method in agricultural planting.

[0017] Preferably, the straw-based biochemical fulvic acid is used in an amount of 10-20 kg / mu, and is applied by spraying it evenly on the soil surface and then rotary tilling and planting.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention can be directly returned to the field as fertilizer, demonstrating significant growth-promoting and soil-improving properties, simultaneously addressing the two major challenges of straw resource utilization and soil fertility improvement. Specific data: Compared to unapplied soil, soil application of this invention increased the emergence rate of cauliflower by 20-30%, yield by 23.5-45.1%, and plant height by 21.2-23.4%. It also increased the available nitrogen, available phosphorus, available potassium, and organic matter in the soil by 16.2-28.1%, 17.2-21.7%, 11.3-12.5%, and 18.2-19.9%, respectively, and reduced bulk density by 18.7-29.3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Comparison of three-dimensional fluorescence images of raw materials and products in Example 2;

[0021] Figure 2 This is a comparison chart of the soil improvement and growth promotion effects after using straw-based biochemical fulvic acid in Application Example 3;

[0022] Figure 3 This is a comparison chart of soil improvement and growth promotion data after using straw-based biochemical fulvic acid in Application Example 3;

[0023] Figure 4 This is a comparison chart of the length of the earthworm test in Application Example 1;

[0024] Figure 5 This is a weight comparison chart of the earthworm test in Application Example 1;

[0025] Figure 6 It is the effect diagram of the germination rate test of Application Example 2. DETAILED DESCRIPTION

[0026] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0027] Example 1:

[0028] (1) Grinding crop straw (water content 20%) to 100 mesh to obtain straw powder;

[0029] (2) Tap water (3 g), sodium hydroxide (0.1 g), and hydrogen peroxide (0.01 g) were added to 10 g of straw powder, stirred (1000 rpm) for 10 min, and then irradiated with a high-energy electron beam (5 MeV, 10 kGy) for 1 min, and then heated at 100 °C for 0.5 h;

[0030] (3) The material obtained in (2) was ground into 100 mesh, mixed with deionized water at a mass ratio of 1:10 and stirred (1000 rpm) for 10 min, and then centrifuged (8000 rpm) for 5 min to separate the liquid;

[0031] (4) Concentrated hydrochloric acid (1 ml) was added to the solution obtained in (3) to adjust the pH to 1, and then centrifuged for 5 minutes using a centrifuge (8000 rpm) to separate the liquid, which was the biochemical fulvic acid aqueous solution;

[0032] (5) The biochemical fulvic acid prepared in (4) was evenly sprayed on the soil surface at a rate of 10 kg / mu, and after rotary tillage, sauerkraut (Shouhe) was planted. The harvest results on the 60th day showed that the treatment increased the emergence rate of sauerkraut by 20%, increased the yield by 23.5%, and increased the plant height by 21.2% compared with the control without fertilizer application. The treatment also increased the available nitrogen, available phosphorus, available potassium, and organic matter in the soil by 16.2%, 17.2%, 11.3%, and 18.2%, respectively, and reduced the bulk density by 18.7%.

[0033] Example 2:

[0034] (1) Grinding crop straw (water content 26%) to 100 mesh to obtain straw powder;

[0035] (2) Tap water (5 g), sodium hydroxide (0.3 g), and hydrogen peroxide (0.04 g) were added to 15 g of straw powder, stirred (1000 rpm) for 15 min, and then irradiated with a high-energy electron beam (7 MeV, 15 kGy) for 2 min, and then heated at 130 °C for 1 h;

[0036] (3) The material obtained in (2) was ground into 100 mesh, mixed with deionized water at a mass ratio of 1:10 and stirred (1200 rpm) for 10-30 min, and then centrifuged (9000 rpm) for 10 min to separate the liquid;

[0037] (4) Concentrated hydrochloric acid (1.2 ml) was added to the solution obtained in (3) to adjust the pH to 1, and then centrifuged for 8 minutes (9000 rpm) to separate the liquid, which was the biochemical fulvic acid aqueous solution;

[0038] (5) The straw powder (1 g) in (1) was added to deionized water (100 mL) and mixed evenly, and ultrasonically vibrated (45000 Hz) for 10 min;

[0039] (6) Add 1 g of the biochemical fulvic acid solution in (4) to deionized water (100 mL), mix well, and ultrasonically vibrate (45,000 Hz) for 10 min;

[0040] (7) Use a syringe (10 mL) to extract the solution obtained in step (5) and step (6), filter it through a syringe filter (0.45 μm), pour it into a four-way light cuvette, and then place the cuvette into a fluorescence spectrophotometer to detect three-dimensional fluorescence. Use the software origin to draw a three-dimensional fluorescence spectrum with the highest peak EM of the emission spectrum as the horizontal axis and the highest peak EX of the excitation spectrum as the vertical axis, as shown in the figure. Figure 1 ;

[0041] (8) The biochemical fulvic acid prepared in (4) was evenly sprayed on the soil surface at a rate of 16 kg / mu, and then rotary tillage was performed to plant safflower (Shouhe). The harvest results on the 60th day showed that compared with the unfertilized control, this treatment increased the emergence rate of safflower by 30%, increased the yield by 45.1%, and increased the plant height by 23.4%. It also increased the available nitrogen, available phosphorus, available potassium, and organic matter in the soil by 28.1, 21.7, 12.5, and 19.9%, respectively, and reduced the bulk density by 29.3%.

[0042] Example 3:

[0043] (1) Grinding crop straw (water content 30%) to 200 mesh to obtain straw powder;

[0044] (2) Tap water (6 g), sodium hydroxide (1 g), and hydrogen peroxide (0.1 g) were added to 20 g of straw powder, stirred (2000 rpm) for 30 min, and then irradiated with a high-energy electron beam (10 MeV, 30 kGy) for 2 min, and then heated at 160 °C for 2 h;

[0045] (3) The material obtained in (2) was ground to 200 mesh, mixed with deionized water at a mass ratio of 1:10 and stirred (2000 rpm) for 30 min, and then centrifuged (10000 rpm) for 10 min to separate the liquid;

[0046] (4) Concentrated hydrochloric acid (2 ml) was added to the solution obtained in (3) to adjust the pH to 2, and then centrifuged for 10 minutes using a centrifuge (10,000 rpm) to separate the liquid, which was the biochemical fulvic acid aqueous solution;

[0047] (5) The biochemical fulvic acid prepared in (4) was evenly sprayed on the soil surface at a rate of 20 kg / mu, and after rotary tillage, sauerkraut (Shouhe) was planted. The harvest results on the 60th day showed that the treatment increased the emergence rate of sauerkraut by 26%, increased the yield by 31.6%, and increased the plant height by 21.9% compared with the control without fertilizer application. The treatment also increased the available nitrogen, available phosphorus, available potassium, and organic matter in the soil by 22.8%, 19.6%, 12.1%, and 18.9%, respectively, and reduced the bulk density by 23.7%.

[0048] Application Example 1 Earthworm Experiment

[0049] (1) A blank control group, a crop straw group, and a product group were set up, with 3 parallel samples in each group. Soil and sand were mixed in a mass ratio of 7:3 to prepare culture soil (490 g). Soil (10 g) was added to the culture soil of the blank group, crop straw powder (10 g) was added to the culture soil of the crop straw group, and biochemical fulvic acid (10 g) prepared in Example 2 was added to the culture soil of the product group.

[0050] (2) Select 54 active earthworms of similar length and weight, and culture six earthworms per 490 g of culture soil. Record the length and weight of the earthworms in each group. Culture the earthworms in a dark, well-ventilated area for 14 days.

[0051] (3) After the culture is completed, the earthworms are taken out and their length and weight are recorded. The first day of culture with different components and the 14th day of culture are used as the horizontal axis to draw a graph, such as Figure 4 、 5 The results showed that compared with the pre-cultivation period, the weight of earthworms in the product group increased by 53.3% and their length increased by 20.6%. Compared with the blank control group and the crop straw group, the weight of earthworms in the product group increased by 16.7% and their length increased by 10%.

[0052] Application Example 2 Germination Rate Test

[0053] (1) Select 90 plump cucumber seeds;

[0054] (2) Crop straw powder (1 g) was poured into deionized water (100 mL) and mixed evenly, and ultrasonically vibrated (45000 Hz) for 10 min;

[0055] (3) The biochemical fulvic acid (1 g) prepared in Example 2 was poured into deionized water (100 mL), mixed evenly, and ultrasonically vibrated (45,000 Hz) for 10 min;

[0056] (4) Qualitative filter paper (9 cm in diameter) was placed in a glass culture dish. A blank control group, a crop straw group, and a product group were set up. Each group had three parallel samples. Ten cucumber seeds were placed in each culture dish.

[0057] (5) Deionized water (10 mL), solution (2) (10 ml), and solution (3) (10 mL) were injected into the culture dishes of the blank control group, crop straw group, and product group, respectively;

[0058] (6) The glass culture dish was placed in a biological incubator and cultured at a constant temperature in the dark for 14 days. The germination rate, average root length, GI index, average plant height, fresh weight and dry weight were recorded. Taking Example 2 as an example, the data are shown in Table 1. The effect comparison is as follows: Figure 6 shown.

[0059] Table 1 Germination rate test data

[0060] blank raw material product Germination rate 40％ 60％ 100％ Average root length / mm 50.75 78.33 115.83 GI index / 231.53％ 570.59％ Average plant height / mm 100.00 80.00 85.83 Fresh weight / g 0.63 0.85 1.80 Dry weight / g 0.15 0.14 0.16

[0061] Application Example 3 Potted Plant Test

[0062] (1) A blank control group, a crop straw group, and a product group were set up, with two parallel samples set up in each group. Soil and sand were mixed in a mass ratio of 7:3 to prepare culture soil. Culture soil (490 g) was poured into each pot. Soil (10 g) was added to the culture soil of the blank group. Crop straw powder (10 g) was added to the culture soil of the crop straw group. The biochemical fulvic acid aqueous solution (10 g) prepared in Example 2 was added to the culture soil of the product group.

[0063] (2) Soak the choy sumac (Shouhe) in deionized water at 25°C for 6 hours, and place the soaked seeds neatly on the soil surface, placing 10 seeds in each pot. After placement, cover with a layer of culture soil.

[0064] (3) The potted plants were placed in a well-ventilated place with suitable light, and watered every three days (10 mL per pot) for 21 days. Figure 2This is a graph showing the effect of culturing the product group using the biochemical fulvic acid aqueous solution prepared in Example 2 for 21 days in comparison with the blank group and the crop straw group;

[0065] (4) After the cultivation, the wet weight, dry weight, plant height, leaf length, root length and chlorophyll content of the three groups of radish were tested and the data were recorded with the three groups as the horizontal axis. Figure 3 The results showed that compared with the blank group, the wet weight, dry weight, plant height, root length, leaf length, and chlorophyll content of the product group increased by 33.6%, 57.3%, 37.3%, 107.5%, 16.2%, and 44.9%, respectively. Compared with the crop straw group, the product group increased by 42.2%, 84.9%, 28.5%, 61.5%, 8.7%, and 28.7%, respectively.

[0066] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing straw-based biochemical fulvic acid, characterized in that: The following steps are involved: Step 1, grinding the straw to 100-200 mesh to obtain straw powder; Step 2: Add tap water, sodium hydroxide and hydrogen peroxide to 10-20 g of straw powder, stir, irradiate with a high-energy electron beam, and then heat and dry; Step 3, grinding the substance obtained in step 2 to 100-200 mesh, mixing and stirring with deionized water at a mass ratio of 1:10, and then centrifuging to separate the liquid; Step 4: Add concentrated hydrochloric acid to the solution obtained in step 3 to adjust the pH value to 1-2, and then centrifuge to separate the liquid, which is the straw-based biochemical fulvic acid.

2. The method for preparing straw-based biochemical fulvic acid according to claim 1, characterized in that: In step 1, the straw is one or more of corn, wheat and rice.

3. The method for preparing straw-based biochemical fulvic acid according to claim 1, characterized in that: In the step 2, 3-6 g of tap water, 0.1-1 g of sodium hydroxide, and 0.01-0.1 g of hydrogen peroxide are added; the stirring speed is 1000-2000 rpm, and the stirring time is 10-30 min; the high-energy electron beam is 5-10 MeV, 10-30 kGy; the irradiation time is 1-2 minutes, the heating time is 0.5-2 hours, and the temperature is 100-160 degrees Celsius.

4. The method for preparing straw-based biochemical fulvic acid according to claim 1, characterized in that: In the step 3, the stirring speed is 1000-2000 rpm, and the time is 10-30 min; the centrifugal speed is 8000-10000 r / min, and the time is 5-10 min.

5. The method for preparing straw-based biochemical fulvic acid according to claim 1, characterized in that: In the step 4, 1-2 ml of concentrated hydrochloric acid is added, the centrifugal speed is 8000-10000 r / min, and the time is 5-10 min.

6. Use of the straw-based biochemical fulvic acid prepared by the method according to any one of claims 1 to 5 in agricultural planting.

7. The use according to claim 6, characterized in that The dosage of the straw-based biochemical fulvic acid is 10-20 kg / mu, and the application method is to spray it evenly on the soil surface and then plant it after rotary tillage.

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