Preparation and application of solid microbial nutrition excitant

Abstract

The invention discloses a preparation method and application of a solid microbiological nutrition excitant, and belongs to the technical field of agricultural environment. The invention provides a solid-state microbiological nutrition excitant. The solid-state microbiological nutrition excitant is prepared from 70 to 90 weight percent of blue-green algae charcoal and 10 to 30 weight percent of microbiological nutrition excitant. According to the method, the solid microbiological nutrient excitant is prepared from the blue-green algae biochar, so that enrichment of nutrient substances and excitation substances can be realized, and the defects that the microbiological nutrient excitant is easy to lose, uneven in nutrient distribution and low in utilization rate when the microbiological nutrient excitant is independently applied are overcome. The cyanobacteria biochar as a carrier of microorganisms is combined with MNS to generate a synergistic effect, so that the effectiveness of soil organic matters is improved, and the planted tomatoes have a better sugar-acid ratio and higher vitamin C and soluble protein contents.

Description

Technical Field

[0001] The invention relates to preparation and application of a solid micro-nutrient stimulant, belonging to the technical field of agricultural environment. Background Art

[0002] Chemical fertilizers are fast-acting and easy to use, but due to their single nutrient content, long-term application can easily cause soil compaction and acid-base imbalance, which in turn leads to nutritional imbalance and quality degradation in crops. Therefore, actively seeking efficient and environmentally friendly fertilizer substitutes, improving crop quality, and developing sustainable agriculture has become a research hotspot. Microbial nutrientstimulants (MNS) are high-nitrogen liquid products that are rich in organic nutrients such as peptides, amino acids, and humus, as well as essential trace elements for plants such as Ca, Fe, Mg, and Zn, produced by alkaline-thermal hydrolysis of activated sludge microorganisms from sewage treatment plants. MNS enriches the beneficial nutrients in sludge microorganisms, and the application method is simpler and more efficient, which indirectly reduces the transportation cost of sludge and reduces manual operations.

[0003] The nutrients such as N, P, K and proteins, polysaccharides, humus, nucleic acids and lipids in microbial nutrient stimulants play a positive role in crop growth and quality improvement, and have great potential for agricultural use. However, as a water-soluble liquid fertilizer, MNS has the disadvantages of nutrient loss and low nutrient utilization efficiency during application. MNS is difficult to directly contact plant roots, and the macromolecular organic matter and biostimulant components contained in it cannot be directly absorbed by plants. It is necessary to use the action of soil microorganisms to decompose the above substances and convert them into nutrients that can be directly used by plants. Therefore, it is necessary to study the preparation of a solid sludge nutrient stimulant to improve the utilization efficiency of MNS, thereby improving soil quality and crop quality.

[0004] Patent CN 118084564 A in the prior art discloses a microbial nutrient stimulant nutrient enrichment and its application, the method involved is to prepare a nutrient stimulant dilution, then add biomass activated carbon for mixing, stirring, filtering to obtain a material adsorbing nutrients from sludge sources, wherein the biochar used is sawdust biochar or straw biochar. However, this technical solution still has room for improvement. Summary of the invention

[0005] Technical issues

[0006] As a water-soluble fertilizer, micronutrient stimulants have the problems of easy nutrient loss and low nutrient utilization rate during application. They need to be applied in small amounts and multiple times during plant growth and development, and are not suitable for large-scale agricultural production. Therefore, it is necessary to provide a method for preparing solid sludge nutrient stimulants to improve the utilization efficiency of MNS.

[0007] Technical Solution

[0008] The object of the present invention is to provide a method for preparing a solid microbial nutrient stimulant, which is to fix the nutrients, organic matter and biostimulant components in the microbial nutrient stimulant in the cyanobacterial biochar, so as to improve the problems of nutrient loss and low nutrient utilization efficiency when the microbial nutrient stimulant is applied alone. In addition, the use of cyanobacterial biochar to prepare solid fertilizers also helps to realize the resource utilization of sludge and cyanobacteria. Using cyanobacterial biochar as a carrier to prepare solid microbial nutrient stimulants for application in soil can improve soil quality and reduce nutrient loss, improve nutrient utilization, and become a potential substitute for solid compound fertilizers.

[0009] The invention provides a solid micro-nutrient stimulant, which consists of cyanobacteria biochar and micro-nutrient stimulants.

[0010] Furthermore, in the solid micro-nutrient stimulant, the cyanobacteria biochar accounts for 70-90wt% and the micro-nutrient stimulant accounts for 10-30wt% by mass.

[0011] Preferably, in the solid micro-nutrient stimulant, the cyanobacteria biochar accounts for 75-85wt% and the micro-nutrient stimulant accounts for 15-25wt% by mass.

[0012] Specifically, optionally, in the solid micro-nutrient stimulant, the cyanobacteria biochar accounts for 80wt% and the micro-nutrient stimulant accounts for 20wt% by mass.

[0013] Furthermore, the preparation method of the cyanobacteria biochar is: wash and dry the cyanobacteria, and then calcine them at 450-650° C. for 0.5-2 hours to obtain the cyanobacteria biochar.

[0014] Furthermore, the particle size of the cyanobacteria biochar is 100-150 mesh and the specific surface area is 850-950m 2 ·g -1 , pore volume is 0.7~1cm 3 ·g -1 .

[0015] Furthermore, the preparation method of the microbial nutrient stimulant is: take activated sludge, add CaO and stir evenly, treat it at 150-200°C for 1-3 hours to rupture the microbial cells in the activated sludge and release protein, then inactivate the pathogens by flash evaporation, and finally obtain the microbial nutrient stimulant by solid-liquid separation and supernatant concentration.

[0016] Furthermore, the solid content of the activated sludge is 15-20%.

[0017] Furthermore, the ratio of the volume of activated sludge to the mass of CaO is 75 mL: 1-2 g.

[0018] The present invention provides the application of the solid micro-nutrient stimulant in the field of planting or fertilizer.

[0019] The present invention also provides a method for preparing the solid micro-nutrient stimulant, which comprises the following steps:

[0020] The blue algae biochar is added to the microbial nutrient stimulant solution and mixed, and then allowed to stand, the supernatant is removed, and the precipitate is dried to obtain the solid microbial nutrient stimulant.

[0021] Furthermore, the concentration of the micronutrient stimulant in the micronutrient stimulant solution is 1 to 5 mg / mL.

[0022] Furthermore, the ratio of the mass of the microbial nutrient stimulus to the mass of the cyanobacteria biochar in the microbial nutrient stimulus solution is 1-3:7-9.

[0023] Specifically, the ratio of the mass of the microbial nutrient stimulus to the mass of the cyanobacteria biochar in the microbial nutrient stimulus solution is 2:8.

[0024] Furthermore, the mixing time is 2 to 5 hours.

[0025] Furthermore, the standing time is 20 to 24 hours.

[0026] Furthermore, drying includes natural air drying or heat drying.

[0027] Beneficial Effects

[0028] (1) The present invention prepares solid micro-nutrient stimulants by using cyanobacteria biochar, which can achieve the enrichment of nutrients and stimulants, so as to improve the disadvantages of easy loss, uneven nutrient distribution and low utilization rate of micro-nutrient stimulants when applied alone. As a carrier of microorganisms, cyanobacteria biochar can produce a synergistic effect when combined with MNS, which is beneficial to improve the effectiveness of soil organic matter, so that the grown tomatoes have a better sugar-acid ratio, higher vitamin C and soluble protein content.

[0029] (2) The cyanobacteria biochar used in the present invention is derived from agricultural waste Taihu cyanobacteria, which is an environmentally friendly and low-cost adsorption material. Using cyanobacteria biochar as an adsorption carrier of MNS to prepare solid nutrient stimulants as a fertilization strategy to enhance soil fertility and improve crop quality can simplify the operation process and reduce economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 NO 3 - -N and TKN content changes.

[0031] Figure 2 For PO 4 - -Changes in the content of P and TP.

[0032] Figure 3 is the change of free amino acid (FAA) content.

[0033] Figure 4 It is composed of the FAA.

[0034] Figure 5 The adsorption amount of TOC by SBC and LBC changes with time.

[0035] Figure 6 is the adsorption capacity of total organic carbon.

[0036] Figure 7 This is a diagram showing the adsorption effect of cyanobacteria biochar on plant hormones and allelopathic substances. DETAILED DESCRIPTION

[0037] Source of raw materials

[0038] Preparation of microbial nutrient stimulant (MNS): 75 mL of activated sludge (solid content 16%) was added with 1.8 g of CaO and stirred evenly, and treated at 160°C for 2 hours to rupture the microbial cells in the activated sludge and release protein, and then the pathogens were inactivated by flash evaporation, and finally the microbial nutrient stimulant was obtained by solid-liquid separation and supernatant concentration; the activated sludge was sourced from a sewage treatment plant in Jiangsu.

[0039] Preparation of cyanobacteria biochar (LBC): After washing and drying the cyanobacteria from Taihu Lake, the cyanobacteria were fired at 550℃ for 1 hour to obtain cyanobacteria biochar. The particle size of the obtained cyanobacteria biochar was 100-150 mesh, and the specific surface area and pore volume were 882.36m 2 ·g -1 and 0.83cm 3 ·g -1 .

[0040] Preparation of sawdust biochar (SBC): Sawdust was used as raw material and fired at 550℃ for 1 hour to obtain sawdust biochar. The particle size of the obtained sawdust biochar was 100-150 mesh, and the specific surface area and pore volume were 793.41m 2 ·g -1 and 0.76cm 3 ·g -1 .

[0041] Example 1: Immobilization of nutritional stimulants

[0042] After diluting 1g of microbial nutrient stimulant 400 times (2.5mg / mL), add 4g of cyanobacteria biochar, mix at 20℃ and 200rpm for 4 hours, let it stand for 20 to 24 hours, skim off the supernatant, and let the precipitate dry naturally to obtain the solid microbial nutrient stimulant.

[0043] Example 2: Detection of nutrients

[0044] Sawdust biochar and cyanobacteria biochar were used to conduct adsorption experiments on microbial nutrient stimulants. The specific operation was as follows: 1g SBC and LBC were mixed with 300mL MNS dilution solution (diluted 800 times, 1.25mg / mL) at 20℃ and 200rpm for 1 hour, and the supernatant was used to analyze the nutritional indicators and biostimulant composition after natural precipitation for 24 hours; the total phosphorus and phosphate contents were determined by molybdenum antimony colorimetry; the total nitrogen, ammonia nitrogen and nitrate nitrogen contents were determined by standard methods; the results are shown in Figure 2. Figures 1 to 4 shown.

[0045] exist Figure 1 After LBC adsorption, NO 3 - -N and NH 4 + -N content decreased by 90.37% and 66.85% respectively, and TN content decreased by 39.65%, indicating that LBC can adsorb various forms of N in MNS solution, especially the inorganic nitrogen content in the solution is greatly reduced, indicating that LBC has a good adsorption effect on inorganic nitrogen and is better than SBC in adsorbing nitrogen in MNS. Figure 2 After SBC adsorption, the P content in the MNS solution decreased. After LBC adsorption, the PO 4 3- -P and TP contents increased significantly (46.34-62.32 times), which may be due to the presence of PO in LBC 4 3- -P, resulting in a large amount of phosphorus leaching in the solution. Figure 3 In the experiment, the free amino acid (FAA) content in the MNS solution decreased by 30.87% after SBC adsorption, and decreased by 64.89% during LBC adsorption, indicating that LBC has a better adsorption effect on FAA. Figure 4 In the amino acid composition, the proportion of glycine and alanine decreased, the proportion of glutamic acid increased, and the composition of other amino acids was similar to MNS.

[0046] In general, cyanobacteria biochar can be used as a carrier of MNS to enrich nutrients such as N and P and free amino acids. Compared with SBC, LBC has a larger specific surface area and has a better fixation effect on nutrients in MNS.

[0047] Example 3: Static adsorption experiment

[0048] Take 1g of SBC and LBC and add them to 300mL of alkaline MNS (diluted 800 times, pH = 10.49) respectively, and shake at 20°C and 200rpm. Collect samples at 0, 1, 5, 10, 15, 60, and 240 minutes after the start of shaking. Collect 1mL of sample each time, and use total organic carbon (TOC) to characterize the adsorption capacity of SBC and LBC on MNS organic matter after passing through a 0.45μm filter membrane. The calculation method of adsorption amount is as follows:

[0049] Qt=(C0-Ct)×V / m

[0050] Among them C 0 and C t are the TOC concentrations at the initial time and time t (mg TOC / g), Q t represents the amount of TOC adsorbed by SBC and LBC at time t (mg TOC / g), m is the mass of SBC and LCB (g), and V represents the volume of MNS solution (L). When the adsorption reaches equilibrium, the equilibrium TOC concentration C e Represents C t , and then the equilibrium adsorption amount Q e .

[0051] like Figure 5 and 6 As shown, the adsorption amounts of total organic carbon (TOC) of alkaline MNS by SBC and LBC were 47.80% and 68.70%, respectively, indicating that LBC had a better adsorption and fixation effect on carbon-containing organic matter in MNS.

[0052] Example 4: Plant hormone and allelopathic substance adsorption

[0053] 0.4 g of SBC and LBC were mixed with 30 mL of MNS dilution (diluted 200 times, 5 mg / mL), shaken at 20°C and 200 rpm for 24 h, then allowed to stand for 2 h, and the supernatant was used to determine plant hormones and allelopathic substances.

[0054] like Figure 7As shown, the MNS dilution solution contains a large amount of plant hormones (indene acetic acid AAAs and hydroxyphenylacetic acid IDDs) and allelopathic substances (indene derivatives HPAs and aromatic amino acids IAA). After adsorption by SBC and LBC, trace amounts of indene derivatives HPAs and aromatic amino acids IAA were detected in the MNS solution, indicating that biochar has a good fixation effect on them. In addition, after adsorption by SBC and LBC, the content of hydroxyphenylacetic acid (IDDs) in the solution decreased by 58.43% and 62.77%, respectively, and the content of indene acetic acid (AAAs) decreased by 59.62% and 68.17%, indicating that LBC can better adsorb and fix these two types of substances. This is consistent with the higher TOC removal rate of SBC and LBC in MNS solution, ( Figure 7 and Figure 5 , 6 Comparison) showed that LBC had a good adsorption and fixation effect on plant hormones and allelopathic substances in MNS.

[0055] Comparative Example 1: Effect of solid nutrient stimulants prepared by LBC on tomato quality

[0056] Testing process: Set up a blank group, MNS group, LBC group and LBC-MNS group, take a 2-gallon planting pot for each group, add 2kg of soil (natural garden sandy soil, pH value 7.29, N content 129.6mg / kg, soil SOM content 23.14g / kg) to each pot, and plant tomato seedlings with 5 true leaves in the pot, with one seedling planted in each pot. The planting pots are placed in the same environment and watered every day to keep the moisture content at about 70%. The blank group did not add any additional substances; the MNS group required each pot to be fertilized with 100 mL of MNS dilution (diluted 400 times, 2.5 mg / mL), and fertilized once every 3 days, for a total of 20 times, with a total of 5 g of MNS; the LBC group added 20 g of cyanobacteria biochar to the soil; the LBC-MNS group added 20 g of the solid microbial nutrient stimulant prepared in Example 1 (containing 5 g of MNS) to the soil. After 60 days, the tomato fruits were taken for testing, and the results are shown in Table 1 below:

[0057] Table 1

[0058]

[0059] The solid micronutrient stimulant prepared by absorbing micronutrient stimulants with cyanobacteria biochar can significantly improve the quality and taste of tomatoes. The sugar-acid ratio of tomato fruits treated with MNS group increased by 33.3%, LBC group increased by 16.67%, and LBC-MNS group increased by 54.16% (33.3% + 16.67% < 54.16%), indicating that the application of LBC-MNS is beneficial to improve the taste and flavor of fresh tomatoes. LBC-MNS significantly increased the content of vitamin C in tomato fruits. The MNS group and LBC group increased the vitamin C content by 15.5% and 38.82%, respectively, while the LBC-MNS group increased by 54.70% (15.5% + 38.82% < 54.70%). The soluble protein content in tomato fruits treated with LBC-MNS group increased by 12.9% and 16.45%, respectively, while the LBC-MNS group increased by 28.67%.

[0060] In summary, the application of solid micronutrient stimulants can significantly increase the sugar-acid ratio, soluble protein and vitamin C content in tomatoes, achieve a synergistic effect, and effectively improve the taste, flavor and nutritional quality of tomato fruits.

[0061] Comparative Example 2: Effect of LBC-prepared solid nutrient stimulus on soil quality

[0062] Testing process: Set up a blank group, MNS group, LBC group and LBC-MNS group, take a 2-gallon planting pot for each group, add 2kg of soil (natural garden sandy soil, pH value 7.29, N content 129.6mg / kg, soil SOM content 23.14g / kg) to each pot, and plant tomato seedlings with 5 true leaves in the pot, with one seedling planted in each pot. The planting pots are placed in the same environment and watered every day to keep the moisture content at about 70%. Among them, the blank group did not add any additional substances; the MNS group needed to apply 100mL of MNS dilution (diluted 400 times, 2.5mg / mL) to each pot each time, and fertilization was performed every 3 days, for a total of 20 times, with a total of 5g MNS; the LBC group added 20g of cyanobacteria biochar to the soil; the LBC-MNS group added 20g of the solid microbial nutrient stimulant prepared in Example 1 (containing 5g of MNS) to the soil. After 60 days, the soil of the planting pot was taken for testing, and the results are shown in Table 2 below:

[0063] Table 2

[0064]

[0065] In terms of TN, the MNS group, LBC group and LBC-MNS group increased by 7.65%, 6.41% and 76.30% respectively compared with the CK group. and The content of SOM in CK and MNS soils was the highest. After planting tomatoes, the SOM content in CK and MNS soils decreased compared with the original soil. The SOM content in the MNS group decreased by 37.03%, while the SOM content in the LBC group increased by 59.63% compared with the original soil. The SOM content in the LBC-MNS group increased by 89.80% compared with the original soil. Therefore, applying LBC-MNS can supplement SOM in the soil, increase the nitrogen level in the soil, effectively restore soil fertility, and create favorable environmental conditions for crop growth.

[0066] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A solid micronutrient stimulant, characterized in that: Calculated by mass fraction, the solid micro-nutrient stimulant contains 70-90wt% of cyanobacteria biochar and 10-30wt% of micro-nutrient stimulant.

2. The solid micronutrient stimulant according to claim 1, characterized in that: The solid micro-nutrient stimulant contains 75-85wt% of blue algae biochar and 15-25wt% of micro-nutrient stimulant.

3. The solid micronutrient stimulant according to claim 1, characterized in that: The solid micro-nutrient stimulant contains 80 wt% of blue algae biochar and 20 wt% of micro-nutrient stimulant.

4. The solid micronutrient stimulant according to claim 1, characterized in that: The preparation method of the cyanobacteria biochar is as follows: washing and drying the cyanobacteria, and then calcining the cyanobacteria at 450 to 650° C. for 0.5 to 2 hours to obtain the cyanobacteria biochar.

5. The solid micronutrient stimulant according to claim 1, characterized in that: The preparation method of the microbial nutrient stimulant is as follows: adding CaO to activated sludge and stirring evenly, treating at 150-200°C for 1-3 hours to rupture the microbial cells in the activated sludge and release protein, then inactivating the pathogens by flash evaporation, and finally obtaining the microbial nutrient stimulant by solid-liquid separation and supernatant concentration.

6. Use of the solid micronutrient stimulant according to any one of claims 1 to 5 in the field of planting or fertilizer.

7. The method for preparing the solid micronutrient stimulant according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The blue algae biochar is added to the microbial nutrient stimulant solution and mixed, and then allowed to stand, the supernatant is removed, and the precipitate is dried to obtain the solid microbial nutrient stimulant.

8. The preparation method according to claim 7, characterized in that: The concentration of the micronutrient stimulant in the micronutrient stimulant solution is 1 to 5 mg / mL.

9. The preparation method according to claim 7, characterized in that: The ratio of the mass of the micronutrient stimulant to the mass of the cyanobacteria biochar in the micronutrient stimulant solution is 1-3:7-9.

10. The preparation method according to claim 7, characterized in that: The mixing time is 2 to 5 hours, and the standing time is 20 to 24 hours.

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