Slow-release microbial humic acid compound fertilizer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of slow-release fertilizers, and relates to a slow-release microbial humic acid compound fertilizer as well as a preparation method and application thereof. The invention provides a preparation method of a slow-release microbial humic acid compound fertilizer. The preparation method comprises the following steps: calcining vermiculite to obtain expanded vermiculite; uniformly mixing expanded vermiculite, tetrabutyl titanate and water, placing at normal temperature for 48-72 hours, drying and collecting to obtain modified expanded vermiculite; uniformly mixing the modified expanded vermiculite, bacillus subtilis and bacillus mucilaginosus to obtain a mixture; stirring is kept, a sodium alginate-humic acid mixed solution is sprayed to the mixture, a 2-5 wt% calcium chloride solution continues to be sprayed into the rotary drum, a reaction is conducted for 5-15 min for crosslinking, and finally a semi-finished fertilizer product is prepared after freezing and vacuum drying; and mixing the fertilizer semi-finished product with arbuscular mycorrhizal fungi to prepare the slow-release microbial humic acid compound fertilizer. The fertilizer provided by the invention can effectively improve the morbidity of salvia miltiorrhiza during continuous cropping and improve the quality of medicinal materials.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of slow-release fertilizer, and relates to a slow-release microbial humic acid compound fertilizer as well as a preparation method and application thereof. BACKGROUND

[0002] Salvia miltiorrhiza Bunge, as a perennial herb of the Labiatae family, its dried roots and rhizomes are traditional precious Chinese medicinal materials, which have irreplaceable medicinal value in the treatment of cardiovascular diseases, antibacterial and anti-inflammatory fields. With the continuous rise of market demand, the artificial cultivation scale of Salvia miltiorrhiza is expanding, but the problems such as continuous cropping obstacles and quality decline gradually exposed in the long-term planting process have become the core bottleneck restricting the sustainable development of the industry. Fertilization is a key agronomic measure to regulate the growth and development, yield formation and effective component accumulation of Salvia miltiorrhiza. In traditional cultivation, although the excessive use of chemical fertilizers can short-term increase the yield, long-term use will lead to soil structure destruction and deterioration of physical and chemical properties, not only reducing the fertilizer utilization rate, but also inhibiting the secondary metabolism of Salvia miltiorrhiza, causing the content of core medicinal ingredients such as Danshensu and Salvianolic acid B to decrease, and also aggravating the breeding of soil pathogenic bacteria, making the incidence of continuous cropping Salvia miltiorrhiza significantly increase. To solve this problem, the industry gradually turns to the research and application of organic fertilizer, biological fertilizer and compound fertilizer, among which Chinese medicine residue organic fertilizer and humic acid fertilizer are widely concerned due to their advantages of improving soil and promoting growth. Studies have shown that humic acid, as a natural organic substance, can improve fertilizer efficiency through chelation of trace elements and regulation of nutrient release rate, and also stimulate plant root growth and enhance stress resistance; Chinese medicine residue can be converted into high-quality organic fertilizer after treatment, which provides comprehensive nutrition for Salvia miltiorrhiza and realizes the resource utilization of waste. In addition, biological bacterial fertilizer inhibits the reproduction of pathogenic bacteria by introducing beneficial microorganisms, which has shown good application prospect in the prevention and treatment of diseases of Chinese medicinal materials, providing a new path to solve the continuous cropping obstacles.

[0003] However, the existing special fertilizer for Salvia miltiorrhiza still has many technical defects: firstly, the ordinary humic acid compound fertilizer lacks targeted slow-release design, and the nutrient release rate does not match the nutrient demand of Salvia miltiorrhiza growth period, which is prone to problems such as insufficient fertilizer supply in the early stage and nutrient loss in the later stage; secondly, the beneficial microorganisms in biological fertilizer are easily affected by environmental stress and antagonism of indigenous microorganisms in the soil, and the activity is difficult to maintain for a long time, resulting in unstable bacteriostatic and disease prevention effect; thirdly, if the traditional Chinese medicine residue fertilizer is not properly treated, not only the release of effective components is uneven, but also it may carry pathogenic bacteria, which increases the risk of soil pests and diseases, and the single raw material or single function fertilizer is difficult to meet the comprehensive needs of Salvia miltiorrhiza for nutrient supply, disease prevention and control and quality improvement; fourthly, the existing technology cannot effectively synergize the functional advantages of humic acid, beneficial microorganisms and carrier materials, and the promotion of functional microorganisms such as arbuscular mycorrhizal fungi (AMF) and other symbiotic microorganisms of Salvia miltiorrhiza roots is insufficient, which restricts the improvement of nutrient absorption efficiency of Salvia miltiorrhiza roots. Therefore, it is of important practical significance to develop a compound fertilizer which can realize slow-release supply of nutrients, maintain long-term activity of microorganisms, efficiently prevent and control continuous cropping diseases, and specifically promote the accumulation of medicinal ingredients of Salvia miltiorrhiza, so as to realize the synergistic effect of soil improvement, disease control and quality improvement of medicinal materials, break through the bottleneck of Salvia miltiorrhiza industry development, and promote the green and high-quality planting of Chinese herbal medicines. SUMMARY

[0004] The present application aims to provide a slow-release microbial humic acid compound fertilizer for improving the disease incidence of Salvia miltiorrhiza in continuous cropping and improving the quality of medicinal materials.

[0005] In one aspect, the present application relates to a preparation method of a slow-release microbial humic acid compound fertilizer, which comprises: calcining vermiculite to obtain expanded vermiculite;

[0006] The expanded vermiculite, tetrabutyl titanate and water are uniformly mixed and then placed at room temperature for 48-72 h, and the modified expanded vermiculite is obtained by drying and collecting;

[0007] The modified expanded vermiculite, Bacillus subtilis and Bacillus mucilaginosus are uniformly mixed to obtain a mixture;

[0008] While stirring, a sodium alginate-humic acid mixed solution is sprayed onto the mixture, 2-5 wt% calcium chloride solution is continuously sprayed into the rotating drum, and crosslinking is carried out by reacting for 5-15 minutes, and finally the fertilizer semi-product is prepared by freeze-drying.

[0009] The slow-release microbial humic acid compound fertilizer is prepared by mixing the fertilizer semi-product and arbuscular mycorrhizal fungi.

[0010] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the present application, the calcination temperature is 1000-1100℃, and the time is 4-6 h.

[0011] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the application, the mass ratio of the expanded vermiculite, tetrabutyl titanate and water is 10:8-10:25-35.

[0012] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the application, in the mixture, 5-15 mL of 5×10 7 CFU / mL bacillus subtilis and 5-15 mL of 5×10 7 CFU / mL bacillus mucilaginosus correspond to 10 g of the modified expanded vermiculite.

[0013] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the application, in the sodium alginate-humic acid mixed solution, the concentration of sodium alginate is 1-3 wt%, and the concentration of humic acid is 0.5-2 wt%.

[0014] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the application, the mass ratio of the mixture, the sodium alginate-humic acid mixed solution and the calcium chloride solution is 10:3-5:0.5-1.5.

[0015] Further, in the preparation method of the slow-release microbial humic acid compound fertilizer provided by the application, the mass ratio of the fertilizer semi-product and the arbuscular mycorrhizal fungus is 400-500:20.

[0016] In another aspect, the application relates to a slow-release microbial humic acid compound fertilizer prepared by the preparation method of the slow-release microbial humic acid compound fertilizer.

[0017] In another aspect, the application relates to the application of the slow-release microbial humic acid compound fertilizer in the planting of salvia miltiorrhiza.

[0018] In another aspect, the application relates to the application of the slow-release microbial humic acid compound fertilizer in reducing the incidence of salvia miltiorrhiza continuous cropping and improving the quality of salvia miltiorrhiza medicinal materials.

[0019] Compared with the prior art, the technical scheme provided by the application has at least the following beneficial effects or advantages:

[0020] (1) The arbuscular mycorrhizal fungus infection efficiency is significantly improved: the application constructs a special carrier by modifying the expanded vermiculite with tetrabutyl titanate, and cooperates with the slow-release structure of sodium alginate-humic acid composite coating and calcium chloride crosslinking, so that the antagonism between beneficial microorganisms is effectively avoided, the AMF infection rate of salvia miltiorrhiza root is increased to 53.6%-59.5%, which is much higher than that of the prior art and the control treatment, and the absorption capacity of salvia miltiorrhiza root to soil nutrients is greatly enhanced.

[0021] (2) Efficiently solve the problem of continuous cropping disease of Salvia miltiorrhiza: Bacillus subtilis and Bacillus mucilaginosus produce beneficial substances together, directly inhibit the reproduction of pathogenic bacteria in continuous cropping soil; humic acid and modified expanded vermiculite are combined to improve soil aeration and fertility, and destroy the breeding environment of pathogenic bacteria; the slow-release structure realizes the sustained release of beneficial microorganisms and nutrients, and long-term beneficial effects, so that the incidence of Salvia miltiorrhiza continuous cropping is reduced to 20%~24%, the disease index is as low as 6.67~8.00, and the decrease is significant compared with the blank control and traditional fertilizer treatment, which effectively solves the continuous cropping obstacle.

[0022] (3) Greatly improve the quality of Salvia miltiorrhiza medicinal materials: the combination of high AMF infection rate and nutrient transformation of beneficial microorganisms provides sufficient raw materials for the synthesis of effective components of Salvia miltiorrhiza; humic acid as a natural growth regulator promotes the secondary metabolism of Salvia miltiorrhiza; the slow-release structure ensures long-term stability of nutrient supply and microbial activity, so that the contents of core water-soluble components such as salvianic acid A, rosmarinic acid and salvianolic acid B are significantly increased, and the content of salvianolic acid B is as high as 2.3039%, and the total amount of effective components is better than that of existing technologies and control treatments, which significantly improves the quality of medicinal materials. DETAILED DESCRIPTION

[0023] In the following, the technical solutions of the present application will be described in conjunction with examples. However, the present application is not limited to the following examples. The experimental methods and detection methods described in each example are conventional methods unless otherwise specified. The reagents and materials described are commercially available unless otherwise specified. In the following examples, % is the weight percentage content unless otherwise specified. The ratio in the following examples is weight ratio unless otherwise specified.

[0024] In the following examples, the AMF microbial agent is obtained by expanding Funneliforeis mosseae, and Bacillus subtilis and Bacillus mucilaginosus are obtained by commercial purchase.

[0025] Example 1: This example provides the preparation of a fertilizer semi-product.

[0026] Step 1: Take 100 grams of vermiculite powder and place it in a high-temperature muffle furnace. Increase the temperature to 1000℃ at a rate of 5℃ / min, and calcine at this temperature for 4h. Naturally cool to room temperature to obtain expanded vermiculite with a lot of pores, which is ready for use.

[0027] Step 2: Take the expanded vermiculite prepared in Step 1, and according to the mass ratio of expanded vermiculite: tetrabutyl titanate: water = 10:8:25, measure the tetrabutyl titanate and deionized water respectively. Add the expanded vermiculite, tetrabutyl titanate and water into a beaker, and stir on a magnetic stirrer at a speed of 500 rpm for 30 minutes to fully mix and uniform. Place the mixture at room temperature and let it stand for 48 hours. Transfer the aged material to a forced air drying oven and dry at 60°C for 12 hours. Grind and pass through a 100 mesh sieve to collect the modified expanded vermiculite.

[0028] Step 3: Take 100 grams of the modified expanded vermiculite prepared in Step 2 and place it in a rotating drum. Keep the drum rotating at a speed of 10 r / min. According to the ratio of 5 mL Bacillus subtilis suspension (diluted to 5 x 10 7 CFU / mL) and 5 mL Bacillus mucilaginosus suspension (diluted to 5 x 10 7 CFU / mL) per 10 grams of modified expanded vermiculite, measure the two bacterial solutions respectively. Spray the bacterial solutions evenly onto the modified expanded vermiculite and continue stirring for 10 minutes to obtain a wet mixture loaded with two types of microorganisms.

[0029] Step 4: Dissolve sodium alginate and humic acid in deionized water and stir magnetically until completely dissolved to obtain a mixed solution with a concentration of 1 wt% sodium alginate and 0.5 wt% humic acid. According to the mass ratio of mixture: sodium alginate-humic acid solution: 2 wt% calcium chloride solution = 10:3:0.5, calculate the required sodium alginate-humic acid solution and calcium chloride solution. Keep the rotating drum rotating and use an airbrush to evenly spray the sodium alginate-humic acid mixed solution onto the surface of the tumbling material. Then, spray the calcium chloride solution into the rotating drum and continue the reaction for 10 minutes to cause the sodium alginate to ionically crosslink and gel, and the microorganisms and humic acid to be coated and fixed on the surface and pores of the expanded vermiculite carrier. Transfer the wet granular material after reaction to a freeze dryer and vacuum dry at -50°C for 24 hours to obtain a dry fertilizer semi-finished product.

[0030] Example 2: This example provides the preparation of a fertilizer semi-finished product.

[0031] Step 1: Take 100 grams of vermiculite powder and place it in a high-temperature muffle furnace. Heat at a rate of 5°C / min to 1050°C and calcine at this temperature for 5 hours. Naturally cool to room temperature to obtain expanded vermiculite with loose and porous structure, ready for use.

[0032] Step 2: Take the expanded vermiculite prepared in Step 1, and according to the mass ratio of expanded vermiculite: tetrabutyl titanate: water = 10:9:30, measure the tetrabutyl titanate and deionized water respectively. Add the expanded vermiculite, tetrabutyl titanate and water into a beaker, and stir on a magnetic stirrer at a speed of 500 rpm for 30 minutes to fully mix and uniform. Place the mixture at room temperature and let it stand for 60 hours. Transfer the aged material to a forced air drying oven and dry at 60°C for 12 hours. Grind and pass through a 100 mesh sieve to collect the modified expanded vermiculite.

[0033] Step 3: Take 100 grams of the modified expanded vermiculite prepared in Step 2 and place it in a rotating drum. Keep the drum rotating at a speed of 10 r / min. According to the ratio of 10 mL Bacillus subtilis suspension (diluted to 5 x 10 7 CFU / mL) and 10 mL Bacillus mucilaginosus suspension (diluted to 5 x 10 7 CFU / mL) per 10 grams of modified expanded vermiculite, measure the two bacterial solutions respectively. Spray the bacterial solutions evenly onto the modified expanded vermiculite and continue stirring for 10 minutes to obtain a wet mixture loaded with two kinds of microorganisms.

[0034] Step 4: Dissolve sodium alginate and humic acid in deionized water and stir magnetically until completely dissolved to obtain a mixed solution with a concentration of 2 wt% sodium alginate and 1.2 wt% humic acid. According to the mass ratio of mixture: sodium alginate-humic acid solution: 3.5 wt% calcium chloride solution = 10:4:1, calculate the required sodium alginate-humic acid solution and calcium chloride solution. Keep the rotating drum rotating and use a spray gun to evenly spray the sodium alginate-humic acid mixed solution onto the surface of the tumbling material. Then, spray the calcium chloride solution into the rotating drum and continue the reaction for 10 minutes to cause the sodium alginate to ionically crosslink and gel, and the microorganisms and humic acid to be coated and fixed on the surface and pores of the expanded vermiculite carrier. Transfer the wet granular material after reaction to a freeze dryer and vacuum dry at -50°C for 24 hours to obtain a dry fertilizer semi-finished product.

[0035] Example 3: This example provides the preparation of a fertilizer semi-finished product.

[0036] Step 1: Take 100 grams of vermiculite powder and place it in a high-temperature muffle furnace. Heat at a rate of 5°C / min to 1100°C and calcine at this temperature for 6 hours. Naturally cool to room temperature to obtain a fluffy and porous expanded vermiculite, ready for use.

[0037] Step 2: Take the expanded vermiculite prepared in Step 1, and according to the mass ratio of expanded vermiculite: tetrabutyl titanate: water = 10:10:35, measure the tetrabutyl titanate and deionized water respectively. Add the expanded vermiculite, tetrabutyl titanate and water into a beaker, and stir on a magnetic stirrer at a speed of 500 rpm for 30 minutes to fully mix and uniform. Place the mixture at room temperature and let it stand for 72 hours. Transfer the aged material to a forced air drying oven and dry at 60°C for 12 hours. Grind and pass through a 100 mesh sieve to collect the modified expanded vermiculite.

[0038] Step 3: Take 100 grams of the modified expanded vermiculite prepared in Step 2 and place it in a rotating drum. Keep the drum rotating at a speed of 10 r / min. According to the ratio of 15 mL Bacillus subtilis suspension (diluted to 5 x 10 7 CFU / mL) and 15 mL Bacillus mucilaginosus suspension (diluted to 5 x 10 7 CFU / mL) per 10 grams of modified expanded vermiculite, measure the two bacterial solutions respectively. Spray the bacterial solutions evenly onto the modified expanded vermiculite and continue stirring for 10 minutes to obtain a wet mixture loaded with two types of microorganisms.

[0039] Step 4: Dissolve sodium alginate and humic acid in deionized water and magnetically stir until completely dissolved to obtain a mixed solution with a concentration of 3 wt% sodium alginate and 2 wt% humic acid. According to the mass ratio of mixture: sodium alginate-humic acid solution: 5 wt% calcium chloride solution = 10:5:1.5, calculate the required sodium alginate-humic acid solution and calcium chloride solution. Keep the rotating drum rotating and use an airbrush to evenly spray the sodium alginate-humic acid mixed solution onto the surface of the tumbling material. Then, spray the calcium chloride solution into the rotating drum and continue the reaction for 10 minutes to cause the sodium alginate to ionically crosslink and gel, fixing the microorganisms and humic acid on the surface and pores of the expanded vermiculite carrier. Transfer the wet granular material after reaction to a freeze dryer and vacuum dry at -50°C for 24 hours to obtain a dry fertilizer semi-finished product.

[0040] Comparative Example 1: This comparative example is the same as Example 1, except that the tetrabutyl titanate in Step 2 is replaced by titanium dioxide.

[0041] Comparative Example 2: This comparative example is the same as Example 1, except that the modified expanded vermiculite in Step 3 is replaced by expanded vermiculite.

[0042] Comparative Example 3: This comparative example is the same as Example 1, except that no calcium chloride is sprayed in Step 4, i.e. without a slow-release structure.

[0043] Test Example: This test example provides a pot experiment of different fertilizers.

[0044] Treatment 1#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 400 g of the semi-finished product of Example 1 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0045] Treatment 2#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 450 g of the semi-finished product of Example 2 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0046] Treatment 3#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 500 g of the semi-finished product of Example 3 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0047] Comparative Treatment 1#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 400 g of the semi-finished product of Comparative Example 1 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0048] Comparative Treatment 2#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 400 g of the semi-finished product of Comparative Example 2 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0049] Comparative Treatment 3#: 2.5 kg of Dan-shen field soil continuously planted for 3 years, 20 g of AMF inoculant and 400 g of the semi-finished product of Comparative Example 3 fertilizer were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0050] CK: 2.5 kg of Dan-shen field soil continuously planted for 3 years and 20 g of AMF inoculant were mixed, ensuring that at least 25 mature and healthy spores per gram of inoculated substrate were contained after mixing, and then 5 Dan-shen seedlings were transplanted per pot.

[0051] Each of the above treatments was repeated 5 pots, and unified water and fertilizer management was carried out, and after 90 days of cultivation, Dan-shen plants were harvested for indoor analysis and determination test.

[0052] (1) AMF infection rate statistics.

[0053] The fresh Dan-shen fibrous roots were cut off, the root soil was washed clean with tap water, and after fixation with a fixing solution, the root system was cut into root segments of about 2 cm, and the infection rate was calculated under a microscope (Giovanneti, 1980), and the results are shown in Table 1.

[0054] Table 1 AMF infection rate under different treatments

[0055] Infection rate (%) Treatment 1 53.6 Treatment 2 59.5 Treatment 3 57.1 Comparative treatment 1 36.4 Comparative treatment 2 46.8 Comparative treatment 3 18.9 CK 23.6

[0056] From Table 1, it can be seen that the compound fertilizer provided by the application can significantly improve the AMF infection rate of the root system of Salvia miltiorrhiza (53.6%~59.5%), wherein the treatment effect of Example 2 is optimal, which is much higher than each comparative treatment (18.9%~46.8%) and the blank control (23.6%). From comparative treatment 1# and comparative treatment 2#, it can be seen that after replacing tetrabutyl titanate with titanium dioxide, since the titanium dioxide is not attached to the vermiculite, it has an adverse effect on the production of Bacillus subtilis, Bacillus mucilaginosus and arbuscular mycorrhizal fungi after slow-release. Under the condition of slow hydrolysis of tetrabutyl titanate at room temperature, the main product is amorphous titanium hydroxide / titanium oxide gel, which is different from titanium dioxide and plays an excellent promoting function. From comparative treatment 3#, it can be seen that the lack of slow-release structure may lead to rapid decay of microbial activity on the one hand, and on the other hand, it may lead to antagonism of Bacillus subtilis, Bacillus mucilaginosus and arbuscular mycorrhizal fungi, thereby reducing the AMF infection efficiency.

[0057] (2) Incidence rate statistics.

[0058] Disease grading standard: 0 level: the main root of the plant grows normally, and there is no disease at the stem base; 1 level: the epidermis shows slight disease, but the disease does not invade the internal tissue; 3 level: the epidermis shows obvious disease, and the vascular bundle is brown; 5 level: the vascular bundle is dark brown, the vessel is lignified, the root starts to rot, the rotten part accounts for less than 30% of the total root, and the growth is hindered; 7 level: the root rotting part accounts for more than 30% of the total root or the whole plant wilts due to disease; 9 level: the aboveground part of the plant is completely dried and dead, and the root system is completely rotted.

[0059] Disease incidence (%) = (number of diseased plants / total number of plants surveyed) x 100%.

[0060] Disease index = [∑ (number of plants at each level x number value of the disease level) / (total number of plants surveyed x number value of the highest disease level)] x 100.

[0061] The disease incidence and disease index were counted, and the results are shown in Table 2.

[0062] Table 2 Disease incidence and disease index under different treatments

[0063] Morbidity rate (%) Disease index Treatment 1 24 8.00 Treatment 2 20 7.56 Treatment 3 20 6.67 Comparative treatment 1 44 28.89 Comparative treatment 2 48 31.11 Comparative treatment 3 80 42.67 CK 64 36.44

[0064] As shown in Table 2, the compound fertilizer provided by the application can significantly reduce the incidence (20%-24%) and disease index (6.67-8.00) of continuous cropping Danshen, and the reduction is obvious compared with the blank control (incidence of 64%, disease index of 36.44) and the comparative treatment, and the disease control effect of Example 3 is the best. Bacillus subtilis and Bacillus mucilaginosus can produce soil improvement materials to directly inhibit the reproduction of pathogenic bacteria in continuous cropping soil; humic acid and modified vermiculite can improve soil aeration and fertility and reduce the breeding environment of pathogenic bacteria; the slow-release structure can continuously release beneficial microorganisms and nutrients and long-term inhibit diseases; the comparative treatment cannot continuously and fully play the beneficial role due to the lack of modified carrier, effective microorganisms or slow-release structure, and thus leads to more serious diseases.

[0065] (3) Effective ingredient statistics.

[0066] The water-soluble components of Danshen are counted by chromatography, and the specific method refers to Chinese Pharmacopoeia and literature (Li Minhui et al., 2008).

[0067] Table 3: Statistics of water-soluble components

[0068] Unit: % Danshensu Rosmarinic acid Salvianolic acid B Treatment 1 0.6150 1.4388 2.1677 Treatment 2 0.6437 1.5227 2.1053 Treatment 3 0.6178 1.4567 2.3039 Comparative treatment 1 0.4513 1.2540 1.9604 Comparative treatment 2 0.5059 1.3143 1.7396 Comparative treatment 3 0.3110 1.2185 1.8570 CK 0.4307 1.2367 1.7413

[0069] As shown in Table 3, the compound fertilizer provided by the application can significantly improve the content of danshensu, rosmarinic acid and salvianolic acid B in Danshen, and the total amount of effective ingredients is higher than that of each comparative treatment and the blank control. The content of salvianolic acid B in Example 3 is the highest (2.3039%), which greatly improves the quality of medicinal materials. High AMF infection rate enhances the absorption capacity of Danshen root system to soil nutrients; Bacillus subtilis and Bacillus mucilaginosus can decompose soil insoluble nutrients to provide raw materials for the synthesis of effective components of Danshen; humic acid as a natural growth regulator promotes the secondary metabolism of Danshen; the slow-release structure ensures the long-term stability of nutrients and microbial activity, and provides protection for the continuous synthesis of effective components; the comparative treatment is limited in the synthesis of effective components due to unstable nutrient supply and microbial resistance.

[0070] As described above, the basic principles, main features and advantages of the application are better described. The above examples and specification only describe the preferred embodiments of the application, and the application is not limited by the above examples. Without departing from the spirit and scope of the application, various changes and improvements to the technical solutions of the application made by those skilled in the art shall fall within the scope of protection of the application.

Claims

1. A method for preparing a slow-release microbial humic acid compound fertilizer, characterized in that, The application relates to a preparation method of a slow-release microbial humic acid compound fertilizer. The expanded vermiculite is obtained by calcining vermiculite; The modified expanded vermiculite is obtained by uniformly mixing the expanded vermiculite, tetrabutyl titanate and water, and then placing the mixture at normal temperature for 48-72 hours and drying and collecting the modified expanded vermiculite; The mixture is obtained by uniformly mixing the modified expanded vermiculite, bacillus subtilis and bacillus mucilaginosus; The fertilizer semi-product is prepared by spraying a sodium alginate-humic acid mixed solution into the mixture under stirring, continuously spraying 2-5 wt% calcium chloride solution into the rotating drum, crosslinking for 5-15 minutes, and finally freezing and vacuum drying. The slow-release microbial humic acid compound fertilizer is prepared by mixing the fertilizer semi-product and arbuscular mycorrhizal fungi.

2. The method of claim 1, wherein the slow-release microbial humic acid compound fertilizer is prepared by the steps of: The calcining temperature is 1000-1100 DEG C, and the time is 4-6 hours. ​ 3. The method for preparing the slow-release microbial humic acid compound fertilizer according to claim 1, characterized in that, The mass ratio of the expanded vermiculite, tetrabutyl titanate and water is 10:8-10:25-35.

4. The method for preparing the slow-release microbial humic acid compound fertilizer according to claim 1, characterized in that, In the mixture, 5~15 mL 5×10 7 CFU / mL Bacillus subtilis and 5~15 mL 5×10 7 CFU / mL Bacillus mucilaginosus per 10 g of the modified expanded vermiculite.

5. The method for preparing the slow-release microbial humic acid compound fertilizer according to claim 1, characterized in that, In the sodium alginate-humic acid mixed solution, the concentration of sodium alginate is 1-3 wt%, and the concentration of humic acid is 0.5-2 wt%.

6. The method for preparing the slow-release microbial humic acid compound fertilizer according to claim 1, characterized in that, The mass ratio of the mixture, the sodium alginate-humic acid mixed solution and the calcium chloride solution is 10:3-5:0.5-1.

5.

7. The method for preparing the slow-release microbial humic acid compound fertilizer according to claim 1, characterized in that, The mass ratio of the fertilizer semi-product and arbuscular mycorrhizal fungi is 400-500:

20.

8. A slow release microbial humic acid compound fertilizer, characterized in that, The slow-release microbial humic acid compound fertilizer is prepared by the preparation method of any one of claims 1-7.

9. The slow-release microbial humic acid compound fertilizer of claim 8 is applied to the planting of salvia miltiorrhiza.

10. The slow-release microbial humic acid compound fertilizer of claim 8 is applied to reducing the incidence of salvia miltiorrhiza continuous cropping and improving the quality of salvia miltiorrhiza medicinal materials.