Microbial agent for improving yield and quality of cotton and preparation method thereof

Abstract

The application discloses a microbial agent for improving cotton yield and quality and a preparation method thereof, and belongs to the technical field of organic fertilizer and microbial fertilizer manufacturing. The microbial agent for improving cotton yield and quality comprises the following raw materials in parts by weight: 50-60 parts of a compound microbial liquid, 8-10 parts of alginate oligosaccharide, 6-8 parts of humic acid chelated boron zinc, 4-5 parts of polyglutamic acid, 12-15 parts of modified attapulgite, and 2-3 parts of glycerol; the compound microbial liquid comprises Candida valensis, Arthrobacter mysorens, and Pseudomonas psychrophilus. The three strains are colonized in the rhizosphere of cotton together, synergistically promote the growth of cotton, make cotton seeds full, increase the yield of cotton, effectively improve the quality of lint, realize the dual targets of yield increase and quality improvement, reduce the use of chemical fertilizers and pesticides, and are a very promising technical scheme for promoting green, high-yield, high-quality and efficient production of cotton.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic fertilizer and microbial fertilizer manufacturing, and particularly relates to a microbial agent for improving cotton yield and quality and a preparation method thereof. BACKGROUND

[0002] Cotton is an important economic crop in the world, and its yield and quality are directly related to the supply of raw materials for the textile industry and the economic benefits of agriculture. However, in traditional cotton cultivation, long-term reliance on chemical fertilizers and pesticides not only leads to soil compaction, imbalance of microbial communities, and decreased nutrient utilization, but also causes environmental pollution and safety risks of agricultural products. At the same time, cotton often faces problems such as micronutrient deficiency, frequent soil-borne diseases, and abiotic stress such as drought and low temperature during growth, which seriously affect its yield and fiber quality.

[0003] In the past, the large amount of fertilizer applied in farmland and the unreasonable application of fertilizer have caused problems such as decline in soil fertility and low fertilizer utilization. As a green agricultural input, microbial agents have attracted widespread attention due to their potential in promoting crop growth, improving stress resistance, and improving soil health. The activation of soil nutrients by microbial agents is of great significance in tapping the potential of soil nutrients, reducing fertilizer application to some extent, and alleviating resource shortages. However, existing microbial agents are mostly single strains or simple combinations, which often have problems such as insufficient synergy between strains, poor environmental adaptability, or low survival rate, resulting in unstable effects and short duration. At the same time, the deterioration of soil structure and the degradation of rhizosphere microecology also limit the function of microorganisms, making it difficult to meet the comprehensive needs of high-yield and high-quality cotton production.

[0004] Therefore, it is of great significance to develop a complex microbial agent that can integrate the synergistic effects of multiple functional microorganisms to achieve green, high-yield, and high-quality cotton production. SUMMARY

[0005] The present application provides a microbial agent specifically for cotton to effectively improve the growth performance of cotton and significantly increase the yield and quality of cotton by compounding specific functional strains.

[0006] To achieve the above technical purpose, the technical solution adopted by the present application is as follows:

[0007] A microbial agent for improving the yield and quality of cotton, comprising the following raw materials by weight: 50-60 parts of complex microbial liquid, 8-10 parts of brown algal oligosaccharide, 6-8 parts of humic acid chelated boron zinc, 4-5 parts of polyglutamic acid, 12-15 parts of modified attapulgite, and 2-3 parts of glycerol.

[0008] The complex microbial liquid comprises Candida valensis, Arthrobacter misoolensis, and Pseudomonas psychrophila.

[0009] Further, the complex microbial bacteria liquid is prepared by the following steps:

[0010] Further, the preparation method of the complex microbial bacteria liquid is as follows:

[0011] (1) First, the freeze-dried powder of Candida valensis is prepared into a bacterial suspension, 100 μL of the bacterial suspension is added dropwise to a malt juice agar culture medium and cultured for 48 h, a single colony is picked and inoculated into a malt juice liquid culture medium, and cultured at 25°C and 160 rpm until OD 600 = 0.6 to obtain a seed liquid, the seed liquid is inoculated into a small seed tank at an inoculation amount of 1%, and cultured at 25°C and 160 rpm until OD 600 = 3.0 to obtain a Candida valensis fermentation liquid;

[0012] (2) First, the freeze-dried powders of Arthrobacter mysorens and Pseudomonas psychrophila are prepared into bacterial suspensions, respectively, 100 μL of the bacterial suspensions are added dropwise into nutrient broth agar and cultured for 72 h, respectively, a single colony is picked and inoculated into a nutrient broth liquid culture medium, and cultured at 30°C and 180 rpm until OD 600 = 0.6 to obtain a seed liquid, and the seed liquid is inoculated into a small seed tank at an inoculation amount of 1%, and cultured at 30°C and 180 rpm until OD 600 = 3.0 to obtain an Arthrobacter mysorens fermentation liquid and a Pseudomonas psychrophila fermentation liquid, respectively;

[0013] (3) The Candida valensis fermentation liquid in step (1) and the Arthrobacter mysorens fermentation liquid and the Pseudomonas psychrophila fermentation liquid in step (2) are mixed in a volume ratio of 1:1:2 to obtain a complex microbial bacteria liquid.

[0014] Further, the preparation method of the humic acid chelated boron zinc is as follows:

[0015] (1) 70 kg of humic acid and 15 kg of deionized water are added to a reaction kettle, slowly stirred and added dropwise with ammonia water, the slurry pH is adjusted to 8.0-9.0 to obtain an ammonium humate solution;

[0016] (2) 4.55 kg of zinc sulfate heptahydrate is dissolved in 5 kg of 50 DEG C hot water to obtain a zinc sulfate solution, and the zinc sulfate solution is slowly added to the ammonium humate solution under continuous stirring, the reaction temperature is kept at 50-60 DEG C, and the stirring is continuously reacted for 30 min to obtain a mixed slurry A;

[0017] (3) 9.52 kg of sodium octaborate tetrahydrate is dissolved in 10 kg of 60 DEG C hot water to obtain a sodium borate solution, and the sodium borate solution is slowly added to the mixed slurry A under vigorous stirring, the temperature is kept at 50-60 DEG C, and the stirring is continuously reacted for 45 min to obtain a mixed slurry B;

[0018] (4) The mixed slurry B is transferred to a vacuum drying oven, dried to a moisture content of less than 5%, and the dried block is crushed by a crusher and sieved through an 80-mesh sieve to obtain uniform humic acid chelated boron zinc.

[0019] Further, the preparation method of the modified attapulgite is:

[0020] (1) 100 kg of attapulgite is mixed with 300 kg of deionized water in a reaction tank to form a uniform slurry, 10% hydrochloric acid is slowly added, the pH of the slurry is adjusted to 3.0-4.0, and the stirring is reacted at 60-70 DEG C for 2 h, then the solid-liquid separation is carried out, and the filter cake is washed with deionized water until the filtrate is neutral to obtain the filter cake;

[0021] (2) The filter cake is added to 300 kg of deionized water to form a uniform slurry, 5 kg of CTAB is added, and heated to 75-80 DEG C, and the stirring is reacted for 4 h;

[0022] (3) The above reaction is repeatedly washed with deionized water until the filtrate does not contain Br⁻ detected by silver nitrate solution, the washed filter cake is subjected to solid-liquid separation, and the washed filter cake is sent to a drying room and dried at 105-110 DEG C by blowing to a moisture content of less than 8%, and sieved through a 100-mesh sieve to obtain the modified attapulgite.

[0023] A microbial agent for improving cotton yield and quality, comprising the following steps:

[0024] First, the compound microbial liquid is mixed with glycerol and freeze-dried to prepare a microbial powder, and then the microbial powder, brown algae oligosaccharide, humic acid chelated boron zinc, polyglutamic acid and modified attapulgite are mixed in proportion, granulated, and the particles with a particle size of 1-2 mm are screened to obtain the final product microbial agent.

[0025] The raw materials used in the application are commercially available.

[0026] The humic acid chelated boron and zinc in the application can significantly improve the pollination success rate, the bud and boll retention rate of cotton, and promote the healthy growth of the plant by efficiently supplementing the key trace elements boron and zinc; the attapulgite is a natural one-dimensional nanoscale silicate clay mineral, after acid washing and modification by cetyltrimethylammonium bromide, the efficiency of the attapulgite is prolonged by improving the physical and chemical properties of the soil, water and fertilizer retention, and serving as a soil environment for the survival of microorganisms, so as to create a stable and superior rhizosphere growth environment for high yield and high quality of cotton.

[0027] The composite microbial liquid used in the application comprises Candida valensis, Arthrobacter mysorens and Pseudomonas psychrophilus, wherein the Candida valensis can secrete auxin IAA, stimulate the growth of cotton root system, promote cell division and elongation, and develop the root system to more effectively absorb water and nutrients, improve the drought resistance, and improve the overall physiological state of the plant, thereby laying a foundation for high yield, and the Candida valensis can also play a function of releasing potassium. The Arthrobacter mysorens can convert the insoluble phosphorus in the soil into soluble phosphate, significantly improve the availability of soil phosphorus, and promote the absorption and utilization of phosphorus by the cotton root system, and in addition, the Arthrobacter mysorens can also decompose silicate minerals to release potassium elements. The Pseudomonas psychrophilus has the abilities of dissolving phosphorus and releasing potassium, producing auxin IAA and producing iron carrier, the function of releasing potassium releases the fixed potassium elements in the soil into soluble state for the cotton to absorb, and the iron carrier produced by the Pseudomonas psychrophilus can efficiently chelate iron elements to form an iron carrier-iron complex for the plant to utilize, thereby helping the plant to improve the iron nutrition.

[0028] Beneficial effects

[0029] The three strains colonize in the rhizosphere of cotton together, and the metabolic activities of the three strains can secrete organic acids, polysaccharides and other substances, improve the soil aggregate structure, create a microenvironment more conducive to the growth of cotton root system and the absorption of nutrients, and promote the growth of plants in adversity such as drought;

[0030] The three strains synergize to comprehensively promote the growth of cotton, make the cotton seeds full, increase the yield, effectively improve the quality of ginned cotton, realize the dual goals of yield increase and quality improvement, and reduce the use of chemical fertilizers and pesticides, which is a very promising technical solution to promote the green, high-yield, high-quality and efficient production of cotton. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a co-culture test diagram of the three strains used in the application; note: a is Candida valensis, b is Arthrobacter mysorens, and c is Pseudomonas psychrophilus. DETAILED DESCRIPTION

[0032] The technical solutions of the application will be further described below in combination with specific embodiments, but are not limited thereto.

[0033] Example 1

[0034] A microbial agent for improving cotton yield and quality comprises the following raw materials in parts by weight: 50 parts of a composite microbial liquid, 8 parts of brown algal oligosaccharide, 6 parts of humic acid chelated boron zinc, 4 parts of polyglutamic acid, 12 parts of modified attapulgite, and 2 parts of glycerol.

[0035] The composite microbial liquid comprises Candida valensis, Arthrobacter mysorens, and Pseudomonas psychrophila.

[0036] The preservation number of the Candida valensis in the composite microbial liquid is CGMCC No. 2.5520; the preservation number of the Arthrobacter mysorens is CGMCC No. 1.15895; and the preservation number of the Pseudomonas psychrophila is CGMCC No. 1.15631.

[0037] The preparation method of the composite microbial liquid is as follows:

[0038] (1) First, the freeze-dried powder of Candida valensis is prepared into a bacterial suspension, 100 muL of the bacterial suspension is added dropwise to a malt juice agar culture medium and cultured for 48 hours, a single colony is picked and inoculated into a malt juice liquid culture medium, and the culture is carried out at 25 DEG C and 160 rpm until the OD 600 =0.6 to obtain a seed liquid, and the seed liquid is inoculated into a small seed tank at an inoculation amount of 1% and cultured at 25 DEG C and 160 rpm until the OD 600 =3.0 to obtain a Candida valensis fermentation liquor;

[0039] (2) First, the freeze-dried powders of Arthrobacter mysorens and Pseudomonas psychrophila are prepared into bacterial suspensions, respectively, 100 muL of the bacterial suspensions is added dropwise into a nutrient broth agar and cultured for 72 hours, respectively, a single colony is picked and inoculated into a nutrient broth liquid culture medium, and the culture is carried out at 30 DEG C and 180 rpm until the OD 600 =0.6 to obtain a seed liquid, and the seed liquid is inoculated into a small seed tank at an inoculation amount of 1% and cultured at 30 DEG C and 180 rpm until the OD 600 =3.0 to obtain an Arthrobacter mysorens fermentation liquor and a Pseudomonas psychrophila fermentation liquor, respectively;

[0040] (3) The Candida valensis fermentation liquor in step (1) and the Arthrobacter mysorens fermentation liquor and the Pseudomonas psychrophila fermentation liquor in step (2) are mixed in a volume ratio of 1:1:2 to obtain a composite microbial liquid.

[0041] The preparation method of the humic acid chelated boron zinc is as follows:

[0042] (1) 70 kg of humic acid and 15 kg of deionized water are added to a reaction kettle, slowly stirred and added dropwise with ammonia water, the slurry pH is adjusted to 8.0 to obtain an ammonium humate solution;

[0043] (2) 4.55 kg of zinc sulfate heptahydrate is dissolved in 5 kg of 50℃ hot water to obtain a zinc sulfate solution, and the zinc sulfate solution is slowly added to the ammonium humate solution under continuous stirring, the reaction temperature is maintained at 50℃, and the stirring is continued for 30 min to obtain a mixed slurry A;

[0044] (3) 9.52 kg of sodium octaborate tetrahydrate is dissolved in 10 kg of 60℃ hot water to obtain a sodium borate solution, and the sodium borate solution is slowly added to the mixed slurry A under vigorous stirring, the temperature is maintained at 50℃, and the stirring is continued for 45 min to obtain a mixed slurry B;

[0045] (4) The mixed slurry B is transferred to a vacuum drying oven and dried to a moisture content of less than 5%, and the dried block is crushed by a crusher and sieved through an 80 mesh sieve to obtain a uniform humic acid chelated boron zinc.

[0046] The preparation method of the modified attapulgite is:

[0047] (1) 100 kg of attapulgite is mixed with 300 kg of deionized water in a reaction tank to form a uniform slurry, 10% hydrochloric acid is slowly added, the pH of the slurry is adjusted to 3.0, and the stirring is continued at 60℃ for 2 h, then the solid-liquid separation is carried out, and the filter cake is washed with deionized water until the filtrate is neutral to obtain the filter cake;

[0048] (2) The filter cake is added to 300 kg of deionized water and stirred to form a uniform slurry, 5 kg of CTAB is added, and the stirring is continued at 75℃ for 4 h;

[0049] (3) The reaction mixture is repeatedly washed with deionized water until the filtrate does not contain Br⁻ as detected by silver nitrate solution, then the solid-liquid separation is carried out, the washed filter cake is sent to a drying room and dried at 105℃ by blowing air until the moisture content is less than 8%, and then sieved through a 100 mesh sieve to obtain the modified attapulgite.

[0050] A microbial agent for improving the yield and quality of cotton, comprising the following steps:

[0051] First, the composite microbial liquid is mixed with glycerol and freeze-dried to obtain a microbial powder, and then the microbial powder, brown algae oligosaccharide, humic acid chelated boron zinc, polyglutamic acid and modified attapulgite are mixed in proportion, granulated, and the particles with a particle size of 1-2 mm are sieved to obtain the final product microbial agent.

[0052] Example 2

[0053] A microbial agent for improving the yield and quality of cotton, comprising the following raw materials by weight: composite microbial liquid 55 parts, brown algae oligosaccharide 9 parts, humic acid chelated boron zinc 7 parts, polyglutamic acid 4 parts, modified attapulgite 13 parts, and glycerol 3 parts.

[0054] The complex microbial bacteria liquid comprises Candida valensis, Arthrobacter mysorens, and Pseudomonas psychrophila.

[0055] The preservation number of the Candida valensis in the complex microbial bacteria liquid is CGMCC No. 2.5520; the preservation number of the Arthrobacter mysorens is CGMCC No. 1.15895; and the preservation number of the Pseudomonas psychrophila is CGMCC No. 1.15631.

[0056] The preparation method of the complex microbial bacteria liquid is as follows:

[0057] (1) First, the freeze-dried powder of Candida valensis is prepared into a bacterial suspension, 100 μL of the bacterial suspension is added dropwise to a malt juice agar culture medium for culture for 48 h, a single colony is picked and inoculated into a malt juice liquid culture medium, and culture is carried out at 25°C and 160 rpm until OD 600 = 0.6 to obtain a seed liquid, and the seed liquid is inoculated into a small seed tank at an inoculation amount of 1% and cultured at 25°C and 160 rpm until OD 600 = 3.0 to obtain a Candida valensis fermentation liquid;

[0058] (2) First, the freeze-dried powders of Arthrobacter mysorens and Pseudomonas psychrophila are prepared into bacterial suspensions, respectively, 100 μL of the bacterial suspensions is added dropwise to a nutrient broth agar for culture for 72 h, respectively, a single colony is picked and inoculated into a nutrient broth liquid culture medium, and culture is carried out at 30°C and 180 rpm until OD 600 = 0.6 to obtain a seed liquid, and the seed liquid is inoculated into a small seed tank at an inoculation amount of 1% and cultured at 30°C and 180 rpm until OD 600 = 3.0, respectively, to obtain an Arthrobacter mysorens fermentation liquid and a Pseudomonas psychrophila fermentation liquid, respectively;

[0059] (3) The Candida valensis fermentation liquid in step (1) and the Arthrobacter mysorens fermentation liquid and the Pseudomonas psychrophila fermentation liquid in step (2) are mixed in a volume ratio of 1:1:2 to obtain a complex microbial bacteria liquid.

[0060] The preparation method of the humic acid chelated boron-zinc is as follows:

[0061] (1) 70 kg of humic acid and 15 kg of deionized water are added to a reaction kettle, and ammonia water is slowly added while stirring, and the pH of the slurry is adjusted to 8.5 to obtain an ammonium humate solution;

[0062] (2) 4.55 kg of zinc sulfate heptahydrate is dissolved in 5 kg of 50°C hot water to obtain a zinc sulfate solution, and the zinc sulfate solution is slowly added to the ammonium humate solution under continuous stirring, the reaction temperature is maintained at 55°C, and the stirring reaction is continued for 30 min to obtain a mixed slurry A;

[0063] (3) 9.52 kg of sodium octaborate decahydrate is dissolved in 10 kg of 60℃ hot water, and a sodium borate solution is obtained after complete dissolution. The sodium borate solution is slowly added to the mixed slurry A under vigorous stirring, the temperature is maintained at 55℃, and the stirring reaction is continued for 45 minutes to obtain mixed slurry B;

[0064] (4) The mixed slurry B is transferred to a vacuum drying oven and dried to a moisture content of less than 5%. The dried block is crushed by a crusher and sieved through an 80-mesh sieve to obtain uniform humic acid chelated boron zinc.

[0065] The preparation method of the modified attapulgite is as follows:

[0066] (1) 100 kg of attapulgite is mixed with 300 kg of deionized water in a reaction tank to form a uniform slurry. 10% hydrochloric acid is slowly added, and the pH of the slurry is adjusted to 3.5. The slurry is stirred at 65℃ for 2 hours. After solid-liquid separation, the filter cake is washed with deionized water until the filtrate is neutral. The filter cake is obtained.

[0067] (2) The filter cake is added to 300 kg of deionized water and stirred to form a uniform slurry. 5 kg of CTAB is added and heated to 75℃. The stirring reaction is carried out for 4 hours.

[0068] (3) The reaction mixture is repeatedly washed with deionized water until the filtrate does not contain Br⁻ as detected by silver nitrate solution. The washed filter cake is dried in a drying room at 105℃ until the moisture content is less than 8%. The modified attapulgite is obtained by sieving through a 100-mesh sieve.

[0069] A microbial agent for improving the yield and quality of cotton includes the following steps:

[0070] First, the composite microbial liquid is mixed with glycerol and freeze-dried to produce a microbial powder. The microbial powder, brown algae oligosaccharide, humic acid chelated boron zinc, polyglutamic acid, and modified attapulgite are mixed in proportion, granulated, and sieved to obtain granules with a particle size of 1-2 mm to obtain the final product microbial agent.

[0071] Example 3

[0072] A microbial agent for improving the yield and quality of cotton includes the following weight parts of raw materials: composite microbial liquid 60 parts, brown algae oligosaccharide 10 parts, humic acid chelated boron zinc 8 parts, polyglutamic acid 5 parts, modified attapulgite 15 parts, and glycerol 3 parts.

[0073] The composite microbial liquid includes Candida valensis, Arthrobacter misoolensis, and Pseudomonas psychrophilus.

[0074] The preservation number of the said Candida valderi in the complex microbial bacteria solution is CGMCC No. 2.5520; the preservation number of the said Arthrobacter mysorensis is CGMCC No. 1.15895; and the preservation number of the said Pseudomonas psychrophila is CGMCC No. 1.15631.

[0075] The preparation method of the said complex microbial bacteria solution is:

[0076] (1) First, the freeze-dried powder of Candida valderi is prepared into a bacteria suspension, 100 μL of the bacteria suspension is added dropwise to a malt juice agar culture medium for culture for 48 h, a single colony is picked and inoculated into a malt juice liquid culture medium, and culture is carried out at 25°C and 160 rpm until OD 600 = 0.6 to obtain a seed liquid, the seed liquid is inoculated into a small seed tank at an inoculation amount of 1%, and culture is carried out at 25°C and 160 rpm until OD 600 = 3.0 to obtain a Candida valderi fermentation liquid;

[0077] (2) First, the freeze-dried powders of Arthrobacter mysorensis and Pseudomonas psychrophila are respectively prepared into bacteria suspensions, 100 μL of the bacteria suspensions are respectively added dropwise to a nutrient broth agar for culture for 72 h, single colonies are respectively picked and inoculated into a nutrient broth liquid culture medium, and culture is carried out at 30°C and 180 rpm until OD 600 = 0.6 to obtain seed liquids, and the seed liquids are respectively inoculated into small seed tanks at an inoculation amount of 1%, and culture is carried out at 30°C and 180 rpm until OD 600 = 3.0 to respectively obtain Arthrobacter mysorensis fermentation liquid and Pseudomonas psychrophila fermentation liquid;

[0078] (3) The Candida valderi fermentation liquid in step (1) and the Arthrobacter mysorensis fermentation liquid and the Pseudomonas psychrophila fermentation liquid in step (2) are mixed according to a volume ratio of 1:1:2 to obtain a complex microbial bacteria solution.

[0079] The preparation method of the said humic acid chelated boron zinc is:

[0080] (1) 70 kg of humic acid and 15 kg of deionized water are added into a reaction kettle, ammonia water is slowly added under slow stirring, the slurry pH is adjusted to 9.0 to obtain an ammonium humate solution;

[0081] (2) 4.55 kg of zinc sulfate heptahydrate is dissolved in 5 kg of 50°C hot water to obtain a zinc sulfate solution, the zinc sulfate solution is slowly added into the ammonium humate solution under continuous stirring, the reaction temperature is kept at 60°C, and the stirring reaction is continuously carried out for 30 min to obtain a mixed slurry A;

[0082] (3) 9.52 kg of sodium octaborate decahydrate is dissolved in 10 kg of 60℃ hot water, and after complete dissolution, a sodium borate solution is obtained, and under vigorous stirring, the sodium borate solution is slowly added to the mixed slurry A, the temperature is maintained at 60℃, and stirring is continued for 45 minutes to obtain mixed slurry B;

[0083] (4) The mixed slurry B is transferred to a vacuum drying oven, and dried to a moisture content of less than 5%, and the dried block is crushed by a crusher and sieved through an 80 mesh sieve to obtain uniform humic acid chelated boron zinc.

[0084] The preparation method of the modified attapulgite is:

[0085] (1) 100 kg of attapulgite is mixed with 300 kg of deionized water in a reaction tank to form a uniform slurry, 10% hydrochloric acid is slowly added, the pH of the slurry is adjusted to 4.0, and the slurry is stirred at 70℃ for 2 hours, then the solid-liquid separation is carried out, and the filter cake is washed with deionized water until the filtrate is neutral to obtain the filter cake;

[0086] (2) The filter cake is added to 300 kg of deionized water and stirred to form a uniform slurry, 5 kg of CTAB is added, and heated to 80℃ and stirred for 4 hours;

[0087] (3) The reaction mixture is repeatedly washed with deionized water until the filtrate does not contain Br⁻ as detected by silver nitrate solution, and the washed filter cake is sent to a drying room and dried at 110℃ with air blowing to a moisture content of less than 8%, and sieved through a 100 mesh sieve to obtain the modified attapulgite.

[0088] A microbial agent for improving cotton yield and quality, comprising the following steps:

[0089] First, the composite microbial liquid is mixed with glycerol and freeze-dried to produce a microbial powder, and then the microbial powder, alginate oligosaccharide, humic acid chelated boron zinc, polyglutamic acid and modified attapulgite are mixed in proportion, granulated, and the particles with a particle size of 1-2 mm are sieved to obtain the final product microbial agent.

[0090] Comparative Example 1

[0091] This comparative example is compared with Example 1, except that the volume ratio of Candida valensis fermentation liquid, Myceliopthora vermiculata fermentation liquid and Pseudomonas syringae fermentation liquid in the composite microbial liquid is 1:1:1, and the rest of the raw materials and steps are the same as Example 1.

[0092] Comparative Example 2

[0093] This comparative example is compared with Example 1, except that only Candida valensis fermentation liquid and Myceliopthora vermiculata fermentation liquid are used in the composite microbial liquid, and the volume ratio of the two is 1:1, and the rest of the raw materials and steps are the same as Example 1.

[0094] Comparative Example 3

[0095] The comparative example is compared with example 1, except that the composite microbial bacteria liquid only uses the fermentation liquor of Candida valensis and Pseudomonas syringae with a volume ratio of 1:1, and the rest of the raw materials and steps are the same as example 1.

[0096] Comparative example 4

[0097] The comparative example is compared with example 1, except that the composite microbial bacteria liquid only uses the fermentation liquor of Arthrobacter mysorens and Pseudomonas syringae with a volume ratio of 1:1, and the rest of the raw materials and steps are the same as example 1.

[0098] Comparative example 5

[0099] The comparative example is compared with example 1, except that the composite microbial bacteria liquid only uses the fermentation liquor of Candida valensis, and the rest of the raw materials and steps are the same as example 1.

[0100] Comparative example 6

[0101] The comparative example is compared with example 1, except that the composite microbial bacteria liquid only uses the fermentation liquor of Arthrobacter mysorens, and the rest of the raw materials and steps are the same as example 1.

[0102] Comparative example 7

[0103] The comparative example is compared with example 1, except that the composite microbial bacteria liquid only uses the fermentation liquor of Pseudomonas syringae, and the rest of the raw materials and steps are the same as example 1.

[0104] Performance test

[0105] Strain antagonism test:

[0106] After the freeze-preserved Candida valensis, Arthrobacter mysorens and Pseudomonas syringae were activated, they were streaked on LB medium plates, and after 2-3 days of culture at 27°C, the growth condition of each combination at the intersection of the streaks was observed, and the results are shown in Table 1 (Note: a is Candida valensis, b is Arthrobacter mysorens, and c is Pseudomonas syringae). Figure 1 The normal growth of each strain at the intersection indicates that the compatibility between the strains is good, indicating that there is no obvious inhibition between the three strains, and they can be used as composite microbial bacteria liquid.

[0107] Strain growth-promoting ability test:

[0108] The molybdenum-antimony anti-colorimetric method was used to determine the strain phosphorus solubilizing ability; the flame atomic spectrophotometry method was used to determine the strain potassium solubilizing ability; the Salkowski colorimetric liquid colorimetric method was used to determine the strain indole acetic acid secretion ability; and the CAS detection liquid detection method was used to determine the strain siderophore synthesis ability. Each group has 3 repeated results and the mean value is taken.

[0109] Table 1 Identification of the growth-promoting ability of each strain

[0110]

[0111] Note: “—” indicates that the function does not exist.

[0112] Planting test

[0113] The test site is located in Awat County, Aksu Prefecture, Xinjiang Uygur Autonomous Region, on the northern edge of the Taklimakan Desert, with a typical warm temperate extreme arid continental desert climate. The area has ample sunshine, large diurnal temperature differences, low rainfall, and high evaporation.

[0114] The tested cotton variety is Tahe No. 2. The test uses a randomized block design, with a total of 11 treatment groups, including a blank control (CK0), the use of microbial inoculants prepared by the present application Examples 1-3 and Comparative Examples 1-7, each treatment group is repeated 3 times, and each plot area is 200m 2 . Cotton was planted on April 21, 2024, and harvested on October 12, 2024. Cotton was planted with 2m wide film 1 film 6 rows 3 strips, with a row spacing of 38cm and a plant spacing of 10cm. The microbial inoculants of each treatment group were applied to the roots of the plants at the three-leaf-one-heart stage, with an application rate of 3kg / acre. The microbial inoculants were applied at the first young boll stage of the cotton plants (about 20 days after budding), with an application rate of 1kg / acre. Other cultivation and management measures were the same as the local conventional cotton field.

[0115] Index determination

[0116] Agronomic trait determination: Two weeks before harvest, 10 cotton plants with consistent growth were selected in the middle row of each plot, and their plant height, fruit branch number per plant, stem diameter, and boll number per plant were determined.

[0117] Yield trait determination: 100 cotton bolls were continuously taken from the bottom to the top of the cotton plants with consistent growth in each plot, and the single boll weight, ginned cotton weight, and lint percentage were determined. The actual yield was calculated for each plot to obtain the cottonseed yield, and the lint yield was calculated based on the seed cotton yield and lint percentage;

[0118] Fiber quality determination: 20g of mixed ginned cotton samples were selected from each plot, and the quality was determined, including the average length of the upper half of the fiber, the breaking specific strength, the micronaire value, the uniformity index, and the elongation rate.

[0119] The above test data are shown in Tables 2, 3 and 4.

[0120] Table 2 Effect of different treatments on cotton agronomic traits

[0121]

[0122] Table 3 Effect of different treatments on cotton yield

[0123]

[0124] From the data of Table 2 and Table 3, compared with the blank control, the microbial inoculant of the embodiments 1-3 of the present application can effectively increase the number of bolls per plant and the weight of single boll, and further increase the yield. The cottonseed yields of the comparative examples 1-7 which change the composition of the microbial inoculant all have different degrees of decline, because the three strains cannot play the synergistic effect of the complex, and thus the various performance traits have different degrees of decline, and further lead to the yield decline.

[0125] Table 4 Effects of different treatments on the fiber quality of cotton

[0126]

[0127] From the data of Table 4, compared with the blank control, the fiber quality of the ginned cotton treated by the microbial inoculant of the present application has different degrees of improvement in various aspects, especially the breaking tenacity and elongation have significant improvement, wherein the breaking tenacity of the embodiment 1 increases by 18.6% compared with CK, and the elongation increases by 12.4% compared with CK.

[0128] It should be noted that the above embodiments are only part of the preferred modes of implementing the present application, rather than all the embodiments. Obviously, based on the above embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.

Claims

1. A microbial inoculant for improving yield and quality of cotton, characterized in that, The raw materials include the following components by weight: 50-60 parts of a complex microbial bacteria solution, 8-10 parts of brown algal oligosaccharide, 6-8 parts of humic acid chelated boron zinc, 4-5 parts of polyglutamic acid, 12-15 parts of modified attapulgite, and 2-3 parts of glycerol; The complex microbial bacteria solution comprises Candida valensis, Arthrobacter mysorens, and Pseudomonas psychrophilus. The preservation number of the Candida valensis in the complex microbial bacteria solution is CGMCC No. 2.5520; the preservation number of the Arthrobacter mysorens is CGMCC No. 1.15895; and the preservation number of the Pseudomonas psychrophilus is CGMCC No. 1.15631. The preparation method of the microbial bacteria solution is as follows: (1) First, the freeze-dried powder of Wickerhamiella jordani is prepared into a bacterial suspension, 100 μL of the bacterial suspension is dropped onto the malt juice agar medium and cultured for 48 h, a single colony is picked and inoculated into the malt juice liquid medium, and cultured at 25°C, 160 rpm until OD 600 = 0.6 to obtain a seed liquid, which is inoculated into a small seed tank at an inoculation amount of 1%, and cultured at 25°C, 160 rpm until OD 600 = 3.0 to obtain a Wickerhamiella jordani fermentation liquid; (2) First, the freeze-dried powder of M. mesophilica and P. psychrotolerans was prepared into a bacterial suspension, respectively. 100 μL of the bacterial suspension was added dropwise into nutrient broth agar and cultured for 72 h, respectively. Single colonies were picked and inoculated into nutrient broth liquid medium, and cultured at 30°C, 180 rpm until OD 600 = 0.

6. Then, the seed liquid was inoculated into a small seed tank at an inoculation amount of 1%, and cultured at 30°C, 180 rpm until OD 600 = 3.0, to obtain the M. mesophilica fermentation liquid and the P. psychrotolerans fermentation liquid, respectively. (3) The fermentation liquid of the Candida valensis in step (1), the fermentation liquid of the Arthrobacter mysorens in step (2), and the fermentation liquid of the Pseudomonas psychrophilus are mixed in a volume ratio of 1:1:2 to obtain the complex microbial bacteria solution.

2. The microbial inoculant for improving cotton yield and quality according to claim 1, characterized in that, The preparation method of the humic acid chelated boron zinc is as follows: (1) 70 kg of humic acid and 15 kg of deionized water are added to a reaction kettle, and ammonia water is slowly added while stirring to adjust the pH of the slurry to 8.0-9.0 to obtain an ammonium humate solution; (2) 4.55 kg of zinc sulfate heptahydrate is dissolved in 5 kg of 50°C hot water to obtain a zinc sulfate solution, and the zinc sulfate solution is slowly added to the ammonium humate solution under continuous stirring, the reaction temperature is maintained at 50-60°C, and the stirring is continued for 30 min to obtain a mixed slurry A; (3) 9.52 kg of sodium octaborate tetrahydrate is dissolved in 10 kg of 60°C hot water to obtain a sodium borate solution, and the sodium borate solution is slowly added to the mixed slurry A under vigorous stirring, the temperature is maintained at 50-60°C, and the stirring is continued for 45 min to obtain a mixed slurry B; (4) The mixed slurry B is transferred to a vacuum drying oven and dried to a moisture content of less than 5%, and the dried block is crushed by a crusher and sieved through an 80-mesh sieve to obtain uniform humic acid chelated boron zinc.

3. The microbial inoculant for improving cotton yield and quality according to claim 1, characterized in that, The preparation method of the modified attapulgite is as follows: (1) 100 kg of attapulgite and 300 kg of deionized water are mixed in a reaction kettle to form a uniform slurry, and 10% hydrochloric acid is slowly added to adjust the pH of the slurry to 3.0-4.0, and the slurry is stirred at a constant temperature of 60-70°C for 2 h, and then the solid-liquid separation is performed and washed with deionized water until the filtrate is neutral to obtain a filter cake; (2) The filter cake is added to 300 kg of deionized water to form a uniform slurry, 5 kg of CTAB is added, and the temperature is heated to 75-80°C for stirring for 4 h. (3) The above reactants are repeatedly washed with deionized water until the filtrate is free of Br as detected by silver nitrate solution - The washed filter cake is sent to a drying room and dried at 105-110°C by blowing air until the moisture content is less than 8%, and then sieved through a 100-mesh screen to obtain the modified attapulgite.

4. A method of preparing the microbial inoculant for improving yield and quality of cotton according to any one of claims 1 to 3, characterized in that, The following steps are included: First, the complex microbial bacteria solution is mixed with glycerol and freeze-dried to obtain a bacteria powder, and then the bacteria powder, brown algal oligosaccharide, humic acid chelated boron zinc, polyglutamic acid, and modified attapulgite are mixed in a certain proportion, granulated, and sieved to obtain granules with a particle size of 1-2 mm to obtain the final product microbial agent.

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