Application of complex microbial inoculant in improving effectiveness of nitrogen in peanut rhizosphere soil

Abstract

The invention discloses an application of a complex microbial inoculant in improving the effectiveness of nitrogen in peanut rhizosphere soil, and belongs to the technical field of microorganisms. According to the invention, the composite microbial agent composed of active bacteria, namely arthrobacter plantarum ARZ1 and sphingomonas melonis SPZ1, is applied to the field of peanut planting for the first time, and the two bacteria in the composite microbial agent have an obvious promoting effect on increasing the content of total nitrogen, nitrate nitrogen and ammoniacal nitrogen in rhizosphere soil of peanuts through a synergistic effect, so that the content of the total nitrogen, nitrate nitrogen and ammoniacal nitrogen in the rhizosphere soil of the peanuts is increased, and the content of the total nitrogen, nitrate nitrogen and ammoniacal nitrogen in the rhizosphere soil of the peanuts is increased; particularly, the fruit number, the fruit weight and the kernel weight of a single peanut plant can be increased, and the peanut yield can be greatly increased in the peanut planting process.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to the application of a composite bacterial agent in improving the nitrogen effectiveness of peanut rhizosphere soil. Background Art

[0002] China is one of the countries with the largest cultivated land in the world. According to statistics, the average utilization rate of nitrogen fertilizer in farmland in my country is only 33% in the current season, and the nitrogen effectiveness is low. In recent years, the annual loss of urea, for example, has reached more than 20 million tons. At the same time, the low utilization rate of nitrogen fertilizer has also caused problems such as waste of resources, environmental pollution, and decline in crop yield and quality, which seriously restricts the sustainable development of agriculture.

[0003] Peanut is a major oil and cash crop in my country, and an important source of export earnings. The total output of peanut ranks first among oil crops, and its oil yield is higher than other oil crops, which plays a key role in ensuring my country's grain and oil security and improving the dietary structure. At the same time, peanut rhizobia play a vital role in the nitrogen fixation process. These rhizobia can form a symbiotic relationship with the roots of peanuts. Through this symbiotic relationship, they can convert atmospheric nitrogen into nitrogen compounds that can be directly absorbed and utilized by plants. However, excessive nitrogen fertilizer will inhibit the nitrogen fixation of rhizobia, resulting in a "nitrogen repression" effect. However, when the nitrogen supply during the growth of peanuts, that is, nitrogen effectiveness, is synchronized with the demand for nutrients during the growth of peanuts, the utilization rate of nitrogen can be significantly improved. This means that if reasonable measures can be taken to synchronize nutrient supply with peanut demand, sufficient nitrogen can be provided in time during the critical period of peanut growth to meet the needs of peanuts at different growth and development stages, it can not only improve nitrogen utilization efficiency, reduce nitrogen waste and environmental pollution, but also promote the healthy growth of peanuts and improve yield and quality.

[0004] Microorganisms are key factors in regulating soil nutrient turnover. If we can screen effective microbial preparations to promote the effectiveness of nitrogen in the rhizosphere soil of peanuts and improve the nitrogen utilization rate of peanuts, it will be of great significance to promoting high-yield and high-quality production of peanuts as well as sustainable development. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a composite bacterial agent for improving the nitrogen effectiveness of peanut rhizosphere soil and its application in peanut production.

[0006] In order to achieve the above technical purpose, the inventors conducted a large number of experiments to explore the effects of different strains on total nitrogen, ammonia nitrogen, nitrate nitrogen, fruit number per plant, fruit weight per plant and kernel weight per plant in the rhizosphere soil of peanuts, and finally obtained the following technical solutions: a plant Arthrobacter oryzae ARZ1, whose strain preservation number is CCTCC No: M20241883. A melon Sphingomonas melonis SPZ1, whose strain preservation number is CCTCC No: M20241884.

[0007] It should be noted that the plant Arthrobacter ARZ1 (Arthrobacter oryzae) used in the present invention is isolated from the rhizosphere soil of peanuts, can survive in the rhizosphere and soil of peanuts, grows well under pH 7.0-9.0 environmental conditions, and survives well under pH 8.0. The strain was identified as Arthrobacter ARZ1 (Arthrobacter oryzae) by microbiological characteristics such as morphological characteristics, culture characteristics, and physiological and biochemical characteristics. The strain has been deposited in the China Center for Type Culture Collection, with a preservation date of September 2, 2024, and a preservation number of CCTCC No: M20241883.

[0008] The cucurbit sphingomonas SPZ1 (Sphingomonas melonis) used in the present invention is also isolated from the rhizosphere soil of peanuts, can survive in the rhizosphere and soil of peanuts, grows well under pH 6.0-9.0 environmental conditions, and survives well under pH 7.0. The strain was identified as cucurbit sphingomonas melonis SPZ1 by microbiological characteristics such as morphological characteristics, culture characteristics, and physiological and biochemical characteristics. The strain was deposited in the China Center for Type Culture Collection on September 2, 2024, with the deposit number CCTCC No: M20241884.

[0009] When the above two strains are used alone or in combination, they have a significant positive promoting effect on the total nitrogen, ammonia nitrogen, nitrate nitrogen, fruit number per plant, fruit weight per plant and kernel weight per plant of the two peanut varieties Qinghua No. 6 and Qinghua No. 22. Therefore, the present invention provides the following new uses:

[0010] (1) Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 in increasing the total nitrogen content in the rhizosphere soil of peanut;

[0011] (2) Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 to increase the nitrate nitrogen content in the rhizosphere soil of peanut;

[0012] (3) Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 to increase the ammonia nitrogen content in the rhizosphere soil of peanut;

[0013] (4) Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 to increase the fruiting rate of peanuts;

[0014] (5) Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 in increasing peanut fruit weight;

[0015] (6) Application of ARZ1 strain or SPZ1 strain or composite strain of ARZ1 and SPZ1 in increasing peanut kernel weight.

[0016] In the above application, the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCCNo: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCCNo: M20241884.

[0017] Further preferably, when the composite strain is used, the ratio of the number of live bacteria of Sphingomonas melonis SPZ1 and Arthrobacter oryzae ARZ1 is 1:1.

[0018] It should be noted that the inventors unexpectedly discovered when screening strains for improving nitrogen utilization efficiency of peanuts that Sphingomonas melonis SPZ1, Arthrobacter oryzae ARZ1 and the composite bacterial solution of these two strains have a significant effect on improving the total nitrogen in the rhizosphere soil of peanuts, and can significantly increase the content of ammonia nitrogen and nitrate nitrogen in the rhizosphere soil of peanuts, and can also significantly increase the number of fruits, fruit weight and kernel weight of a single peanut plant. Based on this discovery, the inventors prepared these two strains into a composite bacterial agent by inoculating and fermenting them in a nitrogen-fixing culture solution.

[0019] The composite bacterial agent can be prepared by the following method: mixing the bacterial solution of Sphingomonas melonis SPZ1 and Arthrobacter oryzae ARZ1 cultured to the logarithmic growth phase, and adding a protective agent to the mixed bacterial solution to adjust the number of viable bacteria to 1.0×10 10cfu / mL, pH 6-9; the protective agent is composed of: 90-120g / L skim milk powder, 25-35mL / L glycerol, 90-120g / L maltodextrin, 120-180g / L lacquer sugar and 8-13g / L L-sodium glutamate.

[0020] The fermentation culture method of Sphingomonas melonis SPZ1 is as follows: Sphingomonas melonis SPZ1 is inoculated into beef extract peptone culture medium at an inoculum amount of 4%-10%, and is cultured at a constant temperature of 25-27°C for 24-72 hours. After centrifugal washing, a mixed solution containing 0.5g / L Yeast Extract, 20g / L Mannitol, 0.2g / L K2HPO4, 0.8g / L KH2PO4, 0.2g / L MgSO4·7H2O, 0.1g / L CaSO4·2H2O, 0.01g / L FeCl3, 0.002g / L Na2MoO4·2H2O, and 15g / L Agar is added to each bacterial precipitate, and the pH is 4. 6-9, and the viable count of Sphingomonas melonis SPZ1 was adjusted to 1.0×10 10 cfu / mL, mix well and pour into culture.

[0021] The fermentation culture method of Arthrobacter oryzae ARZ1 is as follows: oryzae ARZ1 was inoculated into beef extract peptone culture medium at an inoculum rate of 4%-10%, and cultured at a constant temperature of 25-27°C for 24-72 hours. After centrifugation and washing, a mixed solution containing 0.5 g / L Yeast Extract, 20 g / L Mannitol, 0.2 g / L K2HPO4, 0.8 g / L KH2PO4, 0.2 g / L MgSO4﹒7H2O, 0.1 g / L CaSO4﹒2H2O, 0.01 g / L FeCl3, 0.002 g / L Na2MoO4﹒2H2O, and 15 g / L Agar was added to each bacterial precipitate, and the pH was adjusted to 6-9, and the viable count of Arthrobacter oryzae ARZ1 was adjusted to 1.0×10 10 cfu / mL, mix well and pour into culture.

[0022] Still more preferably, the composite strain is prepared to have a total viable cell count of 1.0×10 10cfu / mL of compound fungal agent; the first application is in the beginning flowering stage of peanuts, the dosage is 2.5-3.5L / 667m 2 The second application is during the peanut pod-setting period, with a dosage of 2.5-3.5L / 667m 2 .

[0023] Still more preferably, if manual application is adopted, the bacterial solution is diluted with clean water and then sprayed on the roots of peanuts using an agricultural sprayer; if drone spraying is used, the bacterial solution is directly diluted with clean water and placed in a medicine barrel and sprayed before rain.

[0024] Still more preferably, when peanuts are planted in a film-covered planting method, drip irrigation with bacterial solution is adopted, and the irrigation depth is sufficient to moisten the soil 8-10 cm.

[0025] Still more preferably, no matter which method of applying the bacterial agent is selected, it should be noted that the applied bacterial solution and pesticide cannot be used together, and the interval between their use should be more than 2 days.

[0026] Compared with the prior art, the active bacteria in the composite bacterial agent of the present invention are composed of Arthrobacter oryzae ARZ1 and Sphingomonas melonis SPZ1. The two bacteria in the composite bacterial agent have a synergistic effect on increasing the total nitrogen, nitrate nitrogen and ammonia nitrogen contents in the rhizosphere soil of peanuts, and can especially increase the fruit number, fruit weight and kernel weight of a single peanut plant. The application of the composite bacterial agent in the peanut planting process can greatly increase the peanut yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 :Plant culture and scanning electron microscopy images of Arthrobacter oryzae ARZ1;

[0028] Figure 2 :Plate culture and scanning electron microscopy images of Sphingomonas melonis SPZ1;

[0029] Figure 3 :The effects of each group of microbial agents on total nitrogen in peanut soil;

[0030] Figure 4 :The effects of each group of microbial agents on nitrate nitrogen in peanut soil;

[0031] Figure 5 :The effects of each group of microbial agents on ammonium nitrogen in peanut soil;

[0032] Figure 6 :The effect of each group of fungicide application on the number of fruits per peanut plant;

[0033] Figure 7 :The effect of each group of fungicide application on the fruit weight of peanut per plant;

[0034] Figure 8 :The effect of each group of fungicide application on the kernel weight of peanut per plant;

[0035] in, Figure 3-Figure 8 Different letters in the text represent significant differences among different treatments in the same group (p<0.05). DETAILED DESCRIPTION

[0036] The above contents of the present invention are further described in detail below by way of examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies realized based on the above contents of the present invention belong to the scope of the present invention. In addition, the experimental methods in the following examples are conventional methods unless otherwise specified.

[0037] Example 1: Screening and Isolation of ARZ1 and SPZ1 Strains

[0038] (1) The process of discovery, screening, isolation and identification of strains. Based on the test of adding specific root secretions of corn and peanut intercropping, the inventors found that the addition of root secretions can increase the nitrogen content of peanut rhizosphere soil and stimulate the nitrogen absorption of peanut plants. Therefore, we speculate that the addition of root secretions reassembles the soil microbial community, thereby promoting the absorption and utilization of soil nitrogen by peanuts. On this basis, we prepared the peanut rhizosphere soil samples treated with the above-mentioned root secretions into a suspension, applied the bacterial solution to the bacterial culture medium, and isolated and purified the strains. The 16S rRNA sequence of the isolated strain was obtained using high-throughput sequencing technology, and the 16S rRNA sequence was compared with the nr database of NCBI. The sequence cluster analysis was performed by comparing the degree and similarity, and a phylogenetic tree was constructed. The isolated and purified strains were compared with known strains, and a comprehensive analysis was performed in terms of morphology, physiology and biochemistry to determine the bacterial species. In order to further verify the function of the strains, the strains obtained by separation and purification were used to carry out peanut cultivation addition experiments.

[0039] (2) Mycological properties of microorganisms. The colonies of Arthrobacter oryzae ARZ1 are white, round, and moist. Figure 1 ), can grow on nitrogen-fixing medium, with a suitable pH of 6-9 and a temperature of 25-27°C. The colonies of Sphingomonas melonis SPZ1 are yellow, round, small, moist and smooth, opaque, with neat edges and no halos ( Figure 2 ), can grow on nitrogen-fixing medium, suitable growth pH is 6-9, temperature is 25-27℃.

[0040] Example 2: Preparation of ARZ1, SPZ1 and composite bacterial agents

[0041] (1) Arthrobacter oryzae ARZ1 was inoculated at an inoculum size of 4% to 10% into beef extract peptone culture medium (beef extract 3 g / L, peptone 10 g / L, NaCl 5 g / L, agar 15 g / L), pH 7.4-7.6, and cultured at 25-27° C. for 24-72 hours. After centrifugation and washing, 0.5 g / L Yeast Extract, 20 g / L Mannitol, 0.2 g / L K2HPO4, 0.8 g / L KH2PO4, 0.2 g / L MgSO4·7H2O, 0.1 g / L CaSO4·2H2O, 0.01 g / L FeCl3, 0.002 g / L The nitrogen-fixing medium was a 15 g / L agar medium containing Na2MoO4·2H2O, pH 6-9, and the viable count of Arthrobacter oryzae ARZ1 was adjusted to about 1.0 × 10 10 cfu / mL, mix well and then pour culture; the specific operation method of pour culture is: dilute the plant Arthrobacter oryzae (Arthrobacter oryzae) ARZ1 suspension and add it to the sterile nitrogen-fixing medium, invert and culture after solidification, a single strain proliferates to form colonies, take a single colony to make a suspension, repeat several times to obtain a pure culture.

[0042] (2) Sphingomonas melonis SPZ1 was inoculated at an inoculum amount of 4% to 10% in a beef extract peptone culture medium (beef extract 3 g / L, peptone 10 g / L, NaCl 5 g / L, agar 15 g / L), and cultured at a constant temperature of 25-27° C. for 24-72 hours. After centrifugation and washing, a mixed solution containing 0.5 g / L Yeast Extract, 20 g / L Mannitol, 0.2 g / L K2HPO4, 0.8 g / L KH2PO4, 0.2 g / L MgSO4·7H2O, 0.1 g / L CaSO4·2H2O, 0.01 g / L FeCl3, 0.002 g / L Na2MoO4·2H2O, and 15 g / L Agar was added to each bacterial precipitate, and the pH was adjusted to 8. 6-9, and the viable count of Sphingomonas melonis SPZ1 was adjusted to about 1.0×10 10cfu / mL, mix well and then pour culture; the specific operation method of pour culture is: dilute the Sphingomonas melonis SPZ1 suspension and add it to the sterile nitrogen-fixing medium, invert and culture after solidification, a single strain proliferates to form colonies, take a single colony to make a suspension, repeat several times to obtain a pure culture.

[0043] (3) Prepare a protective agent, the composition of which is: 100 g / L skim milk powder, 30 mL / L glycerol, 100 g / L maltodextrin, 150 g / L lacquer sugar and 10 g / L sodium L-glutamate, pH 6-9.

[0044] (4) Add the protective agent prepared in step (3) to the Arthrobacter ARZ1 bacterial solution obtained in step (1) to adjust the viable bacterial count to about 1.0×10 10 cfu / mL to obtain ARZ1 bacterial agent. The protective agent prepared in step (3) was added to the Sphingomonas cucurbitae SPZ1 bacterial solution obtained in step (2) to adjust the viable bacterial count to about 1.0×10 10 cfu / mL, and obtained SPZ1 bacterial agent.

[0045] The bacterial liquid obtained in steps (1) and (2) was mixed at a ratio of 1:1 of the number of live bacteria of Sphingomonas cucurbitae SPZ1 and Arthrobacter plantum ARZ1, and the protective agent prepared in step (3) was added to the mixed bacterial liquid to adjust the total number of effective live bacteria to about 1.0×10 10 cfu / mL to obtain a composite bacterial agent.

[0046] Example 3: Experiment of ARZ1 inoculant in potted peanut cultivation

[0047] Test type: Pot test

[0048] Experimental location: Qingdao Agricultural University (Qingdao, China)

[0049] Test time: 2023.05-2023.09

[0050] Test crops: Peanuts (varieties: Qinghua No. 6 and Qinghua No. 22)

[0051] Test soil: sterilized soil (soil pH 6.70, organic matter 11.92 g / kg, alkaline nitrogen 99.86 mg / kg, available phosphorus 35.22 mg / kg, available potassium 89.79 mg / kg).

[0052] Experimental groups: CK was the blank control, ARZ1-F and ARZ1-T were treated with Arthrobacter plantarum ARZ1, with 3 replicates per treatment, arranged in random blocks.

[0053] Experimental design: PVC pots were used for potting, with an inner diameter of 16 cm and a height of 23.5 cm. The inoculant was added 25 days after peanut sowing (mix the inoculant with 200 mL of water and pour it on the roots of peanuts), and samples were taken at the harvest time after the inoculant was added.

[0054] Dosage and method: ARZ1-F was treated with 0.05 mL / pot of the ARZ1 inoculant prepared in Example 2, and ARZ1-T was treated with 0.1 mL / pot of the ARZ1 inoculant prepared in Example 2. The bacterial solutions were diluted to 200 mL respectively and poured to the roots of peanuts. CK was 200 mL of blank aqueous solution.

[0055] Table 1 Total nitrogen content in soil under treatment with Arthrobacterium arz1

[0056]

[0057] Note: Different letters indicate significant differences among different treatments in the same group (p<0.05).

[0058] From the experimental results in Table 1, it can be seen that the ARZ1-T treatment has a significant effect on improving the total nitrogen content in the soil of the two peanut varieties. The total nitrogen content of the soil of Qinghua No. 6 was significantly increased by 352.08% and 124.54% under the ARZ1-T treatment compared with CK and ARZ1-F, respectively. The total nitrogen content of the soil of Qinghua No. 22 was significantly increased by 116.35% and 125.00% under the ARZ1-T treatment compared with CK and ARZ1-F, respectively. In summary, the ARZ1-T treatment of Arthrobacter oryzae can significantly increase the total nitrogen content in the rhizosphere of peanut.

[0059] Example 4: Experiment of SPZ1 fungicide in potted peanut planting

[0060] Test type: Pot test

[0061] Experimental location: Qingdao Agricultural University (Qingdao, China)

[0062] Test time: 2023.05-2023.09

[0063] Test crops: Peanuts (variety: Qinghua No. 6, Qinghua No. 22)

[0064] Test soil: sterilized soil (soil pH 6.70, organic matter 11.92 g / kg, alkaline nitrogen 99.86 mg / kg, available phosphorus 35.22 mg / kg, available potassium 89.79 mg / kg).

[0065] Experimental groups: CK was the blank control, SPZ1-F and SPZ1-T were treated with Sphingomonas cucurbitae SPZ1, each treatment was repeated 3 times and arranged in random blocks.

[0066] Experimental design: PVC pots were used for potting, with an inner diameter of 16 cm and a height of 23.5 cm. The inoculant was added 25 days after peanut sowing (mix the inoculant with 200 ml of water and pour it on the roots of peanuts), and samples were taken at the harvest time after the inoculant was added.

[0067] Dosage and method: SPZ1-F was treated with 0.05 mL / pot of the SPZ1 inoculant prepared in Example 2, and SPZ1-T was treated with 0.1 mL / pot of the SPZ1 inoculant prepared in Example 2. The bacterial solutions were diluted to 200 mL respectively and poured to the roots of peanuts. CK was 200 mL of blank aqueous solution.

[0068] Table 2 Total nitrogen content in soil under treatment with Sphingomonas cucurbitae SPZ1

[0069] Note: Different letters indicate significant differences among different treatments in the same group (p<0.05).

[0070] From the test results in Table 2, it can be seen that the SPZ1-T treatment has a significant effect on improving the total nitrogen content in the soil of the two varieties. The total nitrogen content of the soil of Qinghua No. 6 was significantly increased by 69.00% and 53.64% under the SPZ1-T treatment compared with CK and SPZ1-F, respectively. The total nitrogen content of the soil of Qinghua No. 22 was significantly increased by 27.88% and 12.71% under the SPZ1-T treatment compared with CK and SPZ1-F, respectively. In summary, the SPZ1-T treatment of Sphingomonas melonis SPZ1 can significantly increase the total nitrogen content in the soil for peanut plants.

[0071] Example 5: Experiment of composite bacterial agent in field peanut planting

[0072] Test location: Pingdu City, Qingdao City, Shandong Province

[0073] Test time: 2024.05-2024.09

[0074] Test crops: Peanuts (variety: Qinghua No. 6, Qinghua No. 22)

[0075] Experimental soil: The soil is mortar black soil (soil pH is 7.06, organic matter is 16.18g / kg, alkaline nitrogen is 77.76mg / kg, available phosphorus is 45.58mg / kg, and available potassium is 78.69mg / kg).

[0076] Test groups:

[0077] CK is a blank aqueous solution control,

[0078] The ARZ1-F group was administered with the ARZ bacterial agent prepared in Example 2 (the total number of viable bacteria was about 1.0×10 10 cfu / mL), the application amount was 1.5L / 667m 2 ;

[0079] The ARZ1-T group was administered with the ARZ bacterial agent prepared in Example 2 (the total number of viable bacteria was about 1.0×10 10 cfu / mL), the application rate is 3L / 667m 2 ;

[0080] The SPZ1-F group was administered with the SPZ1 bacterial agent prepared in Example 2 (the total number of viable bacteria was about 1.0×10 10 cfu / mL), the application amount was 1.5L / 667m 2 ;

[0081] The SPZ1-T group was administered with the SPZ1 bacterial agent prepared in Example 2 (the total number of viable bacteria was about 1.0×10 10 cfu / mL), the application rate is 3L / 667m 2 ;

[0082] The ST+AT group was treated with the composite bacterial agent prepared in Example 2, i.e., Sphingomonas cucurbitae SPZ1 and Arthrobacter plantarum ARZ1 were mixed in a ratio of 1:1 (the total number of viable bacteria was about 1.0×10 10 cfu / mL), the application rate is 3L / 667m 2 ;

[0083] Dosage and method: The first application is at the beginning of flowering of peanuts. Dilute the amount of microbial agent per mu in the above test group mentioned in the above treatment to 15L with clean water, and then use an agricultural sprayer to spray it on the roots of peanuts manually; the second application is at the pod-setting stage of peanuts, and the dosage and application method are the same as the first application. It should be noted that the microbial solution should not be used together with pesticides, and the two should be used at least 2 days apart.

[0084] Planting management: Peanuts are planted in a ridge-covered manner, with a ridge spacing of 90 cm, 2 rows per ridge, a small row spacing of 35 cm on the ridge, and a hole spacing of 11 cm (2 seeds per hole). 50 kg of compound fertilizer (N-P2O5-K2O: 15-15-15) is applied per mu, and no additional fertilizer is required in the later stage.

[0085] Test results:

[0086] 1) Impact on total nitrogen in peanut soil

[0087] pass Figure 3The results of the experiment were compared and found that compared with CK and four single strain groups, the composite strain ST+AT treatment can significantly increase the total nitrogen content of the soil of the two peanut varieties. Among them, compared with the control group CK, the total nitrogen content of the soil of Qinghua No. 6 increased significantly by 442.29%, and the total nitrogen content of the soil of Qinghua No. 22 increased significantly by 179%. Statistical analysis found that the total nitrogen content of the soil under the composite strain ST+AT treatment was significantly or extremely significantly higher than that of the single strain addition treatment.

[0088] 2) Impact on nitrate nitrogen in peanut soil

[0089] pass Figure 4 The results of the experiment were compared and found that compared with CK and four single strain groups, the composite strain ST+AT treatment can significantly increase the soil nitrate nitrogen content of the two peanut varieties. Among them, compared with the control group CK, the composite strain ST+AT treatment significantly increased the soil nitrate nitrogen of Qinghua No. 6 by 49.36% and the soil nitrate nitrogen of Qinghua No. 22 by 87.37%. Statistical analysis found that the soil nitrate nitrogen content under the composite strain ST+AT treatment was significantly or extremely significantly higher than that of the single bacteria addition treatment.

[0090] 3) Effects on ammonium nitrogen in peanut soil

[0091] pass Figure 5 The results of the experiment were compared and found that compared with CK and four single strain groups, the compound strain ST+AT treatment can significantly increase the soil ammonium nitrogen content of the two peanut varieties. Among them, compared with the control group CK, the compound strain ST+AT treatment significantly increased the soil ammonium nitrogen of Qinghua No. 6 by 42.28%, and the soil ammonium nitrogen of Qinghua No. 22 by 21.13%. Statistical analysis found that the soil ammonium nitrogen content under the compound strain ST+AT treatment was significantly or extremely significantly higher than that under the single strain addition treatment.

[0092] 4) Impact on the number of fruits per peanut plant

[0093] pass Figure 6 The results of the experiment were compared and found that compared with CK and four single strain groups, the composite strain ST+AT treatment can significantly increase the number of fruits per plant of the two peanut varieties. Among them, compared with the control group CK, the composite strain ST+AT treatment significantly increased the number of fruits per plant of Qinghua No. 6 peanut by 39.48%, and the number of fruits per plant of Qinghua No. 22 peanut by 49.91%. Statistical analysis found that the number of fruits per plant of peanuts under the composite strain ST+AT treatment was significantly or extremely significantly higher than that under the single strain addition treatment.

[0094] 5) Effect on the weight of peanut fruit per plant

[0095] pass Figure 7The results of the experiment were compared and found that compared with CK and four single strain groups, the composite strain ST+AT treatment can significantly increase the fruit weight of two peanut varieties per plant. Among them, compared with the control group CK, the composite strain ST+AT treatment significantly increased the fruit weight of Qinghua No. 6 peanut per plant by 69.41%, and the fruit weight of Qinghua No. 22 peanut per plant by 97.53%. Statistical analysis found that the fruit weight of peanut per plant under the composite strain ST+AT treatment was significantly or extremely significantly higher than that under the single strain addition treatment.

[0096] 6) Impact on the kernel weight of peanut plants

[0097] pass Figure 8 The results of the experiment were compared and found that compared with CK and four single strain groups, the composite strain ST+AT treatment can significantly increase the kernel weight of two peanut varieties. Among them, compared with the control group CK, the composite strain ST+AT treatment significantly increased the kernel weight of Qinghua No. 6 peanut by 98.75%, and the kernel weight of Qinghua No. 22 peanut by 103.03%. Statistical analysis found that the kernel weight of peanuts under the composite strain ST+AT treatment was significantly or extremely significantly higher than that of single strain addition treatment.

[0098] In summary, statistical comparison showed that compared with single strains and blank control, the total nitrogen, nitrate nitrogen and ammonia nitrogen contents in the soil, as well as the number of fruits, fruit weight and kernel weight of a single peanut plant, were significantly improved under the treatment of the composite agent ST+AT. This indicates that the composite agent (the total number of effective live bacteria is about 1.0×10 10 cfu / mL), can significantly increase the total nitrogen, nitrate nitrogen and ammonia nitrogen contents in the rhizosphere soil of peanuts, and can significantly increase the fruit number, fruit weight and kernel weight of peanuts. Application in the process of peanut planting can improve the nitrogen effectiveness and yield of peanut rhizosphere.

Claims

1. Application of ARZ1 strain or SPZ1 strain or composite strain of ARZ1 and SPZ1 in improving total nitrogen content in rhizosphere soil of peanut, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No: M20241884.

2. Application of ARZ1 strain or SPZ1 strain or composite strain of ARZ1 and SPZ1 in improving the nitrate nitrogen content in peanut rhizosphere soil, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No: M20241884.

3. Application of ARZ1 strain or SPZ1 strain or composite strain of ARZ1 and SPZ1 in improving the ammonia nitrogen content in rhizosphere soil of peanut, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No: M20241884.

4. Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 in increasing the fruiting number of peanut plants, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No. No:M20241884.

5. Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 in increasing the weight of peanut fruit per plant, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No: M20241883 No:M20241884.

6. Application of ARZ1 strain or SPZ1 strain or a composite strain of ARZ1 and SPZ1 in increasing the kernel weight of a single peanut plant, wherein the ARZ1 strain is Arthrobacter oryzae ARZ1 CCTCC No: M20241883, and the SPZ1 strain is Sphingomonas melonis SPZ1 CCTCC No. No:M20241884.

7. The use according to any one of claims 1 to 6, characterized in that: When the composite strain is used, the ratio of the number of live bacteria of Sphingomonas melonis SPZ1 and Arthrobacter oryzae ARZ1 is 1:

1.

8. The use according to claim 7, characterized in that: The composite strain is prepared to have a total viable count of 1.0×10 10 cfu / mL of bacterial solution; the first application is in the beginning flowering stage of peanuts, the dosage is 2.5-3.5L / 667m 2 The second application is during the peanut pod-setting period, with a dosage of 2.5-3.5L / 667m 2 .

9. The use according to claim 7, characterized in that: If manual application is adopted, the solution will be diluted with clean water and sprayed on the roots of peanuts with an agricultural sprayer; if drone spraying is used, the bacterial solution will be directly diluted with clean water and placed in a medicine barrel and sprayed before rain.

10. The use according to claim 7, characterized in that: When peanuts are planted in a film-covered planting method, the bacterial solution is dripped under the film, and the irrigation depth is 8-10cm to moisten the soil.

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