A composite bacterial agent for straw composting

Abstract

A composite bacterial agent for straw composting, the present invention relates to a composite bacterial agent. In order to increase the speed of natural straw composting, the present invention provides a composite bacterial agent for straw composting. The composite bacterial agent for straw composting of the present invention is composed of Bacillus subtilis HW1404 and Aspergillus niger HW1409. The present invention is composed of Bacillus subtilis and Aspergillus niger separated from corn straw compost samples, wherein Bacillus subtilis mainly produces pectinase and polygalacturonate lyase, and Aspergillus niger mainly produces cellulase. The straw composting agent prepared on this basis has significantly improved ability to decompose and soften straw, and achieves good results when used in the field.

Description

Technical Field

[0001] The invention relates to a composite bacterial agent. Background Art

[0002] In recent years, the resource utilization of straw has been one of the focuses of agricultural scientific research, and a large number of scientific research results have been achieved. Among them, returning straw to the field has been widely used as an effective soil improvement method and is the most important technical method in the "Soil Organic Matter Improvement Project" being implemented in my country. However, since straw naturally decomposes slowly, incompletely decomposed straw will affect the growth of the next crop. Therefore, increasing the decomposition rate of returned straw is a key technical issue for returning straw to the field. In nature, microorganisms play a decisive role in the decomposition process of crop straw. They grow on straw and decompose plant components such as cellulose, hemicellulose, pectin, and lignin through enzymatic hydrolysis to complete the humification of straw. Based on this principle, the addition of some exogenous functional microorganisms will enhance the decomposition effect and thus achieve the purpose of increasing the decomposition rate. This is feasible in theory and has been proven in practice. Summary of the invention

[0003] The invention provides a composite bacterial agent for straw composting in order to increase the natural straw composting speed.

[0004] The composite bacterial agent for straw composting of the present invention consists of Bacillus subtilis HW1404 and Aspergillus niger HW1409; wherein, Bacillus subtilis HW1404 is deposited in the General Microbiological Center of China National Microbiological Culture Collection (CGMCC), with a deposit number of CGMCC No. 25836, and a deposit date of September 28, 2022; Aspergillus niger HW1409 is deposited in the General Microbiological Center of China National Microbiological Culture Collection (CGMCC), with a deposit number of CGMCC No. 40329, and a deposit date of September 28, 2022.

[0005] Furthermore, the composite microbial agent is prepared by mixing equal volumes of the fermentation broth of Bacillus subtilis HW1404 and the fermentation broth of Aspergillus niger HW1409; wherein the effective viable count of Bacillus subtilis HW1404 in the fermentation broth of Bacillus subtilis HW1404 is ≥5.0×10 9CFU / ml; the effective viable count of Aspergillus niger HW1409 in the fermentation broth of Aspergillus niger HW1409 is ≥5.0×10 6 CFU / ml.

[0006] The deposit address of the above-mentioned strains is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0007] When observed under a microscope, Bacillus subtilis HW1404 was Gram-stain positive, in the shape of long rods, most of which were solitary, with a very small number of two rods connected in a straight line, near the mesospores, oval, and not swollen; when observed under a water slide microscope, the bacteria were motile, indicating the presence of flagella.

[0008] The colony of Aspergillus niger HW1409 is white at first and then turns brown; the apical capsule is large and spherical, the stalks are double-layered, the conidia are spherical, the hyphae are well-developed and branched, colorless, and have septa.

[0009] Bacillus subtilis HW1404 does not produce cellulase, but produces weak protease and amylase. In the detection of various pectinases, it was found that its polygalacturonate lyase (PGL) was the most abundant, and it also produced a small amount of pectinesterase (PE), while polygalacturonase (endo-PG) and polygalacturonase (exo-PG) were not detected.

[0010] Aspergillus niger HW1409 produces cellulase with excellent cellulose degradation ability. Taking the ability of producing cellulase in liquid shake flask as the standard, its CMC-Na enzyme activity and filter paper enzyme activity in Czapek medium containing corn stalk powder reached 672.8U and 77.6U respectively. Using sterilized corn stalks of about 2.0cm as raw materials, inoculated with Aspergillus niger HW1409 spore suspension, buried in soil and statically cultured at 25℃ for 14 days, the weight loss rate of corn stalks reached 31.4%.

[0011] In the composite bacterial agent for straw composting of the present invention, Aspergillus niger HW1409 and Bacillus subtilis HW1404 have synergistic effects without antagonism, and have significant ability to decompose and soften straw, and have achieved good results when used in the field. The composite bacterial agent for straw composting of the present invention not only accelerates the speed of straw composting, but also has the characteristics of a long shelf life. In particular, the effective live bacteria count of Bacillus subtilis HW1404 in the composite bacterial agent is still higher than 3.4×10 after being stored for 98 days under the natural temperature (4-6°C) of the production season. 8 CFU / ml, the effective viable count of Aspergillus niger HW1409 was still higher than 3.1×10 4 CFU / ml, and CMC enzyme activity is still higher than 8.6U / ml. Moreover, the composite bacterial agent used for straw composting of the present invention can also improve the growth of crops and play an effect of increasing yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The morphology of Bacillus subtilis HW1404 strain on pectin-nutrient agar plate (72 hr);

[0013] Figure 2 The growth morphology of Bacillus subtilis HW1404 strain on nutrient agar plate (48 hr);

[0014] Figure 3 The bacterial morphology of Bacillus subtilis HW1404 strain after 48 hours of growth on nutrient agar (1200×);

[0015] Figure 4 This is the microscopic morphology of Aspergillus niger HW1409 spores;

[0016] Figure 5 This is the colony morphology of Aspergillus niger HW1409 growing on PDF medium. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0019] Specific implementation method 1: The composite bacterial agent used for straw composting in this implementation method is composed of Bacillus subtilis HW1404 and Aspergillus niger HW1409; wherein, Bacillus subtilis HW1404 is deposited in the General Microbiological Center of China Culture Collection Administration (CGMCC), with a deposit number of CGMCC No.25836, and a deposit date of September 28, 2022; Aspergillus niger HW1409 is deposited in the General Microbiological Center of China Culture Collection Administration (CGMCC), with a deposit number of CGMCC No.40329, and a deposit date of September 28, 2022.

[0020] 1. Method for obtaining Bacillus subtilis of this embodiment:

[0021] 1. Strain selection

[0022] In November 2011, corn stalk samples were collected from corn-growing areas in the suburbs of Harbin, Heilongjiang Province. The rotten samples were directly isolated for strains, and the non-rotten samples were naturally decomposed in the laboratory and then isolated. A total of 22 main bacterial strains that produced large transparent circles on nutrient agar plates containing pectin were obtained. Among these isolated strains, three strains with larger transparent circles were selected for re-screening tests. The re-screening used shake flask test-weight loss method and soil burial-weight loss method as technical means to study their ability to decompose corn stalks (Table 1, Table 2). The results showed that strain HW1404 had the best effect in both tests.

[0023] Table 1 Effect of selected strains on straw weight reduction (shake flask test)

[0024]

[0025]

[0026] Note: About 0.2 g of dry corn stalk powder was accurately added to the beef extract peptone liquid culture medium. After inoculation, the culture was placed on a shaker. The residual corn stalk powder was filtered and recovered through an 80-mesh steel mesh. After drying, it was weighed and the weight loss rate was calculated.

[0027] Table 2 Effect of selected strains on weight reduction of straw (soil burial weight reduction method)

[0028]

[0029] Note: 1.5 kg of soil was placed in a culture pot, and 5.0 g of corn stalks (about 4 cm long were placed in a nylon bag) were soaked in the bacterial suspension for 10 minutes, taken out and buried in the soil, and sterile water treatment was used as the control. Each treatment was repeated 3 times. The culture was carried out in a 28°C plant incubator.

[0030] 2. Strain identification

[0031] When the target strain HW1404 grows on pectin-peptone agar plates, as the pectin concentration increases, the amount of pigment produced by the strain also increases, the color around the colonies deepens, and the colony diameter also increases (e.g. Figure 1 The results show that strain HW1404 can effectively use pectin as a carbon source and has the ability to decompose pectin. When cultured in a shaker in a medium composed of corn flour and soybean meal, it began to produce pigment after 48 hours, and the color of the medium gradually deepened from light blue to brown after 72 hours. Strain HW1404 grew well on ordinary nutrient agar medium but did not produce pigment (as shown in Figure 2). Figure 2 As shown), the colonies are dirty white, with irregular edges, wrinkled and dry surfaces. The middle of the colony is concave and the surrounding areas are convex. It grows well when cultured on a slope and is canyon-shaped.

[0032] The strain HW1404 grown on nutrient agar for 48 hours was Gram-positive, long rod-shaped, mostly solitary, with a very small number of two rods connected in a straight line, near the middle of the spores, oval, not swollen (such as Figure 3 ); when observed under a microscope of a water film, the bacteria were motile, indicating the presence of flagella. The culture characteristics of strain HW1404 showed that it belonged to Bacillus. According to the classification standards of Bacillus in the eighth edition of Bergey's Manual of Bacterial Identification and the methods in the Microbiology Laboratory Manual edited by Zhou Deqing, the target strain was tested for its physiological characteristics, and the results are listed in Table 3. According to the results of the test, it was preliminarily determined that the target strain HW1404 was Bacillus subtilis and was named Bacillus subtilis HW1404.

[0033] Table 3 Some physiological characteristics of strain HW1404

[0034]

[0035]

[0036] 2. Enzyme production characteristics of Bacillus subtilis HW1404

[0037] To be close to the actual production conditions, the enzyme production medium is composed of beef extract peptone liquid medium + 0.2% pectin. Bacillus subtilis HW1404 was inoculated in the medium, kept at 30-32°C, and the activities of various enzymes were measured after shaking culture for 72 hours. The results are listed in Table 4. Under this condition, Bacillus subtilis HW1404 did not produce cellulase, but produced weak protease and amylase. Among the various pectinases detected, polygalacturonic acid lyase (PGL) was the most abundant, and a small amount of pectin esterase (PE) was also produced, while polygalacturonase (endo-PG) and polygalacturonase (exo-PG) were not detected. The experimental results show that polygalacturonic acid lyase (PGL) and pectin esterase (PE) play a major role in the process of straw composting (especially the former), and also reveal that there is a large amount of unsaturated galacturonic acid in corn straw.

[0038] Table 4 Enzyme production characteristics of Bacillus subtilis HW1404 strain

[0039]

[0040] Note: ND was not detected

[0041] In order to better understand polygalacturonate lyase (PGL) and to facilitate its greater role in practical applications, the effect of pH on enzyme activity was studied (as shown in Table 5). It can be seen from the test results in Table 5 that the enzyme exhibits the greatest activity under neutral to alkaline conditions. The HW1404 culture solution was kept warm at 45°C to prevent the growth of microorganisms in the culture solution. The culture solution was used as an enzyme solution to treat strip filter paper, 2.0% pectin and 0.5% gum arabic respectively. After 48 hours, the filter paper did not change. 1.82% reducing sugar was detected in the culture solution treated with pectin, and no reducing sugar was detected in the culture solution treated with gum arabic. The results show that Bacillus subtilis HW1404 mainly plays a role in decomposing pectin during the straw composting process.

[0042] Table 5 Effect of pH on polygalacturonic acid lyase (PGL) produced by Bacillus subtilis HW1404 strain

[0043]

[0044] 3. Method for obtaining Aspergillus niger HW1409 of this embodiment

[0045] 1. Breeding and identification of highly active cellulose decomposing strains

[0046] Corn stalks collected in the suburbs of Harbin, Heilongjiang Province in November 2011 were used as samples. Congo red CMC-Na medium plates were used for separation. The diameter and stability of the transparent circle were used as the judgment criteria to screen the cellulase-producing bacteria. Eight strains that produced transparent circles were screened. These eight molds with different morphologies were further tested on Congo red CMC-Na medium plates and straw powder medium plates. Among them, two strains numbered 1409 and 1411 produced large and stable transparent circles with diameters of 1.8 cm to 2.2 cm and 2.6 cm to 4.3 cm, respectively. Further rescreening was based on the ability to produce cellulase in liquid shake flasks as the standard. In Czapek medium containing straw powder, the CMC-Na enzyme activity and filter paper enzyme activity of strain 1409 reached 672.8U and 77.6U, respectively, and the CMC-Na enzyme activity and filter paper enzyme activity of strain 1411 reached 457.9U and 57.6U, respectively. Using sterilized corn stalks of about 2.0 cm as raw materials, spore suspensions of strains 1409 and 1411 were inoculated respectively, and buried in soil at 25°C for 14 days. The weight loss rates of the corn stalks reached 31.4% and 28.3%, respectively, further demonstrating the excellent effect of strain 1409 in the straw decomposition process.

[0047] 2. Strain 1409 grew on PDA agar medium. The colonies were white at first and then turned brown. The apical capsule was large and spherical, the pedicels were double-layered, the conidia were spherical, the hyphae were well-developed and multi-branched, colorless, and had septa. Results: Figure 4 Microscopic morphology of Aspergillus niger spores. Figure 5 The colony morphology is that of the strain growing in PDA medium. ITS sequence analysis showed that the sequence had 99.5% homology with the 18S rDNA gene sequence of Aspergillus niger. The strain was identified as Aspergillus niger and named Aspergillus niger HW1409.

[0048] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the composite bacterial agent is prepared by mixing equal volumes of the fermentation broth of Bacillus subtilis HW1404 and the fermentation broth of Aspergillus niger HW1409; wherein the effective viable count of Bacillus subtilis HW1404 in the fermentation broth of Bacillus subtilis HW1404 is ≥5.0×10 9 CFU / ml; the effective viable count of Aspergillus niger HW1409 in the fermentation broth of Aspergillus niger HW1409 is ≥5.0×10 6CFU / ml. Other steps and parameters are the same as those in the second embodiment.

[0049] Example 1 Preparation and field experiment of the composite bacterial agent for straw decomposition of the present invention

[0050] 1. Production process of straw composting compound bacterial agent

[0051] Bacillus subtilis and Aspergillus niger were cultured in liquid submersion, respectively. Submerged culture of Bacillus subtilis: Bacillus subtilis HW 1404 was inoculated into a slant culture medium and activated for 48 hours at 32°C, and then a second-level liquid strain was shaken at 32°C for 48 hours to obtain a seed solution, which was transferred into a fermenter and fermented for 48 hours at 32°C to obtain a fermentation liquid of Bacillus subtilis HW1404; wherein the fermentation liquid medium was a beef extract peptone liquid medium. Submerged culture of Aspergillus niger: Aspergillus niger HW1409 was inoculated into a slant culture medium and activated for 48 hours at 32°C, and then a second-level liquid strain was shaken at 32°C for 48 hours to obtain a seed solution, which was transferred into a fermenter and fermented for 72 hours at 32°C to obtain a fermentation liquid of Aspergillus niger HW1409; wherein the fermentation liquid medium was a beef extract peptone liquid medium. After that, the two fermentation liquids are mixed and prepared in a mixing tank at a ratio of 1:1 to obtain a composite bacterial agent for straw composting. Then, the product is packaged through a liquid filling system with a packaging specification of 2.0 liters / bottle. After packaging, the product is boxed (8 bottles / box) and stored in a normal temperature warehouse.

[0052] In the fermentation broth of Bacillus subtilis HW1404, the effective viable bacteria count reached 7.3-8.2 billion / ml, and in the fermentation broth of Aspergillus niger HW1409, the effective viable bacteria count reached 560 million / ml, the carboxymethyl cellulase activity (CMC) reached 362.4U / ml, and the filter paper enzyme activity (FAT) reached 78.3U / ml.

[0053] 2. Field Trials

[0054] 1. Community arrangement

[0055] The plot area was 42 square meters, with 4 treatments, 5 repetitions, a total of 20 plots, and random block arrangement.

[0056] 2. Experimental treatment

[0057] Treatment 1: returning straw to the field + conventional fertilization + 2.0 kg / mu straw composting agent (composite bacterial agent for straw composting prepared in this example)

[0058] Treatment 2: Returning straw to the field + conventional fertilization + 2.0 kg / mu of inactivated straw compost (substrate control)

[0059] Treatment 3: Returning straw to the field + conventional fertilization + clean water (clean water control)

[0060] Treatment 4: Returning straw to the field + conventional fertilization (blank control)

[0061] 3. Determination of straw maturity - weight loss method: Based on the "Determination of straw maturity - weight loss method" formulated by the National Agricultural Technology Extension Center, the test method was appropriately modified and improved. The specific operation is as follows: Select complete crop straws with similar thickness and length, cut them into small segments of 3 to 5 cm, weigh about 50 g and put them into nylon mesh bags, number the prepared samples, and then dry them at 85°C for 6 hours, accurately weigh and record the initial weight of each bag NO0 (the average value is taken as the initial weight). After the preparation, the above straw samples (nylon bags), like other crushed straws for returning to the field, are placed on the soil surface of the plots with different treatments (each group treats 3 plots with a total of 10 bags, and 4 groups treat a total of 40 bags). After the completion of different test treatments in the test plots, the nylon sample bags are buried nearby, the surface is covered with 5 to 10 cm of soil, and marked. Randomly take out 5 bags of samples at 30 days, 60 days, and 100 days after the test, rinse with tap water until the dripping water is colorless, then dry the samples at 85℃ for 6 hours, accurately weigh and record the weight of each bag (NO x ). The weight loss rate is calculated based on the weight change before and after the test.

[0062] 4. Field test results

[0063] The experiment was conducted in Zhaodong City and Shuangcheng City. In the small-scale experiment, as time went on, the straw showed signs of being gradually decomposed. Due to the low temperature and insufficient soil humidity in the early stage, the decomposition speed was slow. After entering July, with the increase in temperature and rainfall, the decomposition speed of the straw accelerated, and the appearance color, smell, and mycelium growth of corn straw showed obvious changes. The difference in the decomposition effect also began to appear at this stage. In terms of color change, treatment 4 had the fastest speed, and it had turned dark brown by mid-July. The other three groups of treatments were not much different, and all showed dark brown by the end of July. In terms of the growth of white mycelium growing on the surface of the straw, treatment 1 showed that the plaque appeared early and the area was large, especially in July when the mycelium grew vigorously, and the area of ​​plaque growing on most of the straw could cover more than one-third; plaques also appeared on the surface of the straw in treatments 2, 3, and 4, but the area was small and the time was late. After the decomposition entered mid-August, the plaques on the straw subsided until they disappeared completely. Throughout the decomposition process, the inner part of corn stalks is easier to decompose, while the outer gelatinous layer is more difficult to decompose. Based on the field test results, as shown in Table 5, the decomposition effect of corn stalks is from strong to weak in the following order: treatment 1 ≥ treatment 2 ≥ treatment 3 ≥ treatment 4.

[0064] Table 5 Visual comparison of straw maturity in field trials

[0065]

[0066]

[0067] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0068] In order to further understand the effect of straw composting agent on straw decomposition, the weight loss method was used to test the effect of different treatments on straw maturity. The results of variance analysis of the experimental data showed that the difference between treatments was much greater than the difference between replicates, F>F0.01, reaching an extremely significant level, indicating that different treatments had an extremely significant effect on straw maturity. The results are shown in Table 6-12. As the time of straw field maturity increases, the F value gradually decreases, indicating that the treatment effects between treatments are gradually approaching.

[0069] The results of the subsequent multiple comparisons showed that at 30 days, the differences between treatments were extremely significant; at 60 days, treatment 1 was extremely different from other treatments, while there was no significant difference between treatment 2 and treatment 3. The results of the weight loss analysis of the field composting results showed that at the test site in Shuangcheng, at 30 days, the weight loss rate of treatment 1 reached 29.01%, which was 15.90% higher than treatment 2, 14.76% higher than treatment 3, and 19.24% higher than treatment 4; at 60 days, the weight loss rate of treatment 1 reached 38.75%, which was 13.19% higher than treatment 2, 15.03% higher than treatment 3, and 17.80% higher than treatment 4. At the test site in Zhaodong City, at 30 days, the weight loss rate of treatment 1 reached 28.04%, 14.24% higher than treatment 2, 15.57% higher than treatment 3, and 18.34% higher than treatment 4; at 60 days, the weight loss rate of treatment 1 reached 37.39%, 12.86% higher than treatment 2, 13.16% higher than treatment 3, and 18.79% higher than treatment 4. Based on the results of the two-site test (Table 8), the use of straw composting agent increased the composting speed by 92.86% on average compared with the blank control.

[0070] Table 6 Residual weight measurement results of weight loss test

[0071]

[0072]

[0073] Experimental location: Experimental site of Shuangcheng Agricultural Technology Extension Center, South Third Section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0074] Table 7 Analysis of variance table of straw maturity test results

[0075]

[0076] Experimental location: Experimental site of Shuangcheng Agricultural Technology Extension Center, South Third Section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0077] Table 8 Multiple comparison of straw maturity test results

[0078]

[0079] Experimental location: Experimental site of Shuangcheng Agricultural Technology Extension Center, South Third Section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0080] Table 9 Residual weight measurement results of weight loss test

[0081]

[0082]

[0083] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0084] Table 10 Analysis of variance table of straw maturity test results

[0085]

[0086] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0087] Table 11 Multiple comparison of straw maturity test results

[0088]

[0089]

[0090] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0091] Table 12 Effect of using straw composting agent on composting speed

[0092]

[0093] It can be seen from the field experiment of the straw composting agent product that the composite bacterial agent used for straw composting of the present invention significantly improves the field decomposition rate of corn straw. Combining the above results, the decomposition rate of the straw composting agent is increased by an average of 92.86% compared with the blank control.

[0094] Among various pectinases detected by Bacillus subtilis HW1404 of the present invention, polygalacturonic acid lyase (PGL) is the most abundant, and a small amount of pectin esterase (PE) is also produced. A large amount of unsaturated galacturonic acid exists in corn stalks. The polygalacturonic acid lyase (PGL) and pectin esterase (PE) produced by Bacillus subtilis HW1404 of the present invention play a major role (especially the former) in the stalk ripening process. Bacillus subtilis HW1404 has the function of decomposing unsaturated galacturonic acid and pectin in the stalk ripening process. Aspergillus niger HW1409 of the present invention produces cellulase, and Aspergillus niger and Bacillus subtilis have synergistic synergy without antagonism, thereby accelerating the ripening speed of the stalks.

[0095] 5. Impact on seasonal crops

[0096] The crop of the season in this experiment was soybean. In the experimental area of ​​Zhaodong City, the use of straw compost had no effect on the entire growth period of soybean, but had an effect on the soybean yield components, and the results are shown in Tables 13-23. Compared with the conventional fertilization treatment 4, the number of pods per plant increased by 1.0, the number of grains per plant increased by 4.6, and the 100-grain weight increased by 0.2g; compared with the water control treatment 3, the number of pods per plant increased by 0.5, the number of grains per plant increased by 2.2, and the 100-grain weight increased by 0.1g; compared with the substrate control treatment 2, the number of pods per plant increased by 0.7, the number of grains per plant increased by 2.4, and the 100-grain weight increased by 0.1g. In the Shuangcheng test area, compared with treatments 4, 3 and 2, treatment 1 only advanced the flowering period by 1 day, and had no effect on other growth periods; compared with treatment 2, plant height increased by 1.1cm and 0.5cm, the number of nodules per plant increased by 1.7-3.8, the number of pods per plant increased by 0.4, the number of grains per plant increased by 2.4, and the 100-grain weight increased by 0.4g; compared with treatment 3, plant height increased by 1.3cm and 1.3cm, the number of nodules per plant increased by 2.2-4.7, the number of pods per plant increased by 3.9, the number of grains per plant increased by 3.0, and the 100-grain weight increased by 0.5g; compared with treatment 4, plant height increased by 1.3cm and 2.6cm, the number of nodules per plant increased by 4.2-5.0, the number of pods per plant increased by 5.3, the number of grains per plant increased by 3.3, and the 100-grain weight increased by 0.5g. This shows that the use of composite microbial agents for straw decomposition can improve soybean growth and increase yield.

[0097] The yield data were processed using SPSS statistical software. The results showed that the variation between treatments was significantly greater than that between replicates, with F0.05<F<F0.01, and the variation reached a significant level, indicating that the effect of different treatments on yield was significantly greater than the repeated test error within each treatment group; further multiple comparisons showed that treatment 1 was significantly different from treatment 3 and treatment 4, but not significantly different from treatment 2. Compared with the actual yield measurement results, treatment 1 using straw compost in the Shuangcheng experimental area increased yield by 8.47 kg per mu compared with the substrate control (treatment 2), 11.64 kg per mu compared with the clear water control (treatment 3), and 10.58 kg per mu compared with the blank control (treatment 4); the year-on-year yield increase rates reached 5.00%, 7.00%, and 6.33%, respectively. In the Zhaodong test area, treatment 1 using straw composting agent increased yield by 7.41kg per mu compared with the substrate control (treatment 2), 7.41kg per mu compared with the water control (treatment 3), and 10.58kg per mu compared with the blank control (treatment 4); the year-on-year yield increase rates were 5.10%, 5.10%, and 7.43%, respectively.

[0098] Table 13 Survey on soybean growth period

[0099]

[0100] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0101] Table 14 Survey on biological characteristics of soybean

[0102]

[0103] Test location: Qianbijiatun, Dongsheng Village, Wuliming Town, Zhaodong City

[0104] Table 15 Questionnaire on soybean growth and development

[0105]

[0106] The experimental site of Shuangcheng Agricultural Technology Extension Center is located in the southern third section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0107] Table 16 Questionnaire on soybean growth characteristics (1)

[0108]

[0109]

[0110] The experimental site of Shuangcheng Agricultural Technology Extension Center is located in the southern third section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0111] Table 17 Soybean Growth Traits Questionnaire (2)

[0112]

[0113] Table 18 Plot yield measurement results

[0114]

[0115] Table 19 Variance analysis table of plot yield measurement

[0116]

[0117] Table 20 Multiple comparison of plot yield measurement results

[0118]

[0119] Table 21 Plot yield measurement results

[0120]

[0121]

[0122] The experimental site of Shuangcheng Agricultural Technology Extension Center is located in the southern third section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0123] Table 22 Variance analysis table of plot yield measurement

[0124]

[0125] The experimental site of Shuangcheng Agricultural Technology Extension Center is located in the southern third section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0126] Table 23 Multiple comparison of plot yield measurement results

[0127]

[0128] The experimental site of Shuangcheng Agricultural Technology Extension Center is located in the southern third section of Fuxiang Village, Shuangcheng Town, Shuangcheng City.

[0129] Comprehensive test results on the impact on seasonal crops show that the use of straw composting agent products has a significant yield-increasing effect on seasonal soybean crops, with the increase ranging from 6.33% to 7.43%.

Claims

1. A composite bacterial agent for straw composting, characterized in that The composite bacterial agent used for straw composting is composed of Bacillus subtilis ( Bacillus subtilis) HW1404 and Aspergillus niger ( Aspergillus niger ) HW1409; among them, Bacillus subtilis Bacillus subtilis The deposit number of HW1404 is CGMCC No. 25836; Aspergillus niger Aspergillus niger The deposit number of HW1409 is CGMCC No. 40329.

2. The composite bacterial agent for straw composting according to claim 1, characterized in that Bacillus subtilis Bacillus subtilis Fermentation broth of HW1404 and Aspergillus niger Aspergillus niger The fermentation broth of HW1409 was mixed in equal volumes; among them, Bacillus subtilis Bacillus subtilis In the fermentation broth of HW1404 Bacillus subtle The effective viable count of HW1404 is ≥5.0×10 9 CFU / ml; Aspergillus niger Aspergillus niger The effective viable count of Aspergillus niger HW1409 in the fermentation broth of HW1409 was ≥5.0×10 6 CFU / ml.

3. A fungus that can be used for straw decomposition, characterized in that It is Bacillus subtilis ( Bacillus subtilis ) HW1404, Bacillus subtilis Bacillus subtilis The deposit number of HW1404 is CGMCC No. 25836.

4. A fungus that can be used for straw decomposition, characterized in that Aspergillus niger Aspergillus niger HW1409, Aspergillus Aspergillus niger The deposit number of HW1409 is CGMCC No. 40329.

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