Planting management method for improving yield of machine-harvested and rolled sugarcane field stubble cane

Abstract

The application discloses a kind of planting management methods for improving the yield of machine harvesting and rolling cane field ratoon cane, and relates to the technical field of sugarcane planting.The planting management method comprises the following steps: interplanting leguminous grass, applying microbial inoculant, timely ploughing and interplanting fat field radish.The planting management method can improve the physical and chemical structure of soil.Under the condition of mechanical high pressure, it can increase the ratoon cane sprouting rate, increase the number of effective stems and increase the plant height, thereby achieving the purpose of high yield and stable yield of ratoon cane for many years in succession.Meanwhile, the method is simple to operate, the effect is obvious, and is suitable for promotion.

Description

Technical Field

[0001] This invention belongs to the field of sugarcane planting and management technology, specifically relating to a planting and management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields. Background Technology

[0002] Rapeseed sugarcane refers to the new crop of sugarcane that is cultivated artificially after the previous sugarcane harvest, when the lateral buds of the sugarcane stump in the soil sprout and emerge under suitable environmental conditions. It is the main planting system in various sugarcane producing areas and occupies an important position in sugarcane production. In China's sugarcane-growing areas, sugarcane is generally kept as ratoon for 2-4 years, and the area of ​​ratoon sugarcane usually accounts for 50%-70% of the total sugarcane area.

[0003] While mechanized sugarcane harvesting is highly efficient, the compaction caused by machine harvesting alters the soil's physical structure, increasing soil penetration resistance and bulk density, reducing soil aeration and water permeability, and decreasing the number and quantity of soil microorganisms. This negatively impacts the growth and yield of ratoon sugarcane. Studies have found that mechanized harvesting compaction leads to a lower ratoon sugarcane stalk emergence rate, fewer effective stalks, reduced plant height, and decreased yield, thus hindering the application and promotion of mechanized harvesting.

[0004] Currently, the main solutions to the yield reduction caused by crushing of ratoon sugarcane are rational planting management and the breeding of new varieties with high resistance to crushing. However, current planting and management methods are mostly traditional, making it difficult to guarantee high and stable yields of ratoon sugarcane in the second and third years. Breeding new varieties is time-consuming, and there are currently no large-scale, crush-resistant sugarcane varieties available for widespread planting. Therefore, finding a planting and management method to increase the yield of ratoon sugarcane in fields subjected to mechanized harvesting is of great significance for promoting continuous high and stable yields of ratoon sugarcane and advancing mechanized harvesting. Summary of the Invention

[0005] To address the above problems, the technical problem to be solved by the present invention is to provide a planting and management method for increasing the yield of ratoon sugarcane in machine-harvested and compacted sugarcane fields. Based on the growth characteristics of highly compacted ratoon sugarcane, this method uses a series of technical means such as intercropping leguminous forage grasses, applying microbial agents, timely plowing, and intercropping with fertilizer radishes to achieve high and stable yields of ratoon sugarcane for many consecutive years under high mechanical pressure.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A planting management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields includes the following steps:

[0008] (1) Intercropping with legume forage grass: After the first year's ratoon sugarcane sprouts and grows to 5-8cm, start planting legume forage grass;

[0009] (2) Application of microbial agents: Microbial agents are applied during the vigorous growth period of the legume forage grasses;

[0010] (3) Tillage: The legume forage grasses are tilled into the soil 1-2 months before the first year’s ratoon sugarcane harvest;

[0011] (4) Intercropping with Feitian Radish: After the first year of ratoon sugarcane is harvested and the sugarcane field is cleared, Feitian Radish is sown. When the sugarcane is hilled up in the middle stage, the Feitian Radish is plowed into the soil.

[0012] (5) After harvesting the second year's ratoon sugarcane, repeat the above steps of intercropping leguminous forage, applying microbial agents, tilling, and intercropping with fertilizer radishes; the management of ratoon sugarcane should repeat the above steps every year thereafter.

[0013] Furthermore, the legume forage grass is one of white clover, red clover, and dwarf styrax.

[0014] Furthermore, the method for planting the legume forage grass is to sow it in the sugarcane rows and between the rows, with a sowing rate of 3-6 kg / mu, and to scatter the seeds evenly on the sugarcane ground during sowing.

[0015] Furthermore, the microbial agent is composed of equal weights of *Paecilomyces lilacinus* and *Bacillus tekirae*.

[0016] Further, the method for culturing *Bacillus tekirae* is as follows: Mix 8-15 parts peptone, 1-10 parts yeast extract, 5-15 parts sodium chloride, 0.09-0.1 parts leucine, 0.06-0.09 parts isoamyl alcohol, 0.08-0.12 parts isopentenyl pyrophosphate, 0.01-0.05 parts vitamin B4, and 1000-1500 parts water, adjust the pH to 7.0-7.5, and sterilize at 121℃ for 3 minutes. 0-40 min, culture medium is obtained; Bacillus tekirae strain is inoculated into the cooled culture medium under aseptic conditions, and cultured in a shaker at 30-38℃ and 180-250 r / min for 18-24 h to obtain Bacillus tekirae bacterial suspension; the above Bacillus tekirae bacterial suspension is centrifuged at 3500-4000 r / min for 20-30 min, the lower precipitate is taken and dried to obtain Bacillus tekirae.

[0017] Furthermore, the method of using the microbial agent is as follows: after mixing the microbial agent with water at a weight ratio of 1:1000-1500, pour the mixture onto the sugarcane stubble, applying 100-200 mL of the microbial-water mixture to each stubble.

[0018] Furthermore, the tillage depth is 10-15cm, and the legume forage is completely buried in the soil during tillage.

[0019] Furthermore, the planting method for the fertile radish is as follows: sow in rows between sugarcane rows, 10-15cm away from the sugarcane stubble, with a sowing rate of 4-6kg / mu.

[0020] Furthermore, after the sugarcane is harvested by the machinery, all debris on the sugarcane field must be cleaned up.

[0021] Furthermore, the management of ratoon sugarcane planting also includes reasonable fertilization. In May, apply fertilizer to promote stem growth, using 100-150 kg of 20% sugarcane-specific compound fertilizer or 70-80 kg of ammonium nitrate calcium fertilizer per mu; in July and August, apply fertilizer to strengthen the tail end, using 6-8 kg of ammonium sulfate or 3-4 kg of urea per mu.

[0022] Compared with existing technologies, the present invention has the following advantages:

[0023] 1. Based on the growth characteristics of high-compaction ratoon sugarcane, this invention uses a series of technical means, such as intercropping with leguminous forage grasses, applying microbial agents, timely plowing, and intercropping with fertilizer radishes, to improve the germination rate, increase the number of effective stems, and increase plant height under high mechanical pressure, thereby achieving the goal of high and stable yield of ratoon sugarcane for many consecutive years.

[0024] 2. The root system of the legume forage grass of this invention can increase the porosity of mechanically compacted soil, reduce soil bulk density, improve soil physical properties, optimize soil structure, and promote sugarcane root growth and elongation, thereby increasing the germination rate. Simultaneously, the legume forage grass of this invention can also form a dominant population, suppressing the growth of other weeds and reducing the labor costs of weed management.

[0025] 3. The legume forage grass of the present invention can regulate the soil into a microenvironment conducive to the growth of microorganisms during its vigorous growth period, which is very beneficial to the survival and reproduction of the microbial agent of the present invention. After the forage grass is applied during its vigorous growth period, its viable bacteria count is high and the total amount of soil microorganisms increases, thereby promoting the growth of sugarcane.

[0026] 4. The microbial inoculant of this invention can release a large amount of growth hormones, stimulating the growth and elongation of sugarcane roots, effectively increasing root length and weight. Specifically, the optimized culture medium for *Bacillus tekirae* containing leucine, isoamyl alcohol, isopentenyl pyrophosphate, and vitamin B4 significantly improves the release of plant growth hormones compared to unoptimized *Bacillus tekirae*. Furthermore, the optimized *Bacillus tekirae* combined with *Paecilomyces lilacinus* forms the microbial inoculant of this invention. The mutualistic symbiosis between *Paecilomyces lilacinus* and the optimized *Bacillus tekirae* enhances the activity of the optimized *Bacillus tekirae* in the soil, allowing it to function effectively and further promote the growth of ratoon sugarcane roots.

[0027] 5. This invention involves tilling leguminous forage into the soil 1-2 months before the harvest of ratooned sugarcane. This not only serves as green manure to improve soil fertility but also enhances the soil's resistance to mechanical compaction and reduces soil compaction stress.

[0028] 6. The radish intercropped with sugarcane in this invention grows quickly, is drought-resistant, has a short growing season, and has a well-developed root system. It can effectively improve soil compaction, improve the soil microenvironment, promote the growth and development of sugarcane roots, and thus ensure stable sugarcane yield.

[0029] 7. The present invention can effectively increase the soil pH value after the pasture is turned into the soil during the ratooning of sugarcane. However, the soil acidification of ratooning sugarcane is relatively serious, and it is difficult to effectively reduce the soil acidity by relying solely on pasture. By rotating with fertile radish, the root exudates of fertile radish can further increase the soil pH value, which is beneficial to the growth of ratooning sugarcane and thus ensures stable sugarcane yield.

[0030] 8. The planting method of this invention is simple to operate, the selected intercropping plants are easy to obtain, no other extra complicated management is required, it is suitable for sugarcane planting areas in the south, the effect is obvious, and it is suitable for promotion. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0032] The *Paecilomyces lilacinus* strains used in the following examples and comparative examples were purchased from Weifang Ruichen Biotechnology Co., Ltd., and *Bacillus tekirae* strains were purchased from Shanghai Preservation Biotechnology Center.

[0033] Example 1

[0034] A planting management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields includes the following steps:

[0035] (1) Intercropping with leguminous forage grasses: Newly planted sugarcane is planted in March and mechanically harvested in March of the following year. After harvesting, all debris on the sugarcane field is cleaned up. After the first year's ratoon sugarcane sprouts and grows to 5cm, white clover is planted. The white clover is planted in the sugarcane rows and between rows, with a sowing rate of 3kg / mu. When sowing, the seeds are evenly scattered on the sugarcane field.

[0036] (2) Application of microbial inoculants: Apply microbial inoculants during the vigorous growth period of white clover; the microbial inoculants are a mixture of equal weights of Paecilomyces lilacinus and Bacillus tekirae.

[0037] The method for culturing Bacillus tekirae is as follows: Weigh out 8 parts peptone, 1 part yeast extract, 5 parts sodium chloride, 0.09 parts leucine, 0.06 parts isoamyl alcohol, 0.08 parts isopentenyl pyrophosphate, 0.01 parts vitamin B4, and 1000 parts water by weight fraction, mix well, adjust the pH to 7.0, and sterilize at 121℃ for 30-40 min to obtain the culture medium; inoculate Bacillus tekirae strain into the above cooled culture medium under aseptic conditions, and culture in a shaker at 30℃ and 180 r / min for 18 h to obtain Bacillus tekirae bacterial suspension; centrifuge the above Bacillus tekirae bacterial suspension at 3500 r / min for 20 min, take the lower precipitate and dry it to obtain Bacillus tekirae.

[0038] The method of using microbial inoculants is as follows: Mix the microbial inoculants with water at a weight ratio of 1:1000, and then pour the mixture onto the sugarcane stubble, applying 100 mL of the microbial-water mixture to each stubble.

[0039] (3) Tillage: One month before the first year of ratoon sugarcane harvest, the white clover should be tilled into the soil to a depth of 10cm. All the white clover should be buried in the soil during tillage. The ratoon sugarcane should be harvested mechanically and the debris on the sugarcane field should be cleaned up.

[0040] (4) Intercropping with fertile radish: After the first year of ratooning sugarcane is harvested and the sugarcane field is cleared, fertile radish is sown. When the sugarcane is hilled up in the middle stage, the fertile radish is plowed into the soil. The planting method of fertile radish is: sow in rows between sugarcane rows, 10cm away from the sugarcane base, with a sowing amount of 4kg / mu.

[0041] (5) After harvesting the second year's ratoon sugarcane, repeat the above steps of intercropping leguminous forage, applying microbial agents, tilling, and intercropping with fertilizer radishes; the management of ratoon sugarcane should repeat the above steps every year thereafter.

[0042] The following fertilization is also carried out in the management of ratoon sugarcane planting: apply stalk fertilizer in May, with 100 kg of 20% sugarcane-specific compound fertilizer or 70 kg of ammonium nitrate calcium fertilizer per mu; apply tail fertilizer in July, with 6 kg of ammonium sulfate or 3 kg of urea per mu.

[0043] Example 2

[0044] A planting management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields includes the following steps:

[0045] (1) Intercropping with leguminous forage grasses: Newly planted sugarcane is planted in March and mechanically harvested in March of the following year. After harvesting, all debris on the sugarcane field is cleaned up. After the first year's ratoon sugarcane sprouts and grows to 8cm, red clover is planted. The planting method for red clover is to sow it in the sugarcane rows and between rows. The sowing amount is 6kg / mu. When sowing, the seeds are evenly scattered on the sugarcane field.

[0046] (2) Application of microbial inoculants: Apply microbial inoculants during the vigorous growth period of red clover; the microbial inoculant is a mixture of equal weights of Paecilomyces lilacinus and Bacillus tekirae.

[0047] The method for culturing Bacillus tekirae is as follows: Mix 15 parts peptone, 10 parts yeast extract, 15 parts sodium chloride, 0.1 parts leucine, 0.09 parts isoamyl alcohol, 0.12 parts isopentenyl pyrophosphate, 0.05 parts vitamin B4, and 1500 parts water, adjust the pH to 7.5, and sterilize at 121℃ for 40 min to obtain the culture medium. Inoculate the Bacillus tekirae strain into the cooled culture medium under aseptic conditions and culture in a shaker at 38℃ and 250 r / min for 24 h to obtain a Bacillus tekirae bacterial suspension. Centrifuge the Bacillus tekirae bacterial suspension at 4000 r / min for 30 min, collect the lower precipitate, and dry it to obtain the Bacillus tekirae.

[0048] The method of using microbial inoculants is as follows: Mix the microbial inoculants with water at a weight ratio of 1:1500, and then pour the mixture onto the sugarcane stubble, applying 200 mL of the inoculant-water mixture to each stubble.

[0049] (3) Tillage: Two months before the first year's ratoon sugarcane harvest, the red clover is tilled into the soil to a depth of 15cm. During tillage, all the red clover is buried in the soil. The above ratoon sugarcane is harvested mechanically, and the debris on the sugarcane field is cleaned up, leaving the ratoon sugarcane stumps.

[0050] (4) Intercropping with fertile radish: After the first year of ratoon sugarcane is harvested and the sugarcane field is cleared, fertile radish is sown. When the sugarcane is hilled up in the middle stage, the fertile radish is plowed into the soil. The planting method of fertile radish is: sow in rows between sugarcane rows, 15cm away from the sugarcane base, with a sowing amount of 6kg / mu.

[0051] (5) After harvesting the second year's ratoon sugarcane, repeat the above steps of intercropping leguminous forage, applying microbial agents, tilling, and intercropping with fertilizer radishes; the management of ratoon sugarcane should repeat the above steps every year thereafter.

[0052] The following fertilization is also carried out in the management of ratoon sugarcane planting: apply stalk fertilizer in May, with 150 kg of 20% sugarcane-specific compound fertilizer or 80 kg of ammonium nitrate calcium fertilizer per mu; apply tail fertilizer in August, with 8 kg of ammonium sulfate or 4 kg of urea per mu.

[0053] Example 3

[0054] A planting management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields includes the following steps:

[0055] (1) Intercropping with leguminous forage grass: Newly planted sugarcane is planted in March and mechanically harvested in March of the following year. After harvesting, all debris on the sugarcane field is cleaned up. After the first year's ratoon sugarcane sprouts and grows to 7cm, dwarf stylosus is planted. The planting method of dwarf stylosus is to sow in the sugarcane rows and between rows, with a sowing amount of 5kg / mu. When sowing, the seeds are evenly scattered on the sugarcane field.

[0056] (2) Application of microbial inoculants: Apply microbial inoculants during the vigorous growth period of dwarf styrax; the microbial inoculant is a mixture of equal weights of Paecilomyces lilacinus and Bacillus tekirae.

[0057] The method for culturing Bacillus tekirae is as follows: Mix 10 parts peptone, 5 parts yeast extract, 10 parts sodium chloride, 0.095 parts leucine, 0.08 parts isoamyl alcohol, 0.10 parts isopentenyl pyrophosphate, 0.03 parts vitamin B4, and 1200 parts water. Adjust the pH to 7.2 and sterilize at 121℃ for 35 min to obtain the culture medium. Inoculate the Bacillus tekirae strain into the cooled culture medium under aseptic conditions and culture at 37℃ and 200 r / min on a shaker for 20 h to obtain a Bacillus tekirae bacterial suspension. Centrifuge the Bacillus tekirae bacterial suspension at 3800 r / min for 25 min, collect the lower precipitate, and dry it to obtain the Bacillus tekirae.

[0058] The method of using microbial inoculants is as follows: Mix the microbial inoculants with water at a weight ratio of 1:1200, and then pour the mixture onto the sugarcane stubble, applying 150 mL of the inoculant-water mixture to each stubble.

[0059] (3) Tillage: 1.5 months before the first year's ratoon sugarcane harvest, dwarf styrax is tilled into the soil to a depth of 12cm. During tillage, all the dwarf styrax is buried in the soil. The above ratoon sugarcane is harvested mechanically, and the debris on the sugarcane field is cleaned up, leaving the ratoon sugarcane stumps.

[0060] (4) Intercropping with fertile radish: After the first year of ratooning sugarcane is harvested and the sugarcane field is cleared, fertile radish is sown. When the sugarcane is hilled up in the middle stage, the fertile radish is plowed into the soil. The planting method of fertile radish is: sow in rows between sugarcane rows, 12cm away from the sugarcane base, with a sowing amount of 5kg / mu.

[0061] (5) After harvesting the second year's ratoon sugarcane, repeat the above steps of intercropping leguminous forage, applying microbial agents, tilling, and intercropping with fertilizer radishes; the management of ratoon sugarcane should repeat the above steps every year thereafter.

[0062] The following fertilization is also carried out in the management of ratoon sugarcane planting: apply stalk fertilizer in May, with 120 kg of 20% sugarcane-specific compound fertilizer or 75 kg of ammonium nitrate calcium fertilizer per mu; apply tail fertilizer at the end of July, with 7 kg of ammonium sulfate or 3.5 kg of urea per mu.

[0063] Comparative Example 4

[0064] In this comparative example, step (1) involves intercropping sweet potatoes, while the other steps are the same as those in Example 1.

[0065] Comparative Example 5

[0066] In this comparative example, step (1) involves intercropping potatoes, while the other steps are the same as those in Example 1.

[0067] Comparative Example 6

[0068] This comparative example omits step (1), i.e., no plants are intercropped, and all other steps are the same as those in Example 1.

[0069] Comparative Example 7

[0070] This comparative example omits step (2), i.e., no microbial agent is applied, and all other steps are the same as those in Example 1.

[0071] Comparative Example 8

[0072] In this comparative example, step (2) did not contain *Paecilomyces lilacinus*, but only *Bacillus tekirae* after optimized culture. All other steps were the same as those in Example 1.

[0073] Comparative Example 9

[0074] In this comparative example, step (2) did not involve optimized culture of Bacillus tekirae, but only Paecilomyces lilacinus. All other steps were the same as those in Example 1.

[0075] Comparative Example 10

[0076] The Bacillus tekirae in step (2) of this comparative example was not obtained using this culture method, but rather using commercially available Bacillus tekirae. All other steps were the same as those in Example 1.

[0077] Comparative Example 11

[0078] The culture medium used for Bacillus tekirae in step (2) of this comparative example did not contain leucine and isoamyl alcohol, and the other steps were the same as those in Example 1.

[0079] Comparative Example 12

[0080] The culture medium used for Bacillus tekirae in step (2) of this comparative example did not contain isopentenyl pyrophosphate and vitamin B4, and the other steps were the same as those in Example 1.

[0081] Comparative Example 13

[0082] In this comparative example, step (4) is performed without planting fertile radishes; all other steps are the same as those in Example 1.

[0083] Comparative Example 14

[0084] In this comparative example, step (4) involves intercropping perilla, while the other steps are the same as those in Example 1.

[0085] Comparative Example 15

[0086] In this comparative example, step (4) involves continuing to intercrop white clover, while the other steps are the same as those in Example 1.

[0087] Comparative Example 16

[0088] In this comparative example, step (1) involves intercropping with Feitian radish, while the other steps are the same as those in Example 1.

[0089] The application time of the microbial agents in all the above embodiments and comparative examples was in mid-July, which is the peak growth period of leguminous forage grasses.

[0090] All the above embodiments and comparative examples were conducted by the applicant in Dingdang Town, Long'an County, Guangxi Province, and the sugarcane variety planted was Guitang 42. Embodiments 1 to 3 are the planting and management methods of the present invention. To illustrate the effects of the present invention, the applicant also set up comparative examples 4 to 12 as comparative examples. The planting area of ​​each embodiment and comparative example was 1 mu, the planting row length was 10m, the row spacing was 1.2m, and 3 replicates were performed. The newly planted sugarcane in each embodiment and comparative example was planted in March 2020 and harvested in March 2021, 2022, and 2023, for a total of 3 harvests. Harvesting was completed using a Case 4000 cutting harvester, and then transported by a Chenglong medium-duty truck with a total weight of 10t. During transportation, the sugarcane rows and the spaces between rows were compacted the same number of times.

[0091] To illustrate the effectiveness of intercropping leguminous forage crops in this invention, the applicant set up Example 1, Comparative Example 4 (intercropping sweet potato), and Comparative Example 5 (intercropping potato) for comparison. Soil compaction at the sugarcane row and between rows was measured using a TJSD-750-IV digital display soil compaction instrument at the sugarcane seedling stage (April 2021), elongation stage (August 2021), and maturity stage (December 2021). The soil depth was measured at 30 cm, and the average value was taken. Planting rate was investigated at the sugarcane seedling stage, plant height at the elongation stage, and plant height, effective stem number, and sugarcane stalk yield at the maturity stage. Average values ​​were also calculated. Data from Examples 2 and 3 were also investigated. Specific results are shown in Table 1:

[0092] Table 1. Agronomical characteristics of sugarcane in each embodiment.

[0093]

[0094]

[0095] Table 1 shows that compared with intercropping sweet potatoes and potatoes, the intercropping of leguminous forage grasses in this invention has a greater impact on the agronomic traits of ratoon sugarcane. Specifically, the seedling emergence rate, plant height during the elongation period, plant height at maturity, number of effective stems, and sugarcane stalk yield all show significant increases and improvements. This indicates that the root growth of the intercropped leguminous forage grasses in this invention can increase the porosity of mechanically compacted soil, reduce soil compaction, improve soil physical properties, optimize soil structure, and benefit the healthy growth of sugarcane.

[0096] To illustrate the synergistic effect of intercropping leguminous forage grasses and applying microbial inoculants in this invention, the applicant set up Example 1, Comparative Example 6 (without leguminous forage grasses), and Comparative Example 7 (without microbial inoculants) for comparison. Plant height during the elongation stage (August 2021) and maturity stage (December 2021), plant height at the elongation stage, plant height at maturity, number of effective stems, and sugarcane stalk yield were investigated, and average values ​​were calculated. Soil microbial totals (total microorganisms per gram of soil) were investigated during the elongation stage of ratooned sugarcane (August 2021). Soil samples were collected from the topsoil (0-20 cm) between rows of each example and comparative example. Bacterial culture medium (LB medium), fungal culture medium (PDA medium), and actinomycete culture medium (Gao's No. 1 medium) were prepared for cultivation. Soil microorganisms were isolated using the dilution plate method, colony counts were counted, and the average total microbial totals for each sample were calculated. Data from Examples 2 and 3 were also investigated. The results are shown in Table 2.

[0097] Table 2. Agronomical characteristics of sugarcane in each example.

[0098]

[0099] Table 2 shows that planting leguminous forage grasses alone or applying microbial inoculants alone is insufficient to increase the height and yield of ratooned sugarcane. The leguminous forage grasses of this invention can regulate the soil into a microenvironment conducive to microbial growth during their vigorous growth period, which is highly beneficial to the survival and reproduction of the microbial inoculants of this invention. After applying the microbial inoculants during the vigorous growth period of the forage grasses, the number of viable bacteria is high, the total amount of soil microorganisms increases, and thus promotes sugarcane growth.

[0100] To illustrate the mutually beneficial symbiotic relationship between *Paecilomyces lilacinus* and *Bacillus tekirae* after optimized culture, the applicant established Example 1, Comparative Example 8 (no *Paecilomyces lilacinus*, only *Bacillus tekirae* after optimized culture), Comparative Example 9 (no *Bacillus tekirae* after optimized culture, only *Paecilomyces lilacinus*), and Comparative Example 10 (*Paecilomyces lilacinus* + commercially available *Bacillus tekirae*) for comparison. Roots were harvested from the sugarcane rows at the ratooning sugarcane maturity period (December 2021), with excavation dimensions of 120cm long, 40cm wide, and 40cm deep. Three points were collected from each example and comparative example to measure and analyze the root length, diameter, volume, surface area, and dry weight of the ratooned sugarcane. Data from Examples 2 and 3 were also investigated. The results are shown in Table 3.

[0101] Table 3 Sugarcane root system conditions in each example

[0102] deal with Root length (cm) <![CDATA[Surface area (cm 2 )]]> <![CDATA[Volume (cm 3 )]]> Diameter (mm) Dry weight (g) Example 1 5322±93.5 1577±99.7 40.12±1.1 1.32±0.15 9.5±0.77 Example 2 5211±75.7 1512±87.9 44.11±2.2 1.10±0.21 9.2±0.06 Example 3 5410±93.8 1623±69.3 46.89±1.9 1.44±0.16 9.7±0.43 Comparative Example 8 4978±66.7 1400±88.3 33.0±1.6 0.89±0.16 7.9±0.16 Comparative Example 9 4789±69.0 1379±76.8 31.9±1.0 0.75±0.12 7.2±0.33 Comparative Example 10 5112±88.7 1480±79.5 39.22±2.6 0.95±0.11 9.0±0.19

[0103] As shown in Table 3, the combination of optimized cultured Bacillus tekirae and Paecilomyces lilacinus forms the microbial agent of this invention. Paecilomyces lilacinus and optimized cultured Bacillus tekirae exhibit a mutually beneficial symbiotic relationship, which enhances the activity of optimized cultured Bacillus tekirae in the soil, enabling it to function effectively in the soil and further promote the growth of ratoon sugarcane roots.

[0104] To illustrate the effects of the optimized culture of *Bacillus tekirae* in this invention, the applicant set up Example 1, Comparative Example 11 (the culture medium used for *Bacillus tekirae* did not contain leucine and isoamyl alcohol), and Comparative Example 12 (the culture medium used for *Bacillus tekirae* did not contain isopentenyl pyrophosphate and vitamin B4) for comparison. Roots were harvested from the cane rows at the ratooning sugarcane maturity period (December 2021), with excavation dimensions of 120cm long, 40cm wide, and 40cm deep. Three points were collected from each example and comparative example to measure and analyze the root length, diameter, volume, surface area, and dry weight of the ratooned sugarcane. Data from Examples 2 and 3 were also investigated. The results are shown in Table 4.

[0105] Table 4 Sugarcane root system conditions in each example

[0106] deal with Root length (cm) <![CDATA[Surface area (cm 2 )]]> <![CDATA[Volume (cm 3 )]]> Diameter (mm) Dry weight (g) Example 1 5322±93.5 1577±99.7 40.12±1.1 1.32±0.15 9.5±0.77 Example 2 5211±75.7 1512±87.9 44.11±2.2 1.10±0.21 9.2±0.06 Example 3 5410±93.8 1623±69.3 46.89±1.9 1.44±0.16 9.7±0.43 Comparative Example 11 4989±79.1 1488±82.1 39.1±1.1 0.96±0.12 8.4±0.34 Comparative Example 12 4911±66.2 1478±70.5 38.4±1.8 0.99±0.10 8.6±0.25

[0107] As shown in Table 4, the microbial agent of this invention can release a large amount of growth hormones, stimulating the growth and elongation of sugarcane roots, effectively increasing the root length and weight of sugarcane. Specifically, the optimized culture medium for *Bacillus tekirae* containing leucine, isoamyl alcohol, isopentenyl pyrophosphate, and vitamin B4 significantly improved the release of plant growth hormones compared to *Bacillus tekirae* without optimization, further promoting the growth of ratoon sugarcane roots.

[0108] To illustrate the effect of intercropping with fertile radish in this invention, the applicant set up Example 1, Comparative Example 13 (no fertile radish), Comparative Example 14 (intercropping with perilla), Comparative Example 15 (continuous intercropping with clover), and Comparative Example 16 (planting fertile radish in step 1) for comparison. The yield of sugarcane stalks at the ratoon sugarcane maturity stage (December) was investigated in 2021 and 2022, and the average value was calculated. The soil pH value of the ratoon sugarcane fields was investigated during the mid-growth stage of sugarcane in 2021 and 2022. Data from Examples 2 and 3 were also investigated. The investigation results are shown in Table 5.

[0109] Table 5 Sugarcane yield in different years for each example

[0110]

[0111] Table 5 shows that the yields of forage grass and radish rotation remained basically the same in 2021 and 2022. The yields of grass-grass rotation, forage grass and perilla rotation, and forage grass and radish rotation alone all decreased in 2022. Furthermore, grass-grass rotation, forage grass and perilla rotation, forage grass rotation alone, and radish rotation alone were not as effective at improving soil acidity as forage grass and radish rotation. Rotation of radish rotation with leguminous forage grass increased soil pH and significantly improved soil acidity. Therefore, the radish rotation with leguminous forage grass in sugarcane fields, as described in this invention, is beneficial for the growth of ratooned sugarcane, thereby ensuring stable sugarcane yields.

[0112] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A planting management method for improving the yield of ratoon cane in a mechanically harvested and rolled sugarcane field, characterized by, Includes the following steps: (1) Intercropping with legume forage: After the first year's ratoon sugarcane sprouts and grows to 5-8cm, start planting legume forage; (2) Application of microbial inoculants: Microbial inoculants are applied during the vigorous growth period of the legume forage; the microbial inoculants are composed of equal weights of *Paecilomyces lilacinus* and *Bacillus tekirae*. The method for culturing *Bacillus tekirae* is as follows: Mix 8-15 parts peptone, 1-10 parts yeast extract, 5-15 parts sodium chloride, 0.09-0.1 parts leucine, 0.06-0.09 parts isoamyl alcohol, 0.08-0.12 parts isopentenyl pyrophosphate, 0.01-0.05 parts vitamin B4, and 1000-1500 parts water. Adjust the pH to 7.0-7.5 and sterilize at 121℃ for 30-40 minutes to obtain a culture medium. Inoculate *Bacillus tekirae* strain into the above culture medium under aseptic conditions and culture on a shaker at 30-38℃ and 180-250 rpm for 18-24 hours to obtain a *Bacillus tekirae* bacterial suspension. Centrifuge the above *Bacillus tekirae* bacterial suspension at 3500-4000 rpm for 20-30 minutes, collect the lower precipitate, and dry it to obtain the *Bacillus tekirae*. (3) Tillage: The legume forage grasses shall be tilled into the soil 1-2 months before the first year’s ratoon sugarcane harvest; (4) Intercropping with fertile radish: After the first year of ratoon sugarcane is harvested and the sugarcane field is cleared, fertile radish is sown. When the sugarcane is hilled up in the middle stage, the fertile radish is plowed into the soil. (5) After harvesting the second year's ratoon sugarcane, repeat the above steps of intercropping leguminous forage, applying microbial agents, tilling, and intercropping fertile radishes; the management of ratoon sugarcane should repeat the above steps every year thereafter.

2. The planting management method for increasing yield of ratoon cane in a mechanically harvested and rolled sugarcane field according to claim 1, characterized in that, The legume forage grass mentioned is one of white clover, red clover, and dwarf styrax.

3. The planting management method for increasing yield of ratoon cane in a mechanically harvested and rolled sugarcane field according to claim 1 or 2, characterized in that, The method for planting the legume forage grass is to sow it in the rows and between the rows of sugarcane, with a sowing rate of 3-6 kg / mu. When sowing, the seeds are evenly scattered on the sugarcane ground.

4. The planting management method for increasing yield of ratoon cane in a mechanically harvested and roll-pressed sugarcane field according to claim 1, characterized in that, The method of using the microbial agent is as follows: mix the microbial agent with water at a weight ratio of 1:1000-1500, and then pour the mixture onto the sugarcane stubble, applying 100-200 mL of the microbial-water mixture to each stubble.

5. The planting and management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields according to claim 1, characterized in that, The tillage depth is 10-15cm, and the legume forage is completely buried in the soil during tillage.

6. The planting and management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields according to claim 1, characterized in that, The planting method for the fertile radish is as follows: sow in rows between sugarcane rows, 10-15cm away from the sugarcane stubble, with a sowing rate of 4-6kg / mu.

7. The planting and management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields according to claim 1, characterized in that, After the sugarcane is harvested by machinery, all debris on the sugarcane field must be cleaned up.

8. A planting management method for increasing the yield of ratooned sugarcane in machine-harvested and compacted sugarcane fields according to claim 1, characterized in that, The management of ratoon sugarcane planting also includes reasonable fertilization. In May, apply fertilizer to promote stem growth, using 100-150 kg of 20% sugarcane-specific compound fertilizer or 70-80 kg of ammonium nitrate calcium fertilizer per mu; from July to August, apply fertilizer to strengthen the tail end, using 6-8 kg of ammonium sulfate or 3-4 kg of urea per mu.

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