Saline-alkali soil improver prepared based on crop straw blasting waste and preparation method

Abstract

The invention relates to the technical field of preparation of saline-alkali soil modifying agents from wastes, in particular to a saline-alkali soil modifying agent prepared based on crop straw blasting wastes and a preparation method of the saline-alkali soil modifying agent. The azotobacter halophilus strain is preserved in the China General Microbiological Culture Collection Center on May 19, 2025 with the preservation number of CGMCC No.34575, and the lysobacter capsici is preserved in the China General Microbiological Culture Collection Center on May 19, 2025 with the preservation number of CGMCC No.34573. The application of the azotobacter halophilus and the lysobacter capsici in the saline-alkali soil improvement agent is that the azotobacter halophilus and the lysobacter capsici can be applied to saline-alkali soil improvement agents. According to the saline-alkali soil improver prepared on the basis of the crop straw blasting waste and the preparation method, the saline-alkali soil improver is used for coastal saline-alkali soil plough layer improvement and agricultural production, the cost of improvement materials is saved, the salt leaching function of heavy saline-alkali soil is enhanced, the ecological function and soil fertility of saline-alkali soil are improved, and improvement of crop (plant) productivity is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing saline-alkali soil improvers from waste, and particularly relates to a saline-alkali soil improver prepared from crop straw explosion waste and a preparation method thereof. Background Art

[0002] At present, the methods for treating saline-alkali land include physical, chemical, soil and water engineering, biological treatment and other methods. The single physical method has slow effects, the chemical improver causes secondary soil pollution, the soil and water engineering has high costs, and the biological treatment of saline-alkali land is healthy and environmentally friendly, which is the main direction for saline-alkali land in China. Some biological improvers, microbial bacterial fertilizers, and the salt absorption and soil improvement characteristics of salt-tolerant plants can achieve good improvement effects. However, the biomass improver has high costs, and the plant soil improvement has slow effects, which affect the process of saline-alkali land treatment. Especially, the treatment of severely saline-alkali land is difficult, costly, and has slow effects. How to use low-cost materials to efficiently and healthily improve the quality of saline-alkali soil has become a major problem in the treatment of severely saline-alkali land.

[0003] Crop straw mainly comes from the remaining stem parts after harvesting various crops in the agricultural production process. For example, grains: wheat straw, peanut straw, rice straw, corn straw, etc. At present, the main treatment methods for crop straw waste include direct field return, incineration, feed utilization, energy utilization, etc., but these methods all have certain defects: Direct field return Slow decomposition: Straw contains a large amount of difficult-to-decompose substances such as cellulose, hemicellulose, and lignin, and its natural decomposition rate in the soil is slow. It takes a long time to be decomposed and transformed into effective nutrients by microorganisms, which affects the absorption and utilization of nutrients by the current season's crops.

[0004] Incineration treatment Resource waste: Straw contains rich organic matter, nitrogen, phosphorus, potassium and other nutrient elements. Incineration will cause these nutrient elements to be lost in the form of gas, resulting in great waste of resources.

[0005] Feed utilization: Low digestibility: The cellulose, hemicellulose, and lignin structures in crop straw are complex and difficult to be digested and absorbed by livestock, resulting in low nutritional value and low utilization rate of straw feed.

[0006] Therefore, a saline-alkali soil improver prepared from crop straw explosion waste and a preparation method thereof are designed to achieve the established conditioner effect while reducing costs, and also improve the added value of waste, turning waste into treasure. Summary of the Invention

[0007] Based on this, in view of the above technical problems, it is necessary to provide a saline-alkali soil improver prepared from crop straw explosion waste and a preparation method thereof to solve the technical problems raised in the above background art.

[0008] To solve the above technical problems, the present invention adopts the following technical solutions: A salt-dwelling nitrogen-fixing bacterium, classified and named as Azotobacter salinestris strain BHX02, was deposited in the China General Microbiological Culture Collection Center on May 19, 2025, with the deposit number CGMCC No. 34575.

[0009] A Lysobacter capsici strain, classified and named as Lysobacter capsici strain BHX03, was deposited in the China General Microbiological Culture Collection Center on May 19, 2025, with the deposit number CGMCC No. 34573.

[0010] Apply the salt-dwelling nitrogen-fixing bacterium and Lysobacter capsici in the saline-alkali soil conditioner. A saline-alkali soil conditioner, which comprises a salt-dwelling nitrogen-fixing bacterium, Lysobacter capsici and additives.

[0011] As a preferred embodiment of the saline-alkali soil conditioner provided by the present invention, the additives are the waste after crop straw fiber blasting protein, semi-fermented livestock and poultry manure, and mineral humic acid.

[0012] As a preferred embodiment of the preparation method of the saline-alkali soil conditioner provided by the present invention, the proportion is as follows: The waste after crop straw fiber blasting protein: 1 part, semi-fermented livestock and poultry manure: 1 part, salt-tolerant growth-promoting compound bacteria concentrated liquid: 8 / 10000 parts, mineral humic acid: 0.05 part, urea: 0.002 part.

[0013] A preparation method of a saline-alkali soil conditioner, the steps are as follows: S1: Mix the waste after crop straw fiber blasting protein and semi-fermented livestock and poultry manure in proportion and stir evenly. S2: Evenly spray the salt-tolerant growth-promoting compound bacteria concentrated liquid on the mixture obtained in step S1. S3: After spraying, add humic acid and urea and stir evenly, and then carry out fermentation.

[0014] As a preferred embodiment of the preparation method of the saline-alkali soil conditioner provided by the present invention, in step S3, at the initial stage of fermentation, stir once a week for a total of 2 - 3 times to obtain the saline-alkali soil conditioner.

[0015] It can be undoubtedly seen that through the above technical solutions of the present application, the technical problems to be solved by the present application can surely be solved.

[0016] Meanwhile, through the above technical solution, the present invention has at least the following beneficial effects: The saline-alkali soil conditioner prepared from crop straw blasting waste and its preparation method provided by the present invention use waste materials such as crop straws after blasting extraction of feed protein, peanut shells, and cow dung as the main raw materials, and form a saline-alkali soil conditioner through mixed fermentation. The waste materials such as crop straws after blasting extraction of feed protein and cow dung mainly involve transportation costs and have no cost for the materials themselves, thereby saving the cost of saline-alkali land improvement.

[0017] The present invention improves the quality of saline-alkali soil. By fully utilizing the incompletely deconstructed straws and the organic acids, amino acids, polysaccharides, oligosaccharides and other substances formed by complete deconstruction in the waste, and mixing and fermenting them with livestock manure and halophilic bacteria. Among them, the incompletely deconstructed straws, peanut shells and other farm waste materials and livestock manure can provide carbon sources for microbial fermentation. The straws are completely deconstructed into cellulose, hemicellulose and lignin, and further decomposed into glucan, xylan, mannan, glucose, xylose, galactose, mannose, arabinose, and polysaccharides and oligosaccharides composed of these monosaccharides. There are also a small amount of amino acids decomposed from proteins and organic acids such as citric acid and lactic acid rich in the blasting process, which can all provide a good growth environment for microbial fermentation. The main materials of the conditioner interact with each other, not only increasing the content of salt-tolerant and growth-promoting bacteria in the soil, but also increasing the content of soil organic matter, promoting the improvement of the basic soil fertility and accelerating the process of soil fertility cultivation, so as to achieve the purpose of improving the quality of saline-alkali soil.

[0018] The present invention has the function of enhancing salt leaching. Since the conditioner is mainly composed of solid organic fertilizer and straw waste, compared with granular soil conditioners, it has a large volume, can increase soil air permeability, improve the salt leaching ability of the plough layer, and thus achieve the purpose of reducing the salt content of saline-alkali soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a schematic diagram of soil salt content, organic matter and Sesbania cannabina biomass after applying the conditioner of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will further describe the present invention in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0022] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] It should be noted that, without conflict, the embodiments in the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0025] To achieve the preparation of a saline-alkali soil conditioner prepared from crop straw blasting waste, we isolated a salt-tolerant nitrogen-fixing bacterium and a Lysobacter capsici from the rhizosphere soil of Sesbania cannabina in severely saline-alkali coastal areas. The salt-tolerant nitrogen-fixing bacterium was named BHX02 nitrogen-fixing bacterium (taxonomic name), and the Lysobacter capsici was named BHX03 bacterium (taxonomic name). The strain of Azotobacter salinestris was deposited in the China General Microbiological Culture Collection Center on May 19, 2025, with the deposit number CGMCC No. 34575; the strain of Lysobacter capsici was deposited in the China General Microbiological Culture Collection Center on May 19, 2025, with the deposit number CGMCC No. 34573.

[0026] The address of the China General Microbiological Culture Collection Center is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0027] Example 1 A saline-alkali soil conditioner prepared from crop straw blasting waste.

[0028] 1. Mix the crop straw fiber blasting waste and semi-fermented cow dung in a ratio of 1:1 to 2 and stir evenly. The crop straw fiber blasting waste is the waste after crop straw fiber blasting protein, which is the by-product after Zhongke Kangyuan (Tangshan) Biotechnology Co., Ltd. uses crop straws such as corn and peanuts to blast and extract feed protein. Its main components are incompletely deconstructed straws, organic acids such as citric acid and lactic acid, a small amount of amino acids decomposed from proteins, cellulose, hemicellulose, and lignin decomposed from straws, and further decomposed dextran, xylan, mannan, glucose, xylose, galactose, mannose, arabinose, and polysaccharides and oligosaccharides composed of monosaccharides therein.

[0029] The semi-fermented cow dung is the cow dung that has been piled up in the cattle farm for more than half a month and has no solid large pieces (in summer and autumn), or the overwintering cow dung directly taken out of the pen in spring.

[0030] 2. Evenly spray the mixed materials with a concentrated solution of salt-tolerant growth-promoting compound bacteria containing Azotobacter salis, Lysobacter capsici, Bacillus amyloliquefaciens, and Bacillus megaterium, which is composed of 4 kinds of bacteria mixed in a ratio of 2:1:1:1 at the same unit concentration. 1:1000 is the dilution volume ratio of the concentrated solution of salt-tolerant growth-promoting compound bacteria. The ratio of the concentrated solution of compound growth-promoting bacteria is 1:1000, specifically the dilution volume ratio of the concentrated solution of salt-tolerant growth-promoting compound bacteria; 3. Ingredients: 0.05 parts of mineral humic acid and 0.002 parts of urea.

[0031] 4. In the initial stage of fermentation, stir once a week for a total of 2 - 3 times.

[0032] 5. Cost calculation.

[0033] The main costs of the waste after crop straw fiber blasting protein and cow dung are transportation costs. The waste is 50 - 60 yuan per cubic meter, and the cow dung is 100 - 150 yuan per cubic meter. The mineral humic acid fertilizer is calculated at 1700 yuan per ton, the concentrated solution of salt-tolerant growth-promoting compound bacteria is calculated at 40 yuan per kilogram, and the urea is calculated at 2.5 yuan per kilogram. The preparation cost according to the ratio is 141 yuan per cubic meter.

[0034] It is mainly used in severely saline-alkali land with a total soil salt content greater than 6‰. The application rate per mu is determined according to the total soil salt content, calculated at 5 - 7 cubic meters per mu, and the cost per mu is 705 - 987 yuan per mu. Compared with "A Method for the Treatment and Utilization of Silty Coastal Saline Soil (Patent No. 201110164108.0)", the cost per mu is reduced by 99.1 - 99.4% from 166.21 yuan per square meter 2 (equivalent to 110695.86 yuan per mu).

[0035] Example Two On the basis of the above Example One, the preparation methods of Azotobacter salis and Lysobacter capsici are disclosed.

[0036] Fermentation medium for Azotobacter salis: Soluble starch 10.0 g / L, Dipotassium hydrogen phosphate 0.2 g / L, Magnesium sulfate 0.2 g / L, Sodium chloride 0.2 g / L, Calcium sulfate 0.1 g / L, Calcium carbonate 5.0 g / L, Agar 18.0 g / L.

[0037] Fermentation medium for Lysobacter capsici: Medium formula (Ashby medium): Mannitol 10.0 g / L, Dipotassium hydrogen phosphate 0.2 g / L, Magnesium sulfate 0.2 g / L, Sodium chloride 0.2 g / L, Calcium sulfate 0.1 g / L, Calcium carbonate 5.0 g / L, Agar 18.0 g / L.

[0038] The fermentation conditions of Azotobacter salinus and Lysobacter capsici include: the fermentation time is preferably 48 - 72 h, more preferably 60 h; the fermentation temperature is preferably 28 - 32 °C, more preferably 30 °C.

[0039] Azotobacter salinus has the characteristic of salt tolerance and can convert free nitrogen in the air into ammonia nitrogen that can be utilized by plants, significantly improving soil fertility. It is used for microbial remediation research in the improvement of saline-alkali land environment and has important application value in the agricultural ecosystem; Lysobacter capsici inhibits the germination of fungal spores, dissolves the hyphae of fungi or oomycetes by secreting non-enzymatic heat-stable antibacterial substances (HSAF), and has significant antagonistic effects against a variety of plant pathogenic bacteria and Gram-positive bacteria; as a plant growth-promoting rhizobacterium (PGPR), it colonizes in the rhizosphere soil of crops such as wheat, protects plant health by inhibiting pathogenic bacteria, and reduces the use of chemical pesticides; it is suitable for microbial remediation research in saline-alkali land or barren soil to improve soil ecological functions.

[0040] Example 3 On the basis of the above Example 1, its preparation method is disclosed as follows: Mix the waste after blasting crop straw fiber with semi-fermented livestock and poultry manure in proportion and stir evenly; Spray the concentrated solution of salt-tolerant growth-promoting compound bacteria evenly on the mixed materials; After spraying, add mineral humic acid and urea and stir evenly, and carry out fermentation for 30 - 60 days (varying with seasons); when the environmental temperature is 21 - 30 °C, the initial moisture content is 50%, and the fermentation temperature can reach 50 - 60 °C; the fermentation time can be extended in spring and autumn with lower temperatures; In the initial stage of fermentation, stir once a week, a total of 2 - 3 times, to obtain a saline-alkali soil conditioner.

[0041] Example 4 Reference Figure 1 , on the basis of the above Example 1 and Example 2, an application method is disclosed, and the "conditioner" is used for the improvement of the plough layer of coastal severely saline-alkali land and agricultural production.

[0042] I. Application Example Under the condition of muddy coastal saline-alkali soil with a total salt content of 1.2% in a farm in Caofeidian, Tangshan, corn is planted. Using the method of the present invention and the application rate of the composite material soil conditioner is 7 cubic meters per mu, irrigation is carried out by drip irrigation, Sesbania cannabina is sown in rows, the sowing rate is 5 kg per mu, the soil salt content is reduced to less than 0.5%, the desalination rate is more than 50%, the soil organic matter is increased from 0.6% to more than 2.0%, the fresh weight of Sesbania cannabina per mu is 3256 kg, an increase of 28.6%. Compared with other soil conditioners, the effects are shown in Table 2.

[0043] II. Application Comparative Example When planting corn (Wo Yu 3) in silt coastal severely saline-alkali soil with a salt content of 0.90% and a pH of 7.82 in the plough layer, the waste after blasting crop straw fiber with protein, semi-fermented livestock and poultry manure, salt-tolerant growth-promoting compound bacteria concentrated liquid, and mineral humic acid are mixed and fermented in the ratios of 1:1:0.0004:0.03 and 1:1:0.0008:0.05 to make two compound soil conditioners, conditioner 1 and conditioner 2, and compared with other soil conditioners and a blank control without applying a conditioner. Five levels are set for each material, and each level is comprehensively considered according to the recommended commercial dosage and the traditional fertilization dosage of farmers (Table 1). Except for the blank control, 40 kg / mu of compound fertilizer base fertilizer (NPK 15-15-15) is uniformly applied to all plots. After the corn is normally harvested, the yield is measured, and at the same time, soil samples are taken at three points along the diagonal in the plough layer (0-20 cm) of each plot and mixed to detect soil organic matter, soil bulk density, and salt content.

[0044] Table 1: Application rates of soil conditioners

[0045] III. Application effects (1) Yield improvement effect: The average yields of the two self-made fertilizers are 9.99 kg and 10.8 kg respectively, both significantly higher than those of other treatment groups. In terms of the application level, the plot yield generally shows a trend of first increasing and then decreasing with the application amount. Except for the bacterial agent soil conditioner, the other treatment groups perform best at the L3 and L4 levels (Table 2). At the L3 level, the average yields of the two self-made fertilizers are about 12.2 kg, which are 3.9%, 31.3%, 47.5%, and 112.9% higher than those of the slag, bacterial agent soil conditioner, cow dung, and blank group respectively.

[0046] Table 2: Yield data (kg) of each plot treatment and different application amounts

[0047] (2) Soil organic matter improvement effect In terms of the average soil organic matter content in the plough layer, except for the bacterial agent soil conditioner, the other treatments are significantly higher than those of the cow dung and blank group. The average soil organic matter content of the two self-made fertilizers is 23 g / kg, which is 46%, 31.8%, and 90.4% higher than those of the bacterial agent soil conditioner, cow dung control, and blank control group respectively. In terms of the application level, except for the bacterial agent soil conditioner, the soil organic matter content of the other treatment groups shows an increasing trend with the application amount. At the L3 level, the soil organic matter content of the bacterial agent soil conditioner group is the highest, but it is still significantly lower than that of the self-made fertilizer group. Although the soil organic matter content of the straw slag group is the highest at the L5 level, the soil organic matter content of the two self-made fertilizers is still significantly higher than that of other groups.

[0048] Table 3: Soil organic matter content (g / kg) of each treatment and different application amounts

[0049] (3) Reduction effects of bulk density and salt content in plow layer soil The changes in bulk density and salt content of the plow layer (0 - 20 cm) soil are key indicators for evaluating the structural quality of saline - alkali land. Generally, with the increase in the application amount of each material, the soil bulk density shows a decreasing trend. When most materials reach the L4 level, the soil bulk density drops to the lowest. All treatments significantly reduce the soil bulk density compared with the blank control. Among them, the average soil bulk density of the self - made fertilizer and straw residue is equivalent and the lowest, about 1.19 g / cm 3 , which is 1.6%, 4.8% and 8.4% lower than that of the microbial agent modifier, cow dung and the blank group respectively. The decrease in soil bulk density means an increase in soil porosity and water infiltration capacity, and is also conducive to the leaching of plow layer salts.

[0050] The average salt content of the plow layer soil in the blank control group is 0.626%, belonging to medium - heavy saline - alkali land. After applying various materials, the salt content of the plow layer soil drops below 0.4%, showing a trend of first decreasing and then increasing overall. Among them, the average salt content of the two self - made fertilizers is 0.403%, which is 8.4%, 7.6%, 8.0% and 35.6% lower than that of straw residue, microbial agent modifier, cow dung and the blank control group respectively. From the perspective of application levels, when the two self - made fertilizers reach the L3 level (5 m³ / mu), the salt content of the plow layer soil drops to the lowest of 0.235%, achieving the largest reduction amplitude, changing from medium - heavy saline - alkali land to light - medium saline - alkali land.

[0051] Table 4: Bulk density of plow layer soil (g / cm 3 )

[0052] Table 5: Salt content of plow layer soil (%) for each treatment and different application amounts

[0053] Summary: The two self - made fertilizers have obvious effects on increasing crop yield, improving soil nutrients, improving the soil structure of saline - alkali land and reducing salt content at the L1 - L5 levels. Considering comprehensive factors such as crop yield, salt reduction effect and cost in saline - alkali land, the waste after fiber explosion of crop straw, semi - fermented livestock and poultry manure, salt - tolerant growth - promoting compound bacteria concentrate, and mineral humic acid are mixed and fermented in the ratios of 1:1:0.0004:0.03 and 1:1:0.0008:0.05 to make two compound modifiers, Modifier 1 and Modifier 2. The L3 level of Modifier 2 is the best level. In production, the corresponding level can be reasonably selected according to the actual situation.

[0054] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A salt-dwelling nitrogen-fixing bacterium, characterized in that, The salt-dwelling nitrogen-fixing bacterium strain was deposited on May 19, 2025 at the General Microbiology Center of the China Microbial Culture Collection Center, with the deposit number CGMCC No. 34575.

2. A Lysobacter capsici, characterized in that, The Lysobacter capsici strain was deposited on May 19, 2025 at the General Microbiology Center of the China Microbial Culture Collection Center, with the deposit number CGMCC No. 34573.

3. Apply the salt-dwelling nitrogen-fixing bacterium described in claim 1 and the Lysobacter capsici described in claim 2 in the saline-alkali soil conditioner.

4. A saline-alkali soil conditioner, characterized in that, The saline-alkali soil conditioner includes the salt-dwelling nitrogen-fixing bacterium described in claim 1, the Lysobacter capsici described in claim 2, and additives.

5. The soil conditioner for saline-alkali soil according to claim 4, characterized in that The additives are the waste after blasting crop straw fiber with protein, semi-fermented livestock and poultry manure, and mineral humic acid.

6. The soil conditioner for saline-alkali soil according to claim 4, wherein The ratio is as follows: The waste after blasting crop straw fiber with protein: 1 part, semi-fermented livestock and poultry manure: 1 part, salt-tolerant growth-promoting complex bacteria concentrated liquid: 8 / 10000 parts, mineral humic acid: 0.05 part, urea: 0.002 part.

7. A preparation method of a saline-alkali soil conditioner, characterized in that, The steps are as follows: S1: Mix the waste after blasting crop straw fiber with protein and semi-fermented livestock and poultry manure in proportion and stir evenly. S2: Evenly spray the salt-tolerant growth-promoting complex bacteria concentrated liquid on the mixture obtained in step S1. S3: After spraying, add humic acid and urea and stir evenly for fermentation.

8. The preparation method of a saline-alkali soil conditioner according to claim 7, characterized in that, In step S3, at the initial stage of fermentation, stir once a week for a total of 2 - 3 times to obtain the saline-alkali soil conditioner.

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