Microbial function activator for rice and vegetable rotation soil and preparation method thereof

Abstract

The invention belongs to the technical field of soil activators. The invention provides a microbial function activator for rice and vegetable rotation soil. The microbial function activator comprises 20-30 parts of a quick-acting carbon source, 10-15 parts of a slow-release carbon source, 5-8 parts of an oxygenation component, 3-6 parts of a microbial function cofactor and 25-40 parts of a carrier. According to the invention, the quick-acting and slow-release carbon sources are combined to provide instant and continuous energy supply for aerobic microorganisms attenuated after amphibious conversion; the oxygenation component can improve the ventilation condition of the soil, promote the restoration of nitrifying bacteria and enhance the nitrification effect; the microbial functional cofactors can improve the metabolic activity of the key nitrogen circulating microorganisms; and the carrier can realize uniform loading and slow release of the components. The method can significantly improve the activity of aerobic microorganisms, accelerate the formation of nitrate nitrogen, improve the effectiveness of soil nitrogen and promote the early growth of vegetables, and has a good application prospect in a rice-vegetable rotation system.

Description

Technical Field

[0001] This invention relates to the field of soil activator technology, and in particular to a microbial functional activator for rice-vegetable rotation soil and its preparation method. Background Technology

[0002] The rice-vegetable rotation system is widely distributed in my country's southern rice-growing areas and some facility agriculture areas, and it is of great significance for making full use of land resources and ensuring the dual supply of grain and vegetables. In a typical rice-vegetable rotation system, the previous crop is rice, whose root zone is in a submerged or semi-submerged environment for a long time; the next crop is mostly aerobic vegetables, such as cabbage, cauliflower, tomatoes, and peppers. Although this alternating water and dryland planting pattern improves land use efficiency, it also leads to drastic changes in the topsoil environment in a short period of time, significantly affecting soil microbial structure, nutrient cycling processes, and vegetable growth.

[0003] During the rice growing season, paddy fields are typically managed with continuous or intermittent irrigation, which hinders soil oxygen diffusion, resulting in low dissolved oxygen content and a significant decrease in redox potential, creating a typical anaerobic environment. Under these prolonged flooding conditions, the activity of a large number of aerobic microorganisms in the soil is inhibited, and many even die off. Instead, a community structure dominated by anaerobic or facultative anaerobic microorganisms such as denitrifying bacteria, iron-reducing bacteria, and methanogens gradually becomes dominant. While this adjustment in microbial structure is beneficial for nutrient supply at specific stages of rice growth, it weakens the number and activity of nitrification-related microorganisms in the soil (such as ammonia-oxidizing bacteria, ammonia-oxidizing archaea, and nitrite-oxidizing bacteria). Nitrifying microorganisms play a crucial role in the soil nitrogen cycle by converting ammonium nitrogen into nitrate nitrogen, and are a core functional group ensuring that dryland vegetables obtain absorbable nitrogen sources.

[0004] However, after rice harvest, the fields are quickly drained and exposed to air, rapidly shifting the soil environment from anaerobic to aerobic. But the aerobic microorganisms suppressed during the flooding period often exhibit a significant lag in recovery, and community structure reconstruction takes a considerable amount of time. During this period, the nitrogen cycle remains dominated by ammonium nitrogen and organic nitrogen, while nitrate nitrogen supply is insufficient, leading to widespread "nitrogen hunger" in vegetables in the early stages of transplanting, manifested as weak root growth, pale leaf color, and slow growth, severely impacting yield and quality.

[0005] To improve the microbial activity and nitrogen supply in rice-vegetable rotation soil, existing technologies have proposed measures such as applying organic fertilizer, supplementing microbial agents, returning straw to the field, and improving soil aeration. However, these measures generally suffer from problems such as insufficient carbon source availability, incomplete improvement of oxygen supply, delayed recovery of microbial activity, weak nitrification function, and unstable effects under low temperature and alternating wet and dry conditions, making it difficult to meet the demand for "rapidly providing effective nitrogen" in the early stages of vegetable transplanting.

[0006] Therefore, the research and development of a microbial functional activator that can comprehensively improve soil microbial activity, promote nitrification function recovery, enhance nitrogen availability, adapt to water-drought transition and low-temperature environment, and be used in rice-vegetable rotation soil, as well as its preparation method, has good application prospects. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the rice-vegetable rotation system, such as slow recovery of aerobic microbial activity, insufficient nitrification function, decreased nitrogen availability, and limited nutrient supply in the early stages of vegetable growth. This invention provides a microbial function activator for rice-vegetable rotation soil and its preparation method, in order to improve soil microbial function under water-dry transition conditions, promote nitrogen conversion, and improve nutrient utilization efficiency and crop growth performance in the rotation system.

[0008] This invention selects small-molecule fast-acting carbon sources that are easily absorbed by microorganisms and slow-release carbon sources that can maintain long-term carbon supply, enabling soil microorganisms to maintain a continuous substrate supply capacity under low-temperature conditions. Combined with oxygen-enhancing components that can slowly release oxygen and functional cofactors that promote the activity of microbial metabolic enzymes, it can significantly improve the recovery speed and nitrogen conversion capacity of soil microorganisms during water-drought transitions and under low-temperature conditions.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a microbial functional activator for rice-vegetable rotation soil, comprising the following components in parts by weight: 20-30 parts of fast-acting carbon source, 10-15 parts of slow-release carbon source, 5-8 parts of oxygen-enhancing component, 3-6 parts of microbial functional cofactor, and 25-40 parts of carrier.

[0010] Preferably, the fast-acting carbon source is one or more of glucose, glycerol, molasses, soluble starch, and oligosaccharides; The slow-release carbon source is one or more of sodium humate, potassium humate, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, and sodium lignosulfonate.

[0011] Preferably, the oxygenating component is one or more of calcium peroxide, sodium percarbonate, manganese dioxide, and ferric oxide.

[0012] Preferably, the microbial functional cofactor is a metal ion and / or a microbial functional auxiliary agent; The metal ions are and One or more of them; The microbial functional aid is vitamin. Vitamins One or more of citrate and amino acids.

[0013] Preferably, the carrier is biochar or bentonite.

[0014] The present invention also provides a method for preparing the aforementioned microbial functional activator, comprising the following steps: 1) Dissolve the fast-acting carbon source in water to obtain a fast-acting carbon source solution; 2) The slow-release carbon source is combined with a support to obtain a solid carbon source support; 3) Mix the oxygen-enhancing components with microbial functional cofactors to obtain a functional component mixture; 4) Stir the mixture of fast-acting carbon source solution, solid carbon source carrier and functional components, and then granulate it to obtain a microbial functional activator for rice-vegetable rotation soil.

[0015] Preferably, the mass fraction of the fast-acting carbon source solution in step 1) is 8-12%; Step 2) The compounding rotation speed is 30~50 r / min, the compounding temperature is 30~40℃, and the compounding time is 10~20 min.

[0016] Preferably, the mixing speed in step 3) is 80~100 r / min, the mixing temperature is 15~35℃, and the mixing time is 3~5 min.

[0017] Preferably, the stirring speed in step 4) is 80~120 r / min, the stirring temperature is 20~30℃, and the stirring time is 10~15 min; The granulation is carried out by extrusion granulation, with an extrusion pressure of 0.5~0.8MPa, and the resulting particles have a diameter of 3~5mm.

[0018] Preferably, after the granulation in step 4) is completed, a drying process is performed; The drying process is carried out at a temperature of 60~80℃ until the moisture content of the resulting particles is ≤10%.

[0019] The beneficial effects of this invention include the following: 1) Significantly promotes the recovery and proliferation of aerobic microorganisms under water-drought transition conditions: This invention provides an immediate and continuous carbon source supply for aerobic microorganisms through the synergistic design of fast-acting carbon sources, slow-release carbon sources and oxygen-enhancing components, and improves soil aeration, enabling aerobic microorganisms to recover rapidly after flooding.

[0020] 2) Enhance nitrification function and increase nitrogen conversion efficiency: This invention can effectively promote the metabolism of nitrifying bacteria by providing sufficient carbon source, improving oxygen supply conditions, and adding metal ions and vitamin-like functional cofactors, thereby increasing the conversion rate of ammonium nitrogen to nitrate nitrogen.

[0021] 3) Improve soil nitrogen availability and enhance continuous nitrogen supply capacity: This invention contains both fast-acting and slow-release carbon sources, which ensures that microorganisms have a suitable carbon source supply throughout the cultivation process. This is conducive to the continuous participation of microorganisms in the soil nitrogen transformation process, thereby increasing the level of available nitrogen such as alkaline nitrogen and nitrate nitrogen.

[0022] 4) Improve early growth conditions for vegetables, increase emergence rate, biomass and yield: This invention improves the availability of nutrients in the early growth stage of vegetables by increasing the number of aerobic microorganisms, accelerating the nitrification rate and increasing the available nitrogen supply in the soil, so that the crop grows more uniformly, resulting in a higher emergence rate, greater biomass per plant and higher final yield.

[0023] 5) The components are rationally proportioned and complementary in function, and the overall effect is better than that of a single improvement measure: The present invention forms a synergistic mechanism among carbon source type, oxygen-enriching component, microbial functional cofactor and carrier, which can not only provide the nutrients required for microbial metabolism, but also improve soil aeration and enhance the activity of microorganisms under low temperature conditions.

[0024] 6) The preparation process is simple, the parameters are controllable, the resulting activator particles have a stable structure, and the application is convenient: The preparation method of the present invention consists of steps such as compounding, homogenization, extrusion granulation and drying. The process conditions are mild and the parameters are controllable. The resulting particles have advantages such as good formability, stable structure, non-hygroscopic clumping, and convenient application. Detailed Implementation

[0025] This invention provides a microbial functional activator for rice-vegetable rotation soil, comprising the following components in parts by weight: 20-30 parts of fast-acting carbon source, 10-15 parts of slow-release carbon source, 5-8 parts of oxygen-enhancing component, 3-6 parts of microbial functional cofactor, and 25-40 parts of carrier.

[0026] The microbial functional activator of the present invention comprises 20 to 30 parts of fast-acting carbon source, preferably 22 to 28 parts, more preferably 24 to 26 parts, and even more preferably 25 parts.

[0027] In this invention, the fast-acting carbon source is preferably one or more of glucose, glycerol, molasses, soluble starch, and oligosaccharides.

[0028] In this invention, the readily available carbon source is a small-molecule organic carbon that is easily soluble and absorbed by microorganisms. It can rapidly enter the metabolic pathways of soil microorganisms in the early stages after soil drainage transitions to dryness, providing a directly usable energy source for aerobic microorganisms. Especially during the sensitive transition from water to drought, the number of functional microbial communities such as nitrifying bacteria and ammonia-oxidizing archaea decreases due to flooding inhibition. Providing a readily available carbon source can rapidly promote microbial cell recovery, metabolic activation, and increase the rates of key processes such as nitrite oxidation and ammonia oxidation. Furthermore, the small-molecule carbon source maintains high availability even under low-temperature conditions, significantly enhancing the nitrogen conversion potential of microorganisms during cold seasons, which is of great significance for improving early nitrogen supply in vegetables.

[0029] The microbial functional activator of the present invention comprises 10-15 parts of slow-release carbon source, preferably 11-14 parts, more preferably 12-13 parts, and more preferably 12.5 parts.

[0030] In this invention, the slow-release carbon source is preferably one or more of sodium humate, potassium humate, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, and sodium lignosulfonate.

[0031] In this invention, the slow-release carbon source is characterized by its stable structure and controllable degradation rate. In soil, it continuously releases soluble organic carbon through microbial enzymatic degradation or slow chemical decomposition. This long-term carbon supply mode compensates for the shortcomings of fast-acting carbon sources, which are characterized by rapid release and consumption. It provides a stable and continuous substrate supply for aerobic soil microorganisms, preventing them from re-entering a metabolic stagnation state due to carbon source depletion in the later stages of recovery. Simultaneously, humic substances improve soil aggregate structure, enhance water retention and cation exchange capacity, contributing to microenvironmental stability and thus improving the survival and reproduction conditions of nitrifying microorganisms. The introduction of the slow-release carbon source achieves a dual carbon supply mode of "rapid activation in the early stage + continuous maintenance in the later stage," which is more in line with the gradual recovery pattern of soil microorganisms during water-dry transition.

[0032] The microbial functional activator of the present invention comprises 5 to 8 parts of oxygen-enriching components, preferably 5.5 to 7.5 parts, more preferably 6 to 7 parts, and even more preferably 6.5 parts.

[0033] In this invention, the oxygenating component is preferably one or more of calcium peroxide, sodium percarbonate, manganese dioxide, and ferric oxide.

[0034] In this invention, the oxygenating component gradually releases oxygen under soil moisture and microbial metabolism, thereby improving the localized anoxic microenvironment in the early stages of water-dry transition. Because flooding in paddy fields causes the death of a large number of aerobic microorganisms, although air diffusion recovers after soil drainage, the micropores may still remain in a relatively low-oxygen state for a long time, limiting the physiological activity of nitrifying bacteria. The continuous oxygen supply from the oxygenating component can significantly increase dissolved oxygen and oxygen diffusion rate in the soil, providing a more suitable oxygen environment for the re-proliferation of aerobic microorganisms and facilitating the reconstruction of key nitrogen cycle processes such as nitrification and denitrification. Simultaneously, the oxygenating component can also promote the oxidative decomposition of some recalcitrant organic matter in the soil, accelerate substrate turnover, and indirectly promote the recovery of the microbial community and improve nitrogen conversion efficiency.

[0035] The microbial functional activator of the present invention comprises 3 to 6 parts of microbial functional cofactor, preferably 4 to 5.5 parts, more preferably 4.5 to 5 parts, and even more preferably 4.8 parts.

[0036] In this invention, the microbial functional cofactor is preferably a metal ion and / or a microbial functional auxiliary agent; The metal ions are preferably... and One or more of them; The microbial functional adjuvant is preferably a vitamin. Vitamins One or more of citrate and amino acids.

[0037] In this invention, the microbial functional cofactor is an activator of key enzyme systems in the microbial metabolic process. Metal ions act as cofactors for many oxidoreductases, ammonia oxidases, and nitrite oxidases, significantly enhancing the rate of enzymatic reactions in microorganisms, particularly important for restoring nitrification. Simultaneously, substances such as B vitamins, citrates, and amino acids serve as co-substrate for microbial cell metabolism, promoting energy metabolism and cell proliferation, and enhancing the microorganisms' adaptability to adverse conditions such as low temperatures and alternating wet and dry periods. These cofactors can improve microbial carbon metabolism in the early stages of water-dry transition. Improving the utilization efficiency of nitrogen and oxygen sources, and enhancing microbial activity at the metabolic level, is an important supplementary component for promoting soil function restoration.

[0038] The microbial functional activator of the present invention comprises 25 to 40 parts of carrier, preferably 28 to 36 parts, more preferably 30 to 34 parts, and even more preferably 32 parts.

[0039] In this invention, the carrier is preferably biochar or bentonite.

[0040] In this invention, the carrier possesses excellent specific surface area, pore structure, and water retention, providing a stable loading platform for microbial functional components. Biochar, rich in various oxygen-containing functional groups, exhibits strong adsorption capacity and abundant microporous structure, improving soil aeration and increasing microbial attachment. Bentonite, with its excellent water absorption and layered structure, adsorbs and slowly releases water and nutrients, promoting microbial activity in the soil. The addition of the carrier promotes the directional release and local accumulation of various functional components in the soil, prolongs the component's action time, improves the microbial living environment, and enhances the overall stability and effectiveness of the activator in rice-vegetable rotation soils.

[0041] Through the synergistic effect of the above-mentioned components, this invention can provide the soil with a readily available carbon source, a stable and continuous substrate supply, a suitable oxygen environment, and metabolic promotion conditions under water-dry transition conditions, thereby accelerating the recovery of nitrification-related functional microorganisms, improving soil nitrogen conversion efficiency, and improving the nutrient supply environment in the early stages of vegetable growth.

[0042] The present invention also provides a method for preparing the aforementioned microbial functional activator, preferably comprising the following steps: 1) Dissolve the fast-acting carbon source in water to obtain a fast-acting carbon source solution; 2) The slow-release carbon source is combined with a support to obtain a solid carbon source support; 3) Mix the oxygen-enhancing components with microbial functional cofactors to obtain a functional component mixture; 4) Stir the mixture of fast-acting carbon source solution, solid carbon source carrier and functional components, and then granulate it to obtain a microbial functional activator for rice-vegetable rotation soil.

[0043] In this invention, the mass fraction of the fast-acting carbon source solution in step 1) is preferably 8-12%, more preferably 9-11%, and even more preferably 10%. Step 2) The rotational speed for the compounding is preferably 30~50 r / min, more preferably 35~45 r / min, and even more preferably 40 r / min; the compounding temperature is preferably 30~40℃, more preferably 34~36℃, and even more preferably 35℃; the compounding time is preferably 10~20 min, more preferably 14~16 min, and even more preferably 15 min.

[0044] In this invention, the mixing speed in step 3) is preferably 80~100 r / min, and more preferably... The mixing speed is 85~95 r / min, more preferably 90 r / min; the mixing temperature is preferably 15~35℃, further preferably 20~30℃, more preferably 25℃; the mixing time is preferably 3~5 min, further preferably 3.5~4.5 min, more preferably 4 min.

[0045] In this invention, the stirring speed in step 4) is preferably 80~120 r / min, more preferably 90~110 r / min, and even more preferably 100 r / min; the stirring temperature is preferably 20~30℃, more preferably 25℃; and the stirring time is preferably 10~15 min, more preferably 12~14 min, and even more preferably 13 min. The granulation is preferably carried out by extrusion granulation, with an extrusion pressure preferably of 0.5~0.8MPa, more preferably 0.6~0.7MPa, and even more preferably 0.65MPa. The particle size of the resulting particles is preferably 3~5mm, and even more preferably 4mm.

[0046] In this invention, after the granulation in step 4) is completed, it is preferable to perform a drying process; The drying temperature is preferably 60~80℃, more preferably 65~75℃, and even more preferably 70℃. The moisture content of the resulting particles is preferably ≤10%, more preferably ≤8%, and even more preferably ≤5%.

[0047] The steps and parameters in the preparation method of this invention are designed based on the physicochemical properties of each functional component in the activator and its mechanism of action in the soil, demonstrating clear process rationality. Firstly, dissolving the readily available carbon source in water ensures that the small molecule carbon source can enter the soil in a completely dissolved state, improving the absorption efficiency of the carbon source by microorganisms in the early stages of water-dry transition. The mass fraction of the readily available carbon source solution is controlled within the range of 8-12%, ensuring good fluidity and permeability while avoiding excessive concentration that could lead to microbial metabolic imbalance or excessive humidity during granulation, thus affecting the granulation effect.

[0048] Secondly, the composite step of the slow-release carbon source and the carrier is carried out at a gentle rotation speed of 30-50 r / min and at a temperature of 30-40℃. This helps the slow-release carbon source to be evenly dispersed in the pores or surface of the carrier, improving its slow-release stability in the soil. Too high a rotation speed may cause the carrier structure to break down and the slow-release carbon source to agglomerate, while too low a rotation speed makes it difficult to achieve a uniform composite effect. The temperature range is also set based on the material properties to avoid agglomeration or property changes of cellulose derivatives or humic acid substances at high temperatures.

[0049] Secondly, the mixing speed of the oxygenating components and microbial functional cofactors is selected at 80-100 r / min to ensure that the solid components are thoroughly mixed, so that trace metal ions and oxygenating materials are evenly distributed, thereby improving their subsequent local availability in the soil. The temperature in this step is controlled within the normal temperature range of 15-35℃ to avoid the inactivation of vitamins at high temperatures, while maintaining the stability of metal ions.

[0050] In the final stirring step, the mixture of the fast-acting carbon source solution, solid carbon source carrier, and functional components is stirred at a speed ranging from 80 to 120 rpm. This speed is determined based on the differences in viscosity, moisture content, and particle size among the different materials. A higher stirring speed ensures that the liquid phase components are uniformly loaded onto the surface of the solid particles, resulting in a uniformly distributed, mutually coated wet material that provides a good material basis for granulation. Maintaining the stirring temperature within the range of 20 to 30°C helps maintain stable solution viscosity and prevents material adhesion or stratification due to improper temperature control.

[0051] The granulation process employs extrusion granulation, with the extrusion pressure controlled at 0.5~0.8MPa. This aims to form functional components into particles with uniform structure and suitable strength. Too low a pressure will cause the particles to loosen, affecting subsequent application; too high a pressure may cause some components to become inactive under pressure or result in excessively hard particles, hindering dispersion in the soil. The particle size obtained from granulation is controlled at 3~5mm, balancing operability during application with good dispersibility in the soil.

[0052] In the final drying step, the temperature is controlled within the range of 60~80℃. This not only quickly removes excess moisture and ensures the stability of the granules during storage, but also prevents the degradation of readily available carbon sources or vitamins at high temperatures. Controlling the moisture content of the granules to no more than 10% by mass ensures that the granules have good mechanical strength, are not prone to moisture absorption and clumping, and have suitable dissolution characteristics after being applied to the soil.

[0053] In summary, the steps and process parameters of the preparation method of this invention are scientifically designed based on the physicochemical properties of the components, their behavior in the soil, and the final application effect, and are not arbitrarily limited. Reasonable process conditions can ensure the uniform distribution and stable fixation of various functional components, resulting in good application performance, thereby fully leveraging the overall application effect of the microbial functional activator of this invention in rice-vegetable rotation soil.

[0054] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0055] The "biochar" described in this specification is prepared using a conventional oxygen-limited pyrolysis method. The preparation steps are as follows: Using rice husks as biomass raw material, the rice husks are first washed and impurities removed, and then dried at 105℃ to constant weight. The dried rice husks are then placed in a tubular furnace and heated under conditions of limited or anaerobic environment maintained by introducing a small amount of nitrogen. The heating rate is controlled at 10℃ / min, raising the temperature to 550℃, and holding at this temperature for 2 hours to allow the biomass to fully undergo pyrolysis, generating porous carbonaceous material. After pyrolysis, heating is stopped, and the material is allowed to cool naturally to room temperature. Throughout the cooling process, a small amount of nitrogen is maintained to prevent oxidation. The cooled solid material is removed from the furnace, lightly pulverized, and sieved through a 4mm sieve to obtain biochar with a high specific surface area and well-developed pore structure. Example 1

[0056] Dissolve 25g of glucose in deionized water to obtain a glucose solution with a mass fraction of 10%.

[0057] 12g of sodium humate and 35g of biochar were added to a mixing device and compounded at 35℃ for 15 minutes at a speed of 40r / min to obtain a solid carbon source carrier.

[0058] Add 6g of calcium peroxide and 2g of magnesium sulfate heptahydrate (provided) ) and 3g vitamins Add them together to the mixer and mix at 90 r / min at 25°C for 4 min to obtain a functional component mixture.

[0059] The glucose solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 100 r / min for 12 min, while maintaining the stirring temperature at 25℃.

[0060] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.6 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 70°C to dry until the moisture content of the granules drops to 8%, resulting in microbial functional activator granules with a particle size of 4 mm for use in rice-vegetable rotation soil. Example 2

[0061] Dissolve 20g of glycerol in deionized water to obtain a glycerol solution with a mass fraction of 8%.

[0062] 10g of potassium humate and 25g of biochar were added to a mixing device and compounded at 30r / min and 30℃ for 20min to obtain a solid carbon source carrier.

[0063] Add 5g of sodium percarbonate and 2g of ferrous sulfate heptahydrate (provided) ) and 4g vitamins Add them together to the mixer and mix at 80 r / min at 15°C for 5 min to obtain a functional component mixture.

[0064] The glycerol solution, solid carbon source carrier, and functional component mixture were sequentially added to a stirring device and stirred at 80 r / min for 15 min, while maintaining the stirring temperature at 20℃.

[0065] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.5 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 60°C to dry until the moisture content of the granules drops to 10%, resulting in microbial functional activator granules with a particle size of 3 mm for use in rice-vegetable rotation soil. Example 3

[0066] Add 30g of molasses to deionized water, stir to dilute and mix well to obtain a molasses solution with a mass fraction of 12%.

[0067] 15g of sodium carboxymethyl cellulose and 40g of bentonite were added to a mixing device and compounded at 50r / min and 40℃ for 10min to obtain a solid carbon source carrier.

[0068] Add 8g of manganese dioxide and 2g of copper sulfate pentahydrate (provided) Add 5g of sodium citrate and 5g of sodium citrate to a mixer and mix at 100r / min at 35℃ for 3min to obtain a functional component mixture.

[0069] The molasses solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 120 r / min for 10 min, while maintaining the stirring temperature at 30℃.

[0070] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.8 MPa. The wet granules are then evenly spread in a drying tray and placed in an 80°C hot air drying oven to dry until the moisture content of the granules drops to 9%, resulting in microbial functional activator granules with a particle size of 5 mm for use in rice-vegetable rotation soil. Example 4

[0071] Dissolve 22g of soluble starch in deionized water to obtain a soluble starch solution with a mass fraction of 9%.

[0072] 13g of hydroxypropyl methylcellulose and 30g of biochar were added to a mixing device and compounded at 35r / min and 35℃ for 14min to obtain a solid carbon source carrier.

[0073] Add 7g of ferric oxide and 1.5g of manganese sulfate (provided) Add 3.5g of glutamic acid to a mixer and mix at 85r / min at 30℃ for 3min to obtain a functional component mixture.

[0074] The soluble starch solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 110 r / min for 15 min, while maintaining the stirring temperature at 25℃.

[0075] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.7 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 65°C to dry until the moisture content of the granules drops to 10%, resulting in microbial functional activator granules with a particle size of 4 mm for use in rice-vegetable rotation soil. Example 5

[0076] Dissolve 26g of maltodextrin in deionized water to obtain a maltodextrin solution with a mass fraction of 11%.

[0077] 14g of sodium lignosulfonate and 38g of bentonite were added to a mixing device and compounded at 45r / min and 40℃ for 16min to obtain a solid carbon source carrier.

[0078] Add 5.5g of ferric oxide and 2g of magnesium sulfate (provided) ) and 3g vitamins Add them together to the mixer and mix at 95 r / min at 20°C for 5 min to obtain a functional component mixture.

[0079] The maltodextrin solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 105 r / min for 11 min, while maintaining the stirring temperature at 30℃.

[0080] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.8 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 75°C to dry until the moisture content of the granules drops to 8%, resulting in microbial functional activator granules with a particle size of 5 mm for use in rice-vegetable rotation soil. Comparative Example 1

[0081] Dissolve 30g of glucose in deionized water to obtain a glucose solution with a mass fraction of 12%.

[0082] 40g of biochar was added separately to the mixing device without adding a slow-release carbon source, and stirred at 40r / min at 35℃ for 10min to obtain a solid material containing only the carrier.

[0083] Add 8g of calcium peroxide and 3g of magnesium sulfate heptahydrate (provided) ) and 4g vitamins Add them together to the mixer and mix at 90 r / min at 25°C for 4 min to obtain a functional component mixture.

[0084] Glucose solution, solid material containing only biochar, and mixture of functional components were added sequentially to a stirring device and stirred at 80 r / min for 10 min, while maintaining the stirring temperature at 20℃.

[0085] After mixing, the wet material is fed into an extrusion granulator and extruded under an extrusion pressure of 0.6 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 70°C to dry until the moisture content of the granules drops to 8%, resulting in activator granules with a particle size of 4 mm that do not contain a slow-release carbon source. Comparative Example 2

[0086] Add 25g of glycerol to deionized water and stir to mix well to obtain a 10% glycerol solution.

[0087] 12g of potassium humate and 35g of biochar were added to a mixing device and compounded at 30℃ for 15 minutes at a speed of 40r / min to obtain a solid carbon source carrier.

[0088] Add 3g of ferrous sulfate heptahydrate (provided) ) and 5g vitamin Add them together to the mixer, without adding oxygenating components, and mix at 80 r / min at 20°C for 5 min to obtain a functional component mixture without oxygenating components.

[0089] The glycerol solution, solid carbon source carrier, and functional component mixture were sequentially added to a stirring device and stirred at 80 r / min for 10 min, while maintaining the stirring temperature at 25℃.

[0090] After mixing, the wet material is fed into an extrusion granulator and extruded under an extrusion pressure of 0.5 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 60°C to dry until the moisture content of the granules drops to 10%, resulting in activator granules with a particle size of 3 mm that do not contain oxygen-enriching components. Comparative Example 3

[0091] Add 28g of molasses to deionized water and stir to dilute, resulting in a molasses solution with a mass fraction of 11%.

[0092] 15g of sodium carboxymethyl cellulose and 40g of bentonite were added to a mixing device and compounded at 50r / min and 40℃ for 12min to obtain a solid carbon source carrier.

[0093] Subsequently, only 8g of manganese dioxide was added as an oxygenating component, without adding any microbial functional cofactors. The mixture was then mixed at 100r / min at 30℃ for 3min to obtain a functional component mixture containing only oxygenating materials.

[0094] The molasses solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 120 r / min for 10 min, while maintaining the stirring temperature at 25℃.

[0095] After mixing, the wet material is fed into an extrusion granulator and extruded under an extrusion pressure of 0.7 MPa. The wet granules are then evenly spread in a drying tray and placed in a hot air drying oven at 75°C to dry until the moisture content of the granules drops to 9%, resulting in activator granules with a particle size of about 5 mm that do not contain microbial functional cofactors. Comparative Example 4

[0096] Dissolve 40g of glucose in deionized water to obtain a glucose solution with a mass fraction of 16%.

[0097] 5g of sodium humate and 20g of biochar were added to a mixing device and compounded at 30r / min and 30℃ for 10min to obtain a solid carbon source carrier.

[0098] Add 3g of sodium percarbonate and 1g of ferrous sulfate heptahydrate (provided) ) and 2g vitamin Add them together to the mixer and mix at 80 r / min at 20°C for 3 min to obtain a functional component mixture.

[0099] The glucose solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at 90 r / min for 5 min, with the stirring temperature controlled at 20℃.

[0100] After mixing, the wet material is fed into an extrusion granulator and extruded into shape under an extrusion pressure of 0.6 MPa. Then, the wet granules are evenly spread in a drying tray and placed in a hot air drying oven at 65°C to dry until the moisture content of the granules drops to 10%. This yields activator granules with a particle size of 4 mm, a high proportion of fast-acting carbon source, a significant deficiency in slow-release carbon source and carrier, and a low oxygen-enriching component. Comparative Example 5

[0101] Dissolve 25g of maltodextrin in deionized water to obtain a 10% maltodextrin solution.

[0102] 14g of sodium lignosulfonate and 38g of bentonite were added to a mixing device, but without full compounding, they were simply stirred at 15r / min at 20℃ for 5min to obtain a solid carbon source carrier with insufficient compounding.

[0103] Add 5g of ferric oxide and 2g of magnesium sulfate heptahydrate (provided) ) and 3g vitamins Add them together to the mixer and mix at 50 r / min at 15°C for 2 min to obtain an insufficiently mixed functional component mixture.

[0104] The maltodextrin solution, solid carbon source carrier, and functional component mixture were added sequentially to a stirring device and stirred at a speed of 50 r / min for 5 min with the stirring temperature controlled at 15℃. This did not achieve a sufficiently uniform dispersion.

[0105] After mixing, the wet material is fed into an extrusion granulator and extruded under an extrusion pressure of 0.3 MPa. The resulting granules have poor formability and some are fragmented. After granulation, no hot air drying is performed; the granules are simply left to dry naturally at room temperature until the surface is dry.

[0106] The activator particles obtained in this comparative example have a high moisture content, insufficient hardness, and are prone to absorbing moisture and clumping, with uneven particle size distribution.

[0107] To verify the effects of the microbial functional activator of the present invention on rice-vegetable rotation soil in restoring aerobic microbial activity, enhancing nitrification function, increasing nitrogen availability, and promoting early vegetable growth under water-dry transition conditions, the activator particles prepared in Examples 1-5 and Comparative Examples 1-5 were used in simulated rice-vegetable rotation soil systems for comparative experiments.

[0108] The experimental soil was taken from a field with a long-term rice-vegetable rotation system. After rice harvest, the soil was continuously flooded for 45 days to reduce its condition and cause aerobic microorganisms to decline. It was then allowed to air dry for 7 days. Soil from the 0-20cm topsoil layer was collected, air-dried, and sieved through a 2mm sieve for later use. The initial total nitrogen content was approximately 1.2 g / kg, the available nitrogen content was approximately 90 mg / kg, and the pH was approximately 6.5.

[0109] The granules obtained from Examples 1-5 and Comparative Examples 1-5 were added to plastic seedling boxes containing 2 kg of air-dried soil at an application rate of 0.1 g activator / kg soil, and mixed thoroughly. Water was then slowly added to the boxes to maintain a water level of 3 cm, and the boxes were placed in a 20°C environment for 7 days of flooding cultivation to simulate the anaerobic conditions created during rice cultivation, resulting in a significant reduction in aerobic microorganisms in the soil. After the flooding stage, the surface water was drained, allowing the soil to dry naturally, and the soil moisture content was adjusted to approximately 60% of field capacity. Subsequently, the seedling boxes were placed in an 18°C ​​environment for vegetable cultivation experiments to simulate the recovery stage of soil from anaerobic to aerobic conditions after a transition from water to drought.

[0110] During the vegetable cultivation stage, each treatment was sown with 30 seeds per box, covered with 1cm of soil. The entire cultivation cycle was 30 days, during which water was added as needed based on soil moisture, and no additional nitrogen fertilizer was applied to highlight the effects of different activators on soil nitrogen conversion and supply capacity. During cultivation, samples were taken at the end of flooding and on days 15 and 30 to measure the number of aerobic microorganisms, nitrate nitrogen content, and available nitrogen content in the soil. Comparative analysis revealed that the number of aerobic microorganisms, nitrate nitrogen content, and available nitrogen content on day 30 comprehensively reflected the differences in microbial recovery speed and nitrogen supply capacity among the treatments after the transition from flood to drought. Therefore, the table in this invention selects the data from day 30 as representative results to reflect the actual differences in effects among different treatments; at the end of cultivation, the germination rate was calculated, and plant biomass and yield were measured.

[0111] The number of aerobic microorganisms was determined using the plate dilution method. Soil samples were serially diluted 10-fold and spread onto nutrient agar medium. After incubation at 28℃ for 48 hours, the microorganisms were counted, and the results were expressed as CFU / g dry soil. Nitrate nitrogen content was determined using a colorimetric method, and the results were expressed as mg / kg dry soil. Soil alkaline available nitrogen was determined using the alkaline diffusion method. The emergence rate was calculated as the ratio of the number of normally germinated seedlings to the number of seeds sown. Biomass was the fresh weight of the aboveground parts. Yield was the total fresh weight of the aboveground parts harvested per box. At the end of the experiment, the key indicators for each treatment were shown in Table 1.

[0112] Table 1 Soil microbial activity, nitrogen availability, and growth of Chinese cabbage under different activators.

[0113] As shown in Table 1, the number of aerobic bacteria in each treatment of Examples 1-5 was significantly higher than that in the comparative treatment, with the number of aerobic bacteria in Examples 4 and 5 reaching [number missing]. and The comparative treatments were only This invention demonstrates that by rationally matching fast-acting carbon sources, slow-release carbon sources, oxygen-enhancing components, and microbial functional cofactors, it can accelerate the recovery of aerobic microbial communities after water-dry transitions. Compared with control samples that omit key components or have improper ratios or unreasonable processes, it has a significant activation advantage.

[0114] Regarding nitrification function, the nitrate nitrogen content in Examples 1-5 ranged from 31.2 to 36.1 mg / kg, significantly higher than the 16.8 to 22.8 mg / kg in Comparative Examples 1-5. In particular, Examples 4 and 5 achieved nitrate nitrogen contents of 36.1 mg / kg and 35.4 mg / kg, respectively, while Comparative Example 2 (without oxygenating components) and Comparative Example 3 (without functional cofactors) had nitrate nitrogen contents of only 17.5 mg / kg and 22.8 mg / kg, respectively. This demonstrates that the activator of this invention, while providing a carbon source, improves soil aeration through oxygenating components and promotes the metabolism of nitrification-related microorganisms with the help of cofactors such as metal ions, vitamins, citrates, and amino acids, significantly increasing the conversion rate of ammonium nitrogen to nitrate nitrogen, overcoming the problem of slow nitrification function recovery in existing technologies.

[0115] Regarding soil nitrogen availability, the alkaline available nitrogen content in Examples 1-5 was 117-124 mg / kg. Compared to 90-98 mg / kg in Comparative Examples 1-5, this represents a significant improvement. In Comparative Example 1, when the slow-release carbon source was omitted, the alkaline-hydrolyzable nitrogen was only 95 mg / kg, indicating that relying solely on the readily available carbon source is insufficient to support sustained microbial activation. In Comparative Example 4, the component ratio was unbalanced, with a high readily available carbon source and low carrier and slow-release carbon source, resulting in an alkaline-hydrolyzable nitrogen of 93 mg / kg, which also failed to maintain long-term nitrogen availability. This demonstrates that the present invention, through the combined design of readily available and slow-release carbon sources, enables microorganisms to respond rapidly in the early stages while maintaining a relatively stable carbon source supply during cultivation, thereby ensuring a high level of nitrogen availability.

[0116] Regarding crop growth, the emergence rates of Examples 1-5 were all above 93%, significantly higher than the 82-87% of Comparative Examples 1-5; the emergence rate of Example 4 reached 97%, achieving relatively uniform emergence and early growth. In terms of biomass and yield, the biomass per plant in each of the Examples was 7.2-8.0 g / plant, and the yield was 135-145 g / box, both significantly higher than the 4.8-5.7 g / plant and 105-115 g / box of the Comparative Examples. Among them, Comparative Example 5, due to significantly insufficient compounding, mixing, and granulation process parameters during preparation, resulted in unstable particle structure and asynchronous nutrient release, with a yield of only 105 g / box, reflecting the importance of reasonable process control for maximizing the effectiveness of the activator of this invention.

[0117] In summary, the microbial functional activator of this invention, through the combination of multiple fast-acting and slow-release carbon sources, the introduction of oxygen-enhancing components, and the synergistic effect of microbial functional cofactors such as metal ions, vitamins, citrates, and amino acids, can significantly promote the recovery of aerobic microbial activity, improve nitrification function and nitrogen availability, and improve nutrient supply in the early growth stages of vegetables under rice-vegetable rotation conditions of water-dry transition. Compared with control samples that omit key components, have significantly deviated component ratios, or have unreasonable preparation processes, the embodiments of this invention show significant advantages in terms of microbial quantity, nitrate nitrogen content, soil available nitrogen level, and crop growth and yield. This fully verifies that the microbial functional activator for rice-vegetable rotation soil and its preparation method described in this invention can effectively achieve the technical objectives of "improving soil microbial function under water-dry transition conditions, promoting nitrogen transformation, and improving nutrient utilization efficiency and crop growth performance in the rotation system."

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A microbial functional activator for rice-vegetable rotation soil, characterized in that, The components comprise the following parts by weight: 20-30 parts of fast-acting carbon source, 10-15 parts of slow-release carbon source, 5-8 parts of oxygen-enhancing component, 3-6 parts of microbial functional cofactor, and 25-40 parts of carrier.

2. The microbial functional activator according to claim 1, characterized in that, The fast-acting carbon source is one or more of glucose, glycerol, molasses, soluble starch, and oligosaccharides; The slow-release carbon source is one or more of sodium humate, potassium humate, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, and sodium lignosulfonate.

3. The microbial functional activator according to claim 1 or 2, characterized in that, The oxygenating component is one or more of calcium peroxide, sodium percarbonate, manganese dioxide, and ferric oxide.

4. The microbial functional activator according to claim 3, characterized in that, The microbial functional cofactor is a metal ion and / or a microbial functional aid; The metal ions are and One or more of them; The microbial functional aid is vitamin. Vitamins One or more of citrate and amino acids.

5. The microbial functional activator according to claim 4, characterized in that, The carrier is biochar or bentonite.

6. The method for preparing the microbial functional activator according to any one of claims 1 to 5, characterized in that, It includes the following steps: 1) Dissolve the fast-acting carbon source in water to obtain a fast-acting carbon source solution; 2) The slow-release carbon source is combined with a support to obtain a solid carbon source support; 3) Mix the oxygen-enhancing components with microbial functional cofactors to obtain a functional component mixture; 4) Stir the mixture of fast-acting carbon source solution, solid carbon source carrier and functional components, and then granulate it to obtain a microbial functional activator for rice-vegetable rotation soil.

7. The preparation method according to claim 6, characterized in that, Step 1) The mass fraction of the fast-acting carbon source solution is 8-12%; Step 2) The compounding rotation speed is 30~50 r / min, the compounding temperature is 30~40℃, and the compounding time is 10~20 min.

8. The preparation method according to claim 7, characterized in that, Step 3) The mixture The mixing speed is 80~100 r / min, the mixing temperature is 15~35℃, and the mixing time is 3~5 min.

9. The preparation method according to claim 7 or 8, characterized in that, Step 4) The stirring speed is 80~120 r / min, the stirring temperature is 20~30℃, and the stirring time is 10~15 min; The granulation is carried out by extrusion granulation, with an extrusion pressure of 0.5~0.8MPa, and the resulting particles have a diameter of 3~5mm.

10. The preparation method according to claim 9, characterized in that, After granulation is completed in step 4), a drying process is performed; The drying process is carried out at a temperature of 60~80℃ until the moisture content of the resulting particles is ≤10%.

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