A multifunctional soil conditioner for improving the continuous cropping obstacles of yam and a preparation method thereof

Abstract

The application provides a multifunctional soil conditioner for improving the continuous cropping obstacles of yam and a preparation method thereof, the multifunctional soil conditioner comprises a nutrient component, an intelligent responsive component, an environmental regulation component and an additive, the mass ratio of the nutrient component, the intelligent responsive component, the environmental regulation component and the additive is 4-5:1:1-2:1-1.5, the nutrient component is earthworm compost, potassium humate and modified zeolite, the intelligent responsive component comprises mesoporous silica, ferulic acid and chitin oligosaccharide, the environmental regulation component comprises electron beam irradiation modified potassium polyacrylate, polyglutamic acid and polyacrylamide, and the additive comprises calcined diatomite and calcium carbonate, the soil conditioner provided by the application is not only rich in nutrients, but also has good water retention performance, and can well improve the continuous cropping obstacles of yam.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, specifically to a multifunctional soil conditioner that can improve the continuous cropping obstacles of yam and its preparation method. Background Technology

[0002] As an important crop that is both food and medicine, yam has long been limited by severe continuous cropping obstacles. After continuous planting in the same plot, problems such as weak plant growth, deformed tubers, significant decline in yield and quality, and high incidence of soil-borne diseases are common, which seriously restrict the large-scale and sustainable production of yam.

[0003] In existing technologies, improvement measures for the continuous cropping obstacle of yam are mostly concentrated on single or limited methods, which have the following problems:

[0004] I. The improvement measures are too simplistic and the effects are not obvious: Conventional methods mainly rely on the application of large amounts of chemical fertilizers or farmyard manure to supplement soil nutrients, but they have limited effect on improving the core soil obstacle factors.

[0005] 2. Poor functionality: Some plant growth regulators on the market have poor functionality, focusing on water retention, replenishing organic matter, or introducing probiotics, but they are unable to cope with the complex situation of multiple factors intertwined in continuous cropping obstacles.

[0006] Third, poor responsiveness and inability to achieve intelligent regulation: The release of active ingredients in existing products mostly relies on simple diffusion or hydrolysis, which cannot detect changes in the rhizosphere environment. In continuously cropped soils, changes in the composition of root exudates and pH value are important stress signals. Products lacking responsive ingredients cannot target the release of functional substances at critical times when obstacles occur, resulting in low efficiency and potential waste.

[0007] Therefore, developing a multifunctional soil conditioner that can simultaneously improve the physical, chemical, and biological properties of soil and possess environmental responsiveness to efficiently overcome the obstacles of continuous cropping of yam has become a pressing technical challenge in this field. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a multifunctional soil conditioner and its preparation method for improving the continuous cropping obstacles of yam, in view of the shortcomings of the existing technology. The soil conditioner provided by the present invention is not only rich in nutrients, but also has good water retention performance, which can effectively improve the continuous cropping obstacles of yam.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0010] In the first aspect, a multifunctional soil conditioner that can improve the continuous cropping obstacle of yam includes nutrient components, intelligent responsive components, environmental regulating components, and adjuvants, wherein the mass ratio of the nutrient components, intelligent responsive components, environmental regulating components, and adjuvants is (4-5):1:(1-2):(1-1.5).

[0011] The nutrient components are earthworm compost, potassium humate, and modified zeolite.

[0012] The intelligent responsive components include mesoporous silica, ferulic acid, and chitin oligosaccharides.

[0013] The environmental conditioning components include electron beam irradiation modified potassium polyacrylate, polyglutamic acid, and polyacrylamide;

[0014] The additives include calcined diatomaceous earth and calcium carbonate.

[0015] Preferably, the mass ratio of the earthworm compost, potassium humate, and modified zeolite is 40:(2-3):(5-7).

[0016] Preferably, the method for preparing the mesoporous silica includes: mixing CTAB solution and anhydrous ethanol, heating and adding TEOS and ammonia, stirring vigorously to react, filtering while hot after the reaction is complete, washing the precipitate, drying and calcining to obtain the silica.

[0017] Preferably, the concentration of the CTAB solution is 0.08-0.1 g / ml; the volume ratio of the CTAB solution to the anhydrous ethanol is 5:(5-10).

[0018] Preferably, the concentration of the ammonia solution is 20-30 wt%; the amounts of TEOS and the ammonia solution are 35-42 wt% and 3-5 times the mass of the CTAB solution, respectively.

[0019] Preferably, the temperature for vigorous stirring is 60°C, the stirring speed is 3000-5000 rpm, and the stirring time is 20-30 h.

[0020] Preferably, the mass ratio of the electron beam irradiated modified potassium polyacrylate, polyglutamic acid, and polyacrylamide is (9-10):(2-3):(4-5).

[0021] Preferably, the preparation method of the electron beam irradiation modified potassium polyacrylate includes: mixing potassium polyacrylate powder with N,N-methylenebisacrylamide, and irradiating it at room temperature and in an air atmosphere to obtain electron beam irradiation modified potassium polyacrylate.

[0022] Preferably, the amount of N,N-methylenebisacrylamide used is 0.1-0.5 wt% of the mass of potassium polyacrylate powder.

[0023] Preferably, the irradiation treatment conditions are: beam energy: 1.0-1.5MeV, beam power: 10-50kW, and irradiation dose: 5-15kGy.

[0024] Preferably, the preparation of the modified zeolite includes: mixing natural clinoptilolite powder with sodium chloride solution, soaking at room temperature, and then filtering, washing, and drying to obtain the modified zeolite.

[0025] Preferably, the concentration of the sodium chloride solution is 4-5 wt%; the mass ratio of the natural clinoptilolite powder to the sodium chloride solution is 1:(9-10); and the soaking time at room temperature is 3-4 hours.

[0026] Preferably, the mass ratio of the calcined diatomaceous earth to calcium carbonate is (5-7):8.

[0027] Secondly, a method for preparing a multifunctional soil conditioner that can improve the continuous cropping obstacles of yam includes the following steps:

[0028] S1. Ferulic acid and an initiator are pre-assembled, and then mesoporous silica and a crosslinking agent are added to react and prepare a smart responsive carrier. Finally, it is mixed with an aqueous solution of chitin oligosaccharide, ultrasonically impregnated and stirred to obtain a smart responsive component.

[0029] S2. After drying, crushing and sieving earthworm compost, mix it with potassium humate, modified zeolite, calcined diatomaceous earth and calcium carbonate. Then add electron beam irradiated modified potassium polyacrylate, polyglutamic acid, zeolite, polyacrylamide and smart responsive components. After mixing evenly, granulate and dry to obtain soil conditioner.

[0030] Preferably, in step S1, the initiator is APTES, the crosslinking agent is tetraethyl silicate, and the amounts of the initiator, crosslinking agent, and ferrous acid target molecule are 25-35 wt%, 45-55 wt%, and 10-12 wt% of the molecular weight of mesoporous silica, respectively.

[0031] Preferably, in step S1, the solvent for pre-assembly is toluene, and the pre-assembly conditions are: pre-assembly at room temperature for 1-2 hours; the reaction conditions are: nitrogen protection, reflux reaction at 78-80°C for 10-12 hours.

[0032] Preferably, in step S1, the concentration of the chitin oligosaccharide aqueous solution is 0.1-0.2 g / ml, and the mass ratio of the chitin oligosaccharide aqueous solution to the smart responsive carrier is (10-12):1.

[0033] Preferably, in step S1, the conditions for ultrasonic impregnation are: room temperature, 200-500W, 3-4h; and the conditions for stirring are: 30-50rpm, 35-40℃, 10-12h.

[0034] Preferably, in step S2, during granulation, an aqueous solution of hydroxypropyl methylcellulose is added as a binder, wherein the concentration of the aqueous solution of hydroxypropyl methylcellulose is 4-5 wt%, and its amount is 2-3 wt% of the dry material mass.

[0035] Preferably, in step S2, the drying process includes: drying at 45-50°C for 20-30 minutes, then drying at 60-65°C for 90-100 minutes, and finally drying at 40-50°C for 1 hour.

[0036] In this invention, the intelligent responsive component refers to a functional material system that can sense changes in specific environmental signals in the rhizosphere soil, such as a decrease in pH or an increase in the concentration of specific root exudates, and thereby trigger structural changes or the release of functional substances. Its core mechanism of action is that when yam suffers from rhizosphere acidification and accumulation of specific organic acids due to continuous cropping obstacles, the intelligent responsive component of this invention can respond to such stress signals and rapidly and selectively release the loaded active substances, thereby achieving targeted and efficient release of functional substances at critical periods and locations where continuous cropping obstacles occur, thus avoiding ineffective loss in normal environments.

[0037] In this invention, the environmental regulation component refers to a class of polymeric material components used to improve the physical structure and water regulation capacity of soil. Its main mechanism of action is: through the high water absorption and water retention properties of the polymers in the component, as well as ion exchange and flocculation, it effectively improves the soil aggregate structure, reduces bulk density, and increases porosity. It can significantly improve the soil's water holding capacity and permeability, buffer drastic changes in soil moisture, and create a more coordinated and stable rhizosphere microenvironment of water, fertilizer, air, and heat for the yam roots, thereby directly alleviating the continuous cropping obstacles caused by physical factors such as soil compaction, poor permeability, and weak water retention capacity.

[0038] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0039] The multifunctional soil conditioner of this invention comprises nutrient components, intelligent responsive components, environmental regulating components, and adjuvants. The nutrient components provide basic nutrients, while the environmental regulating components significantly improve soil water retention and structure, creating a favorable environment for yam roots. The intelligent responsive components work precisely in the rhizosphere. The synergistic effect of these components greatly improves the physicochemical properties of continuously cropped soils. Tests showed that yam plants grown in continuously cropped soil treated with the soil conditioner of this application exhibited increases in plant height, stem diameter, and tuber fresh weight by up to 46.9%, 45.1%, and 78.2%, respectively, compared to the control group (CK group).

[0040] The intelligent release components in this soil conditioner contain ferulic acid and chitin oligosaccharides as active substances. The release of these active components exhibits significant dual responsiveness to both pH and root exudates. In a medium simulating normal soil (pH 7.0), the release rate of this soil conditioner is less than 30% after 48 hours. However, in a medium simulating continuous cropping stress rhizosphere (pH 5.5 containing organic acids), the release rate rapidly increases to over 90%. This demonstrates that the soil conditioner of this invention can sense continuous cropping stress and target the release of the aforementioned active components, thereby precisely inhibiting soil-borne diseases, activating plant resistance, and avoiding the ineffective loss of effective components under unnecessary conditions.

[0041] In the environmental conditioning components and additives of the soil conditioner of this invention, calcined diatomaceous earth, modified zeolite, and calcium carbonate effectively improve the soil particle composition and porosity; electron beam irradiation modified potassium polyacrylate combined with polyacrylamide can greatly improve the soil's water retention capacity. Tests show that the soil conditioner of this invention has a water absorption ratio as high as 387 times and a 48-hour water retention rate as high as 72%, effectively regulating the alternation of dry and wet soil conditions. Furthermore, the soil bulk density of continuously cropped soil treated with the soil conditioner of this application significantly decreased from 1.35 g / cm³ in the control group to 1.15 g / cm³, and the porosity increased from 45% to 55%, effectively breaking up soil compaction. In terms of chemical fertility, the contents of soil organic matter, available nitrogen, available phosphorus, and available potassium increased by 66.7%, 76.9%, 286.7%, and 66.7% respectively compared with the control group, indicating a significant enhancement in nutrient supply capacity. In terms of biological characteristics, the soil bacteria / fungus ratio in the soil treated with the soil conditioner of this invention increased from 4.4 to 9.0, and the activities of urease and sucrase also increased significantly, indicating that the soil microecology has been restored to health and the nutrient transformation and cycling activity has been enhanced. Detailed Implementation

[0042] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0043] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0044] In the following examples and comparative examples,

[0045] The method for preparing the mesoporous silica is as follows:

[0046] Mix 50 ml of 0.09 g / ml CTAB aqueous solution with 75 ml of anhydrous ethanol, heat to 60 °C, and add TEOS (38% of the mass of CTAB solution) and 25 wt% ammonia (4 times the mass of CTAB solution) while stirring at 4000 rpm. React at 60 °C for 24 hours. After the reaction is complete, filter while hot, wash the filter cake with anhydrous ethanol and deionized water respectively, and dry it. Place the dried powder in a muffle furnace and calcine at 550 °C for 6 hours to obtain mesoporous silica.

[0047] The preparation method of the electron beam irradiation modified potassium polyacrylate is as follows:

[0048] Potassium polyacrylate powder was mixed with N,N-methylenebisacrylamide at a mass ratio of 1:003. The mixed material was spread evenly in a polyethylene tray with a layer thickness of 1.5 cm. The polyethylene tray was placed on the conveyor belt of the electron beam irradiation equipment. Under normal temperature and air atmosphere, the irradiation parameters were set as follows: beam energy 1.2 MeV, beam power 30 kW, and irradiation dose 10 kGy. The equipment was started for irradiation treatment. After irradiation was completed, the material was removed to obtain electron beam irradiated modified potassium polyacrylate.

[0049] The modified zeolite is prepared as follows:

[0050] Natural clinoptilolite powder was mixed with a 5 wt% sodium chloride solution at a mass ratio of 1:9.5, stirred and soaked at room temperature for 3.5 hours. After soaking, the mixture was filtered, and the filter cake was backwashed with deionized water and dried to obtain modified zeolite.

[0051] The performance parameters or sources of some raw materials in the following examples and comparative examples are as follows:

[0052] Chitosan oligosaccharides: Chitosan oligosaccharide DP2 from Shanghai Saikerui Biotechnology Co., Ltd.;

[0053] Potassium polyacrylate: Shandong Guohua Chemical Co., Ltd.;

[0054] Polyglutamic acid: Wuhan Kangluda Biotechnology Co., Ltd.;

[0055] Polyacrylamide (cationic): purchased from Tianjin Damao Chemical Reagent Factory;

[0056] Calcined diatomaceous earth: Guangdong Dongguan Senda Diatomaceous Earth Materials Co., Ltd., calcination temperature is 900℃, calcination time is 1h;

[0057] Vermicompost: Provided by Ningxia Wanhui Biotechnology Co., Ltd.;

[0058] Hydroxypropyl methylcellulose: Batch No. F16 W040, Alfaesa (Tianjin) Chemical Co., Ltd.;

[0059] Natural clinoptilolite: sourced from Yuanheng Water Purification Materials Factory in Gongyi City, Henan Province. The zeolite is washed with deionized water, dried at low temperature, ground into powder, and passed through a nylon sieve with a diameter of 0.2mm.

[0060] Unless otherwise specified, all other raw materials and conditions are commercially available and are standard in the field.

[0061] Example 1

[0062] A method for preparing a multifunctional soil conditioner that can improve the continuous cropping obstacles of yam includes the following steps:

[0063] (1) 10g of mesoporous silica powder was dispersed in 100ml of toluene, 2.8g of APTES (γ-aminopropyltriethoxysilane) and 1.1g of ferulic acid were added, and the mixture was stirred at room temperature for 1.5h for pre-assembly. Under nitrogen protection, the temperature was raised to 79℃, 5.0g of TEOS was added, and the mixture was refluxed for 11h. After the reaction was completed, the mixture was centrifuged, and the centrifuged precipitate was washed three times with toluene and ethanol, and dried under vacuum at 60℃ to obtain the smart responsive carrier.

[0064] (2) The above-mentioned intelligent responsive carrier was added to 110g of 0.15g / ml chitin oligosaccharide aqueous solution and ultrasonically impregnated at room temperature and 350W for 3.5h. Then it was transferred to a stirred reactor and stirred at 40℃ and 40rpm for 11h. After stirring, it was centrifuged and the centrifuged precipitate was vacuum dried at 40℃ to constant weight and pulverized to obtain the intelligent responsive component.

[0065] (3) Dry 40 parts of earthworm compost at 70℃ until the moisture content is <5%, and crush it through a 60-mesh sieve; mix the sieved earthworm compost with 2.5 parts of potassium humate, 6 parts of modified zeolite, 6 parts of calcined diatomaceous earth and 6 parts of calcium carbonate in a mixer for 20 minutes to obtain the basic dry material; add 9 parts of electron beam irradiated modified potassium polyacrylate, 2.5 parts of polyglutamic acid, 4.5 parts of polyacrylamide and 10 parts of smart responsive component to the basic dry material in sequence, and continue mixing for 30 minutes;

[0066] (4) Spray 2.5% of the total dry mass of the above material with a 4.5wt% HPMC aqueous solution as a binder, granulate in a swing pellet mill, then dry at 48℃ for 25 min, then at 62℃ for 95 min, and finally at 45℃ for 1 h; then cool to room temperature and pass through a 200 mesh sieve to obtain a soil conditioner.

[0067] Example 2:

[0068] A method for preparing a multifunctional soil conditioner that can improve the continuous cropping obstacles of yam includes the following steps:

[0069] (1) 10g of mesoporous silica powder was dispersed in 100ml of toluene, 2.8g of APTES (γ-aminopropyltriethoxysilane) and 1.1g of ferulic acid were added, and the mixture was stirred at room temperature for 1.5h for pre-assembly. Under nitrogen protection, the temperature was raised to 79℃, 5.0g of TEOS was added, and the mixture was refluxed for 11h. After the reaction was completed, the mixture was centrifuged, and the centrifuged precipitate was washed three times with toluene and ethanol, and dried under vacuum at 60℃ to obtain the smart responsive carrier.

[0070] (2) The above-mentioned intelligent responsive carrier was added to 110g of 0.15g / ml chitin oligosaccharide aqueous solution and ultrasonically impregnated at room temperature and 350W for 3.5h. Then it was transferred to a stirred reactor and stirred at 40℃ and 40rpm for 11h. After stirring, it was centrifuged and the centrifuged precipitate was vacuum dried at 40℃ to constant weight and pulverized to obtain the intelligent responsive component.

[0071] (3) Dry 40 parts of earthworm compost at 70℃ until the moisture content is <5%, and crush it through a 60-mesh sieve; mix the sieved earthworm compost with 2 parts of potassium humate, 5 parts of modified zeolite, 5 parts of calcined diatomaceous earth and 5 parts of calcium carbonate in a mixer for 20 minutes to obtain the basic dry material; add 8.1 parts of electron beam irradiated modified potassium polyacrylate, 2 parts of polyglutamic acid, 3.9 parts of polyacrylamide and 10 parts of smart responsive component to the basic dry material in sequence, and continue mixing for 30 minutes;

[0072] (4) Spray 2% of the total dry mass of the above material with a 4wt% HPMC aqueous solution as a binder, granulate in a swing pellet mill, and then dry at 45℃ for 30 min, then at 60℃ for 100 min, and finally at 40℃ for 1 h; then cool to room temperature and pass through a 200 mesh sieve to obtain a soil conditioner.

[0073] Example 3

[0074] A method for preparing a multifunctional soil conditioner that can improve the continuous cropping obstacles of yam includes the following steps:

[0075] (1) 10g of mesoporous silica powder was dispersed in 100ml of toluene, 2.8g of APTES (γ-aminopropyltriethoxysilane) and 1.1g of ferulic acid were added, and the mixture was stirred at room temperature for 1.5h for pre-assembly. Under nitrogen protection, the temperature was raised to 79℃, 5.0g of TEOS was added, and the mixture was refluxed for 11h. After the reaction was completed, the mixture was centrifuged, and the centrifuged precipitate was washed three times with toluene and ethanol, and dried under vacuum at 60℃ to obtain the smart responsive carrier.

[0076] (2) The above-mentioned intelligent responsive carrier was added to 110g of 0.15g / ml chitin oligosaccharide aqueous solution and ultrasonically impregnated at room temperature and 350W for 3.5h. Then it was transferred to a stirred reactor and stirred at 40℃ and 40rpm for 11h. After stirring, it was centrifuged and the centrifuged precipitate was vacuum dried at 40℃ to constant weight and pulverized to obtain the intelligent responsive component.

[0077] (3) Dry 40 parts of earthworm compost at 70℃ until the moisture content is <5%, and crush it through a 60-mesh sieve; mix the sieved earthworm compost with 3 parts of potassium humate, 7 parts of modified zeolite, 7 parts of calcined diatomaceous earth and 8 parts of calcium carbonate in a mixer for 20 minutes to obtain the basic dry material; add 10 parts of electron beam irradiated modified potassium polyacrylate, 3 parts of polyglutamic acid, 5 parts of polyacrylamide and 10 parts of smart responsive component to the basic dry material in sequence, and continue mixing for 30 minutes;

[0078] (4) Spray 3% of the total dry mass of the above material with a 5wt% HPMC aqueous solution as a binder, granulate in a swing pellet mill, then dry at 50℃ for 20 min, then at 65℃ for 90 min, and finally at 50℃ for 1 h; then cool to room temperature and pass through a 200 mesh sieve to obtain a soil conditioner.

[0079] The performance of the soil conditioner in the above embodiments was tested, and the test methods and results are as follows.

[0080] I. Intelligent Response Release Test:

[0081] Testing process:

[0082] (1) Preparation of simulated solution:

[0083] Simulation solution A: Acidified rhizosphere environment simulation solution (pH 5.5);

[0084] Weigh 21.01 g of citric acid monohydrate, dissolve it in deionized water and dilute to 1 L to prepare a 0.1 mol / L citric acid solution; weigh 35.60 g of disodium hydrogen phosphate dihydrate, dissolve it in deionized water and dilute to 1 L to prepare a 0.2 mol / L disodium hydrogen phosphate solution; mix 26.7 ml of citric acid solution and 23.3 ml of disodium hydrogen phosphate solution, add 50 ml of deionized water, and adjust the system pH to 5.5 using the above citric acid solution or disodium hydrogen phosphate solution. Transfer the above solution to a 200 ml volumetric flask, dilute to the mark with deionized water, and shake well to obtain simulation solution A;

[0085] Simulation solution B: Simulation solution of normal soil rhizosphere environment (pH 7.0);

[0086] Weigh 15.60 g of sodium dihydrogen phosphate dihydrate, dissolve it in deionized water and dilute to 1 L to prepare a 0.1 mol / L sodium dihydrogen phosphate solution; weigh 35.81 g of disodium hydrogen phosphate dihydrate, dissolve it in deionized water and dilute to 1 L to prepare a 0.1 mol / L disodium hydrogen phosphate solution; mix 16.5 ml of sodium dihydrogen phosphate solution with 83.5 ml of disodium hydrogen phosphate solution, add 80 ml of deionized water, adjust the pH of the system to 7.0 with the above sodium dihydrogen phosphate solution or disodium hydrogen phosphate solution, then transfer to a 200 ml volumetric flask, dilute to volume, and shake well to obtain simulation solution B.

[0087] Simulated solution C: Simulated solution for the enrichment of root exudates (pH 5.5);

[0088] Weigh 1.05 mg of citric acid, 0.67 mg of malic acid, and 0.59 mg of succinic acid, add them to 200 ml of simulated solution A, and stir for 30 min in the dark to obtain simulated solution C.

[0089] (2) Experimental method: Weigh 1.0g of the soil conditioner from Examples 1-3 respectively, and then place them in the three simulated liquids mentioned above. The release experiment was carried out in a constant temperature shaker (25℃, 100 rpm).

[0090] (3) Sample collection and determination: Samples were taken at 1h, 4h and 12h respectively. After centrifugation, the supernatant was taken and the release concentration of ferulic acid was determined by high performance liquid chromatography. The release concentration of chitin oligosaccharide was determined by sulfuric acid-anthrone colorimetric method.

[0091] The test results are shown in Table 1.

[0092] Table 1

[0093]

[0094] As can be seen from the test results in Table 1, in simulated solution B, the release of the soil conditioner in all embodiments was very slow, with a release rate of less than 30% after 48 hours, indicating that the soil conditioner of the present invention has good stability under normal conditions. However, the release was significantly accelerated in simulated solution A, and the fastest release was observed in simulated solution C, further demonstrating the dual response of the soil conditioner of the present invention to rhizosphere acidification and specific root exudates. The above test results show that the release of the soil conditioner of the present invention mainly occurs within 0-12 hours, especially in simulated solution C, where the release rate exceeds 75% after 12 hours, indicating that the soil conditioner of the present invention can respond rapidly to stress environments. In the environment simulating normal soil (simulated solution B), the cumulative release rates of ferulic acid and chitin oligosaccharides were both less than 30% within 12 hours, indicating good stability and slow-release properties under non-stress conditions.

[0095] II. Nutritional Components and Physicochemical Properties Testing

[0096] Testing process:

[0097] Organic matter content: determined by potassium dichromate titration method;

[0098] Nitrogen, phosphorus, and potassium contents: After digestion with concentrated sulfuric acid-hydrogen peroxide, the total nitrogen, total phosphorus, and total potassium contents were determined by the Kjeldahl method, the vanadium molybdenum yellow colorimetric method, and the flame photometry method, respectively.

[0099] The test results are shown in Table 2.

[0100] Table 2

[0101]

[0102] As can be seen from the test results in Table 2, the soil conditioner of the present invention has a balanced nutrient composition and is suitable for soils with continuous cropping obstacles to yam.

[0103] III. Physical Performance Testing

[0104] Testing process:

[0105] Water absorption ratio and water retention:

[0106] Weigh out a dry granule with a mass of W0, immerse it in deionized water, drain it through a filter screen, weigh it again and record the weight as W1, and calculate the water absorption ratio; place the above saturated water granules in a dry environment to simulate natural water loss conditions, weigh them at 2h, 24h, 48h, and 72h and record the weight as Wt, and calculate the water retention rate at different time periods.

[0107] The formula for calculating the water absorption ratio is: (W1-W0) / W0;

[0108] The formula for calculating the water retention rate is: [(Wt-W0) / (W1-W0)]×100%.

[0109] The test results are shown in Table 3:

[0110] Table 3

[0111]

[0112] As can be seen from the test results in Table 3, the soil conditioners prepared in this embodiment all have good water retention properties. They can quickly retain a large amount of water during irrigation or rainfall, reducing runoff and deep infiltration, thereby significantly improving water use efficiency. Even after 72 hours, the soil conditioners prepared in Examples 1-3 can still maintain more than 45% of their initial water holding capacity, indicating that the soil conditioner of this invention is not simply a water storage agent, but rather forms a micro-reservoir that can be slowly utilized by plant roots by generating a strong binding force on water molecules through a hydrogel network. This slow release characteristic is crucial for resisting intermittent drought and stabilizing the rhizosphere water environment.

[0113] To further illustrate the soil conditioner prepared in Examples 1-3 on the improvement effect of continuously cropped soil, the following verification was conducted using the yam planting area of ​​Xincheng Ximao Yam Farmers Professional Cooperative in Huantai County, Shandong Province as the test subject. The specific methods are as follows:

[0114] IV. Potted Plant Verification Experiment:

[0115] Testing process:

[0116] (1) The yam planting land of Xincheng Ximao Yam Farmers Professional Cooperative in Huantai County, Shandong Province, which has been continuously planted with yam for 2-3 years, was used as potting soil.

[0117] (2) Set up the following processing groups respectively:

[0118] Blank control group (CK): No soil conditioner was applied;

[0119] Conventional treatment group (CF): The soil conditioner was replaced with an equal amount of conventional compound fertilizer (N:P2O5:K2O in a mass ratio of 1:1:1).

[0120] Experimental group 1 (T1): Soil conditioner of Example 1 was applied;

[0121] Experimental Group 2 (T2): Soil conditioner of Example 2 was applied;

[0122] Experimental group 3 (T3): Soil conditioner of Example 3 was applied;

[0123] The application rate of the aforementioned conventional compound fertilizers and soil conditioners is 2.5 wt% of the soil weight.

[0124] (3) The Xincheng fine-haired yam variety was used. Before planting, the soil conditioner or conventional compound fertilizer was mixed with the 0-20 cm topsoil according to the set dosage. The CK group was not treated. One yam seedling was planted in each pot and watered as usual. After 120 days of growth, the following parameters were measured:

[0125] The yam plant is tall, has thick stems, and has a high fresh tuber weight;

[0126] Soil physicochemical properties: bulk density, porosity, organic matter, alkaline nitrogen, available phosphorus, and available potassium;

[0127] Soil biological properties: The bacterial / fungal ratio was analyzed using plate counting and PCR-DGGE techniques; soil urease and sucrase activities were determined using kits.

[0128] The test results are shown in Table 4.

[0129] Table 4

[0130]

[0131] As can be seen from the test results in Table 4, compared with the CK and CF groups, the soil conditioner prepared in this embodiment can effectively improve the physical and chemical properties of the continuously cropped soil and can more effectively overcome the obstacles of continuous cropping. Moreover, compared with the CK and CF groups, the T1-T3 groups have taller plants, thicker stems, and larger tubers, which directly proves the excellent effect of the soil conditioner prepared in this embodiment in alleviating the obstacles of continuous cropping and increasing the yield of yam.

[0132] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A multifunctional soil conditioner for improving continuous cropping obstacles in yam cultivation, characterized in that: It includes nutritional components, intelligent responsive components, environmental regulation components, and additives, wherein the mass ratio of the nutritional components, intelligent responsive components, environmental regulation components, and additives is (4-5):1:(1-2):(1-1.5). The nutrient components are earthworm compost, potassium humate, and modified zeolite. The intelligent responsive components include mesoporous silica, ferulic acid, and chitin oligosaccharides. The environmental conditioning components include electron beam irradiation modified potassium polyacrylate, polyglutamic acid, and polyacrylamide; The additives include calcined diatomaceous earth and calcium carbonate.

2. The multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The mass ratio of the earthworm compost, potassium humate, and modified zeolite is 40:(2-3):(5-7).

3. The multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The method for preparing the mesoporous silica includes: mixing a CTAB solution with a concentration of 0.08-0.1 g / ml and anhydrous ethanol in a volume ratio of 5:(5-10); heating and adding 35-42 wt% TEOS of the CTAB solution and 3-5 times the mass of ammonia solution with a concentration of 20-30 wt%; stirring vigorously at 60°C and 3000-5000 rpm for 20-30 h; filtering while hot after the reaction is completed; washing the precipitate; drying and calcining to obtain the silica.

4. The multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The mass ratio of the electron beam irradiated modified potassium polyacrylate, polyglutamic acid, and polyacrylamide is (9-10):(2-3):(4-5).

5. The multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The preparation method of the electron beam irradiation modified potassium polyacrylate includes: mixing potassium polyacrylate powder with N,N-methylenebisacrylamide at a mass ratio of 100:(0.1-0.5), and irradiating the mixture at room temperature in an air atmosphere. During irradiation, the beam energy is 1.0-1.5MeV, the beam power is 10-50kW, and the irradiation dose is 5-15kGy, to obtain electron beam irradiation modified potassium polyacrylate.

6. The multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The preparation of the modified zeolite includes: mixing natural clinoptilolite powder with a sodium chloride solution of 4-5 wt% at a mass ratio of 1:(9-10), soaking at room temperature for 3-4 hours, and then filtering, washing, and drying to obtain the modified zeolite.

7. A multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 1, characterized in that: The mass ratio of the calcined diatomaceous earth to calcium carbonate is (5-7):

8.

8. A method for preparing a multifunctional soil conditioner for improving continuous cropping obstacles of yam according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Ferulic acid and an initiator are pre-assembled, and then mesoporous silica and a crosslinking agent are added to react and prepare a smart responsive carrier. Finally, it is mixed with an aqueous solution of chitin oligosaccharide, ultrasonically impregnated and stirred to obtain a smart responsive component. S2. After drying, crushing and sieving earthworm compost, mix it with potassium humate, modified zeolite, calcined diatomaceous earth and calcium carbonate. Then add electron beam irradiated modified potassium polyacrylate, polyglutamic acid, zeolite, polyacrylamide and smart responsive components. After mixing evenly, granulate and dry to obtain soil conditioner. Preferably, in step S1, the initiator is APTES, the crosslinking agent is tetraethyl silicate, and the amounts of the initiator, crosslinking agent, and ferrous acid target molecule are 25-35 wt%, 45-55 wt%, and 10-12 wt% of the molecular weight of mesoporous silica, respectively.

9. A method for preparing a multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 8, characterized in that, In step S1, the preparation of the smart responsive component includes at least one of the following characteristics: The solvent used in the pre-assembly is toluene; The pre-assembly conditions are: pre-assembly at room temperature for 1-2 hours; The reaction conditions are: nitrogen protection, reflux reaction at 78-80℃ for 10-12 hours; The concentration of the chitin oligosaccharide aqueous solution is 0.1-0.2 g / ml, and the mass ratio of the chitin oligosaccharide aqueous solution to the intelligent responsive carrier is (10-12):1; The conditions for ultrasonic impregnation are: room temperature, 200-500W, 3-4 hours; The stirring conditions are: 30-50 rpm, 35-40℃, 10-12 h.

10. A method for preparing a multifunctional soil conditioner for improving continuous cropping obstacles of yam according to claim 8, characterized in that, In step S2, during granulation, an aqueous solution of hydroxypropyl methylcellulose was added as a binder. The concentration of the aqueous solution of hydroxypropyl methylcellulose was 4-5 wt%, and its dosage was 2-3 wt% of the dry material mass. Alternatively, the drying process may include: drying at 45-50℃ for 20-30 minutes, then drying at 60-65℃ for 90-100 minutes, and finally drying at 40-50℃ for 1 hour.

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