Seaweed oligosaccharide-containing salinized vegetable planting special fertilizer

Abstract

The invention relates to the technical field of vegetable planting fertilizers, discloses a seaweed oligosaccharide-containing special fertilizer for salinized vegetable planting, and has the core that the seaweed oligosaccharide-containing special fertilizer for salinized vegetable planting is prepared by finding and utilizing the growth promotion effect of seaweed oligosaccharide on vegetables in salinized soil for the first time. The core components comprise seaweed oligosaccharide, a salt-tolerant microbial complex microbial inoculant and polyacrylamide which have a synergistic effect, so that the yield of vegetables planted in the salinized soil is improved, and the mature period is shortened; humic acid, compound amino acid and attapulgite, or compound medium trace elements, or octa-alkyl glucoside and starch grafted polyacrylate can be selected; all the components have a synergistic effect, the growth vigor and yield of vegetables in salinized soil are improved by adjusting related physiological pathways of vegetable plants, improving the soil structure and the like, meanwhile, the problems of salinization aggravation and the like of the soil are relieved through recycling, the fertility of the soil is improved, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of vegetable planting fertilizers, in particular to a special fertilizer for planting salinized vegetables containing seaweed oligosaccharides. Background Art

[0002] Soil salinization refers to the accumulation of soluble salts in the soil surface. Secondary salinization, caused by the accumulation of nitrates over time, has also become a major obstacle to vegetable production, severely impacting both yield and quality. Soil conductivity exceeding 1000 μs / cm (moderate salinization) has been reported to negatively impact crop growth, yield, and quality. Rapeseed is a relatively salt-tolerant leafy vegetable, tolerant of 0.2% to 0.26% salt (conductivity ≤ 1083 μs / cm) in slightly acidic or neutral soils (pH 5.5-6.7) and growing normally. However, soils with a pH < 4.5 and a conductivity ≥ 1178.45 μs / cm show significant salt damage to rapeseed leaves, significantly inhibiting growth and leading to a sharp decline in yield. Severe secondary salinization in vegetable fields highlights problems such as wilting and death of plants after watering and topdressing during the growing season, as well as low disease resistance. Nutrient imbalances in vegetable fields lead to severe physiological diseases, particularly calcium and boron deficiencies caused by excessive application of nitrogen, phosphorus, and potassium fertilizers. Soil acidification or the use of uncomposted organic fertilizers can lead to root rot and severe root nematode infestations. These production issues lead vegetable farmers to overuse pesticides, creating a vicious cycle of excessive pesticide residues in vegetables and exceeding pesticide background levels in soil and water. Currently, the pH of most greenhouse soils is less than 5.5, with conductivity ranging from 500 to 2100 μs / cm. This has severely impacted the development of the vegetable industry, necessitating the urgent need for stable and effective vegetable cultivation technologies in salinized soils.

[0003] Improving saline soil is a complex, difficult and time-consuming task, and specific measures should be formulated according to the specific circumstances. In terms of the causes of formation, a large number of scholars have conducted relatively detailed research, but the research on improvement technology is not sufficient. In recent years, researchers have made a lot of beneficial attempts by adding organic materials to improve the soil and optimizing the soil microbial system, but the results are not consistent, and no stable and effective soil remediation technology has been formed. Patent CN201610042920.9 discloses a method for preparing organic fertilizer for preventing and controlling secondary salinization of greenhouse vegetable fields. It uses agricultural and animal husbandry waste as the main material, combined with natural bactericidal materials such as lime nitrogen, and supplemented with medium and trace elements such as calcium, boron, and zinc. The patent claims that it can solve the problems of vegetable wilting and soil harmful pathogens caused by salinization of greenhouse vegetables. However, in actual application, due to the large-scale use of animal manure, waste tobacco, salts, borax, etc., recycling will lead to a decline in soil quality and expand problems such as salinization and acidification.

[0004] Therefore, there is an urgent need to further study the problem of growing vegetables in salinized soil and obtain a special fertilizer for growing vegetables in salinized soil to improve the growth and yield of vegetables in salinized soil, while recycling it to alleviate the salinization problem of the soil and improve soil fertility. Summary of the Invention

[0005] In order to solve the above-mentioned existing problems, the present invention discloses a special fertilizer for growing vegetables in salinized soil containing seaweed oligosaccharides. The core ingredients include seaweed oligosaccharides, salt-tolerant microbial composite agents and polyacrylamide, and can optionally contain humic acid, composite amino acids and attapulgite, or composite trace elements, or octaalkyl glucoside and starch-grafted polyacrylic acid salts. The various ingredients have a synergistic effect, and the growth and yield of vegetables in salinized soil are improved by regulating relevant physiological pathways of vegetable plants, improving soil structure, etc. At the same time, recycling can alleviate problems such as the aggravation of soil salinization, thereby improving soil fertility, and the application prospect is broad.

[0006] On the one hand, the present invention provides a special fertilizer for salinized vegetable cultivation containing seaweed oligosaccharides, comprising seaweed oligosaccharides, a salt-tolerant microbial composite agent, and polyacrylamide; the seaweed oligosaccharide has a polymerization degree of 2-50 and an active ingredient content of ≥90%; the salt-tolerant microbial composite agent comprises alkaliphilic Halomonas ( 嗜碱嗜盐单胞菌 ) CGMCC 1.7449, viable count ≥ 2 × 10 8 CFU / g; the molecular weight of the polyacrylamide is 8-10 million, the anionicity is 10%-20%, and the cationicity is 30%-60%.

[0007] The core of the present invention is to discover and utilize the growth-promoting effect of seaweed oligosaccharides on vegetables in salinized soil for the first time, and to prepare a special fertilizer for salinized vegetable cultivation containing seaweed oligosaccharides; seaweed oligosaccharides are oligosaccharide substances extracted from seaweed, which have multiple biological activities. Current research has found that seaweed oligosaccharides can be used as fertilizer synergists and added to water-soluble fertilizers or compound fertilizers to promote crop growth by improving nutrient utilization and slow-release fertilizer components; however, there has never been a specific study on salinized vegetable cultivation. The present invention has discovered for the first time that seaweed oligosaccharides have the effect of promoting the growth of vegetables in salinized soil. It has a growth-promoting effect on vegetables in salinized soil. The specific mechanism may be: 1. Enhance the osmotic regulation ability of plants. The high osmotic pressure of salinized soil will cause plant cells to lose water and induce osmotic stress. Seaweed oligosaccharides can act as signal molecules to induce plants to synthesize and accumulate more osmotic regulating substances (such as proline, soluble sugars, betaine, etc.). These substances can increase the concentration of cell fluid, maintain the osmotic pressure balance between cells and the outside world, reduce water loss, and alleviate the inhibition of osmotic stress on plant growth; 2. Activate the antioxidant defense system. Salt stress will cause plant cells to produce a large amount of reactive oxygen, leading to membrane lipid peroxidation, protein denaturation, and damage to cell structure. Seaweed oligosaccharides can induce plants to enhance the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). At the same time, it promotes the synthesis of non-enzymatic antioxidants such as vitamin C and glutathione, efficiently removes reactive oxygen, protects cell membrane integrity, and reduces damage to cells caused by ion toxicity; 3. Regulate plant hormones and growth metabolism. Seaweed oligosaccharides can be used as analogs of plant growth regulators, or induce plants to It synthesizes hormones such as auxin, cytokinin, gibberellin, etc. to promote root development (such as increasing root length and root surface area) and plant growth, and enhance the root system's ability to absorb water and nutrients; at the same time, it inhibits the excessive accumulation of stress hormones such as abscisic acid, and alleviates the inhibition of salt stress on plant growth; 4. It improves the rhizosphere microenvironment. Seaweed oligosaccharides can provide a carbon source for beneficial microorganisms in the rhizosphere, promote their reproduction, indirectly improve the rhizosphere soil microecology, increase the activation efficiency of nutrients in the soil, alleviate the problem of nutrient imbalance in salinized soil, and provide plants with more adequate nutritional support.

[0008] However, the growth-promoting effect of seaweed oligosaccharides on vegetables in salinized soil needs to be combined with other substances to achieve the best effect. Therefore, the present invention continues to study and finds the core ingredients of fertilizers that can meet the needs of growing vegetables at different levels of salinization, namely seaweed oligosaccharides, alkaliphilic halomonas and polyacrylamide; its mechanism of action may be: 1. Polyacrylamide (PAM) optimizes the physical structure of the soil, forms a stable aggregate structure by adsorbing soil particles, reduces soil compaction, increases porosity, thereby improving soil water retention capacity, reducing the osmotic stress of salt on plants, enhancing soil permeability, promoting salt leaching, reducing surface soil salt accumulation, providing a more stable living environment for microorganisms and plant roots, and avoiding drastic fluctuations in salt; 2. Alkaliphilic halomonas regulates the soil chemical environment and microecology, and its functions include converting soil salt through metabolism, such as converting Na + It binds to the cell or converts into a low-toxic form, reduces soil conductivity, secretes extracellular polysaccharides, organic acids and other substances, and synergizes with PAM to enhance aggregate stability, activate soil nutrients, produce plant hormones, directly promote plant growth, and synergizes with seaweed oligosaccharides to regulate plant stress resistance gene expression; 3. Seaweed oligosaccharides strengthen plant stress resistance (as mentioned above) and synergize with microorganisms, provide a carbon source for alkaliphilic halomonas, promote their reproduction and metabolic activity, and synergize with the soil environment improved by PAM to improve microbial efficiency. By regulating plant root secretions, it attracts more beneficial microorganisms and forms a virtuous cycle of "plant-microorganism" interaction. The core of the synergistic effect lies in the fact that PAM provides a basic soil environment for microorganisms and plants, playing a role in water retention, salt permeability, and anti-compaction. Alkaliphilic halomonas reduce soil salinity and activate nutrients, clearing obstacles for plant growth. Seaweed oligosaccharides enhance plant resistance to stress and at the same time feed back to microbial growth. The three form a closed loop of "soil structure improvement → salt reduction → increased microbial activity → enhanced plant resistance to stress → virtuous cycle of soil-plant system", significantly improving the growth ability of vegetables in salinized soil.

[0009] Through experiments and demonstration, it is shown that the vegetable-specific fertilizer using the core ingredients of the present invention can be used in saline soils of different levels and has good effects on different types of vegetables. On the one hand, it can increase vegetable yields and shorten the time it takes for vegetables to mature. On the other hand, it can be recycled and can reduce the electrical conductivity of saline soil. Long-term use can alleviate the salinization problem.

[0010] In some embodiments, the salt-tolerant microbial composite agent further comprises Rhizobium leguminosarum ( 根瘤菌 豆科根瘤菌 ) ACCC 16119 and soil Bacillus ( 食菌芽孢杆菌 )ACCC 11029, viable count ≥ 2 × 10 8 CFU / g.

[0011] After a large number of experimental studies, it was found that composite microbial agents containing multiple microorganisms can be selectively used to enhance the overall effect of special fertilizers for saline-affected vegetable cultivation. Generally speaking, ordinary microorganisms will also be subject to salt stress in saline soil, which will inhibit the activity of microorganisms. However, the present invention found that in the presence of seaweed oligosaccharides, seaweed oligosaccharides can promote the formation of plant-microorganism interactions, provide carbon sources for the survival and reproduction of microorganisms, and regulate pathways such as microbial resistance to salt stress. At the same time, when composite microbial agents composed of specific strains are used, microorganisms utilize enzymes, polysaccharides and other substances produced by different strains to produce a synergistic effect. Therefore, only screening can obtain the composition of the preferred salt-tolerant microbial composite microbial agent; the present invention found that alkaliphilic Halomonas, Rhizobium leguminosarum and soil Bacillus have the above-mentioned synergistic effect, and the main reason may be, The differences in the physiological characteristics of the three complement each other: alkaliphilic halomonas are tolerant to high salt and can reduce the salt concentration in the rhizosphere through metabolism, improving the microenvironment and providing more suitable living conditions for the less salt-tolerant pea rhizobia and soil Bacillus; soil Bacillus can produce spores to resist extreme environments and secrete extracellular polysaccharides, which together with the extracellular secretions of the other two bacteria, such as the extracellular polymers of alkaliphilic halomonas and the nodulation factor-related substances of pea rhizobia, form a biofilm, enhancing the adhesion ability of the three on saline soil particles and reducing the impact of salt fluctuations on them; although pea rhizobia mainly coexists with legumes, it can maintain survival in the non-symbiotic stage by utilizing seaweed oligosaccharides and metabolites produced by other bacteria, such as organic acids. The nitrogen-containing substances produced in its nitrogen fixation process can also feed back to the other two bacteria, playing the role of supplementing the nitrogen source. In addition, the metabolites of the three form a "feedback loop": the organic acids secreted by alkaliphilic halomonas can lower the local soil pH, alleviate high alkaline stress, and at the same time activate insoluble minerals in the soil to provide nutrients for other bacteria; the vitamins, amino acids and other growth factors produced by soil Bacillus can promote the reproduction of pea rhizobia and the metabolic activity of alkaliphilic halomonas; the signal molecules released by pea rhizobia during the proliferation process, such as flavonoid response substances, can cooperate with seaweed oligosaccharides to induce the other two bacteria to express stress-related genes, further enhancing the survival ability of the group.

[0012] In some embodiments, urea, potassium nitrate, and ammonium polyphosphate are further included; the solubility of the ammonium polyphosphate is ≥150g / 100g water, and the degree of polymerization is 2-18.

[0013] According to experiments, ammonium polyphosphate is more suitable for use as a phosphorus fertilizer in special fertilizers for growing vegetables in salinized soils. The reason may be that it is more easily decomposed by the microorganisms in the special fertilizer of the present invention and catalytically decomposed by its metabolites, thereby increasing the phosphorus content in saline soil.

[0014] In some embodiments, humic acid, complex amino acids and attapulgite are also included; the humic acid is weathered coal humic acid, with an organic matter content of ≥60% and a moisture content of ≤30%; the complex amino acids include glutamic acid, aspartic acid, lysine and serine.

[0015] Humic acid from weathered coal contains functional groups such as carboxyl and phenolic hydroxyl groups, which can absorb sodium ions in the soil, reducing salt concentrations while forming humic acid-sodium ion complexes that are discharged with irrigation water. Complex amino acids can serve as a carbon source to promote microbial growth and chelate with metal ions, reducing salt toxicity. They can also be directly utilized by plants to regulate specific physiological processes. The layered structure of attapulgite soil is highly absorptive, fixing free chloride ions in the soil and acting as a slow-release fertilizer carrier, extending its effectiveness. It also absorbs large amounts of water, forming several small water-retention units in the soil. Experiments have shown that only when these three factors work together can they specifically improve the soil structure of saline soil, ensuring water retention, salt permeability, and preventing compaction.

[0016] In some embodiments, the invention further comprises composite trace elements, wherein the composite trace elements include magnesium sulfate, EDTA-Ca and EDTA-Zn; the calcium content of the EDTA-Ca is ≥9wt%; and the zinc content of the EDTA-Zn is ≥14wt%.

[0017] Chelated calcium (EDTA-Ca) avoids reacting with soil sulfate to form gypsum through chelation, while enhancing the toughness of cell walls and improving the salt resistance of vegetables; magnesium sulfate supplements magnesium to promote chlorophyll synthesis, and sulfur can regulate soil pH and reduce the impact of sodium ions on root activity; zinc also exists in a chelated state, and is more stable than an inorganic state in a high-salt environment. It can be directly absorbed by the roots, alleviating trace element deficiencies caused by salt stress. At the same time, the steric hindrance effect of the chelating group prevents high concentrations of sodium ions in saline soil from competing for binding sites.

[0018] In some embodiments, octaalkyl glucoside and starch grafted polyacrylate are also included.

[0019] Octaalkyl glucoside and starch grafted polyacrylate are only added in trace amounts to play a synergistic role. The mechanism is that octaalkyl glucoside, as a non-ionic surfactant, reduces the surface tension of water, promotes the penetration of fertilizer in saline soil, and avoids surface salt accumulation. Starch grafted polyacrylate has a high water absorption rate, forming a water-retaining microenvironment in saline soil, alleviating the combined stress of drought and salt damage. The two are compounded to form a permeability-water retention dual-functional layer, solving the problem of saline soil being easy to compact when watered and prone to drought when not watered, thereby improving fertilizer efficiency.

[0020] On the other hand, the present invention provides a method for increasing the yield of vegetables grown in salinized soil, using the seaweed oligosaccharide-containing special fertilizer for growing salinized vegetables for fertilization.

[0021] In another aspect, the present invention provides a use of seaweed oligosaccharides for preparing a reagent for increasing the yield of vegetables grown in salinized soil, wherein the reagent for increasing the yield of vegetables grown in salinized soil comprises seaweed oligosaccharides, a salt-tolerant microbial composite agent, and polyacrylamide; the seaweed oligosaccharide has a polymerization degree of 2-50 and an active ingredient content of ≥90%; the salt-tolerant microbial composite agent comprises alkaliphilic Halomonas ( 嗜碱嗜盐单胞菌 ) CGMCC 1.7449, viable count ≥ 2 × 10 8 CFU / g; the molecular weight of the polyacrylamide is 8-10 million, the anionicity is 10%-20%, and the cationicity is 30%-60%.

[0022] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The present invention discloses a special fertilizer for growing vegetables in salinized soils, containing seaweed oligosaccharides. The core ingredients include seaweed oligosaccharides, a salt-tolerant microbial compound agent, and polyacrylamide. Humic acid, compound amino acids, and attapulgite, or compound trace elements, or octaalkyl glucoside and starch-grafted polyacrylic acid salts may be optionally included. The ingredients exhibit a synergistic effect, improving the growth and yield of vegetables in salinized soils by regulating relevant physiological pathways of vegetable plants and improving soil structure. The fertilizer also reduces soil salinization and improves soil fertility through recycling, thus having broad application prospects. 2. The seaweed oligosaccharide-containing fertilizer for salinized vegetable cultivation of the present invention can be functionally divided into core components, nutrients, soil improvement components, complex trace elements, and synergistic auxiliary materials. Through experiments, the present invention has found the most optimal composition of each component, which can synergistically achieve the optimal effect. 3. Experiments have shown that the special fertilizer for vegetable cultivation in salinized soil containing seaweed oligosaccharides of the present invention can improve the yield of various types of vegetables grown in salinized soil. For saline soils of different grades, the special fertilizer for vegetable cultivation in salinized soil containing seaweed oligosaccharides of the present invention can improve the yield. Experiments have shown that the special fertilizer for vegetable cultivation in salinized soil containing seaweed oligosaccharides of the present invention can reduce the salinization process of saline soil where vegetables are repeatedly planted, and can be used to improve salinization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : Actual picture of the special fertilizer for growing vegetables in salinized areas containing seaweed oligosaccharides. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with specific examples and accompanying drawings. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The materials, reagents, etc. used in the following examples are commercially available reagents and materials unless otherwise specified. Example 1: Preparation of a special fertilizer for salinized vegetable cultivation containing seaweed oligosaccharides

[0025] The seaweed oligosaccharide-containing fertilizer for salinized vegetable cultivation comprises five components: a core ingredient, a nutrient component, a soil-improving component, a composite medium and trace element, and a synergistic auxiliary material. The core ingredient plays a crucial role in promoting the growth of vegetables in salinized soil; the nutrient component provides nutrients; the soil-improving component improves the salinized soil; the composite medium and trace element regulates the growth of vegetables; and the synergistic auxiliary material enhances overall efficacy. The specific preparation is as follows: Pre-preparation of core ingredients: according to the mass ratio, take 10 parts of seaweed oligosaccharides and 1 part of salt-tolerant microbial compound agent (alkaliphilic halomonas ( 嗜碱嗜盐单胞菌 ) CGMCC 1.7449, Rhizobium leguminosarum ( 根瘤菌 豆科根瘤菌 )ACCC 16119, soil Bacillus ( 食菌芽孢杆菌 ACCC 11029 is mixed at a ratio of 1:1:1, and the viable count is ≥ 2 × 10 8 CFU / g), 1 part of polyacrylamide, and mixed to obtain 12 parts of the core component.

[0026] Pre-preparation of nutrients: Based on parts by mass, take 3 parts of urea, 3 parts of potassium nitrate, and 8 parts of ammonium polyphosphate, and mix them to obtain 14 parts of nutrients.

[0027] Pre-preparation of soil improvement components: According to parts by mass, take 20 parts of humic acid, 2 parts of complex amino acids (0.5 parts each of glutamic acid, aspartic acid, lysine and serine), and 3 parts of attapulgite, and mix them to obtain 25 parts of soil improvement components.

[0028] Pre-preparation of composite trace elements: Based on parts by mass, take 1 part of magnesium sulfate, 1 part of EDTA-Ca, and 0.2 parts of EDTA-Zn, and mix them to obtain 2.2 parts of composite trace elements.

[0029] Pre-preparation of synergistic auxiliary materials: Based on parts by mass, 0.3 parts of octaalkyl glucoside and 0.5 parts of starch grafted polyacrylate are mixed to obtain 0.8 parts of synergistic auxiliary materials.

[0030] The core ingredients (12 parts), nutrients (14 parts), soil improvement ingredients (25 parts), complex trace elements (2.2 parts) and synergistic excipients (0.8 parts) were mixed and granulated at low temperature using an extrusion granulation device. The final sample was black and had a particle size range of 5-15 mm. Figure 1 shown.

[0031] For the specific selection of the above components, the following technical indicators can be used to select the reagents: the polymerization degree of the seaweed oligosaccharide is 2-50, the content of the active ingredient is ≥90%; the alkaliphilic halomonas (嗜碱嗜盐单胞菌 ) can be purchased from the China General Microorganism Collection Center under the collection number CGMCC 1.7449, Rhizobium leguminosarum ( 根瘤菌 豆科根瘤菌 ) can be purchased from the China General Microorganism Collection Center under the deposit number ACCC 16119, soil Bacillus ( 食菌芽孢杆菌 ) can be purchased from the China Agricultural Microorganism Collection Center under the deposit number ACCC 11029. The viable count of each strain is ≥ 2 × 10 8 CFU / g; the molecular weight of the polyacrylamide is 8-10 million, the anionicity is 10%-20%, and the cationicity is 30%-60%; the solubility of the ammonium polyphosphate is ≥150g / 100g water, and the degree of polymerization is 2-18; the calcium content of the EDTA-Ca is ≥9wt%; the zinc content of the EDTA-Zn is ≥14wt%; the other ingredients are all compounds of fixed composition, and products with a purity level of 90% or above can be selected. Example 2: Comparison of different compositions of saline vegetable fertilizers

[0032] The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation of the present invention comprises five parts, namely, a core component, a nutrient component, a soil-improving component, a compound medium and trace element, and a synergistic auxiliary material. The core component plays the most critical role in promoting the growth of vegetable plants in salinized soil, the nutrient component provides nutrients, the soil-improving component is used to improve the salinized soil, the compound medium and trace element plays a role in regulating the growth of vegetable plants, and the synergistic auxiliary material is used to improve the overall efficacy. In order to compare the efficacy of the special fertilizer for salinized vegetable cultivation with different ingredients, and considering that any fertilizer must contain nutrients, an ordinary fertilizer containing only nutrients is used as a blank control, and on the basis of the blank control, corresponding ingredients are added to form an experimental group.

[0033] In order to stably test the improvement effect of different fertilizers on vegetable cultivation in salinized soil, deep soil from the wasteland east of Dajiang in Qiantang District, Hangzhou was selected as the test soil. The soil type is sandy soil with an electrical conductivity test result of 230μs / cm, indicating mild salinization. A potted experiment on growing vegetables in salinized soil was carried out using this soil.

[0034] Baby cabbage has a short growth cycle and is a classic fast-growing vegetable. It can be grown in slightly salinized soil and is suitable for planting on sandy soil. Its growth is similar to that of other major vegetables and can reflect the conditions of major vegetable plants planted in salinized soil. The common "Four Joys" variety of baby cabbage was selected as the tested vegetable variety. A 120×40×40cm foam box was selected for potting, with an opening at the bottom for easy drainage. Three plants were planted in one pot. Before sowing, 100g of the corresponding fertilizer was added to the soil area for each sowing plant to pre-mix the base fertilizer. Baby cabbage from the same batch was purchased. Seeds with plump appearance were selected as test seeds. They were sown in pots on March 21st, and watering, light and fertilizer application were strictly controlled to be the same. When the seedlings grew the third true leaf, 50g of corresponding fertilizer was added to each plant. On the 30th day after sowing, 50g of corresponding fertilizer was added. The fertilizer was applied to the topsoil, and watering promoted the penetration of ingredients into the deep layer. During the heading period, the leaves will quickly embrace to form a compact ball. If there is no depression when lightly pressing the top of the ball, it indicates that it is mature. At this time, the plant was separated from the soil, the roots were removed, the ball was peeled off and weighed immediately (net ball weight) and the average was calculated within the group. The time when the last plant in each group matured was recorded.

[0035] Table 1 shows the average bulb weight of baby cabbages obtained by planting baby cabbages with fertilizers of different ingredients (prepared according to the method of Example 1 based on the presence or absence of the ingredients) according to the above method. The greater the weight, the better the growth of the baby cabbages. Table 2 shows the time it takes for the last baby cabbage plant in each group of corresponding fertilizers to mature according to the above method. The shorter the time, the less the development of the baby cabbage is affected by saline soil.

[0036] Table 1: Different fertilizer compositions and corresponding average cabbage head weights

[0037] Table 2: Different fertilizer ingredients and corresponding baby cabbage maturity time

[0038] According to the above test results, only fertilizers containing core ingredients can significantly increase the net vegetable weight of a single plant and significantly shorten the maturation time. Fertilizers without core ingredients still have no significant effect even if they contain specific soil improvement ingredients or trace elements. This suggests that seaweed oligosaccharides, salt-tolerant microbial composite agents and polyacrylamide are core ingredients that promote the growth of vegetables in salinized soil; when containing core ingredients, adding specific soil improvement ingredients or trace elements can further increase the net vegetable weight of a single plant and shorten the maturation time; when adding synergistic excipients, the efficacy can be further improved; in view of the fact that the fertilization modes and fertilization amounts of the above-mentioned groups are the same, it is suggested that the core ingredients, nutritional ingredients, soil improvement ingredients, composite trace elements and synergistic excipients of the present invention actually have a certain synergistic effect, because when the dosage of each ingredient is reduced, they will produce better effects together.

[0039] The reasons for the above synergistic effect may be as follows: at the soil level: polyacrylamide and microbial extracellular products work together to improve structure and reduce salt content, creating a suitable growth matrix for plants; at the microbial-plant interaction level: salt-tolerant bacteria activate nutrients and secrete hormones, while seaweed oligosaccharides induce stress resistance and promote absorption, and the two work together to enhance the adaptability of plants to adversity; at the plant physiological level: the three work together to optimize photosynthetic efficiency, nutrient distribution and development regulation, accelerate the growth cycle, and ultimately achieve increased yield and shortened maturity time. In addition, nutrients, soil improvement ingredients, complex trace elements and synergistic excipients play an auxiliary role in the above mechanism, and the auxiliary effects of each component have a synergistic effect. Example 3: Efficacy test of core ingredients

[0040] In the study of special fertilizers for salinized vegetable cultivation, the research team first tested multiple components and finally found that seaweed oligosaccharides have the most core efficacy. However, seaweed oligosaccharides still rely on corresponding ingredients to exert their true efficacy. This example cites some experiments and their results from the previous research to facilitate the understanding of the core ingredients of the present invention.

[0041] For the exploration of core components, the early experiments mainly focused on substances that regulate plant growth, microorganisms, and some reagents with water-retention functions commonly used in treating salinization. The specific ingredients are shown in Table 3. The fertilizer was prepared by referring to the method of Example 1. The difference is that it only contains the core ingredients here and the nutrients in Example 1. It was tested according to the method of Example 2. In fact, each embodiment is a series of experiments and their corresponding results selected from the early and mid-term experiments. Table 3 shows the fertilizers composed of different core ingredients and the corresponding average bulb weight of baby cabbage.

[0042] Table 3: Different fertilizer compositions and corresponding average cabbage head weights

[0043] According to the above test results, seaweed oligosaccharides have a significant effect on promoting the growth of baby cabbage in saline soil in the presence of a salt-tolerant microbial compound agent containing at least alkaliphilic halomonas and polyacrylamide, suggesting that the pathway of seaweed oligosaccharide action is affected by the plant-microorganism interaction mechanism and polyacrylamide; when any one component is replaced by other components with similar effects, the fertilizer no longer has a similar effect on the growth of saline-grown vegetables. This is due to the different effects caused by the different active substances such as polysaccharides secreted by microorganisms and the different structures of the compounds; as for the proportion of each component, the ratio of seaweed oligosaccharides, salt-tolerant microbial compound agents and polyacrylamide should be 3-10:1:0.05-1. Example 4: Efficacy test of nutrients

[0044] Nutrients mainly play a role in supporting plant growth. In particular, when growing vegetables under salinization, vegetable plants are affected by various components in fertilizers, and their needs for nutrients will change to a certain extent. This embodiment cites some experiments and their results from preliminary research to facilitate understanding of the nutritional components of the present invention.

[0045] As for the nutrients, the preliminary experiments mainly carried out corresponding tests on the substances that provide the nutrients and their composition ratios. The specific components are shown in Table 4. The fertilizer was prepared by referring to the method of Example 1, except that only the nutrients were adjusted. The test was carried out according to the method of Example 2. Table 4 shows the fertilizers with different nutrient compositions and the corresponding average bulb weight of baby cabbage.

[0046] Table 4: Different fertilizer compositions and corresponding average cabbage bulb weights

[0047] According to the above test results, ammonium polyphosphate is more suitable for use as a phosphorus fertilizer in special fertilizers for salinized vegetable cultivation. In addition to the above tests, other nitrogen fertilizers and potassium fertilizers were also tested, and there was no obvious difference in efficacy. As for the ratio of nutrients, according to the experiments conducted according to the present invention, it can be inferred that the mass ratio of urea, potassium nitrate and ammonium polyphosphate is 3-5:3-5:3-8. Example 5: Efficacy test of soil improvement ingredients

[0048] Taking into account the structural problems of salinized soil, such as compaction and poor water retention, the present invention considers adding certain soil improvement components to improve the soil structure. This example cites some experiments and their results from previous research to facilitate understanding of the soil improvement components of the present invention.

[0049] As for soil improvement components, the present invention mainly focuses on increasing soil organic matter, regulating root growth feedback to the soil, and improving soil water retention capacity. Relevant substances are selected based on these purposes. The specific components are shown in Table 5. The fertilizer is prepared by referring to the method of Example 1, except that only the soil improvement components are adjusted. The test is carried out according to the method of Example 2. Table 5 shows fertilizers composed of different soil improvement components and the corresponding average bulb weight of baby cabbage.

[0050] Table 5: Different fertilizer compositions and corresponding average cabbage head weights

[0051] Based on the above test results, it can be seen that only the simultaneous presence of humic acid, glutamic acid, aspartic acid, lysine, serine, and attapulgite can maximize the yield of baby cabbage grown in salinized soil, and the various components have a synergistic effect. Amino acids can be directly utilized by plant roots, so the type of amino acid has a significant impact on vegetable plants. Experiments have found that only the presence of glutamic acid, aspartic acid, lysine, and serine can maximize baby cabbage yield. Attapulgite and perlite both have the function of improving soil water retention, but only attapulgite can maximize baby cabbage yield because it has a synergistic effect with other components.

[0052] The possible principle behind the above is that weathered coal humic acid contains functional groups such as carboxyl and phenolic hydroxyl groups, which can adsorb sodium ions in the soil, reduce salt concentration, and form humic acid-sodium ion complexes, which are discharged with irrigation water; complex amino acids can not only serve as a carbon source to promote microbial reproduction, but also chelate with metal ions to reduce salt toxicity. They can also be directly used by plants to regulate specific physiological processes. The layered structure of attapulgite has high adsorption capacity and can fix free chloride ions in the soil. At the same time, it can serve as a slow-release carrier for fertilizers to prolong fertilizer effectiveness. It can also absorb a large amount of water and form several small water-retention units in the soil. Example 6: Efficacy test of compound trace elements

[0053] Saline soil contains a large amount of soluble salts and acidic substances, while the content of trace elements essential to plants is relatively low. Vegetables require certain trace elements to grow, especially when grown in saline soil. Due to the regulation of substances such as seaweed oligosaccharides, the demand for trace elements will also change to a certain extent. Therefore, it is necessary to explore it and find suitable composite trace elements. This example cites some experiments and their results from preliminary research to facilitate understanding of the composite trace elements of the present invention.

[0054] For the composite trace elements, the present invention examines the elements required by various vegetables and selects related substances. The specific components are shown in Table 6. The fertilizer is prepared by referring to the method of Example 1, except that only the composite trace elements are adjusted. The test is carried out according to the method of Example 2. Table 6 shows the fertilizers with different composite trace element compositions and the corresponding average bulb weight of baby cabbage.

[0055] Table 6: Different fertilizer compositions and corresponding average cabbage bulb weights

[0056] According to the above test results, only by containing magnesium sulfate, EDTA-Ca and EDTA-Zn at the same time can the yield of baby cabbage grown in salinized soil be maximized, and there is a synergistic effect between the ingredients.

[0057] The possible principle behind this is that chelated calcium (EDTA-Ca) avoids reacting with soil sulfate to form gypsum through chelation, while enhancing the toughness of cell walls and improving the salt resistance of vegetables; magnesium sulfate supplements magnesium to promote chlorophyll synthesis, and sulfur can regulate soil pH and reduce the impact of sodium ions on root activity; zinc also exists in a chelated state, and is more stable than an inorganic state in a high-salt environment. It can be directly absorbed by the roots, alleviating trace element deficiencies caused by salt stress, and at the same time, the steric hindrance effect of the chelating group prevents high concentrations of sodium ions in saline soil from competing for binding sites. Example 7: Efficacy test of synergistic excipients

[0058] After conducting the above research, the present invention considers adding specific synergistic adjuvants to improve the overall efficacy. The main considerations are to promote the penetration of fertilizers in saline soil and form a water-retaining microenvironment. This example cites some experiments and their results in the previous research to facilitate the understanding of the synergistic adjuvants of the present invention. Based on the above purposes, relevant substances are selected. The specific ingredients are shown in Table 7. The fertilizer is prepared with reference to the method of Example 1. The difference is that only the synergistic adjuvant is adjusted. The test is carried out according to the method of Example 2. Table 7 shows the fertilizers composed of different synergistic adjuvants and the corresponding average ball weight of baby cabbage.

[0059] Table 7: Different fertilizer compositions and corresponding average cabbage head weights

[0060] According to the above test results, not all synergistic excipients that have the function of promoting the penetration of fertilizers in saline soil and forming a water-retaining microenvironment can increase the yield of baby cabbage. It is also necessary to consider the compatibility of the synergistic excipients with other ingredients in the fertilizer and the feasibility of using them in saline soil. After a large amount of screening, the synergistic excipients of octaalkyl glucoside and starch grafted polyacrylate were finally discovered. Only a small amount of addition is needed to significantly amplify the overall fertilizer effect and has obvious economic benefits.

[0061] The possible principle behind this is that octaalkyl glucoside, as a non-ionic surfactant, reduces the surface tension of water, promotes the penetration of fertilizers in saline soil, and avoids surface salt accumulation. Starch-grafted polyacrylate has a high water absorption rate, forming a water-retaining microenvironment in saline soil, alleviating the combined stress of drought and salt damage. The two are compounded to form a dual-functional layer of permeability and water retention, solving the problem of saline soil being easily compacted when watered and prone to drought when not watered, thereby improving fertilizer efficiency. Example 8: Cyclic Planting Test

[0062] Generally speaking, even when vegetables are planted in a cyclical manner on non-saline soil, the continued application of inorganic fertilizers can induce soil salinization. Therefore, when planting vegetables on saline soil, it is even more important to consider the impact of fertilizer on the salinization process. In this embodiment, the vegetables were planted according to the scheme in Example 2. When the baby cabbage matured, the roots and soil were removed before the next round of vegetable planting began. The planting plan for the second half of the year was to sow on August 20th, with all other procedures being identical to those in Example 2. At the end of each planting round, samples were taken to measure electrical conductivity, according to standard HJ 802-2016. Table 8 shows the test results of soil conductivity during cyclical planting and the average bulb weight (net weight) of the baby cabbage.

[0063] Table 8: Soil conductivity test results for cyclic planting and average bulb weight (net weight) of baby cabbage

[0064] According to the above test results, soil salinization was slightly aggravated in the first round of planting, while the degree of soil salinization was significantly reduced in subsequent rounds of planting. At the same time, the yield of baby cabbage increased with the increase of rounds. The principle may be that the rapid dissolution of water-soluble inorganic salts in the first round of planting, the mineral entrainment of seaweed oligosaccharides, and the acidic groups in the fertilizer prompted the desorption of cations adsorbed by soil colloids, which directly led to an increase in electrical conductivity. The osmotic pressure of plant roots in salinized soil was unbalanced, and the efficiency of root water and fertilizer absorption was low in the first round of planting, resulting in fertilizer ions retained in the rhizosphere soil and unable to be effectively absorbed and utilized, forming ion accumulation. However, in the subsequent process, The physical interception and water conduction of the polymer network and the aggregate structure construction of seaweed oligosaccharides have improved the soil structure of saline soil. In addition, the root growth-promoting effect of seaweed oligosaccharides, the salt conversion mediated by microorganisms, the antagonistic effect of trace elements, and the chelation of organic components have promoted the formation of soil aggregate structure, further weakening the harm of salt. Salt may also be brought out by plants. After the fourth round of planting, the electrical conductivity was 170μs / cm, which is medium soil and the degree of salinization is lower than that of mildly saline soil. Based on factors such as the reduction in salinization level and the improvement of soil structure, vegetables planted in subsequent rounds are less inhibited and the yield naturally increases. Example 9: Experiment on planting different vegetables in salinized conditions

[0065] The above mainly uses baby cabbage as the test vegetable. This embodiment lists the salinization planting experiments of other vegetables conducted by the present invention. In order to cover as many vegetable categories as possible, baby cabbage belongs to the leafy vegetable category. In addition, carrots are selected as representatives of root vegetables, tomatoes as representatives of fruit vegetables, onions as representatives of bulbs, and soybeans as representatives of legumes. They are planted according to the method recommended by the Ministry of Agriculture and Rural Affairs of the People's Republic of China, and a control group and an experimental group (three parallel groups) are set. The difference between the experimental groups is that the fertilizer in Example 1 of the present invention is used to replace the fertilizer in the recommended method. The test soil is the same as Example 2. The yield improvement ratio of various different vegetables when the special fertilizer for salinization vegetable planting of the present invention is used is calculated. The results are shown in Table 9.

[0066] Table 9: Experiments on planting different vegetables in salinized conditions

[0067] According to the above test results, when the main categories of vegetables are planted in slightly salinized soil, the yield is significantly improved by applying the special fertilizer for planting salinized vegetables of the present invention. The special fertilizer for planting salinized vegetables of the present invention is applicable to different vegetables. Example 10: Vegetable Planting Test with Different Degrees of Salinization

[0068] The above mainly examines the situation of vegetable planting under mild salinization. This embodiment examines the planting of vegetables in more seriously salinized soil and the efficacy of the special fertilizer for planting salinized vegetables of the present invention.

[0069] Spinach has better resistance to salinization than other leafy vegetables. At the same time, spinach has a short growth cycle, which is about 50 days from sowing to harvesting. Tall spinach ("Rumex") was selected as the test variety. The test saline soil was saline soil with different electrical conductivities obtained from Dajiangdong, Qiantang, Hangzhou, mainly including mild salinization (230μs / cm, 310μs / cm), moderate salinization (460μs / cm, 630μs / cm) and one severe salinization (820μs / cm). Planting was carried out according to the method recommended by the Ministry of Agriculture and Rural Affairs of the People's Republic of China, and a control group and an experimental group (three parallel groups) were set up. The difference between the experimental groups was that the fertilizer of Example 1 of the present invention was used instead of the fertilizer in the recommended method. The yield improvement ratio of various vegetables when the special fertilizer for salinized vegetable planting of the present invention was used was calculated. The results are shown in Table 10.

[0070] Table 10: Vegetable planting experiments with different waterlogging degrees

[0071] According to the above test results, it can be seen that the special fertilizer for salinized soil and vegetable cultivation of the present invention has the effect of increasing vegetable yield for various levels of salinized soil.

[0072] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent modifications or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be included in the scope of protection of the present invention.

Claims

1. A special fertilizer for salinized vegetable cultivation containing seaweed oligosaccharides, characterized in that: It includes seaweed oligosaccharides, salt-tolerant microbial compound agents and polyacrylamide; the seaweed oligosaccharide has a polymerization degree of 2-50 and an active ingredient content of ≥90%; the salt-tolerant microbial compound agent includes alkaliphilic halomonas ( Halomonas alkaliphila ) CGMCC 1.7449, viable count ≥ 2 × 10 8 CFU / g; the molecular weight of the polyacrylamide is 8-10 million, the anionicity is 10%-20%, and the cationicity is 30%-60%.

2. The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation according to claim 1, characterized in that: The salt-tolerant microbial composite agent also includes Rhizobium leguminosarum ( Rhizobium leguminosarum ) ACCC 16119 and soil Bacillus ( Bacillus edaphicus )ACCC 11029, viable count ≥ 2 × 10 8 CFU / g.

3. The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation according to claim 1, characterized in that: The invention also includes urea, potassium nitrate and ammonium polyphosphate; the solubility of the ammonium polyphosphate is ≥150g / 100g water, and the degree of polymerization is 2-18.

4. The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation according to claim 1, characterized in that: It also includes humic acid, composite amino acids and attapulgite; the humic acid is weathered coal humic acid, with an organic matter content of ≥60% and a moisture content of ≤30%; the composite amino acids include glutamic acid, aspartic acid, lysine and serine.

5. The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation according to claim 1, characterized in that: The invention also includes composite trace elements, which include magnesium sulfate, EDTA-Ca and EDTA-Zn; the calcium content of the EDTA-Ca is ≥9wt%; the zinc content of the EDTA-Zn is ≥14wt%.

6. The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation according to claim 1, characterized in that: Also included are octaalkyl glucoside and starch grafted polyacrylate.

7. A method for increasing the yield of vegetables grown in salinized soil, characterized in that: The seaweed oligosaccharide-containing special fertilizer for salinized vegetable cultivation as described in any one of claims 1 to 6 is used for fertilization.

8. A method for preparing a reagent for increasing the yield of vegetables grown in salinized soil using seaweed oligosaccharides, characterized in that: The reagent for improving the yield of vegetables grown in salinized soil includes seaweed oligosaccharides, salt-tolerant microbial composite agents and polyacrylamide; the seaweed oligosaccharides have a polymerization degree of 2-50 and an active ingredient content of ≥90%; the salt-tolerant microbial composite agent includes alkaliphilic Halomonas ( Halomonas alkaliphila ) CGMCC 1.7449, viable count ≥ 2 × 10 8 CFU / g; the molecular weight of the polyacrylamide is 8-10 million, the anionicity is 10%-20%, and the cationicity is 30%-60%.

Images