Fertilizer for improving salt tolerance of crops and preparation method thereof

Abstract

The invention discloses a fertilizer for improving salt tolerance of crops and a preparation method thereof, and belongs to the technical field of fertilizers. The fertilizer for improving the salt tolerance of the crops comprises the following components in percentage by weight: 50%-60% of trace elements, 5%-10% of amino acid oligosaccharin, 10%-15% of methionine, 5%-7% of halophilic strains, 5%-10% of salt-tolerant strains, 15%-20% of biochar, biochar-coated halophilic strains and biochar-coated salt-tolerant strains. According to the fertilizer for improving the salt tolerance of the crops, the halophilic strains, the salt-tolerant strains and the microelements are combined for use for the first time, and the influence on the growth of the halophilic strains and the salt-tolerant strains due to the large amount of the microelements in the combination process is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a fertilizer for improving the salt tolerance of crops and a preparation method thereof. Background Art

[0002] Soil salinity is a major environmental constraint affecting agricultural production systems. Salt stress affects the morphological, biochemical and physiological processes of plants, leading to a decrease in biomass. This adverse consequence of soil salinity can be manifested at different growth stages, such as germination, seedling, vegetative and maturity. The initial perception of salt stress occurs in the root system and results in an immediate inhibition of root growth, mainly due to osmotic stress caused by limited water supply. After a few days or weeks, the root system is damaged by excessive uptake of Cl. - and Na + The ion toxicity caused by the nutrient imbalance in the cytoplasm begins to prevail. Under long-term salt stress, the roots and shoots of plants will produce reactive oxygen species (ROS), and a series of adverse reactions will occur one after another, eventually affecting the normal growth and development of the plant.

[0003] Na+ / H+ antiporter is one of the key regulatory mechanisms for plant and microbial cells to cope with high-salt environments. This protein maintains the cell's ion balance and pH by pumping Na+ out of the cell and pumping external H+ into the cell, thereby enhancing the cell's adaptability to salt stress. Trace elements play an important role in plant growth and development. Although their content in plants is very low, they are necessary for the normal physiological activities of plants. The addition of trace elements to fertilizers may affect the function of Na+ / H+ antiporters on the cell membranes of plant and microbial cells, thereby interfering with the cell's ion balance and pH regulation. For example, trace elements such as copper and zinc are cofactors of many enzymes. At high concentrations, they may competitively bind to Na+ / H+ antiporters and affect their activity.

[0004] Fertilizers contain trace elements, but when trace elements are mixed with salt-tolerant strains, possible interactions between them need to be considered. For example, if the concentration of trace elements is inappropriate, it may inhibit the growth and metabolic activity of salt-tolerant strains, thereby affecting their colonization and function in the soil. Therefore, in practical applications, how to reasonably determine the application method and concentration of trace elements and salt-tolerant strains to prevent trace elements from affecting salt-tolerant strains has become a difficult problem that needs to be solved urgently. This is directly related to whether the various components in the fertilizer can work effectively together, which plays a vital role in improving the salt tolerance and yield of crops. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a fertilizer for improving the salt tolerance of crops and a preparation method thereof. The fertilizer for improving the salt tolerance of crops combines halophilic strains and salt-tolerant strains with trace elements for the first time. Through a reasonable weight ratio, the trace elements are effectively prevented from affecting the growth of halophilic strains and salt-tolerant strains during the combined use, so that the fertilizer can effectively improve the salt tolerance of crops and promote crop yields.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] A fertilizer for improving the salt tolerance of crops comprises, by weight percentage, 50%-60% of trace elements, 5%-10% of amino acid oligosaccharides, 10%-15% of methionine, 5%-7% of halophilic strains, 5%-10% of salt-tolerant strains, and 15%-20% of biochar, wherein the biochar coats the halophilic strains and the salt-tolerant strains.

[0008] Furthermore, the trace elements are added in the form of ZnSO4 and CuS04.

[0009] Further, the weight ratio of ZnSO4 to CuSO4 is 2:3-3:4.

[0010] Furthermore, the salt-tolerant strain is a mixture of one or more of the genera Bacillus megaterium, Arthrobacter aureus, Sinorhizobium freundii, Bacillus licheniformis, and Acinetobacter.

[0011] Furthermore, the halophilic strain is a mixture of one or more of Nocardia, Halobacillus, Halomonas, Hylocereus, Pseudonocardia, Vibrio, Bacillus, Aspergillus, and Arthrobacter.

[0012] The present invention also provides a method for preparing a fertilizer for improving the salt tolerance of crops, comprising the following steps: firstly uniformly mixing the halophilic strain, the salt-tolerant strain and the biochar according to weight percentage, granulating, then adding the trace elements, the amino acid oligosaccharide and the methionine, and uniformly mixing to obtain the fertilizer for improving the salt tolerance of crops.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention provides a fertilizer for improving the salt tolerance of crops and a preparation method thereof, wherein biochar is coated with a halophilic strain and a halophilic strain, and the biochar provides a habitat for the halophilic strain and the halophilic strain, thereby enhancing the stress resistance of the halophilic strain and the halophilic strain. Methionine chelates trace elements, so that the methionine metal ion chelate is bound to the extracellular polysaccharide of the halophilic strain and the halophilic strain, thereby avoiding the excessive binding of trace elements to the Na+ / H+ antiporter of the cell membrane, thereby affecting the salt resistance of the halophilic strain and the halophilic strain. In addition, biochar can also play an isolating role for the influence of trace elements on the halophilic strain and the halophilic strain. The fertilizer for improving the salt tolerance of crops combines the halophilic strain and the halophilic strain with trace elements for the first time, and through a reasonable weight ratio, effectively prevents the trace elements from affecting the growth of the halophilic strain and the halophilic strain during the combined use, so that the fertilizer can effectively improve the salt tolerance of crops and promote the yield of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0016] Figure 1 This is the result of the effect of salt stress on the sodium ion content in the roots of rice seedlings;

[0017] Figure 2 This is a graph showing the effect of salt stress on the potassium ion content in the roots of rice seedlings. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0019] A fertilizer for improving the salt tolerance of crops comprises, by weight percentage, 50%-60% of trace elements, 5%-10% of amino acid oligosaccharides, 10%-15% of methionine, 5%-7% of halophilic strains, 5%-10% of salt-tolerant strains, and 15%-20% of biochar, wherein the biochar coats the halophilic strains and the salt-tolerant strains.

[0020] Extracellular Polysaccharides (EPS) are secondary metabolites secreted outside the cell wall by many microorganisms during their growth and metabolism. They play an important role in the physiological activities of microorganisms, including protecting cells from environmental stress, regulating the initial attachment of cells to different matrices, and participating in the formation of biofilms. Extracellular polysaccharide molecules contain a variety of functional groups, such as hydroxyl and carboxyl groups, which can form stable complexes with metal ions. The sulfur atom in the methionine molecule can act as a ligand to form a coordination bond with metal ions, thereby forming a bridge between metal ions and extracellular polysaccharides. Through metal bridging, methionine helps stabilize the structure of metal-polysaccharide chelates and reduce their binding to the Na+ / H+ antiporter in the cell membrane, so as not to affect the function of the Na+ / H+ antiporter.

[0021] Methionine metal ion chelates can be absorbed by plants. Specific transporters in plant roots can recognize and transport these methionine metal ion chelates into the plant body. For example, members of the zinc / iron regulatory protein (ZIP) family, such as ZIP1, ZIP2, ZIP3, and ITR1, are important transporters for heavy metal absorption in plant roots.

[0022] Methionine metal ion chelate: such as methionine zinc (Zn-Met), methionine copper (Cu-Met), methionine manganese (Mn-Met), etc., obtained by the chemical reaction of metal ions and methionine to form a chelate ring.

[0023] Advantages of methionine metal chelate include:

[0024] Improve stability: The ring structure of the chelate makes it more stable in the plant body and less likely to react with other substances and lose its activity.

[0025] Reduce antagonism: Chelates can reduce antagonism between trace elements and other nutrients.

[0026] Improve bioavailability: Studies have shown that the absorption rate of trace elements chelated by amino acids is 2 to 6 times that of inorganic trace elements.

[0027] In this embodiment, trace elements are added in the form of ZnSO4 and CuSO4, and the functions of ZnSO4 and CuSO4 are as follows:

[0028] Zinc sulfate (ZnSO4): Zinc is one of the essential trace elements for plants and plays an important role in plant growth, development and stress resistance. Appropriate amounts of zinc can improve the salt tolerance of crops because it is involved in regulating the activity of multiple enzymes in plants, including those related to salt stress. Zinc also helps maintain the stability and function of plant cell membranes and reduce the damage of salt to plant cells.

[0029] Copper sulfate (CuSO4): Copper is also an essential trace element for plants and is involved in many physiological processes. Copper can enhance the activity of antioxidant enzymes in plants and reduce oxidative damage caused by salt stress. However, the concentration of copper needs to be strictly controlled because excessive copper is harmful to plants.

[0030] Amino acid oligosaccharides: also known as amino oligosaccharides, also known as agricultural chitooligosaccharides, chitooligosaccharides (COS) are soluble oligosaccharides obtained by acidolysis or enzymolysis of chitin after deacetylation. Amino acid oligosaccharides can be used as plant growth regulators. They have multiple physiological functions in plants, including promoting plant growth, improving plant stress resistance and regulating plant osmotic balance. Under salt stress conditions, they can help plants maintain water and reduce the damage of salt to plants.

[0031] Halophilic strains: Halophilic strains can survive in high-salt environments. They can produce some metabolites that help plants tolerate salt, such as amino acids, organic acids and polysaccharides. These substances can help plants regulate the ion balance in cells and reduce the toxic effects of salt on plants.

[0032] Salt-tolerant strains: Salt-tolerant strains can form a symbiotic relationship with plant roots, improving the salt tolerance of plants by secreting growth-promoting substances and improving soil structure. These microorganisms can also help plants absorb water and nutrients more efficiently, reducing the adverse effects of salt on plant growth.

[0033] In the present invention, biochar can effectively improve the tolerance of crops to salt stress by regulating the Na+ / K+ homeostasis in plant cells, reducing oxidative damage, and enhancing plant photosynthesis; the application of biochar can reduce the potential impact of trace elements in the soil on plants, halophilic strains and salt-tolerant strains.

[0034] In the present invention, salt-tolerant strains refer to microorganisms that can grow and reproduce in a high-salt environment. They have important application value in agricultural production, especially in the improvement of saline soil and the promotion of plant growth. The following are some known salt-tolerant strains:

[0035] Bacillus megaterium: It has the ability to solubilize phosphate and secrete indoleacetic acid, and can grow under saline-alkali conditions.

[0036] Arthrobacter aurescens: It has the ability to dissolve potassium and fix nitrogen, which helps plants absorb nutrients.

[0037] Sinorhizobium fredii: Has the ability to fix nitrogen, which helps plant growth.

[0038] Bacillus licheniformis: has the ability to solubilize phosphate and secrete indoleacetic acid.

[0039] Acinetobacter sp.: have little ACC deaminase activity but may have other properties that are beneficial to plant growth.

[0040] Halomonas aquamarina: It has the ability to produce extracellular polymeric substances (EPS), reduce alkali and produce indole-3-acetic acid (IAA), which helps the germination rate and root length of plants under salt stress.

[0041] Preferably, the salt-tolerant strain in the present invention is a mixture of one or more of the genera Bacillus megaterium, Arthrobacter aureus, Sinorhizobium freundii, Bacillus licheniformis and Acinetobacter.

[0042] Halophilic strains are a class of microorganisms that can grow in high-salt environments, including halophilic bacteria, halophilic fungi, and halophilic archaea. These microorganisms have unique physiological structures and metabolic regulation mechanisms that enable them to survive in extreme high-salt environments. The following are some specific halophilic strains and their characteristics: Halophilic Actinomycetes (Actinobacteria), such as Nocardiopsis, Halobacillus, Halomonas, Paludifilum, Pseudonocardia, Vibrio, Bacillus, Aspergillus, Wallemia.

[0043] Preferably, the halophilic strain in the present invention is a mixture of one or more of Nocardiopsis, Halobacillus, Halomonas, Hylocereus, Pseudonocardia, Vibrio, Bacillus, Aspergillus, and Arthrobacterium.

[0044] Example 1

[0045] The fertilizer for improving the salt tolerance of crops provided in this embodiment includes, by weight percentage, 60% of trace elements (wherein the weight ratio of ZnSO4 and CuSO4 is 2:3), 5% of amino acid oligosaccharides, 10% of methionine, 5% of halophilic strains, 5% of salt-tolerant strains, and 15% of biochar, wherein the biochar is coated with the halophilic strains and the salt-tolerant strains.

[0046] In this embodiment, the salt-tolerant strain is of the genus Bacillus megaterium, and the halophilic strain is of the genus Nocardia.

[0047] This embodiment also provides a method for preparing a fertilizer for improving the salt tolerance of crops, comprising the following steps: first, according to weight percentage, uniformly mixing the halophilic strain, the salt-tolerant strain and the biochar, granulating, and then adding the trace elements, the amino acid oligosaccharides and the methionine, and mixing uniformly to obtain the fertilizer for improving the salt tolerance of crops.

[0048] Example 2

[0049] The fertilizer for improving the salt tolerance of crops provided in this embodiment includes, by weight percentage, 50% of trace elements (wherein the weight ratio of ZnSO4 and CuSO4 is 2:3), 10% of amino acid oligosaccharides, 10% of methionine, 5% of halophilic strains, 5% of salt-tolerant strains, and 20% of biochar, wherein the biochar is coated with the halophilic strains and the salt-tolerant strains.

[0050] In this embodiment, the salt-tolerant strain is of the genus Arthrobacter, and the halophilic strain is of the genus Halobacillus.

[0051] This embodiment also provides a method for preparing a fertilizer for improving the salt tolerance of crops, comprising the following steps: first, according to weight percentage, uniformly mixing the halophilic strain, the salt-tolerant strain and the biochar, granulating, and then adding the trace elements, the amino acid oligosaccharides and the methionine, and mixing uniformly to obtain the fertilizer for improving the salt tolerance of crops.

[0052] Example 3

[0053] The fertilizer for improving the salt tolerance of crops provided in this embodiment includes, by weight percentage, 48% of trace elements (wherein the weight ratio of ZnSO4 and CuSO4 is 3:4), 5% of amino acid oligosaccharides, 15% of methionine, 7% of halophilic strains, 10% of salt-tolerant strains, and 15% of biochar, wherein the biochar is coated with the halophilic strains and the salt-tolerant strains.

[0054] In this embodiment, the salt-tolerant strain is from the genus Sinorhizobium freundii, and the halophilic strain is from the genus Halomonas.

[0055] This embodiment also provides a method for preparing a fertilizer for improving the salt tolerance of crops, comprising the following steps: first, according to weight percentage, uniformly mixing the halophilic strain, the salt-tolerant strain and the biochar, granulating, and then adding the trace elements, the amino acid oligosaccharides and the methionine, and mixing uniformly to obtain the fertilizer for improving the salt tolerance of crops.

[0056] Example 4

[0057] The fertilizer for improving the salt tolerance of crops provided in this embodiment includes, by weight percentage, 51% of trace elements (wherein the weight ratio of ZnSO4 and CuSO4 is 3:4), 8% of amino acid oligosaccharides, 12% of methionine, 6% of halophilic strains, 8% of salt-tolerant strains, and 15% of biochar, wherein the biochar is coated with the halophilic strains and the salt-tolerant strains.

[0058] In this embodiment, the salt-tolerant strain is of the genus Bacillus licheniformis, and the halophilic strain is of the genus Trichoderma.

[0059] This embodiment also provides a method for preparing a fertilizer for improving the salt tolerance of crops, comprising the following steps: first, according to weight percentage, uniformly mixing the halophilic strain, the salt-tolerant strain and the biochar, granulating, and then adding the trace elements, the amino acid oligosaccharides and the methionine, and mixing uniformly to obtain the fertilizer for improving the salt tolerance of crops.

[0060] Experimental process and data

[0061] Experimental plots with completely identical conditions such as light, ventilation, irrigation and drainage were selected and divided into 5 plots, which were used as a comparative example group and 4 example example groups.

[0062] Among them, the four embodiment groups are respectively the embodiment group 1, embodiment group 2, embodiment group 3, and embodiment group 4 described above, and the comparative example group uses ordinary rice fertilizer.

[0063] The same batch of rice seeds were used, sown and harvested at the same time, strict and consistent field management was carried out during the planting process, and a certain concentration of saline solution was prepared as salt stress treatment to study the effects of salt stress on rice seed germination and rice seedling growth.

[0064] Seed preparation:

[0065] Seed drying: Before soaking, turn the rice seeds over and dry them for 1 to 2 days to enhance the permeability of the seed coat and improve the germination rate and germination potential. Remove the husk of the seeds and select seeds of good quality and without mold spots.

[0066] Seed soaking: Rice seeds need to absorb enough water to germinate, and the amount of water absorbed by rice seeds is 15% of its weight. When the water temperature is 30℃, it takes about 35 hours, and the seeds are soaked for about 60 hours.

[0067] Sterilization: Sterilize the seeds by rinsing with 75% ethanol for 1-2 minutes and then with 1.5‰ HgCl2 solution for 18-25 minutes.

[0068] Germination: Place the sterilized seeds at the optimum temperature of 28℃-32℃ for germination.

[0069] Germination: Under suitable conditions, the radicle develops, the radicle first breaks through the seed coat, and then the plumule grows. When the radicle length is equal to the seed length and the plumule length reaches half the seed length, it is considered to have germinated.

[0070] Sprouting: After germination, in order to enhance the adaptability of the buds to the natural low temperature environment, they need to be spread out for drying. This is usually done indoors and lasts for more than half a day.

[0071] Sowing: After germination, choose a suitable time for sowing according to weather conditions and field conditions, and randomly divide the rice seeds into 5 groups, each group has 10,000 rice seeds, and sow them in the fields corresponding to the comparative example group, example 1 group, example 2 group, example 3 group, and example 4 group, respectively.

[0072] Fertilization: 2 days after sowing, ordinary fertilizers and the fertilizers for improving crop salt tolerance described in Examples 1, 2, 3 and 4 were applied to the fields corresponding to the control group, Example 1, Example 2, Example 3 and Example 4, respectively.

[0073] Salt stress treatment: One day after fertilization, salt stress treatment was carried out with a certain concentration of saline solution (150 mmol / L NaCl solution). Each group of fields was irrigated for 3 days, and then the emergence of rice seeds was observed and the number of rice seeds emerged was recorded. The results are shown in Table 1.

[0074] Table 1

[0075]

[0076] As can be seen from Table 1, the number of seedlings in Example 1, Example 2, Example 3, and Example 4 is significantly greater than that in the control group, indicating that methionine chelates trace elements, causing methionine metal ion ammine to bind to the extracellular polysaccharides of halophilic and halotolerant strains, thereby avoiding excessive binding of trace elements to the Na+ / H+ antiporter of the cell membrane, which is very important for improving the effect of trace elements on the salt resistance of halophilic and halotolerant strains, thereby increasing the number of rice seedlings.

[0077] After the seedlings of Example 1, Example 2, Example 3, Example 4, and the comparative group grew to about 20 cm, the seedlings of Example 1, Example 2, Example 3, Example 4, and the comparative group were used as research objects, and irrigated with a certain concentration of saline solution (150 mmol / L NaCl solution) to conduct a salt stress test. After the salt stress test was completed, 10 seedlings were randomly selected from each group of fields, and the roots of the 10 seedlings were cut off as samples, placed in a paper bag, and dried in a fan-heated oven at 60°C until constant weight was reached. In order to determine the ion content, the dried sample was ground into powder and transferred to a glass test tube. Double distilled water was added to the glass test tube, and the sample was boiled in a water bath for 2 hours. The extract was filtered through filter paper and diluted, and the Na+ and K+ ion contents were determined using a flame photometer. The experimental results are shown as follows. Figure 1 , Figure 2 shown.

[0078] from Figure 1 , Figure 2 It can be seen that compared with the comparative example group, the Na+ ion content in the roots of the rice seedlings of Example 1, Example 2, Example 3, and Example 4 was significantly reduced, and the K+ ion content was increased, showing a more ideal K+ / Na+ ratio in the roots of the seedlings. This indicates that methionine chelates trace elements, allowing methionine metal ion ammine compounds to bind to the extracellular polysaccharides of the halophilic and halophilic strains, and avoid excessive binding of trace elements to the Na+ / H+ antiporter of the cell membrane, which is very important for improving the effect of trace elements on the salt resistance of the halophilic and halophilic strains, thereby improving the K+ / Na+ ratio in the roots of the seedlings.

[0079] The present invention provides a fertilizer for improving the salt tolerance of crops and a preparation method thereof, wherein biochar coats a halophilic strain and a halophilic strain, and the biochar provides a habitat for the halophilic strain and the halophilic strain, thereby enhancing the stress resistance of the halophilic strain and the halophilic strain. Methionine chelates trace elements, so that the methionine metal ion ammine complex is bound to the extracellular polysaccharide of the halophilic strain and the halophilic strain, thereby avoiding the excessive binding of trace elements to the Na+ / H+ antiporter of the cell membrane, thereby affecting the salt resistance of the halophilic strain and the halophilic strain. In addition, biochar can also play an isolating role for the influence of trace elements on the halophilic strain and the halophilic strain. The fertilizer for improving the salt tolerance of crops combines the halophilic strain and the halophilic strain with trace elements for the first time, and effectively prevents the trace elements from affecting the growth of the halophilic strain and the halophilic strain during the combined use through a reasonable weight ratio, so that the fertilizer can effectively improve the salt tolerance of crops and promote the yield of crops.

[0080] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A fertilizer for improving the salt tolerance of crops, characterized in that: Calculated by weight percentage, it includes 50%-60% trace elements, 5%-10% amino acid oligosaccharides, 10%-15% methionine, 5%-7% halophilic strains, 5%-10% salt-tolerant strains, and 15%-20% biochar, and the biochar coats the halophilic strains and the salt-tolerant strains.

2. A fertilizer for improving crop salt tolerance as claimed in claim 1, characterized in that: The trace elements are added in the form of ZnSO4 and CuSO4.

3. A fertilizer for improving salt tolerance of crops as claimed in claim 2, characterized in that: The weight ratio of ZnSO4 to CuSO4 is 2:3-3:

4.

4. A fertilizer for improving crop salt tolerance as claimed in claim 1, characterized in that: The salt-tolerant strain is a mixture of one or more of Bacillus megaterium, Arthrobacter aureus, Sinorhizobium freundii, Bacillus licheniformis and Acinetobacter.

5. A fertilizer for improving crop salt tolerance as claimed in claim 1, characterized in that: The halophilic strain is a mixture of one or more of Nocardiopsis, Halobacillus, Halomonas, Hylocereus, Pseudonocardia, Vibrio, Bacillus, Aspergillus and Arthrobacter.

6. A method for preparing a fertilizer for improving salt tolerance of crops according to any one of claims 1 to 5, characterized in that: The following steps are involved: According to the weight percentage, the halophilic strain, the salt-tolerant strain and the biochar are firstly mixed evenly and granulated, and then the trace elements, the amino acid oligosaccharides and the methionine are added and mixed evenly to obtain the fertilizer for improving the salt tolerance of crops.

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