Long-acting liquid organic fertilizer for enhancing salt and alkali tolerance of crops and preparation method and application thereof

Abstract

The application provides a long-acting liquid organic fertilizer capable of enhancing salt and alkali tolerance of crops and a preparation method and application thereof, and belongs to the technical field of crop planting. The long-acting liquid organic fertilizer takes fermented tail liquid of citric acid, inorganic chemical fertilizer, micro-fertilizer and strigolactone as raw materials, and comprises the following effective components: organic matter of 220 g / L or more, N of 100 g / L or more, P2O5 of 60 g / L or more, K2O of 40 g / L or more, boron and zinc of 1 g / L or more, and strigolactone of 25 micromoles / L. The raw material components in the long-acting liquid organic fertilizer cooperate with each other and have synergistic effect, and jointly play the roles of promoting crop growth, increasing biomass, improving chlorophyll content, improving nutrient utilization rate and salt and alkali tolerance. In addition, the application is also of great significance in solving environmental pollution, recycling waste liquid, reducing fertilizer production cost and developing green and healthy agriculture.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of crop planting, and particularly relates to a long-acting liquid organic fertilizer capable of enhancing the salt and alkali tolerance of crops, and a preparation method and application thereof. BACKGROUND

[0002] Soil salinization is an important environmental problem affecting crop growth and limiting the sustainable development of agriculture and animal husbandry. Salt and alkali stress leads to ion stress, osmotic stress and oxidative damage in plants, causing metabolic disorders, ion imbalance in cells, and affecting the activity of antioxidant enzymes. Limited plant growth is the most obvious phenomenon caused by salt and alkali stress, which leads to slow plant development, further inhibits plant differentiation function and establishment of various organs, and advances the original development process of plants. During plant growth, photosynthesis and physiological metabolism are affected by salt stress, leading to metabolic disorders during the growth period of plants, and the phenomenon of wilting or death of plants.

[0003] Salinization is widely distributed in more than 100 countries and regions in the world. China ranks third in the world in terms of salinization problems. About 5.5 million mu of various available saline-alkali land resources, of which 1.85 million mu of saline-alkali land has agricultural utilization prospects, accounts for only 33.6% of the available saline-alkali land. With the rapid development of agricultural production and rapid development of land resources, the problem of soil salinization is becoming increasingly serious, and people's demand for strengthening the improvement of salinization is becoming higher and higher. It is urgent to explore new processes and new technologies for improving and utilizing saline-alkali land. In order to improve the salt tolerance of plants and help plants better adapt to salt environment, many scholars have carried out research on the effect of exogenous substances on the salt and alkali tolerance of plants and the mechanism of action. The development of new type of improved saline-alkali soil and products that can improve the salt and alkali tolerance of crops is one of the inevitable conditions for the development of modern agriculture.

[0004] Excessive application of chemical fertilizers is one of the important reasons for soil salinization. The application of organic liquid fertilizer together with chemical fertilizer can reduce the negative effects of excessive application of chemical fertilizer, and the application of organic liquid fertilizer together with chemical fertilizer can promote the absorption and utilization of nitrogen, phosphorus and potassium nutrients by plants, thereby improving crop yield and quality. Therefore, new type of liquid organic fertilizer for crops needs to consider the application of organic liquid fertilizer together with inorganic fertilizer and the fertilizer requirement characteristics of crops.

[0005] Strigolactone (SL) is a natural strigolactone compound and a general term for artificial synthetic derivatives. GR24, an artificial synthetic SL analog, is the most effective one among SL analogs and has been widely used in scientific research and production. Studies have shown that strigolactone can regulate plant branching, root growth, leaf senescence, etc. Some studies have also found that strigolactone can regulate plant growth in adverse conditions.

[0006] But there is no application of strigolactone and industrial waste citric acid fermentation tail liquid mixed inorganic fertilizer as a special liquid organic fertilizer for improving crop salt tolerance. The present application adopts citric acid fermentation tail liquid and inorganic fertilizer mixture, cooperates with strigolactone to relieve the contradiction between chemical fertilizer and saline-alkali soil and crop growth, improves saline-alkali soil, and is absorbed by cotton to promote growth and improve salt tolerance. Ultimately, the effect of high quality and high yield of cotton is realized. SUMMARY

[0007] In order to solve the above technical problems, the present application provides a long-acting liquid organic fertilizer capable of enhancing the salt-tolerance of crops and its preparation method and application. The long-acting liquid organic fertilizer takes citric acid fermentation tail liquid, inorganic chemical fertilizer, micro-fertilizer and strigolactone as raw materials, and includes the following concentrations of effective components: ≥220 g / L of organic matter, ≥100 g / L of N, ≥60 g / L of P2O5, ≥40 g / L of K2O, ≥1 g / L of boron and zinc, and 25 μmol / L of strigolactone. The raw material components in the long-acting liquid organic fertilizer cooperate with each other and have a synergistic effect, and together play a role in promoting crop growth, increasing biomass, improving chlorophyll content, improving nutrient utilization rate and salt-tolerance. In addition, the present application is also of great significance in terms of environmental pollution solution, waste liquid resource utilization, fertilizer production cost reduction and agricultural green and healthy development.

[0008] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0009] The present application provides a long-acting liquid organic fertilizer capable of enhancing the salt-tolerance of crops, which takes citric acid fermentation tail liquid, inorganic chemical fertilizer, micro-fertilizer and strigolactone as raw materials, and includes the following concentrations of effective components: ≥220 g / L of organic matter, ≥100 g / L of N, ≥60 g / L of P2O5, ≥40 g / L of K2O, ≥1 g / L of boron and zinc, and 22-28 μmol / L of strigolactone; the main component composition of the citric acid fermentation tail liquid is: organic matter ≥220 g / L, N = 8-12 g / L, K2O = 16-20 g / L, amino acid = 8.5-9.5 g / L, total sugar = 75-85 g / L, and peptide = 35-40 g / L; the inorganic chemical fertilizer is urea, potassium sulfate and water-soluble monoammonium phosphate, the N content in the urea is ≥46.0%, the K2O content in the potassium sulfate is ≥51%, and the P2O5 content in the water-soluble monoammonium phosphate is ≥73%; the micro-fertilizer is a boron and zinc microelement water-soluble fertilizer.

[0010] The present application also provides a preparation method of the long-acting liquid organic fertilizer, which includes the following steps:

[0011] (1) taking the citric acid fermentation tail liquid as a mother liquor;

[0012] (2) mixing the mother liquor with the inorganic chemical fertilizer, and determining the nutrient content of the mixture, so that the nutrient content meets the requirements of organic matter content ≥220 g / L, N content ≥100 g / L, P2O5 content ≥60 g / L, and K2O content ≥40 g / L, to obtain a liquid fertilizer;

[0013] (3) mixing the liquid fertilizer with the microelement-containing liquid fertilizer to obtain a liquid fertilizer containing boron and zinc ≥1 g / L;

[0014] (4) dissolving the velutin in an acetone solution to prepare a velutin mother liquor;

[0015] (5) mixing the velutin mother liquor with the microelement-containing liquid fertilizer, so that the concentration of velutin reaches 22-28 μmol / L, to obtain the long-acting liquid organic fertilizer.

[0016] The mother liquor in step (1) contains starch, protein, fermentation residues, glucose, ammonia nitrogen, and fat.

[0017] Further, the mixing ratio of the mother liquor to the inorganic chemical fertilizer in step (2) is (950-1050) mL of the mother liquor, (190-200) g of urea, (80-85) g of water-soluble monoammonium phosphate, and (40-45) g of potassium sulfate.

[0018] Further, the mixing ratio of the liquid fertilizer to boron and microelement-containing fertilizer in step (3) is (950-1050) mL of the liquid fertilizer, (6-7) mL of boron fertilizer, and (6-7) mL of zinc fertilizer.

[0019] Further, the mass fraction of the acetone solution in step (4) is 1-3 %, and the concentration of the velutin mother liquor is 8-12 mmol / L.

[0020] Further, the specific preparation method of the velutin mother liquor is as follows: 1 mL of acetone is taken, water is added to make up to 50 mL to obtain a 2 % acetone solution, 10 mg of velutin is dissolved in a small amount of the 2 % acetone solution, and water is added to make up to 3352 μL to obtain a 10 mmol / L velutin mother liquor.

[0021] Further, the mixing ratio of the microelement-containing liquid fertilizer to the velutin mother liquor in step (5) is (950-1050) mL of the microelement-containing liquid fertilizer to (2400-2600) μL of the velutin mother liquor.

[0022] Further, the mixing in the step (2), the step (3) and the step (5) is all carried out by oscillating the box under the constant temperature condition of 28-32 DEG C for 22-26 h.

[0023] The mixing in the step (5) can also add the strigolactone mother liquor into the liquid fertilizer containing trace elements, and stir while adding until the liquid is uniform and non-caking.

[0024] The step (5) further comprises a pH value adjusting step, that is, after mixing the strigolactone mother liquor and the liquid fertilizer containing trace elements, the pH value is adjusted to 6.5-7.5 by using ammonia water.

[0025] The application further provides an application of the long-acting liquid organic fertilizer in the salt-tolerant and alkali-tolerant planting of crops.

[0026] Further, the application time of the long-acting liquid organic fertilizer in the application is the seedling stage of crops.

[0027] Further, the crop type to which the long-acting liquid organic fertilizer is applied in the application is cotton.

[0028] When the long-acting liquid organic fertilizer is used, it needs to be diluted 500 times with water and applied by irrigation.

[0029] After the citric acid fermentation tail liquid and the chemical fertilizer are mixed, complexation, chelation or physical-chemical adsorption may occur, so as to regulate the conversion process of the fertilizer, and then improve the coincidence degree of nutrient supply and crop demand, and optimize the effect of the fertilizer. The organic matter contains rich carbon source, and the nutrient supply to plants is relatively flat and persistent, which is very important for the crops to resist oxidative damage, improve photosynthetic characteristics and salt-tolerance. The nitrogen, phosphorus, potassium, boron and zinc contain a large amount of trace nutrients required by plants, and can promote the growth of plants. The strigolactone can improve the material accumulation amount of plants under salt stress, improve the chlorophyll content and the ability to resist oxidative damage, reduce the cytoplasmic membrane permeability, and improve the photosynthetic capacity and salt-tolerance of crops.

[0030] Compared with the prior art, the application has the following technical effects:

[0031] (1) The application effectively solves the pollution problem of the environment caused by excessive discharge of citric acid fermentation tail liquid and excessive application of chemical fertilizer, and at the same time, the tail liquid is resourceized, waste is turned into treasure, and can be fully utilized, the production cost of liquid fertilizer is reduced, and the healthy development of green agriculture is realized.

[0032] (2) The citric acid fermentation tail liquid of the present invention is rich in organic matter, amino acids, polypeptides and sugars, which can promote crop nutrient absorption, improve soil fertility and increase fertilizer utilization. The organic matter contains abundant carbon sources, which can provide plants with nutrients in a slow and long-lasting manner and play an important role in helping crops resist oxidative damage, improve photosynthetic characteristics and salt and alkali tolerance.

[0033] (3) The nitrogen, phosphorus and potassium mentioned contain a large number of nutrients needed by plants and promote crop growth.

[0034] (4) When the citric acid fermentation tail liquid described in this invention is mixed with chemical fertilizer, complexation, chelation or physical-chemical adsorption will occur, which will regulate the fertilizer conversion process, improve the matching degree between nutrient supply and crop demand, and optimize the fertilizer effect.

[0035] (5) The unicorn lactone described in this invention has the characteristics of low dosage and strong effect; it can increase the amount of material accumulation of crops under salt and alkali stress, reduce the degree of damage to leaves, improve the ability of cotton to scavenge free radicals and peroxides, reduce its damage to cell membranes, and thus improve the salt and alkali resistance of cotton. Attached Figure Description

[0036] Figure 1 These are the measurement results of plant height, root length, and stem diameter under different treatments in Example 2 of the present invention;

[0037] Figure 2 The results of measuring malondialdehyde content and relative permeability of the plasma membrane in leaves under different treatments in Example 2 of this invention;

[0038] Figure 3 These are the measurement results of SPAD values ​​of leaves under different treatments in Example 2 of the present invention;

[0039] Figure 4 These are the measurement results of plant height, root length, and stem diameter under different treatments in Example 3 of the present invention;

[0040] Figure 5 The results of measuring malondialdehyde content and relative permeability of the plasma membrane in leaves under different treatments in Example 3 of this invention;

[0041] Figure 6 The results show the SPAD values ​​of leaves under different treatments in Example 3 of this invention. Detailed Implementation

[0042] The following examples are intended to illustrate the present application but not to limit the scope of the present application. Modifications or substitutions to the methods, steps or conditions of the present application, without departing from the spirit and the essence of the present application, are within the scope of the present application. The present application does not have special restrictions on the source of the citric acid fermentation tail liquid, and the source of the citric acid fermentation tail liquid known in the art can be used. In the present application, the citric acid fermentation tail liquid is from Jiangsu Guoxin Xielian Energy Co., Ltd. The present application does not have special restrictions on the source of the inorganic chemical fertilizer, and the source of the inorganic fertilizer commonly used in the art can be used. In the present application, the inorganic fertilizer is urea, potassium sulfate and water-soluble monoammonium phosphate. The present application does not have special restrictions on the source of the trace elements, and the source of the trace element water-soluble fertilizer commonly used in the art can be used. In the present application, the trace element water-soluble fertilizer is sugar alcohol type boron and zinc, which are purchased from Australia Nonghua Co., Ltd. and Nanjing Jia Nonghexin Biological Technology Co., Ltd. respectively, and the website is http: / / njjnhx.com / wlpeytx.html. The present application does not have special restrictions on the source of the strigolactone, and a conventional drug can be used. In the present application, the strigolactone is purchased from Beijing Coolab Technology Co., Ltd. In the present application, the equipment, raw materials and the like used are commercially available unless otherwise specified, and the method used is consistent with the commonly used method unless otherwise specified.

[0043] The technical solutions of the present application are further described in detail below in combination with examples.

[0044] Example 1

[0045] The citric acid fermentation tail liquid purchased from Jiangsu Guoxin Xielian Energy Co., Ltd. is used as the mother liquor. The mother liquor and the chemical fertilizer are mixed in a ratio of mother liquor: urea: water-soluble monoammonium phosphate: potassium sulfate = 1000:195.7:82.2:43.2, preferably using a shaking box to shake at 30°C constant temperature for 24 h, to obtain the liquid fertilizer. The nutrient substance of the liquid fertilizer is determined, so that the organic matter content is ≥220 g / L, the N content is ≥100 g / L, the P2O5 content is ≥60 g / L and the K2O content is ≥40 g / L. The boron and zinc trace element water-soluble fertilizer is mixed in a ratio of liquid fertilizer: boron fertilizer: zinc fertilizer = 1000:6.67:6.25 to obtain the liquid fertilizer containing trace elements ≥1 g / L. 2500 μL of strigolactone mother liquor is added to the above 1 L of liquid fertilizer containing trace elements, so that the content reaches 25 μmol / L, and the pH value is adjusted to 6.5-7.5 after the shaking box is shaken at 30°C constant temperature for 24 h, to obtain the long-acting liquid organic fertilizer for cotton. The comprehensive content index of the fertilizer is shown in Table 1.

[0046] Table 1 Quality index of long-acting liquid organic fertilizer

[0047]

[0048] Among them:

[0049] The state of the citric acid fermentation tail liquid is liquid, the state of the inorganic chemical fertilizer (urea, potassium sulfate, monoammonium phosphate) is solid particles or powder, the state of the rac-GR24 is powder, and the state of the trace elements (boron, zinc) is liquid.

[0050] The main components of the citric acid fermentation tail liquid are: organic matter ≥220 g / L, nitrogen (N) = 10 g / L, potassium (K2O) = 18 g / L, amino acid = 8.95 g / L, total sugar = 79.4 g / L, and peptide = 37.75 g / L.

[0051] In the inorganic chemical fertilizer (urea, potassium sulfate, water-soluble monoammonium phosphate), urea (N) ≥46.0%, potassium sulfate (K2O) ≥51%, and water-soluble monoammonium phosphate (P2O5) ≥73%.

[0052] The trace element water-soluble fertilizer is: boron ≥150 g / L, and zinc ≥160 g / L.

[0053] The rac-GR24 is ≥98%.

[0054] Example 2

[0055] The long-acting liquid organic fertilizer prepared in Example 1 was subjected to experiments:

[0056] The "Xinluzao 53" cotton variety was used as the test material, and 3.5 kg of normal field soil was used as the substrate for potting test, and the physicochemical properties of the soil samples are shown in Table 2.

[0057] Table 2 Physicochemical properties of soil samples

[0058]

[0059] The experiment was set up 8 treatments, respectively: (1) CK: control + equal amount of distilled water; (2) CK+SM1: control + Longqike saltwei soil remediation agent (purchased from Xingtai Qihuo Agricultural Technology Development Co., Ltd.; registration certificate number: microbial fertilizer (2015) Zhun Zi 1702; website: https: / / www.cnhnb.com / gongying / 7692501 / ); (3) CK+SM2: control + Shidijia saline-alkali soil conditioner (purchased from Chengdu Huahong Biological Technology Co., Ltd.; registration certificate number: agricultural fertilizer (2015) Zhun Zi 4239; website: http: / / www.cdhuahong.com / product / product-info.asp?id=135); (4) CK+ZY: control + cotton special long-acting liquid organic fertilizer prepared in Example 1; (5) S: Na2CO3 + equal amount of distilled water; (6) S+SM1: Na2CO3 + Longqike saltwei soil remediation agent; (7) S+SM2: Na2CO3 + Shidijia saline-alkali soil conditioner; (8) S+ZY: Na2CO3 + cotton special long-acting liquid organic fertilizer prepared in Example 1. Each treatment was repeated 3 times, and each repeat was 5 plants. Before treatment, 1 / 2 Hoagland nutrient solution was used for culture, and the roots were irrigated uniformly every 2 days, with a pouring amount of 200 ml each time; when the cotton grew to 3 leaves 1 heart stage, Na2CO3 treatment was started, in order to avoid salt stress, the prepared Na2CO3 solution was applied to the normal soil in 4 times, with an interval of 12 h each time, so that the final Na2CO3 treatment concentration in the potting was 4 g / kg. After reaching the alkali treatment concentration, the modifier (diluted 500 times) was irrigated once every 3 days, 200 ml each time, a total of 5 times; in addition, the same amount of deionized water was irrigated, and the samples were taken after 15 days, and the relevant indicators were determined.

[0060] Sample determination and method:

[0061] 1. Determination of cotton seedling growth index

[0062] The cotton seedlings were carefully taken out of the flowerpots, washed with clean water to remove the soil on the root surface, and the plant height, root length, leaf length, and leaf width were measured with a ruler. The same part of the third functional leaf was selected for determination after the treatment time; the stem diameter was measured with a vernier caliper, and the measurement site was the cotyledon node of each plant; the fresh weight was measured with a thousandth balance. The results are shown in Table 3 and Figure 1 .

[0063] Table 3 Effect of different modifiers on biomass of cotton under alkali stress

[0064]

[0065] Result analysis:

[0066] From Table 3, it can be seen that CK+ZY treatment significantly increased the leaf area of cotton, which was increased by 13.77% compared with CK. Alkali treatment significantly reduced the biomass accumulation of cotton seedlings, and the leaf length, leaf width, leaf area, stem and leaf fresh weight, and root fresh weight were reduced by 30.88%, 36.24%, 57.94%, 55.59%, and 39.18% respectively compared with CK; the application of the modifier improved the biomass of cotton under alkali treatment to different degrees, wherein the leaf length under S+SM1, S+SM2, and S+ZY treatments was increased by 11.69%, 20.78%, and 55.06% respectively compared with the alkali treatment; the leaf width was increased by 12.21%, 27.37%, and 69.47% respectively; the leaf area was increased by 21.34%, 50.15%, and 151.67% respectively; the stem and leaf fresh weight was increased by 15.20%, 50.00%, and 225.00% respectively compared with the alkali treatment;

[0067] From Figure 1 It can be seen that the application of different modifiers had a significant promoting effect on the plant height of cotton, while the alkali treatment significantly reduced the plant height of cotton by 26.71% compared with CK; the application of the modifier improved the plant height of cotton seedlings under alkali treatment to different degrees, wherein the S+ZY treatment had a more significant effect, which was increased by 41.98% compared with the alkali treatment. The root length of cotton seedlings treated with different modifiers was not significantly different from the control alkali stress treatment. The alkali treatment significantly reduced the stem diameter of cotton seedlings by 27.72% compared with CK; while the application of the modifier improved the stem diameter of cotton seedlings to different degrees, wherein the S+ZY treatment had a more significant effect, which was increased by 35.66% compared with the alkali treatment.

[0068] 2. Determination of malondialdehyde content and relative permeability of plasma membrane of cotton seedlings at seedling stage

[0069] The malondialdehyde content was determined by the thiobarbituric acid method; the relative permeability of plasma membrane was represented by the size of relative conductivity, which was determined by the conductivity method. The results are shown in Figure 2 .

[0070] Result analysis: Malondialdehyde and relative permeability of plasma membrane are indicators for measuring the degree of oxidative damage of plants, and high malondialdehyde content and relative permeability of plasma membrane indicate that the oxidative damage of plants is serious. From Figure 2It can be seen that the alkali treatment significantly increased the cotton leaf plasma membrane permeability, increased by 116.56% compared with CK; while S+SM2, S+ZY treatment significantly reduced the plasma membrane permeability of cotton leaves under alkali treatment, respectively reduced by 16.97%, 28.40% compared with alkali treatment. Alkali treatment significantly increased the cotton leaf malondialdehyde content, increased by 37.65% compared with CK; while S+SM1, S+SM2, S+ZY treatment significantly reduced the plasma membrane permeability of cotton leaves under alkali stress, respectively reduced by 19.62%, 14.23%, 29.08% compared with alkali treatment.

[0071] 3. Determination of cotton seedling leaf SPAD value

[0072] After irrigating the modified agent for 5 times at the cotton seedling stage, representative plants under each treatment were taken; the same functional leaves were selected, and SPAD-502 Plus chlorophyll meter was used for determination. The results are shown in Figure 3

[0073] Results analysis: The application of modified agent has the effect of improving the SPAD value of cotton seedlings, among which the SPAD value under CK+SM2, CK+ZY treatment is significantly higher than that of CK, increased by 6.92%, 5.51% compared with CK. Alkali treatment reduces the SPAD value of cotton leaves. Compared with alkali treatment, the application of modified agent improves the SPAD value of cotton leaves to different degrees, but the difference is not significant, among which the effect of S+SM2, S+ZY treatment is better, the SPAD value is increased by 3.82%, 3.85% compared with alkali treatment.

[0074] In summary, salt-alkali stress significantly reduces the biomass of cotton seedlings, hinders the normal growth of plants, increases the plasma membrane permeability and malondialdehyde content, and indicates that the degree of cell membrane integrity is seriously damaged. While the application of modified agent can alleviate the damage of alkali stress to cotton growth and physiology to different degrees, and improve the salt-alkali tolerance of cotton. Among them, irrigating cotton special long-acting liquid organic fertilizer (diluted 500 times) has the best effect.

[0075] Example 3

[0076] ​The fermentation tail liquid of citric acid is used as a mother liquor, the mother liquor is mixed with chemical fertilizers according to a ratio of mother liquor:urea:water-soluble monoammonium phosphate:potassium sulfate = 1000:195.7:82.2:43.2, preferably, the mixture is shaken in a shaking box at 30 DEG C for 24 h, and a liquid fertilizer is obtained. The liquid fertilizer is subjected to nutrient substance determination, so that the organic matter content is greater than or equal to 220 g / L, the N content is greater than or equal to 100 g / L, the P2O5 content is greater than or equal to 60 g / L, and the K2O content is greater than or equal to 40 g / L. The liquid fertilizer is mixed with boron and zinc micronutrient water-soluble fertilizers according to a ratio of liquid fertilizer:boron fertilizer:zinc fertilizer = 1000:6.67:6.25, and a liquid fertilizer containing micronutrients greater than or equal to 1 g / L (not containing jujube lactone) is obtained, which is hereinafter referred to as "YJ".

[0077] The liquid fertilizer not containing jujube lactone prepared in the present embodiment is subjected to experiments together with the cotton special long-acting liquid organic fertilizer containing jujube lactone in Example 1.

[0078] The test time, method and details are the same as those in Example 1, and the treatment settings are as follows: (1) CK: control + equal amount of distilled water; (2) S: Na2CO3 + equal amount of distilled water; (3) S+ YJ: Na2CO3 + the liquid organic fertilizer not containing jujube lactone in Example 2; (4) S+ ZY: Na2CO3 + the cotton special long-acting liquid organic fertilizer in Example 1. Each treatment is repeated 3 times, and each repetition has 5 cotton plants.

[0079] Sample determination and method:

[0080] 1. Cotton seedling growth index determination

[0081] The cotton seedlings are carefully taken out from the flowerpots, the root system surface soil is washed with clean water, the plant height, root length, leaf length and leaf width are determined by using a ruler, and the same parts of the third functional leaves are selected for determination after the treatment time; the stem diameter is determined by using a vernier caliper, and the determination part is the cotyledon node of each plant; the stem and leaf fresh weight and the root fresh weight are determined by using a one-thousandth balance. The results are shown in Table 4 and Figure 4

[0082] Table 4 Influence of different modifiers on the biomass of cotton under alkali stress

[0083]

[0084] Result analysis:

[0085] ​As can be seen from Table 4, alkali treatment significantly reduces the accumulation of cotton seedling biomass, and the leaf length, leaf width, leaf area, stem and leaf fresh weight and root fresh weight are reduced by 30.88%, 36.24%, 57.94%, 55.59% and 39.18% respectively compared with CK; and the liquid organic fertilizer without carlina lactone and the long-acting liquid organic fertilizer for cotton increase the biomass of cotton under alkali stress in varying degrees, wherein the leaf length under S+YJ and S+ZY treatments is increased by 30.39% and 55.06% respectively compared with the alkali treatment; the leaf width is increased by 55.37% and 69.47% respectively; the leaf area is increased by 101.02% and 151.67% respectively; and the stem and leaf fresh weight is increased by 78.38% and 225.00% respectively.

[0086] As can be seen from Table 4, alkali treatment significantly reduces the accumulation of cotton seedling biomass, and the leaf length, leaf width, leaf area, stem and leaf fresh weight and root fresh weight are reduced by 30.88%, 36.24%, 57.94%, 55.59% and 39.18% respectively compared with CK; and the liquid organic fertilizer without carlina lactone and the long-acting liquid organic fertilizer for cotton increase the biomass of cotton under alkali stress in varying degrees, wherein the leaf length under S+YJ and S+ZY treatments is increased by 30.39% and 55.06% respectively compared with the alkali treatment; the leaf width is increased by 55.37% and 69.47% respectively; the leaf area is increased by 101.02% and 151.67% respectively; and the stem and leaf fresh weight is increased by 78.38% and 225.00% respectively compared with the alkali treatment. Figure 4 As can be seen from Table 4, alkali treatment significantly reduces the accumulation of cotton seedling biomass, and the leaf length, leaf width, leaf area, stem and leaf fresh weight and root fresh weight are reduced by 30.88%, 36.24%, 57.94%, 55.59% and 39.18% respectively compared with CK; and the liquid organic fertilizer without carlina lactone and the long-acting liquid organic fertilizer for cotton increase the biomass of cotton under alkali stress in varying degrees, wherein the leaf length under S+YJ and S+ZY treatments is increased by 30.39% and 55.06% respectively compared with the alkali treatment; the leaf width is increased by 55.37% and 69.47% respectively; the leaf area is increased by 101.02% and 151.67% respectively; and the stem and leaf fresh weight is increased by 78.38% and 225.00% respectively compared with the alkali treatment.

[0087] 2. Determination of cotton seedling leaf malondialdehyde content and plasma membrane relative permeability

[0088] The malondialdehyde content was determined by the thiobarbituric acid method, and the plasma membrane relative permeability was represented by the relative conductivity and determined by the conductivity method. The results are shown in Table 2. Figure 5

[0089] Results analysis: Malondialdehyde and cell membrane permeability are indicators for measuring the degree of plant oxidative damage, and high malondialdehyde content and plasma membrane relative permeability indicate that the plant oxidative damage is serious. As can be seen from Table 2, Figure 5 alkali treatment significantly increases the cell membrane permeability of cotton leaves, which is increased by 116.56% compared with CK; and S+YJ and S+ZY treatments significantly reduce the cell membrane permeability of cotton leaves under alkali stress, which is reduced by 20.24% and 28.40% respectively compared with the alkali treatment. Alkali treatment significantly increases the malondialdehyde content of cotton leaves, which is increased by 37.65% compared with CK; and S+YJ and S+ZY treatments significantly reduce the cell membrane permeability of cotton leaves under alkali stress, which is reduced by 27.39% and 29.08% respectively compared with the alkali treatment.

[0090] 3. Determination of cotton seedling leaf SPAD value ​

[0091] After irrigating 5 times of liquid organic fertilizer at cotton seedling stage, representative plants under each treatment were taken; same functional leaves were selected, and SPAD-502 Plus chlorophyll meter was used for determination. Figure 6

[0092] Result analysis: alkali treatment reduced the SPAD value of cotton leaves; application of liquid organic fertilizer without jimsonweed lactone and cotton special long-acting liquid organic fertilizer increased the SPAD value of cotton leaves to different degrees, and the effect of S+ZY treatment was better, which increased by 3.85% compared with alkali treatment.

[0093] In conclusion, the application provides a preparation method and application of special long-acting liquid organic fertilizer for improving salt tolerance of cotton, and the cotton special liquid organic fertilizer has good application effect on promoting growth of cotton, improving chlorophyll content and resisting active oxygen damage ability.

[0094] The above-described embodiments are only preferred modes of the application, and do not limit the scope of the application; under the premise of not departing from the design spirit of the application, various modifications and improvements of the technical solutions of the application made by those skilled in the art shall fall within the protection scope determined by the claims of the application.​

Claims

1. A long-acting liquid organic fertilizer that enhances crop salt and alkali tolerance, characterized in that, The long-acting liquid organic fertilizer uses citric acid fermentation tail liquid, inorganic chemical fertilizers, micronutrients and styrax lactone as raw materials, and includes the following effective components at the following concentrations: ≥220 g / L organic matter, ≥100 g / L N, ≥60 g / L P2O5, ≥40 g / L K2O, ≥1 g / L boron and zinc and 22~28 μmol / L styrax lactone; The main components of the citric acid fermentation tail liquid are: organic matter ≥220 g / L, N=8~12 g / L, K2O=16~20 g / L, amino acids=8.5~9.5 g / L, total sugar=75~85 g / L, peptides=35~40 g / L; The inorganic chemical fertilizer is urea, potassium sulfate, and water-soluble monoammonium phosphate, wherein the urea contains N ≥ 46.0%, the potassium sulfate contains K2O ≥ 51%, and the water-soluble monoammonium phosphate contains P2O5 ≥ 73%. The micronutrient fertilizer is a water-soluble fertilizer containing boron and zinc trace elements.

2. The method for preparing the long-acting liquid organic fertilizer according to claim 1, characterized in that, Includes the following steps: (1) The citric acid fermentation tail liquid is used as the mother liquor; (2) The mother liquor is mixed with the inorganic chemical fertilizer, and the nutrient content is measured after mixing to ensure that the nutrient content meets the requirements of organic matter content ≥220 g / L, N content ≥100 g / L, P2O5 content ≥60 g / L and K2O content ≥40 g / L, so as to obtain liquid fertilizer; (3) The liquid fertilizer and the micro-fertilizer are mixed to obtain a liquid fertilizer containing boron and zinc ≥1 g / L containing trace elements; (4) Prepare a mother liquor of strigolactone by dissolving strigolactone in acetone solution; (5) Mix the mother liquor of the unicorn lactone and the liquid fertilizer containing trace elements to make the concentration of unicorn lactone reach 22~28μmol / L, and the long-acting liquid organic fertilizer is obtained.

3. The preparation method according to claim 2, characterized in that, In step (2), the mixing ratio of mother liquor and inorganic chemical fertilizer is as follows: mother liquor: urea: water-soluble monoammonium phosphate: potassium sulfate = (950~1050) mL: (190~200) g: (80~85) g: (40~45) g.

4. The preparation method according to claim 3, characterized in that, In step (3), the mixing ratio of liquid fertilizer and micronutrient fertilizer is liquid fertilizer: boron fertilizer: zinc fertilizer = (950~1050) mL: (6~7) mL: (6~7) mL.

5. The preparation method according to claim 4, characterized in that, In step (4), the mass fraction of acetone solution is 1-3%, and the concentration of the unicorn lactone mother liquor is 8-12 mmol / L.

6. The preparation method according to claim 5, characterized in that, In step (5), the mixing ratio of liquid fertilizer containing trace elements to mother liquor of unicorn lactone is: liquid fertilizer containing trace elements: mother liquor of unicorn lactone = (950~1050) mL: (2400~2600) μL.

7. The preparation method according to claim 6, characterized in that, The mixing in steps (2), (3) and (5) is carried out by shaking in a shaking box at a constant temperature of 28-32℃ for 22-26 hours.

8. The application of the long-acting liquid organic fertilizer according to claim 1 or the long-acting liquid organic fertilizer prepared by any of the preparation methods according to claims 2 to 7 in the salt-alkali tolerant planting of crops.

9. The application according to claim 8, characterized in that, The application period for the long-acting liquid organic fertilizer mentioned in this application is the seedling stage of the crop.

10. The application according to claim 9, characterized in that, The long-acting liquid organic fertilizer mentioned in the application is specifically used for cotton.

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