Method for improving soda salinization grassland with low disturbance

Abstract

The invention relates to the technical field of ecological environment restoration, in particular to a method for low-disturbance improvement of soda salinized grassland, which comprises the following steps: applying a surfactant solution to determine that the infiltration promotion effect of a surfactant meets the requirement or does not meet the requirement, and determining a main limiting factor according to the pH value; a modifier solution is applied according to the adjusted improvement parameters, the modifier solution comprises organic acid and desulfurized gypsum, the wetting front advancing depth of the soil is obtained according to the initial detection period, and whether the wetting front of the soil can reach the target improvement depth or not is estimated; and according to the synergistic effect index, determining whether the degree that the combined use effect of the components is greater than the sum of the independent use effects of the components meets the expected requirement or not, and determining the judgment standard that the permeation promotion effect of the surfactant for adjusting the subsequent improvement circulation process does not meet the requirement and the initial detection period. The surfactant is combined with the modifier, so that the salinity and alkalinity of the soda salinized grassland are reduced, and the soil structure is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ecological environment restoration, and particularly relates to a method for low-disturbance improvement of soda salinization grassland. BACKGROUND

[0002] Some natural grasslands in China are suffering from serious soda salinization erosion. Such soils often contain high concentrations of sodium salts (especially sodium carbonate, sodium bicarbonate, etc.), resulting in a soil pH value of up to 9 or more. Salinization deteriorates soil structure, forming a dense or hydrophobic soil layer on the surface, making it difficult for water to infiltrate, and causing surface water accumulation and runoff, and the root system cannot obtain sufficient water. It is reported that salinized soil generally has the challenges of slow infiltration rate, low leaching efficiency, long treatment period, and easy salt return. Traditional methods for treating salinized land mostly use soil plowing, large amounts of water to wash salt, or sand mixing to press salt, etc., but the effect is not good on soda salinized soil, and even the soil may become more cohesive due to sodium ions. Especially in the natural grassland environment, China's policy clearly prohibits the reclamation and plowing of grasslands. For example, the Grassland Law and other regulations require not to plow the original vegetation to avoid damaging the grassland surface ecology. Therefore, it is an urgent technical problem to be solved to carry out salinization improvement without disturbing the soil and damaging the original vegetation.

[0003] Chinese Patent Publication No. CN117918081A discloses a method for repairing salinized grassland, comprising the following steps: S1, deep plowing and harrowing; S2, pressing; S3, applying a modified soil conditioner; S4, mixed sowing of pasture; S5, field management. The modified polymer loaded vermiculite is prepared by the following steps: A1, preparing polyacrylic acid; A2, preparing polyethylene glycol-polyacrylic acid copolymer; A3, preparing modified polymer loaded vermiculite. Through the physical method of deep plowing, the biological method of mixed sowing of pasture, and the chemical method of applying a modified soil conditioner, the salinized soil is synergistically treated, and the salinized land can be quickly and efficiently treated. It can be seen that the method for repairing salinized grassland has the following problems:

[0004] Deep plowing and harrowing of natural grassland affected by soda salinization will damage the grassland surface ecology and soil structure, and planting crops for improvement has a long treatment period and poor soil permeability in salinized grassland. SUMMARY

[0005] Therefore, the present application provides a method for low-disturbance improvement of soda salinized grassland to overcome the problems of poor soil permeability in salinized grassland and damage to the grassland surface ecology and soil structure caused by deep plowing and harrowing in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides a method for low-disturbance improvement of soda salinized grassland, comprising:

[0007] applying a surfactant solution of a certain concentration, determining whether the surfactant has a penetration-promoting effect in accordance with the actual infiltration rate of the soil measured in the initial detection period, and determining whether the surfactant has a penetration-promoting effect in accordance with the initial detection period and the judgment standard;

[0008] adjusting the initial concentration of the surfactant solution according to the stable infiltration duration, adjusting the application rate of the amendment solution according to the stable infiltration rate, and taking corresponding adjustment measures according to the determined main limiting factor;

[0009] applying the amendment solution according to the adjusted amendment parameters, the amendment solution comprising organic acid and desulfurized gypsum, obtaining the wetting front advancing depth of the soil according to the initial detection period, and estimating whether the wetting front of the soil can reach the target amendment depth;

[0010] determining whether the amendment depth meets the standard or not according to the wetting front advancing depth, and reflecting the matching relationship between sodium ion migration and calcium ion implantation through the soil solution conductivity and the molar concentration ratio of sodium ion to calcium ion;

[0011] determining the reason why the amendment depth does not meet the standard according to the matching relationship, determining the adjustment range of applying humic acid or adjusting the amendment cycle process, and increasing the concentration of the amendment solution;

[0012] estimating the synergistic effect index to evaluate the combined use effect of the surfactant, the organic acid and the desulfurized gypsum under the current amendment application parameters of the single amendment cycle process;

[0013] determining whether the degree to which the combined use effect of each component is greater than the sum of the individual use effects meets the expected requirements according to the synergistic effect index, and determining the judgment standard and the initial detection period for adjusting the penetration-promoting effect of the surfactant in the subsequent amendment cycle process.

[0014] Further, the surfactant is one of a non-toxic biodegradable type of alkyl polyglycoside (APG) or a bio-based surfactant, and the certain concentration range of the surfactant solution is 0.1% to 0.5%;

[0015] The ratio of the amendment solution is 50-100 kg / ha of desulfurized gypsum, 20-30 kg / ha of organic acid, and 10-20 kg / ha of optional humic acid.

[0016] Further, the process of determining whether the penetration-promoting effect of the surfactant meets the requirements comprises:

[0017] When the actual ratio of the actual infiltration rate to the historical infiltration rate of the previous initial detection period is less than the ratio evaluation value, the current actual infiltration rate is defined as the stable infiltration rate, and the sum of a plurality of initial detection periods corresponding to the stable infiltration rate is obtained as the stable infiltration duration;

[0018] when the permeability improvement multiple of the stable infiltration rate to the initial infiltration rate is greater than or equal to a standard value, it is determined that the penetration promoting effect of the surfactant meets the requirement;

[0019] when the permeability improvement multiple of the stable infiltration rate to the initial infiltration rate is less than a standard value, it is determined that the penetration promoting effect of the surfactant does not meet the requirement, and the main limiting factor is determined according to the actual pH value of the saline-alkali grassland.

[0020] Further, the process of determining the main limiting factor includes detecting the actual pH value of the saline-alkali grassland after applying the surfactant solution;

[0021] when the actual pH value is greater than the synergistic pH value, it is determined that the main limiting factor of the surfactant penetration promoting effect not meeting the requirement is the current pH value of the saline-alkali grassland, and the concentration of the organic acid in the modifier is adjusted;

[0022] when the actual pH value is less than or equal to the synergistic pH value, it is determined that the main limiting factor of the surfactant penetration promoting effect not meeting the requirement is the physical crust, and the application amount of the surfactant solution is increased and the application timing of the modifier solution is delayed.

[0023] Further, the process of determining whether the improvement depth meets the requirement includes:

[0024] fitting a power function relationship between the wetting front advancing depth and time according to a plurality of wetting front advancing depths and corresponding initial detection periods;

[0025] putting a preset total infiltration time into the power function relationship to calculate a predicted reaching depth, and when the predicted reaching depth is less than a preset target depth, it is determined that the wetting front of the soil cannot reach the target improvement depth.

[0026] Further, the process of reflecting the matching relationship between the sodium ion migration and the calcium ion implantation includes:

[0027] detecting the actual conductivity of a plurality of soil solutions according to the initial detection period, detecting the concentrations of sodium ions and calcium ions to calculate the actual molar concentration ratio of sodium ions and calcium ions;

[0028] when the conductivity ratio of the actual conductivity to the historical conductivity is greater than a critical value, it is determined that the cation concentration in the soil solution increases significantly;

[0029] according to the molar ratio of the actual molar concentration ratio to the historical molar concentration ratio, it is determined that the molar concentration ratio of sodium ions and calcium ions increases significantly or slowly.

[0030] Further, when the cation concentration in the soil solution increases, if the actual molar concentration ratio increases significantly, it is determined that the sodium ion migration and the calcium ion implantation are in a first matching state;

[0031] When the cation concentration in the soil solution increases, if the actual molar concentration ratio slowly rises, it is determined that the sodium ion migration and the calcium ion implantation are in the second matching state.

[0032] Further, the process of determining the cause of the non-standard improvement depth comprises:

[0033] The cause of the non-standard improvement depth in the first matching state is that the activation degree is lower than the requirement of the improved saline grassland, and the application of humic acid increases the improvement depth.

[0034] The cause of the non-standard improvement depth in the second matching state is that the adjustment amplitude setting according to the main limiting factor is unreasonable, and the adjustment amplitude of the improvement cycle process and the total amount of hydrogen ions and calcium ions applied are increased.

[0035] Further, the process of determining the joint use effect of each component comprises: when the synergistic effect index is greater than the first index, it is determined that the joint use effect is greater than the sum of the individual use effects of each component.

[0036] Further, when the synergistic effect index is greater than the first index and less than the second index, it is determined that the joint use effect of each component is lower than the expected requirement, and the judgment standard of the judgment that the penetration effect of the surfactant does not meet the requirements and the initial detection period are adjusted.

[0037] When the synergistic effect index is greater than the second index, it is determined that the joint use effect of each component meets the expected requirement, and the improvement cycle process is continued.

[0038] Compared with the prior art, the beneficial effects of the present application are that the present application provides an innovative formula and method suitable for natural grassland saline-alkalization treatment under the condition of "no tillage". Through the combined application of surfactants, desulfurized gypsum and organic acid, the dual effects of improving soil water penetration and reducing salinity are achieved, which has significant effect on the repair of soda saline soil. The method is simple, low in cost, fast in effect, friendly to the environment and has no side effects, and is suitable for application in grassland areas where plowing is prohibited.

[0039] Further, in the soda saline soil of the present application, the decrease of pH value and the improvement of soil permeability are not in a linear relationship, but there is a key "synergistic inflection point" (for example, pH≈8.5-9.0). Only when the pH is reduced below the inflection point, the dispersion of the alkalized soil colloid decreases sharply, Ca 2+The flocculation effect begins to dominate, and the penetration effect of the surfactant is only exponentially amplified at this time; when the infiltration rate is slow, the method determines whether the pH after the drop is higher than the "synergistic inflection point" to determine whether the pH is the main limiting factor, and adjusts the proportion of organic acid to preferentially reduce the pH below the inflection point, rather than continuing to increase the surfactant; if the pH has been reduced below the inflection point but the penetration rate is still not up to standard, it is determined that physical crust is the main limiting factor, at which point it is determined that the amount of surfactant solution is insufficient, and additional surfactant is added, improving the accuracy of adaptive adjustment of the modified circulation process; at the same time, the longer the stable infiltration time, the greater the dispersion of sodium ions in the modified saline grassland, and the soil colloid is mainly sodium colloid, which requires more calcium ions to replace sodium ions and more hydrogen ions to convert Na + and HCO3 - into Na + and HCO3 2+ The method reflects the degree of soil obstacles of the saline grassland to be modified according to the characteristics of the stable infiltration time, and increases the adaptability of the saline grassland to the improvement and adjustment.

[0040] Further, the method estimates whether the improvement of the saline grassland can reach the target through the relationship between the wetting front penetration depth and time of the soil, and determines that the improvement is not up to standard when the wetting front of the soil cannot reach the target improvement depth according to the matching relationship between sodium ion migration and calcium ion implantation. The problem is that the activation degree is lower than the demand for improving the saline grassland, or the adjustment range set according to the main limiting factor is unreasonable and deviates from the actual situation. Take appropriate adjustment measures to make up for the activation degree or adjust the improvement parameters of the next improvement circulation process, improve the accuracy of the improvement and adjustment of the saline grassland, and ensure that the improvement agent penetrates into the main root distribution layer (20-30 cm).

[0041] Further, the ideal high-efficiency improvement process is to expect as little salt input (EC increase) as possible in exchange for as much sodium ion replacement effect as possible; the method reflects the matching relationship between sodium ion migration and calcium ion implantation through the change trend of the soil solution conductivity and the molar concentration ratio of sodium ion to calcium ion, and the rising trend of the conductivity and the [Na + ] / [Ca 2+ ] ratio.The change trend of the ratio is combined to analyze the "quality" and "efficiency" of the ion replacement reaction, whether the dynamic matching relationship between sodium ions and calcium ions is in the normal range is distinguished, and the reason that the improvement depth does not meet the standard is that the activation degree is not enough or the parameter adjustment is not suitable for the actual situation of the saline grassland, so that the improvement depth is increased by adding the application of humic acid or the adjustment range of the next improvement cycle is adjusted, the amount of hydrogen ions and calcium ions applied is increased, the improvement depth of the current improvement cycle is compensated, the accurate timing of the leaching process is determined in time to avoid the pH rebound and re-salinization of the saline grassland, and the adaptability to different saline grasslands is improved to increase the flexibility of the improvement process.

[0042] Further, the synergistic effect index (SEI) is a quantitative index for measuring whether the effect of multiple components combined is simply additive, antagonistic or truly synergistic. The reduction value of the exchangeable sodium percentage (ESP) is taken as the core evaluation index of the improvement effect of the soda saline grassland, the synergistic effect index is estimated to judge the combined use effect of the surfactant, the organic acid and the desulfurized gypsum, the improvement synergistic effect of the soda saline grassland under the current single improvement cycle process is evaluated, the judgment standard that the penetration effect of the surfactant does not meet the demand is adjusted accordingly, and the detection period of each parameter is shortened, the adaptability to different saline grasslands and the accuracy of the subsequent improvement cycle process are increased. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The method flow chart for low-disturbance improvement of the soda saline grassland in the embodiment of the present application;

[0044] Figure 2 The flowchart for determining whether the penetration effect of the surfactant meets the demand in the embodiment of the present application;

[0045] Figure 3 The flowchart for determining the main limiting factor in the embodiment of the present application;

[0046] Figure 4 The flowchart for determining that the combined use effect of each component meets the expected requirement in the embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the purpose and advantages of the present application clearer and more apparent, the present application will be further described below in conjunction with the embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0048] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and do not limit the protection scope of the present application.

[0049] It should be noted that in the description of the present application, the terms indicating the direction or positional relationship of "upper", "lower", "left", "right", "inner", "outer" and the like are based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0050] In addition, it should also be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] Please refer to Figures 1-4 shown, Figure 1 The flow chart of the method for improving the low-disturbance soda-saline grassland in the embodiments of the present application is shown in the figure; Figure 2 The flow chart for determining whether the penetration-promoting effect of the surfactant meets the requirements is shown in the figure; Figure 3 The flow chart for determining the main limiting factor is shown in the figure; Figure 4 The flow chart for determining whether the joint use effect of each component meets the expected requirements is shown in the figure.

[0052] The present application provides a method for improving low-disturbance soda-saline grassland, comprising:

[0053] Step S1, applying a surfactant solution with a certain concentration, measuring the actual infiltration rate of the soil according to the initial detection period to determine whether the penetration-promoting effect of the surfactant meets the requirements, or does not meet the requirements, and determining the main limiting factor according to the pH value;

[0054] Step S2, adjusting the initial concentration of the surfactant solution according to the stable infiltration duration, adjusting the application rate of the improvement agent solution according to the stable infiltration rate, and taking corresponding adjustment measures according to the determined main limiting factor;

[0055] The adjustment measures include increasing the concentration of organic acid in the improvement agent or adjusting the application amount of the surfactant solution and the application timing of the improvement agent solution;

[0056] Step S3, applying the improvement agent solution according to the adjusted improvement parameters, the improvement agent solution comprising organic acid and desulfurized gypsum, obtaining the wetting front advancing depth of the soil according to the initial detection period, and estimating whether the wetting front of the soil can reach the target improvement depth;

[0057] Step S4, determining whether the improvement depth meets the standard according to the wetting front advancing depth, or not meeting the standard by soil solution conductivity and the molar concentration ratio of sodium ions to calcium ions reflecting the matching relationship of sodium ion migration and calcium ion implantation;

[0058] Step S5, determining the reason for the non-compliance of the improvement depth according to the matching relationship, determining the adjustment range of applying humic acid or adjusting the improvement cycle process, and increasing the concentration of the improvement agent solution;

[0059] Step S6, estimating the synergistic effect index to evaluate the combined use effect of surfactants, organic acids and desulfurized gypsum under the current single improvement cycle process improvement application parameters;

[0060] Step S7, determining whether the degree of the combined use effect of each component being greater than the sum of the individual use effect meets the expected requirements according to the synergistic effect index, determining the judgment standard and initial detection period for the surfactant penetration effect not meeting the demand after adjusting the subsequent improvement cycle process.

[0061] Specifically, the present application provides an innovative formula and method suitable for natural grassland salinization treatment under "no tillage" conditions. Through the combined application of surfactants and desulfurized gypsum, organic acid and other improvement agents, the dual effects of improving soil water permeability and reducing salinity are achieved, which has significant effect on the repair of soda saline soil. The method is simple, low cost, fast-acting, environmentally friendly and has no side effects, and is suitable for application in grassland areas where plowing is prohibited.

[0062] Specifically, spraying surfactant solution is used to solve the problem of poor permeability caused by salt and alkali crust and soil hydrophobicity. Surfactants can significantly reduce the surface tension of water. When they are applied with water, they can quickly wet and penetrate into the soil surface layer, destroy the dense salt and alkali crust, and overcome the hydrophobicity of soil particles. It is equivalent to opening countless "channels" in the hardened soil, creating a prerequisite for the subsequent organic acid and gypsum solution to quickly and deeply enter the soil core reaction area. Without this step, the subsequent improvement agent will only stay on the surface and cannot affect the root layer.

[0063] Spraying the improvement agent solution, the improvement agent solution is prepared by mixing desulfurized gypsum and organic acid in a certain proportion, and a proper amount of humic acid or organic fertilizer can be added.

[0064] Specifically, organic acid (such as citric acid, oxalic acid, etc.), organic small molecule organic acid can quickly neutralize the alkaline components in the soil solution. When the organic acid solution penetrates into the soil pores, it reacts with the excess OH - , CO3 2- in the soil to generate water and the corresponding organic acid salt, reducing the soil pH to a suitable range. For example, citric acid can release H+ Na2CO3 is converted into Na + and HCO3 - The released CO2 helps to aerate the soil. The introduction of organic acids can quickly reduce the soil pH (faster than gypsum application alone) and provide a carbon source for microbial activity. Especially without soil mixing, organic acids can penetrate into the soil interstitial space, attack the surface of alkaline salt crystals, and cause them to dissolve and disintegrate, helping the amendment to work deeply. At the same time, the soda saline grassland may contain a small amount of calcium carbonate, and the organic acid can activate a small amount of calcium ion source.

[0065] Desulfurization gypsum (CaSO4·2H2O) is an industrial by-product gypsum, and its main component calcium sulfate provides a calcium ion source. When calcium ions enter the soil, they can exchange and adsorb sodium ions on colloids, replacing them to form soluble Na2SO4, which is washed away by subsequent water flow. This process reduces the soil alkalinity and exchangeable sodium percentage (ESP), while calcium ions promote soil clay flocculation, improving soil aggregate structure and porosity. In addition, the reaction of desulfurization gypsum with soil carbonates can also generate insoluble CaCO3 precipitates, thereby buffering and reducing soil pH (from Na2CO3 strong alkalinity to CaCO3 weak alkalinity, pH can be reduced from above 9 to about 8).

[0066] In this embodiment, the low-disturbance improvement method is repeated in several improvement cycles.

[0067] The initial infiltration rate, initial pH, and exchangeable sodium percentage of the soil of the saline-alkali grassland to be improved are detected by the double-ring infiltration instrument method, and surface layer wetting is sprayed;

[0068] In the implementation, a surfactant solution is sprayed on the saline-alkali grassland to be improved to completely wet the surface layer of the soil. The surface layer wetting is usually carried out before irrigation or rainfall to ensure that a certain amount of water is brought into the soil to a depth of 5-10 cm. Uniform coverage is required during spraying, with no dead angles.

[0069] In this embodiment, the surfactant selected is a non-toxic biodegradable type of alkyl polyglycoside (APG) or a bio-based surfactant. The surfactant is prepared into a certain concentration (water agent). Preferably, the certain concentration range of the surfactant solution is 0.1%-0.5%.

[0070] The actual infiltration rate of the saline-alkali grassland soil after applying the surfactant solution is measured by the double-ring infiltration instrument method according to the initial detection period;

[0071] when a ratio of the actual infiltration rate to a historical infiltration rate of a previous initial detection period is less than a ratio evaluation value, defining the current actual infiltration rate as a stable infiltration rate, and obtaining a sum of a plurality of initial detection periods corresponding to the stable infiltration rate as a stable infiltration time length;

[0072] when a permeability improvement multiple of the stable infiltration rate to the initial infiltration rate is greater than or equal to a standard value, determining that the penetration promoting effect of the surfactant meets the requirement;

[0073] when the permeability improvement multiple of the stable infiltration rate to the initial infiltration rate is less than the standard value, determining that the penetration promoting effect of the surfactant does not meet the requirement, determining a main limiting factor according to the actual pH of the saline-alkali grassland, and adjusting the initial concentration of the surfactant solution and the application rate of the modifier solution;

[0074] The process of determining the main limiting factor includes: detecting the actual pH of the saline-alkali grassland after applying the surfactant solution;

[0075] when the actual pH is greater than a synergistic pH, determining that the main limiting factor of the penetration promoting effect of the surfactant not meeting the requirement is the current pH of the saline-alkali grassland, and adjusting the solution parameters of the modifier solution;

[0076] Specifically, increasing the concentration of organic acid in the modifier according to the ratio of the actual pH to the synergistic pH.

[0077] when the actual pH is less than or equal to the synergistic pH, determining that the main limiting factor of the penetration promoting effect of the surfactant not meeting the requirement is physical crust, and determining that the surfactant solution is insufficient;

[0078] According to the ratio of the standard value to the permeability improvement multiple, adding the application amount of the surfactant solution, and according to the ratio of the application amount to the initial application amount of the surfactant, delaying the application timing of the modifier solution.

[0079] The process of adjusting the initial concentration of the surfactant solution and the application rate of the modifier solution includes:

[0080] adjusting the initial concentration of the surfactant solution according to the stable infiltration time length, the initial concentration being positively correlated with the stable infiltration time length, and adjusting the application rate of the modifier solution according to the stable infiltration rate, the application rate being positively correlated with the stable infiltration rate.

[0081] The standard value is in the range of 1.5-2, the synergistic pH is in the range of 8.5-9.0, and the ratio evaluation value is in the range of 0.95-1.05.

[0082] Specifically, in this application scenario, the decrease in pH value and the increase in soil permeability in soda-alkali soil are not linearly related, but rather there exists a key "synergistic inflection point" (e.g., pH ≈ 8.5-9.0). Only when the pH decreases below this inflection point does the colloidal dispersion of the alkalized soil decrease sharply, and Ca... 2+ The flocculation effect begins to dominate, at which point the infiltration-enhancing effect of surfactants is exponentially amplified. In this method, when the infiltration rate is slow, pH is determined to be the main limiting factor based on whether the decreased pH is above the "synergistic inflection point." The proportion of organic acids is adjusted to prioritize lowering the pH below the inflection point, rather than further increasing the surfactant. If the pH has already fallen below the inflection point but the infiltration rate still does not meet the target, physical crusting is determined to be the main limiting factor. In this case, the amount of surfactant solution is insufficient, and additional surfactant is added, improving the accuracy of adaptive adjustments to the improved circulation process. Simultaneously, a longer stable infiltration time indicates a greater sodium ion dispersion effect in the improved saline-alkali grassland. Soil colloids are mainly sodium colloids, requiring more calcium ions to replace sodium ions and more hydrogen ions to convert Na₂CO₃ into Na₂. + and HCO3 - This method adaptively adjusts the saline-alkali grassland based on the characteristic that the stable infiltration time reflects the degree of soil obstruction in the saline-alkali grassland to be improved, thereby increasing the adaptability of the saline-alkali grassland improvement adjustment.

[0083] The pre-prepared amendment solution is sprayed onto the grass surface. The amendment solution is made by mixing desulfurized gypsum and organic acids in a certain proportion, and an appropriate amount of humic acid or organic fertilizer can be added to improve the quality.

[0084] The preferred ratio of dosage is 50-100 kg / ha of desulfurized gypsum, 20-30 kg / ha of organic acid, and (optional) 10-20 kg / ha of humic acid.

[0085] In this embodiment, 30-50 tons of water are used per hectare. The total water volume should be sufficient to dissolve the main amendment and penetrate the soil to a depth of 20-30 cm (this amount can be adjusted according to soil moisture).

[0086] Since desulfurized gypsum has limited solubility, fine powdered gypsum can be mixed with water to form a suspension, which can then be mixed with a soluble organic acid solution and sprayed.

[0087] Predict whether the soil wetting front can reach the target improvement depth under the current spraying amount of surfactant solution. Apply humic acid (such as commercial potassium fulvate solution or peat extract) to increase the improvement depth, or adjust the adjustment range based on the main limiting factors.

[0088] Specifically, humic acid substances (soil activators) are added, humic acid includes fulvic acid, humic acid, etc., which is the product of long-term degradation of organic matter, has weak acidity and high CEC. Application of humic acid (such as commercial potassium fulvate solution or peat extract) can directly reduce the soil pH and promote the formation of soil aggregates. The large number of functional groups provided by humic acid can chelate sodium, aluminum and other ions in the soil, reducing their availability, thereby alleviating salt-alkali and aluminum toxicity. More importantly, humic acid is an important carbon source and stimulant for soil microorganisms, which can optimize the soil microbial community structure and improve microbial activity. The restoration of microorganisms in the soil will drive the acceleration of nutrient cycling and the enhancement of soil enzyme activity, further improving soil fertility. Studies have shown that the application of gypsum combined with humic acid can significantly increase the content of soil organic matter and the level of available nutrients, and the plant biomass can be increased by more than 40% compared with no application. Therefore, the application of humic acid modifier together with gypsum and organic acid can enhance the improvement depth and provide better nutrient conditions for plant growth.

[0089] According to the initial detection cycle, a soil water tension meter and a permeameter are used to obtain a plurality of wetting front advancing depths after the application of the modifier solution,

[0090] According to the plurality of wetting front advancing depths and the corresponding initial detection cycle, a power function relationship between the wetting front advancing depth and time is fitted;

[0091] The power function relationship is wetting front advancing depth = a · application time length b , wherein a is a parameter conversion coefficient, b is a parameter conversion index, and the application time length is the real-time time length after spraying the modifier solution;

[0092] In the implementation, the parameter conversion index is less than 1.

[0093] The preset total infiltration time is substituted into the power function relationship to calculate the predicted reaching depth. When the predicted reaching depth is greater than or equal to the preset target depth, it is estimated that the wetting front of the soil can reach the target improvement depth, and the improvement parameter of the modifier solution or the adjustment range of the improvement parameter is set reasonably;

[0094] When the predicted reaching depth is less than the preset target depth, it is judged that the wetting front of the soil cannot reach the target improvement depth, and the possible reason is that the activation degree is lower than the requirement of the improved saline-alkali grassland or the adjustment range setting according to the main limiting factor is unreasonable;

[0095] The adjustment range includes the adjustment range of adjusting the initial concentration of the surfactant solution according to the stable infiltration time and adjusting the application rate of the modifier solution according to the stable infiltration rate, or further includes the adjustment range of taking corresponding adjustment measures.

[0096] When the wetting front of the soil cannot reach the target improvement depth, the application of humic acid increases the improvement depth, or the adjustment of the improvement agent solution parameters increases the adjustment range, according to the matching relationship between the migration of sodium ions and the implantation of calcium ions.

[0097] The parameter conversion coefficient and the parameter conversion index are calibration values calculated according to the advancing depth of the wetting front and the corresponding initial detection period, and the value range of the preset target depth is 20-30 cm, which is positively correlated with the depth of the main root distribution layer of the saline grassland.

[0098] Specifically, the method estimates whether the improvement of the saline grassland can reach the target through the relationship between the advancing depth and the time length of the wetting front of the soil. When the wetting front of the soil cannot reach the target improvement depth, it is determined that the improvement does not meet the standard according to the matching relationship between the migration of sodium ions and the implantation of calcium ions. The problem is that the activation degree is lower than the requirement for improving the saline grassland, or the adjustment range set according to the main limiting factor is unreasonable and deviates from the actual situation. The corresponding adjustment measures are taken to compensate for the activation degree or adjust the improvement parameters of the next improvement cycle, thereby improving the accuracy of the improvement and adjustment of the saline grassland, and ensuring that the improvement agent penetrates to the main root distribution layer (20-30 cm).

[0099] The soil pH value reflects the salinization degree of the saline land, the neutralization effect of the alkalinity of the organic acid, and the synergistic effect of the desulfurized gypsum and the humic acid on the neutralization of the alkalinity. The pH value may rebound during the improvement process, and the replaced Na + The soil body will be re-salinized.

[0100] The matching relationship between the migration of sodium ions and the implantation of calcium ions is reflected by the soil solution conductivity and the molar concentration ratio of sodium ions to calcium ions. In the implementation, the calcium ions include the calcium carbonate in the saline land awakened by the organic acid and the calcium carbonate supplemented by the desulfurized gypsum.

[0101] The soil solution extractor and the spectrometer and the conductivity meter are used to detect the soil solution conductivity (EC) and the molar concentration ratio of [Na + ] to [Ca 2+ ];

[0102] Specifically, the negative pressure soil solution sampler is used to extract a plurality of soil solutions of the saline grassland according to the initial detection period, the actual conductivity of the plurality of soil solutions is detected by the conductivity meter, and the actual molar concentration ratio of sodium ions to calcium ions is calculated by the spectrometer.

[0103] In the implementation, a plurality of soil solutions of the saline grassland at different depths and locations are extracted at any initial detection period, and the average value of the detection parameters of the plurality of soil solutions is taken as the actual detection value of the saline grassland in the corresponding initial detection period.

[0104] The sharp increase in conductivity indicates that gypsum is dissolved, sodium ions in the colloid are replaced, and the reaction is proceeding; the increase in the molar concentration ratio of sodium ions to calcium ions indicates that the replacement reaction is proceeding in the forward direction, and calcium ions are being replaced into the colloid to adsorb the soil.

[0105] When the conductivity ratio of the actual conductivity to the historical conductivity is greater than the critical value, it is determined that the concentration of cations in the soil solution increases (desulfurized gypsum is dissolved and calcium ions are implanted, and sodium ions are replaced from the soil colloid);

[0106] When the molar ratio of the actual molar concentration ratio to the historical molar concentration ratio is greater than the first evaluation ratio, it is determined that the molar concentration ratio of sodium ions and calcium ions increases significantly;

[0107] When the molar ratio of the actual molar concentration ratio to the historical molar concentration ratio is less than the first evaluation ratio and greater than the second evaluation ratio, it is determined that the molar concentration ratio of sodium ions and calcium ions increases slowly;

[0108] When the concentration of cations in the soil solution increases, if the actual molar concentration ratio increases significantly, it is determined that the replacement of sodium ions and the implantation of calcium ions are in the first matching state, and the application of humic acid increases the improvement depth;

[0109] Specifically, the amount of humic acid is adjusted according to the ratio of the preset target depth to the predicted arrival depth;

[0110] When the concentration of cations in the soil solution increases, if the actual molar concentration ratio increases slowly, it is determined that the replacement of sodium ions and the implantation of calcium ions are in the second matching state, and the adjustment amplitude set according to the main limiting factor is unreasonable, and the adjustment amplitude and the concentration of the soil amendment solution are adjusted;

[0111] Specifically, the adjustment amplitude and the concentration of the soil amendment solution are increased according to the ratio of the first evaluation ratio to the molar ratio;

[0112] In the implementation, during the current application of the soil amendment solution to the saline-alkali grassland, the amount of the soil amendment solution can be increased instead of increasing the concentration of the soil amendment solution according to the ratio of the first evaluation ratio to the molar ratio, so as to achieve the purpose of increasing the amount of hydrogen ions and calcium ions applied to the saline-alkali grassland.

[0113] When the conductivity ratio of the actual conductivity to the historical conductivity tends to be constant, and the actual molar ratio of sodium ions to calcium ions decreases slowly, it is determined that the current replacement reaction has been completed;

[0114] It is determined to start the leaching process, and water is used to leach out the generated Na2SO4 from the root layer, and the amount of leaching water can be controlled according to the actual conductivity, and the amount of leaching water is positively correlated with the actual conductivity.

[0115] Specifically, an ideal high-efficiency improvement process is expected to use as little salt input (EC increase) as possible in exchange for as large a sodium ion replacement effect as possible; the present method reflects the matching relationship between sodium ion migration and calcium ion implantation through the change trend of the soil solution conductivity and the molar concentration ratio of sodium ion to calcium ion, and analyzes and judges the "quality" and "efficiency" of the ion replacement reaction by combining the rising trend of the conductivity with the change trend of the [Na + ] / [Ca 2+ ]ratio, and distinguishes the reason for the improvement depth not meeting the standard according to whether the dynamic matching relationship between sodium ion and calcium ion is within the normal range, i.e., whether the activation degree is not enough or the parameter adjustment is not suitable for the actual situation of the saline grassland, and accordingly increases the improvement depth by applying humic acid or adjusts the adjustment range of the next improvement cycle and adds the amount of hydrogen ion and calcium ion to compensate for the improvement depth of the current improvement cycle, while timely determining the accurate timing of the leaching process to avoid pH rebound and re-salinization of the saline grassland, and improve the adaptability to different saline grasslands and increase the flexibility of the improvement process.

[0116] The synergistic effect index is estimated, and the synergistic effect index = the measured synergistic mixture effect value / the expected additive effect value, and the expected additive effect value = the sum of the effect values of the surfactant, the organic acid and the desulfurized gypsum used alone compared with the blank control group.

[0117] In implementation, the activity reduction value, the organic reduction value and the gypsum reduction value are respectively calculated according to the blank exchangeable sodium percentage of the saline grassland and the single application exchangeable sodium percentage after applying a single treatment;

[0118] In the present embodiment, the exchangeable sodium percentage is the percentage of the amount of sodium ions adsorbed in unit mass of soil to the total amount of all cations that can be adsorbed in unit mass of soil;

[0119] The cations include calcium ions, magnesium ions, potassium ions and sodium ions.

[0120] The single application exchangeable sodium percentage includes the active exchangeable sodium percentage, the organic acid exchangeable sodium percentage and the gypsum exchangeable sodium percentage;

[0121] The active exchangeable sodium percentage is the exchangeable sodium percentage detected after applying the surfactant alone, the organic acid exchangeable sodium percentage is the exchangeable sodium percentage detected after applying the organic acid alone, and the gypsum exchangeable sodium percentage is the exchangeable sodium percentage detected after applying the desulfurized gypsum alone;

[0122] In implementation, a test area is divided in a soda saline grassland for calibrating the single application exchangeable sodium percentage through experiments.

[0123] The expected superimposed effect value = the activity reduction value + the organic reduction value + the gypsum reduction value, and the measured synergistic mixture effect value is the absolute value of the difference between the actual exchangeable sodium percentage detected after the leaching is implemented and the blank exchangeable sodium percentage;

[0124] The activity reduction value is the absolute value of the difference between the activity exchangeable sodium percentage and the blank exchangeable sodium percentage, the gypsum reduction value is the absolute value of the difference between the gypsum exchangeable sodium percentage and the blank exchangeable sodium percentage, and the organic reduction value is the absolute value of the difference between the organic acid exchangeable sodium percentage and the blank exchangeable sodium percentage.

[0125] In this embodiment, the blank exchangeable sodium percentage is 38%, the actual exchangeable sodium percentage detected after the leaching is implemented is 24%, and the measured synergistic mixture effect value is 14.

[0126] The synergistic effect index = the measured synergistic mixture effect value / the expected superimposed effect value, when the synergistic effect index is greater than the first index, it is determined that the combined use effect of the components is greater than the sum of the individual use effects of the components;

[0127] When the synergistic effect index is greater than the first index and less than the second index, it is determined that the combined use effect of the components is lower than the expected requirement, and the initial detection period is adjusted to the judgment standard of the surfactant penetration effect not meeting the requirements and the initial detection period;

[0128] Specifically, the standard value is increased according to the ratio of the second index to the synergistic effect index, and the initial detection period is reduced according to the ratio of the synergistic effect index to the second index;

[0129] When the synergistic effect index is greater than the second index, it is determined that the combined use effect of the components meets the expected requirement;

[0130] The first index is 1, and the second index is 1.3, and preferably the second index is 1.5.

[0131] Specifically, the synergistic effect index (SEI) is a quantitative index for measuring whether the effect of multiple components in combination is simply additive, antagonistic or truly synergistic. The reduction value of the exchangeable sodium percentage (ESP) is used as the core evaluation index of the improvement effect of the soda saline grassland, the combined use effect of the surfactant, the organic acid and the desulfurized gypsum is judged by estimating the synergistic effect index, the synergistic effect of the soda saline grassland under the current single improvement cycle process is evaluated, the judgment standard of the surfactant penetration effect not meeting the requirements is adjusted accordingly, and the detection period of each parameter is shortened, the adaptability of the saline grassland under different conditions is increased, and the accuracy of the subsequent improvement cycle process is increased.

[0132] Example 1

[0133] A low-disturbance improvement test was conducted on a typical soda-saline grassland in Northeast China. The surface soil of the grassland had a pH of about 9.1 and a salinity (measured by ESP) of up to 40%, and the original vegetation such as Leymus chinensis grew poorly with a coverage of less than 30%. Two adjacent plots of 1 hectare each were selected, one as a control (without improvement measures) and the other as a test area treated by the method of the present application. The specific steps included: after the soil thawed in spring, 0.2% APG surfactant aqueous solution (40 tons of water per hectare) was first sprayed to the test area to wet the soil to a depth of about 10 cm; then desulfurized gypsum, citric acid and potassium humate were mixed in a mass ratio of 3:1:0.5 (90 kg of gypsum + 30 kg of citric acid + 15 kg of potassium humate per hectare), dissolved in an appropriate amount of water, and uniformly sprayed on the ground surface; after natural settlement for 1 hour, the soil was intermittently washed with a small flow rate by opening the sprinkler facilities, with a total irrigation of 60 tons per hectare, completed in 6 times. The above improvement agent application and washing process was repeated every 3 months during the whole growing season.

[0134] After 1 year of treatment, the soil and vegetation conditions of the test area changed significantly compared with the control:

[0135] Soil water permeability: After improvement, the soil infiltration rate increased significantly, and there was basically no runoff and water accumulation on the surface after rainfall, and the infiltration depth increased from 10 cm in the control to about 25 cm. The soil water holding capacity increased, and the surface water content in the dry season was 15% higher than that in the control.

[0136] Soil salinity index: The soil salinity (measured by a certain comprehensive index) in the 0-20 cm soil layer decreased from 8.5 before improvement to 7.0; the soil solution electrical conductivity EC decreased from 4.2 dS / m to 2.8 dS / m, indicating that the soluble salt content decreased by about 33%. The percentage of exchangeable sodium ESP decreased from 38% to 24%. The soil pH decreased from 9.0 before improvement to about 8.0, which entered the plant tolerable range.

[0137] Soil profile physical and chemical properties: After improvement, the soil profile showed obvious aggregate structure, and the original dense gray-white alkali spots below 20 cm decreased significantly. The soil bulk density decreased from 1.45 g / cm 3 to 1.30 g / cm 3 , and the porosity increased by more than 10%. The soil organic matter content increased from 5.8 g / kg to 8.0 g / kg, and the available nitrogen, phosphorus and potassium contents increased by 20%-30% compared with the control. The microbial respiration intensity increased by more than 1 times, indicating that the soil ecological activity recovered well.

[0138] Vegetation recovery status: The native grass vegetation (Leymus chinensis, Puccinellia distans, etc.) in the improved area grew vigorously, and the vegetation coverage increased from 30% to about 60%; the average height and density of the plants were significantly increased, and the biomass was increased by about 35% compared with the control. The invasion of weeds was reduced, and the grassland community structure developed towards benign succession. The improved area was continuously green in the growing season, while the control area was still exposed to a large area of bare soil and sparse vegetation with yellowing phenomenon. The statistical results of the harvested pasture showed that the dry grass yield of the improved area was 1.5 times that of the control.

[0139] The above test results fully verify the effectiveness of the present application: under the condition of no ploughing, the pH and salt content of the saline-alkali grassland soil are significantly reduced, the permeability and fertility are obviously improved, and the vegetation is well recovered. Especially noteworthy is that the surface is not damaged during the improvement process, and the grassland ecosystem function continuously plays and steadily strengthens in the treatment. This example proves that the present technology has feasibility and superiority in actual grassland saline-alkali treatment.

[0140] No ploughing, eco-friendly: The present method does not damage the surface vegetation and soil structure, and is very suitable for natural grasslands which are prohibited from ploughing due to ecological protection regulations. Through the application of surfactants, the role of mechanical ploughing is replaced, so that the improver can penetrate into the soil without ploughing. This avoids water and soil loss and vegetation damage that may be caused by ploughing, protects the integrity of the original ecological system, and realizes the improvement while preserving. The native grass plants are preserved and gradually recover during the improvement process, and do not need to be re-seeded, thereby maintaining the original biodiversity of the grassland.

[0141] Fast effect, comprehensive improvement of soil physicochemical properties: Through the synergistic effect of chemistry and physics, the soil salinity and pH can be significantly reduced in a short period. The mechanism of calcium ion replacement + organic acid neutralization can rapidly reduce the excess sodium ions and alkali in the soil, and significantly reduce the harm of salinity and alkalinity. Compared with the deep application of gypsum by ploughing and then waiting for rainwater to slowly leach, the present method can see the effect of soil pH reduction and hardening degree reduction in the season of application. Tests show that the soil pH can be reduced by about 1 unit and the salinity index can be reduced by about 20% within one year of improvement. At the same time, the soil structure is improved due to the introduction of calcium ions and the supplement of organic matter, the porosity is increased, the bulk density is decreased, and the water and air permeability is greatly enhanced. The comprehensive improvement of these physicochemical properties creates good conditions for plant growth.

[0142] Maintain grassland productivity, improve vegetation growth: the amendment not only reduces the harm of salinization, but also brings beneficial ingredients to the soil. For example, the sulfur element in gypsum, organic acid and carbon nutrients in humus, etc. are all elements needed for plant and microbial growth. After improvement, the soil fertility and microbial activity rise, providing more sufficient nutrient supply for grassland vegetation. At the same time, since the original turf is not damaged, the grassland can play its ecological function while being improved, and there is no risk of wind and water erosion during the bare land stage after traditional improvement and ploughing. It is observed that the grassland vegetation coverage increases and the edible pasture yield improves after one year of improvement, and the vegetation growth condition is significantly improved. Therefore, this scheme is helpful to restore the ecological function of grassland and the productivity of animal husbandry, and realizes the win-win of ecological and economic benefits.

[0143] Thus far, the technical solutions of the present application have been described in connection with the preferred embodiments shown in the drawings, but it is readily understood by those skilled in the art that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after such changes or replacements will all fall within the protection scope of the present application.

[0144] The above description is only the preferred embodiments of the present application and is not intended to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for low-disturbance improvement of soda-salinized grassland, characterized in that, include: Apply a surfactant solution of a certain concentration, measure the actual infiltration rate of the soil according to the initial detection cycle to determine whether the surfactant's infiltration-promoting effect meets the requirements or not, and determine the main limiting factors based on pH. The initial concentration of the surfactant solution is adjusted according to the stable infiltration time, the application rate of the modifier solution is adjusted according to the stable infiltration rate, and corresponding adjustment measures are taken according to the determined main limiting factor. The amendment solution, which includes organic acid and desulfurized gypsum, is applied according to the adjusted modification parameters. The depth of the soil wetting front is obtained according to the initial detection cycle, and it is estimated whether the soil wetting front can reach the target modification depth. The improvement depth is determined based on the depth of the moist front. Whether the improvement depth meets the standard or not is reflected by the soil solution conductivity and the molar ratio of sodium ions to calcium ions, indicating the matching relationship between sodium ion migration and calcium ion implantation. Based on the matching relationship, determine the reasons why the improvement depth is not up to standard, determine the adjustment range of applying humic acid or adjusting the improvement cycle process, and increase the concentration of the improver solution; The synergistic effect index is estimated to evaluate the combined effect of surfactants, organic acids and desulfurized gypsum under the improved application parameters of the current single-cycle improvement process; Based on the synergistic effect index, determine whether the degree to which the combined effect of each component is greater than the sum of the effects of each component used alone meets the expected requirements, and determine the judgment criteria and initial testing cycle for whether the penetration-enhancing effect of the surfactant used to adjust the subsequent improved cycle process does not meet the requirements.

2. The method for low-disturbance improvement of soda-salinized grassland according to claim 1, characterized in that, The surfactant is a non-toxic, biodegradable alkyl polysaccharide (APG) or a bio-based surfactant, and the concentration range of the surfactant solution is 0.1% to 0.5%. The proportions of the modifier solution are: 50-100 kg / ha of desulfurized gypsum, 20-30 kg / ha of organic acid, and optional 10-20 kg / ha of humic acid.

3. The method for low-disturbance improvement of soda-salinized grassland according to claim 2, characterized in that, The process of determining whether the penetration-enhancing effect of a surfactant meets the requirements includes: When the actual ratio of the actual infiltration rate to the historical infiltration rate of the previous initial detection cycle is less than the ratio evaluation value, the current actual infiltration rate is defined as the stable infiltration rate, and the sum of several initial detection cycles corresponding to the stable infiltration rate is obtained as the stable infiltration duration. When the permeability enhancement factor between the stable infiltration rate and the initial infiltration rate is greater than or equal to the standard value, the infiltration-enhancing effect of the surfactant is deemed to meet the requirements. When the permeability increase factor between the stable infiltration rate and the initial infiltration rate is less than the standard value, it is determined that the infiltration-promoting effect of the surfactant does not meet the requirements, and the main limiting factor is determined based on the actual pH of the saline-alkali grassland.

4. The method for low-disturbance improvement of soda-salinized grassland according to claim 3, characterized in that, The process of determining the main limiting factors includes detecting the actual pH of the salinized grassland after the application of a surfactant solution; When the actual pH is greater than the synergistic pH, the main limiting factor for the surfactant's penetration-enhancing effect not meeting the requirements is the current pH of the saline-alkali grassland, and the concentration of organic acids in the amendment is adjusted. When the actual pH is less than or equal to the synergistic pH, the main limiting factor for the surfactant's penetration-enhancing effect is determined to be physical crusting. Therefore, the amount of surfactant solution applied should be increased and the timing of the spray modifier solution should be delayed.

5. The method for low-disturbance improvement of soda-salinized grassland according to claim 4, characterized in that, The process of determining whether the improvement depth meets the standard includes: The power function relationship between the advance depth of a moist front and time is fitted based on several advance depths of moist fronts and the corresponding initial detection cycles. The predicted depth is calculated by substituting the preset total infiltration time into the power function formula. If the predicted depth is less than the preset target depth, it is determined that the soil wetting front cannot reach the target improvement depth.

6. The method for low-disturbance improvement of soda-salinized grassland according to claim 5, characterized in that, The process reflecting the matching relationship between sodium ion migration and calcium ion implantation includes: The actual electrical conductivity of several soil solutions was measured according to the initial detection cycle, and the concentrations of sodium and calcium ions were measured to calculate the actual molar concentration ratio of sodium and calcium ions. When the ratio of actual conductivity to historical conductivity is greater than a critical value, it is judged that the conductivity has increased significantly and the cation concentration in the soil solution has increased. The molar ratio of sodium ions to calcium ions is used to determine whether the molar ratio of sodium ions to calcium ions has increased significantly or slowly.

7. The method for low-disturbance improvement of soda-salinized grassland according to claim 6, characterized in that, If the actual molar concentration ratio increases significantly when the cation concentration in the soil solution increases, it is determined that sodium ion migration and calcium ion implantation are in the first matching state. If the actual molar concentration ratio increases slowly when the cation concentration in the soil solution increases, it is determined that sodium ion migration and calcium ion implantation are in a second matching state.

8. The method for low-disturbance improvement of soda-salinized grassland according to claim 7, characterized in that, The process of determining the reasons for insufficient improvement depth includes: The reason why the improvement depth was not up to standard in the first matching state was that the activation level was lower than the requirement for improving saline-alkali grassland. Humic acid was applied to increase the improvement depth. The reason why the improvement depth was not up to standard in the second matching state was that the adjustment range set according to the main limiting factor was unreasonable, and the adjustment range of the improvement cycle process and the total amount of hydrogen ions and calcium ions applied were increased.

9. The method for low-disturbance improvement of soda-salinized grassland according to claim 8, characterized in that, The process of determining the combined effect of the components includes, when the synergistic effect index is greater than the first index, determining that the combined effect is greater than the sum of the effects of the individual components.

10. The method for low-disturbance improvement of soda-salinized grassland according to claim 9, characterized in that, When the synergistic effect index is greater than the first index and less than the second index, it is determined that the combined effect of the components is lower than expected, and the judgment criteria for determining that the penetration-promoting effect of the surfactant does not meet the requirements and the initial detection cycle are adjusted. When the synergistic effect index is greater than the second index, it is determined that the combined use of each component meets the expected requirements, and the cycle process is further improved.

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