Method for rapidly determining farmland stability of carbon-based potash fertilizer

Abstract

The invention discloses a method for rapidly determining the farmland stability of a carbon-based potash fertilizer, which is characterized by comprising the following steps of: obtaining the disintegration time of the carbon-based potash fertilizer through a disintegration experiment, and representing the farmland stability of the carbon-based potash fertilizer by the disintegration time; simulating rainfall through a soil column leaching experiment, measuring the potassium content in the leachate, and determining the farmland stability of the carbon-based potash fertilizer according to the potassium content; and determining the corresponding relationship between the disintegration experiment and the soil column leaching experiment, and judging the effectiveness of the experiment result of the farmland stability of the carbon-based potash fertilizer according to the corresponding relationship between the disintegration experiment result and the soil column leaching experiment result. The method can quickly, simply and conveniently determine the farmland stability of the carbon-based potash fertilizer.

Description

Technical Field

[0001] The present invention relates to a method for measuring the farmland stability of carbon-based potassium fertilizers. Background Art

[0002] In the initial stage of plant growth, the demand for nutrients is relatively low. However, traditional potassium fertilizers have high solubility and release most of their nutrients immediately after being applied to the soil, which cannot meet the continuous demand of crops. Therefore, the nutrient use efficiency of these potassium fertilizers is very low, and crops only utilize about 50%-60% of the potassium, resulting in the need for a large amount of fertilization and high agricultural production costs. In short, the high solubility of traditional potassium fertilizers leads to a large amount of nutrient loss, causing economic losses and environmental pollution. Therefore, developing slow-release potassium fertilizers from nutrient-rich organic agricultural waste can become a sustainable alternative to chemical fertilizers, improve fertilizer use efficiency, and reduce environmental impact. Biochar is a carbon-rich substance produced by the thermochemical decomposition of agricultural or organic residues under anaerobic conditions. Biochar has a highly porous structure, diverse functional groups, and a large surface area, making it a promising refractory carrier for environmentally friendly slow-release fertilizers. Biochar has been proven to have a positive impact on many soil physical, chemical, and biological properties, including enhancing water-holding capacity, improving ion exchange properties, and increasing soil pH value. At the same time, biochar can stimulate soil microbial activity or be used to bind toxic pollutants such as heavy metals. In recent years, more and more research has focused on producing slow-release fertilizers by loading chemical fertilizers on biochar. Although several methods for slowing down the nutrient release of biochar-based fertilizers have been proposed, most of these methods require expensive modification technologies, such as metal modification, magnetic activation, or polymer coating. These methods are either expensive, time-consuming, or may cause environmental problems, while an effective slow-release fertilizer should be inexpensive and environmentally friendly. Granulation treatment, as an environmentally friendly and low-cost treatment method, has shown development momentum in the production of slow-release fertilizers. Compared with unprocessed biochar, granular biochar (formed through a granulation process using binders) has a higher bulk density and a lower total porosity, and thus is expected to resist erosion. Through granulation, the unit density volume density of biomass can be increased by about 10 times. After granulation, the regularly shaped particles are more convenient to handle, which can reduce transportation and storage costs. Compared with unmodified biochar, granulated biochar has higher mechanical strength. Therefore, biochar particles may not be easily broken into fine particles. However, the stability of granulated compound fertilizers in farmland is too low to play a slow-release role, while too high stability will lead to too low nutrient release, which is not conducive to crop growth. Field experiments often require months of field sample collection, analysis, and testing, which not only consumes a large amount of manpower and material resources but also makes it difficult to improve the preparation process of granular fertilizers in a timely manner according to the results. At the same time, due to the unevenness of sampling, the results have a large deviation. Therefore, there is an urgent need to establish a new method that is fast and simple to measure the farmland stability of carbon-based potassium fertilizers, timely feedback and adjust the fertilizer production process parameters, achieve increased crop yields and reduced costs. Summary of the Invention

[0003] The present invention aims to avoid the deficiencies of the above-mentioned prior art, and provides a method for rapidly determining the field stability of carbon-based potassium fertilizers, aiming to indirectly quantify the field stability of fertilizers through the disintegration time and expand the test methods for the field stability of carbon-based potassium fertilizers.

[0004] The present invention adopts the following technical solutions to achieve the invention purpose: The characteristics of the method for rapidly determining the field stability of carbon-based potassium fertilizers in the present invention are as follows: the disintegration time of carbon-based potassium fertilizers is obtained through a disintegration experiment, and the field stability of carbon-based potassium fertilizers is characterized by the disintegration time; rainfall is simulated through a soil column leaching experiment, the potassium content in the leachate is measured, and the field stability of carbon-based potassium fertilizers is determined according to the potassium content; the corresponding relationship between the disintegration experiment and the soil column leaching experiment is determined, and the effectiveness of the experimental results of the field stability of carbon-based potassium fertilizers is judged according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment.

[0005] The characteristics of the method for rapidly determining the field stability of carbon-based potassium fertilizers in the present invention also lie in the following steps: Step 1: Prepare carbon-based fertilizers by mixing inorganic fertilizers, organic fertilizers, tobacco stalk biochar and a binder in proportion, and granulating and drying to obtain carbon-based potassium fertilizers. The binder is kaolin. Step 2: Obtain the disintegration time of carbon-based potassium fertilizers through a disintegration experiment, and characterize the field stability of carbon-based potassium fertilizers by the disintegration time of the carbon-based potassium fertilizers. The disintegration experiment is to put carbon-based potassium fertilizer particles into a glass test tube, inject distilled water into the glass tube to submerge the carbon-based potassium fertilizer particles, observe the static glass tube and take pictures regularly until the disintegration is completed and the disintegration time of the carbon-based potassium fertilizers is obtained. The disintegration time of the carbon-based potassium fertilizers refers to the time required from when the carbon-based potassium fertilizer particles are immersed in distilled water until the carbon-based potassium fertilizer particles appear as powder in distilled water. The powder refers to an irregular shape. Step 3: Simulate rainfall through a soil column leaching experiment, measure the potassium content in the leachate, and determine the field stability of carbon-based potassium fertilizers according to the potassium content. Carbon-based potassium fertilizers and soil are mixed and then filled into a glass column to form a soil column. Distilled water is dripped into the soil column at a constant flow rate, the leachate at the lower end of the soil column is collected, and the potassium content in the leachate is detected by a flame photometer. Step 4: Determine the corresponding relationship between the disintegration experiment and the soil column leaching experiment, and judge the effectiveness of the experimental results of the field stability of carbon-based potassium fertilizers according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment.

[0006] The characteristics of the method for rapidly determining the field stability of carbon-based potassium fertilizers in the present invention also lie in that the carbon-based potassium fertilizer particles in the disintegration experiment refer to cylindrical carbon-based potassium fertilizer particles with a cross-sectional diameter of 3.5 mm and a length of 7.0 mm, the glass tube is a flat-bottom glass tube with a bottom diameter of 2 cm, and 5 mL of distilled water is injected into each glass tube.

[0007] The characteristics of the method for rapidly determining the farmland stability of carbon-based potassium fertilizer of the present invention also lie in: setting five groups of repeated experiments for carbon-based potassium fertilizer particles; for the five groups of repeated experiments, removing the values with the longest and shortest disintegration times of the carbon-based potassium fertilizer particles in the repeated experiments, and taking the average of the remaining three values as the disintegration time of the carbon-based potassium fertilizer; the three different moisture contents refer to the moisture contents of 20%, 25% and 30%.

[0008] The characteristics of the method for rapidly determining the farmland stability of carbon-based potassium fertilizer of the present invention also lie in: in the soil column leaching experiment: setting the constant flow rate to be 0.5 ml per minute; the dosage of the carbon-based potassium fertilizer is 1 g, and the carbon-based potassium fertilizer and the soil are mixed at a weight ratio of 1:99; the height of the soil column is 20 cm, and the dosage of the distilled water is 453.6 mL; the 453.6 mL of distilled water is equally divided and dripped into the soil column six times.

[0009] The characteristics of the method for rapidly determining the farmland stability of carbon-based potassium fertilizer of the present invention also lie in: the disintegration experiment is respectively carried out for carbon-based potassium fertilizers with three different moisture contents, and the disintegration times of carbon-based potassium fertilizers with three different moisture contents are correspondingly obtained; the soil column leaching experiment is respectively carried out for the carbon-based potassium fertilizers with the three different moisture contents, and the soil column leaching potassium release rates of carbon-based potassium fertilizers with three different moisture contents are correspondingly obtained; taking the disintegration times of carbon-based potassium fertilizers with the three different moisture contents as independent variables and the soil column leaching potassium release rates of carbon-based potassium fertilizers with the three different moisture contents as dependent variables, a mathematical model is established as shown in formula (1): 1 / r = i / n + h (1) Where: r is the soil column leaching potassium release rate, n is the disintegration time of the carbon-based potassium fertilizer, and i and h are constants; accordingly, it is determined that there is a definite mathematical relationship between the disintegration time of the carbon-based potassium fertilizer and the soil column leaching potassium release rate, and they are strongly correlated; according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment, the effectiveness of the experimental results for judging the farmland stability of the carbon-based potassium fertilizer is determined.

[0010] Compared with the prior art, the beneficial effects of the present invention are reflected in: The present invention provides a new method for testing the farmland stability of carbon-based potassium fertilizer. The fertilizer disintegration is obtained through the disintegration experiment; the potassium release of the carbon-based potassium fertilizer in the farmland during rainfall is simulated through the soil column leaching experiment, and a mathematical model of the fertilizer disintegration time and the cumulative release rate of the laboratory soil column leaching is established. Then, the potassium release of the fertilizer in the farmland is explored through the field experiment, and the potassium release kinetics of the soil column fertilizer and the field fertilizer are compared. A three-level mapping relationship from the disintegration experiment to the soil column experiment and then to the field experiment is established; the farmland stability of the fertilizer is indirectly represented by the fertilizer disintegration time, greatly shortening the field experiment period and reducing the operation complexity, and providing a reference idea for the determination of the farmland stability of granulated compound fertilizers. Description of the Drawings

[0011] Figure 1 Schematic diagram of the method flow of the present invention; Figure 2 XPS diagrams of the biochar used for preparing the carbon-based potassium fertilizer and the carbon-based potassium fertilizer with a moisture content of 20%; Figure 3 Diagrams of the starting and completion states of the disintegration experiment of carbon-based potassium fertilizers with different moisture contents; Figure 4 Schematic diagram of the disintegration time of carbon-based potassium fertilizers with different moisture contents; Figure 5 Schematic diagram of the soil column leaching experiment in the present invention; Figure 6 Schematic diagram of the potassium release kinetics of soil column leaching of carbon-based potassium fertilizers with different moisture contents; Figure 7 Schematic diagram of the relationship between the disintegration time of the carbon-based potassium fertilizer and the potassium release rate of the carbon-based potassium fertilizer leached by the soil column; Figure 8 Fitting diagram of potassium release kinetics between the soil column leaching test and the field test.

[0012] See Figure 1 , in this embodiment, the method for rapidly determining the farmland stability of the carbon-based potassium fertilizer is to obtain the disintegration time of the carbon-based potassium fertilizer through the disintegration experiment, and characterize the farmland stability of the carbon-based potassium fertilizer by the disintegration time; simulate rainfall through the soil column leaching experiment, measure the potassium content in the leachate, and determine the farmland stability of the carbon-based potassium fertilizer according to the potassium content; determine the corresponding relationship between the disintegration experiment and the soil column leaching experiment, and judge the effectiveness of the experimental results of the farmland stability of the carbon-based potassium fertilizer according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment.

[0013] The method for rapidly determining the farmland stability of the carbon-based potassium fertilizer in this embodiment is specifically carried out according to the following steps: Step 1: Prepare the carbon-based fertilizer by mixing inorganic fertilizer, organic fertilizer, tobacco stalk biochar and binder in proportion, and granulating and drying to obtain the carbon-based potassium fertilizer. The binder is kaolin; Step 2: Obtain the disintegration time of the carbon-based potassium fertilizer through the disintegration experiment, and characterize the farmland stability of the carbon-based potassium fertilizer by the disintegration time of the carbon-based potassium fertilizer: the disintegration experiment is to put the carbon-based potassium fertilizer particles into a glass test tube, inject distilled water into the glass tube to submerge the carbon-based potassium fertilizer particles, observe the static glass tube and take pictures regularly until the disintegration is completed and the disintegration time of the carbon-based potassium fertilizer is obtained; the disintegration time of the carbon-based potassium fertilizer refers to the time required from when the carbon-based potassium fertilizer particles are immersed in distilled water until the carbon-based potassium fertilizer particles appear as powder in distilled water, and the powder refers to an irregular shape.

[0014] In the disintegration experiment of this embodiment, the carbon-based potassium fertilizer particles refer to cylindrical carbon-based potassium fertilizer particles with a cross-sectional diameter of 3.5 mm and a length of 7.0 mm. The glass tube is a flat-bottomed glass tube with a bottom diameter of 2 cm, and 5 mL of distilled water is injected into each glass tube. Five groups of repeated experiments are set for the carbon-based potassium fertilizer particles; for the five groups of repeated experiments, the values of the longest and shortest disintegration times of the carbon-based potassium fertilizer particles in the repeated experiments are removed, and the average value of the remaining three values is taken as the disintegration time of the carbon-based potassium fertilizer; the three different moisture contents refer to moisture contents of 20%, 25%, and 30%.

[0015] Step 3: Simulate rainfall through a soil column leaching experiment, measure the potassium content in the leachate, and determine the farmland stability of the carbon-based potassium fertilizer according to the potassium content: mix the carbon-based potassium fertilizer with the soil and load it into a glass column to form a soil column; drip distilled water into the soil column at a constant flow rate, collect the leachate at the lower end of the soil column, and use a flame photometer to detect the potassium content in the leachate; the soil column leaching experiment of this embodiment is as Figure 5 shown: set a constant flow rate of 0.5 ml per minute; the dosage of the carbon-based potassium fertilizer is 1 g, and the carbon-based potassium fertilizer and the soil are mixed at a weight ratio of 1:99; the height of the soil column is 20 cm, and the dosage of distilled water is 453.6 mL; 453.6 mL of distilled water is equally divided into six times and dripped into the soil column.

[0016] Step 4: Determine the corresponding relationship between the disintegration experiment and the soil column leaching experiment, and judge the effectiveness of the experimental results of the farmland stability of the carbon-based potassium fertilizer according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment.

[0017] In this embodiment, the disintegration experiment is carried out for carbon-based potassium fertilizers with three different moisture contents respectively, and the disintegration times of carbon-based potassium fertilizers with three different moisture contents are obtained correspondingly; similarly, the soil column leaching experiment is carried out for carbon-based potassium fertilizers with three different moisture contents respectively, and the soil column leaching potassium release rates of carbon-based potassium fertilizers with three different moisture contents are obtained correspondingly. Taking the disintegration times of carbon-based potassium fertilizers with three different moisture contents as independent variables and the soil column leaching potassium release rates of carbon-based potassium fertilizers with three different moisture contents as dependent variables, a mathematical model is established as shown in Equation (1): 1 / r = i / n + h (1) where: r is the soil column leaching potassium release rate, n is the disintegration time of the carbon-based potassium fertilizer, and i and h are constants; accordingly, it is determined that there is a definite mathematical relationship between the disintegration time of the carbon-based potassium fertilizer and the soil column leaching potassium release rate, and they are strongly correlated; according to the corresponding relationship between the results of the disintegration experiment and the results of the soil column leaching experiment, judge the effectiveness of the experimental results of the farmland stability of the carbon-based potassium fertilizer.

[0018] As can be seen from Figure 2 it, the K 2p 3 / 2 and K 2p 1 / 2 peaks of the tobacco stalk biochar (TSBC) are located at 292.0 and 294.8 eV (Figure 2 As shown in Figure (a) below, referring to the literature, it can be known that potassium exists in the +1 oxidation state. For the carbon-based potassium fertilizer (KPF) with a water content of 20%, the K2p 3 / 2 and K2p 1 / 2 peaks are located at 292.1 and 294.9 eV ( Figure 2 as shown in Figure (b) below). Similarly, it can be known that potassium exists in the +1 oxidation state. From Figure 3 it can be seen that at the start of the disintegration experiment ( Figure 3 as shown in Figure (a) below), the fertilizer has a regular shape and the solution is transparent. At the end of the disintegration experiment ( Figure 3 as shown in Figures (b), (c), and (d) below), the fertilizer is significantly dispersed with an irregular shape, the substances in the fertilizer dissolve out, and the solution significantly changes color. From Figure 4 it can be seen that among the three carbon-based potassium fertilizers with different water contents, the fertilizer with a water content of 20% has a longer disintegration time, which is 29.7 hours, and is more stable in water. Figure 5 Figure [ID] is a schematic diagram of the soil column leaching experiment, Figure 6 Figure [ID] is a schematic diagram of the potassium release kinetics of the soil column leaching of carbon-based potassium fertilizers with different water contents; from Figure 6 it can be seen that among the three carbon-based potassium fertilizers with different water contents, the fertilizer with a water content of 20% has a lower cumulative potassium release rate, which is 24.79%, indicating that the carbon-based potassium fertilizer with a water content of 20% is more stable in the soil. From Figure 7 it can be seen that both the disintegration experiment and the soil column leaching experiment can show the fertilizer stability, and there is a mathematical relationship and a strong correlation between the fertilizer disintegration time and the soil column leaching release rate, and R 2 is close to 0.9. Therefore, the results of the disintegration experiment correspond to the results of the soil column leaching experiment.

[0019] Field experiment: 100 g of the carbon-based potassium fertilizer with a water content of 20% of organic fertilizer biochar was applied to the field soil, and water was poured once every four days to simulate precipitation, with 40 mL of water poured each time and the watering area of 133 cm 2 . Calculate the precipitation in mm based on the watering volume and the watering area. Set the test period to 90 days, and regularly take out a small amount of fertilizer, preferably taking out 5 grains each time, about 0.5 g. Measure the remaining potassium content of the fertilizer through a flame photometer to obtain the results. Fit the potassium release kinetics of the soil column leaching fertilizer and the potassium release kinetics of the field fertilizer, and both conform to Equation (2): ln a = k t + c (2) where: a is the residual rate of fertilizer potassium (%); k is the rate constant; t is the soil column leaching volume (mL) / field precipitation (mm); c is a constant. As Figure 8 shown in Figures (a) and (b) below, it is shown that the potassium release processes of the soil column and the field fertilizers both conform to Equation (2), and their R 2 are both greater than 0.91. Among them, Figure 8 Figure (a) below is a schematic diagram of the potassium release kinetics of the soil column fertilizer, Figure 8Figure (b) is a schematic diagram of the potassium release dynamics of field fertilizers. In order to explore the corresponding relationship between the soil column and the potassium release behavior of field fertilizers, equations (1) and (2) are combined to establish a mathematical model, with the actual precipitation in the field experiment to achieve a certain release rate as the independent variable, and the leaching amount of the laboratory soil column to achieve the same release rate as the dependent variable. The mathematical relationship model between the leaching amount of the laboratory soil column and the actual precipitation in the field experiment is established as shown in equation (3): y = bx + d (3) Where: y is the leaching amount of the laboratory soil column that reaches a certain release rate, x is the actual precipitation in the field experiment that reaches the same release rate, b is the conversion coefficient, and d is a constant. By calculation, we get: (4): y = 74.50 x – 104.17 (4) It can be seen from formula (4) that the leaching amount of the laboratory soil column is linearly related to the actual precipitation in the field experiment, indicating that the leaching results of the laboratory soil column correspond to the actual results of the field experiment. Therefore, the results of the soil column leaching experiment can reflect the actual results of the field experiment, and the disintegration experiment results correspond to the soil column leaching results, that is, a three-level mapping relationship from the disintegration experiment to the soil column experiment and then to the field experiment is established. Therefore, the fertilizer disintegration time can indirectly indicate the stability of the fertilizer in the farmland, further proving the feasibility of the present invention.

Claims

1. A method for quickly determining the stability of carbon-based potash fertilizer in farmland, characterized by: The disintegration time of the carbon-based potash fertilizer is obtained through the disintegration experiment, and the disintegration time is used to characterize the farmland stability of the carbon-based potash fertilizer; the rainfall is simulated through the soil column leaching experiment, the potassium content in the leaching liquid is determined, and the farmland stability of the carbon-based potash fertilizer is determined according to the potassium content; the correspondence between the disintegration experiment and the soil column leaching experiment is determined, and the validity of the experimental results of the farmland stability of the carbon-based potash fertilizer is judged according to the correspondence between the disintegration experiment results and the soil column leaching experiment results.

2. The method for rapidly determining the stability of carbon-based potash fertilizer in farmland according to claim 1, characterized in that Proceed as follows: Step 1: preparing carbon-based fertilizer, which is to mix inorganic fertilizer, organic fertilizer, tobacco stalk biochar and a binder in proportion, granulate and dry to obtain carbon-based potash fertilizer, wherein the binder is kaolin; Step 2: Obtain the disintegration time of the carbon-based potash fertilizer through a disintegration experiment, and use the disintegration time of the carbon-based potash fertilizer to characterize the farmland stability of the carbon-based potash fertilizer: the disintegration experiment is to put the carbon-based potash fertilizer particles into a glass test tube, inject distilled water into the glass tube to immerse the carbon-based potash fertilizer particles, observe the static glass tube and take pictures at regular intervals until the disintegration is completed and the disintegration time of the carbon-based potash fertilizer is obtained; the disintegration time of the carbon-based potash fertilizer refers to the time from the time when the carbon-based potash fertilizer particles are immersed in distilled water to the time when the carbon-based potash fertilizer particles appear in powder form in the distilled water, and the powder form refers to an irregular shape; Step 3: simulate rainfall through soil column leaching experiment, determine the potassium content in the leaching solution, and determine the farmland stability of the carbon-based potash fertilizer according to the potassium content: the carbon-based potash fertilizer is mixed with soil and then loaded into a glass column to form a soil column; distilled water is dripped into the soil column at a constant flow rate, the leaching solution at the lower end of the soil column is collected, and the potassium content in the leaching solution is obtained by flame photometer detection; Step 4: Determine the correspondence between the disintegration test and the soil column leaching test, and judge the validity of the experimental results of the stability of carbon-based potash fertilizer in farmland based on the correspondence between the disintegration test results and the soil column leaching test results.

3. The method for rapidly determining the stability of carbon-based potash fertilizer in farmland according to claim 2, characterized in that: The carbon-based potash fertilizer particles in the disintegration experiment refer to cylindrical carbon-based potash fertilizer particles with a cross-sectional diameter of 3.5 mm and a length of 7.0 mm. The glass tube is a flat-bottomed glass tube with a bottom diameter of 2 cm. 5 mL of distilled water is injected into each glass tube.

4. The method for rapidly determining the stability of carbon-based potash fertilizer in farmland according to claim 2, characterized in that: Five groups of repeated experiments were set up for the carbon-based potash fertilizer particles; for the five groups of repeated experiments, the longest and shortest values ​​of the disintegration time of the carbon-based potash fertilizer particles in the repeated experiments were removed, and the average of the remaining three values ​​was taken as the disintegration time of the carbon-based potash fertilizer; the three different moisture contents refer to moisture contents of 20%, 25% and 30%.

5. The method for quickly determining the stability of carbon-based potash fertilizer in farmland according to claim 2, characterized in that: In the soil column leaching experiment: the constant flow rate is set to be 0.5 ml / minute; the amount of the carbon-based potash fertilizer is 1 g, and the carbon-based potash fertilizer is mixed with the soil in a weight ratio of 1:99; the height of the soil column is 20 cm, and the amount of distilled water is 453.6 mL; the 453.6 mL of distilled water is dripped into the soil column in six equal portions.

6. The method for rapidly determining the stability of carbon-based potash fertilizer in farmland according to claim 2, characterized in that: The disintegration experiment is to conduct disintegration experiments on three carbon-based potassium fertilizers with different moisture contents, and obtain the disintegration time of three carbon-based potassium fertilizers with different moisture contents; the soil column leaching experiment is to conduct experiments on the three carbon-based potassium fertilizers with different moisture contents, and obtain the soil column leaching potassium release rates of three carbon-based potassium fertilizers with different moisture contents; the disintegration time of the three carbon-based potassium fertilizers with different moisture contents is taken as the independent variable, and the soil column leaching potassium release rates of the three carbon-based potassium fertilizers with different moisture contents are taken as the dependent variable, and a mathematical model is established as shown in formula (1): 1 / r =i / n+h (1) Among them: r is the soil column leaching potassium release rate, n is the disintegration time of carbon-based potassium fertilizer, i and h are constants; it is determined that there is a definite mathematical relationship between the disintegration time of carbon-based potassium fertilizer and the soil column leaching potassium release rate, and they are strongly correlated; according to the corresponding relationship between the disintegration test results and the soil column leaching test results, the validity of the experimental results of carbon-based potassium fertilizer farmland stability is judged.

Images