Method for realizing safe potassium chloride application of potatoes by dynamically regulating and controlling irrigation volume based on soil chlorine critical value

Abstract

The invention relates to a method for realizing safe potassium chloride application of potatoes by dynamically regulating and controlling irrigation volume based on a soil chlorine critical value, and belongs to the technical field of potato cultivation. In order to solve the problem that an existing application method easily causes excessive potassium chloride to generate adverse effects on potato quality, the invention provides a method for realizing safe potassium chloride application of potatoes by dynamically regulating and controlling irrigation volume based on a soil chlorine critical value. The required irrigation amount is determined according to the soil clay content of the planting plot, the soil chlorine critical value tolerated by the potatoes and the chlorine application amount, the soil chlorine content can be effectively reduced through dynamic regulation and control of the irrigation amount, water resource waste and soil nutrient leaching loss caused by excessive irrigation are prevented, and it is ensured that the potassium content meets the requirements of the potatoes in different development periods. The method is suitable for different soil conditions, potato varieties and development periods, has wide practicability and flexibility, and can ensure safe application of potassium chloride and high yield and high quality of potatoes.

Description

Technical Field

[0001] The invention belongs to the technical field of potato cultivation and fertilization methods, and in particular relates to a method for realizing safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on a soil chlorine critical value. Background Art

[0002] Potatoes are typical potassium-loving crops, and their demand for potassium is higher than that of crops such as rice, soybeans and corn. Potassium is an activator of various enzymes in potatoes, and can promote the synthesis and operation of substances such as protein and starch. Adequate potassium fertilizer can make the stems and leaves of potatoes grow healthily, accelerate the synthesis and accumulation of organic matter, and promote the formation and expansion of tubers. Potassium fertilizer can also enhance the resistance of potatoes to stress, make the plants grow strong, the stems firm, reduce the content of soluble sugars, promote the synthesis of starch, improve the ability to resist diseases and pests and antioxidant capacity, and improve the yield and quality of potatoes.

[0003] Potassium fertilizers commonly used in agricultural production are mainly potassium sulfate and potassium chloride. Compared with potassium sulfate, potassium chloride has good water solubility, high potassium content, and relatively low price. If potassium chloride can partially replace potassium sulfate, the production cost can be effectively reduced. However, the traditional view is that potatoes are "chlorine-sensitive crops", and the application of chloride-containing fertilizers such as potassium chloride may lead to reduced production and affect the quality of tubers. However, a large number of studies have shown that although potatoes have a low tolerance to chlorine, chlorine is also an essential nutrient for plants including potatoes. The appropriate application of potassium chloride or the use of rainfall and supplementary irrigation can wash the chlorine applied to the soil out of the soil layer where the roots of chlorine-sensitive crops are distributed. However, excessive irrigation not only wastes water resources, but also causes leaching losses of other nutrients in the soil, leading to malnutrition of plants.

[0004] The tolerance of potatoes to chlorine varies with the growth and development stage of the plants. The growth of the root system also leads to different responses to the soil chlorine content in different soil layers. The leaching efficiency of chloride ions in soils of different textures is different, and the availability of soil nutrients is different. Therefore, how to formulate a scientific and safe method of applying potassium chloride based on the soil conditions in different regions and the growth needs and changes in tolerance to chlorine in different periods of crops is an urgent problem to be solved in order to achieve the rational use of potassium chloride and high-yield and high-quality production of potatoes. Summary of the invention

[0005] In order to solve the problem that the existing application method easily causes excessive potassium chloride and has an adverse effect on potato yield and quality, the present invention provides a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on the critical value of soil chloride.

[0006] The technical solution of the present invention:

[0007] A method for achieving safe application of potassium chloride to potatoes by dynamically regulating the irrigation amount based on the soil chloride critical value, wherein potassium chloride is applied in proportion in basal fertilizer or topdressing, and then the required irrigation amount is determined based on the clay content of the soil in the planting plot, the soil chloride critical value tolerated by potatoes and the amount of chlorine applied, and the safe application of potassium chloride during potato cultivation is achieved through dynamic regulation of the irrigation amount.

[0008] Furthermore, the calculation model for determining the required irrigation amount is:

[0009] I=175.8813-4.5662C+0.653F+2.5434S,

[0010] Where I is the required irrigation volume, in mm; C is the critical value of soil chlorine tolerance for potatoes, in mg / kg; F is the amount of chlorine applied, in kg / hm 2 ; S is the clay content of soil, in %.

[0011] Further, when potassium chloride is applied as a basal fertilizer, the potassium (in terms of K2O) provided by potassium chloride in the basal fertilizer does not exceed 35% of the potassium in the basal fertilizer, the remainder is provided by potassium sulfate, and the potassium in the topdressing is provided by potassium sulfate;

[0012] When potassium chloride is applied as topdressing, the potassium in the base fertilizer is provided by potassium sulfate, and the potassium provided by potassium chloride in the topdressing does not exceed 80% of the potassium in the topdressing, and the rest is provided by potassium sulfate. Further, the application ratio of potassium in the base fertilizer and the topdressing is 1:1.

[0013] Furthermore, the soil of the planting plot includes loam and sandy loam.

[0014] Furthermore, the critical value of soil chlorine tolerance of potatoes is the critical value of chlorine contained in loam or sandy loam at a certain depth that potatoes can tolerate during the seedling stage and tuber formation stage that are sensitive to chlorine.

[0015] Furthermore, when the planting land is loam, the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the seedling stage is 18 to 35 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the seedling stage is 16 to 28 mg / kg; the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the tuber formation period is 30 to 50 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the tuber formation period is 20 to 32 mg / kg.

[0016] Furthermore, when the planting land is sandy loam, the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the seedling stage is 9 to 37 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the seedling stage is 28 to 32 mg / kg; the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the tuber formation period is 27 to 40 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the tuber formation period is 55 to 64 mg / kg.

[0017] Furthermore, the required irrigation amount includes the rainfall amount and actual irrigation amount of the planting land after potassium chloride is applied.

[0018] Beneficial effects of the present invention:

[0019] The method for safe application of potato potassium fertilizer provided by the present invention is based on the difference in the demand for potassium fertilizer of potatoes at different growth stages, and combines the soil characteristics of different planting plots, the sensitivity of potatoes to chlorine at different growth stages, the actual chlorine application amount and other key factors to determine the calculation model of the required irrigation amount. By dynamically monitoring the above key factors in the potato growth process and the rainfall in the planting environment, the irrigation amount is adjusted in time, which can not only reduce the chlorine content in the soil to avoid its adverse effect on the potato quality, but also ensure that the potassium content in the soil can meet the demand of potatoes at different growth stages, thereby improving the yield and quality of potatoes.

[0020] It has been verified by experiments that the irrigation amount determined by the calculation model provided by the present invention is accurate and reliable. The model is applicable to different planting environments of loam and sandy loam, potato varieties and growth periods, and other chlorine-sensitive crops for which the critical value of soil chlorine can be determined. It has wide practicality and flexibility, can ensure the safe application of potassium fertilizer and the high yield and high quality of potatoes, further reduce the fertilizer cost of potato cultivation, and improve the economic benefits of potato cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Soil Cl when the field planting plot is loam - Scatter plot of percentage deviation between measured values ​​and preset values;

[0022] Figure 2 Soil Cl in the field planting plot is sandy loam - Scatter plot of percentage deviation between measured values ​​and preset values;

[0023] Figure 3 This is a comparison chart of the growth of potato seedlings of Example 2 and Comparative Example 1 in the seedling stage of the field test in 2022, with the left side of the red line being the example and the right side of the red line being the comparative example;

[0024] Figure 4This is a comparison chart of the growth of potato seedlings of Example 6 and Comparative Example 6 in the seedling stage of the field test in 2023, with the left side of the red line being the comparative example and the right side of the red line being the example;

[0025] Figure 5 This is a photo of the irrigation site of the field test of the present invention, with Example 2 on the left side of the red line and Comparative Example 2 on the right side of the red line. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0027] Example 1

[0028] This example provides the recommended dosage of potassium fertilizer for early-maturing potatoes, and converts the potassium application amount into the total fertilizer dosage of potassium sulfate or potassium chloride, as well as the total amount of chloride ions introduced into the soil when potassium chloride is fully applied.

[0029] Table 1 Total recommended potassium (in K2O) and physical potassium fertilizer amount for early-maturing potatoes

[0030]

[0031] Potatoes have different tolerance to chlorine at different growth stages. Correlation analysis of soil chlorine content and potato tuber yield at different growth stages showed that the seedling stage and tuber formation stage are the most sensitive periods for potatoes to soil chlorine, and the tolerance of the seedling stage is lower than that of the tuber formation stage. At the same time, chlorine has a strong migration ability in the soil, and Cl in different soil layers is different. - The chlorine content in different soil layers at different growth stages and potato tuber yield were analyzed and determined. The Cl - The content was significantly correlated with tuber yield.

[0032] Loam and sandy loam are the most suitable soils for growing potatoes. This example provides the critical values ​​of soil chlorine of two types of soils that potatoes can tolerate at different growth stages.

[0033] Table 2 Critical values ​​of soil chlorine for potato cultivation in soils of different textures (mg / kg)

[0034]

[0035] In this example, a multi-factor indoor simulation test was conducted on soils of different textures with different irrigation intensities, different irrigation amounts, different irrigation frequencies, and different chlorine application amounts. The dynamic leaching regulation law of the irrigation amount on the chloride ion content in soils of different textures was determined. The regression method was used to determine that the irrigation amount, chlorine application amount, and soil clay content were the factors affecting the soil target Cl - The key factor of soil chlorine content was used to establish the functional relationship between irrigation amount, chlorine application amount, soil clay content and soil target chlorine content. Then a calculation model was established to determine the irrigation amount based on the critical value of soil chlorine tolerance of potatoes at different growth stages and under different soil conditions, chlorine application amount and soil clay content:

[0036] I=175.8813-4.5662C+0.653F+2.5434S, where I is the required irrigation amount, in mm; C is the critical value of soil chlorine tolerance of potatoes, in mg / kg; F is the amount of chlorine applied, in kg / hm 2 ; S is the clay content of soil, in %.

[0037] The dynamic chlorine critical value of potatoes in different soil textures at different growth stages is used as the soil target chlorine content. The irrigation amount to keep the soil chlorine content below the critical value can be determined based on the potassium chloride application amount and the soil clay content. During actual irrigation, the actual irrigation amount is controlled within the range of ±5mm of the calculated target irrigation amount.

[0038] This example further verifies the accuracy of the irrigation amount calculation formula of the present invention through field tests.

[0039] In the field test, the clay content of the soil at the test site was determined. By presetting different soil target chlorine contents and setting different initial chlorine-containing fertilizer dosages (calculated based on the actual chlorine dosage), the irrigation amount was determined, and the soil after irrigation was collected to determine the actual Cl content in the soil. - Under different chlorine dosage conditions, the preset soil target chlorine content and the measured value were compared using the Pearson correlation coefficient (r), determination coefficient (R 2 ), normalized mean square error (NRMSE) and percentage bias (PBIAS) were used to judge the goodness of fit of the model, and the results are shown in Table 3.

[0040] Table 3 Model validation results

[0041] Verification indicators Loam Sandy loam Pearson correlation coefficient (r) 0.976 0.969 <![CDATA[Coefficient of determination (R 2 )]]> 0.927 0.933 Normalized mean square error (NRMSE) 0.054 0.063 Percent Bias (PBIAS) [-9.1％,19.3％] [-27.0％,19.0％]

[0042] The comparison between the verification results and the evaluation range in Table 3 shows that r is greater than 0.8, R 2 All of them were higher than 0.75, and NRMSE was less than 0.5, indicating that Cl -The actual content and the preset value are both within the range of extremely high goodness of fit, such as Figure 1 and Figure 2 As shown, the PBIAS range of loam is [-9.1%, 19.3%]; the PBIAS range of sandy loam is [-27.0%, 19.0%]. It can be seen that the irrigation amount determined by the calculation model provided by the present invention is reliable, and the model is suitable for different planting environments, soil conditions, potato varieties and growth periods, and has wide practicality and flexibility.

[0043] The following field tests were carried out in Example 2 to Example 5 and Comparative Example 1 to Comparative Example 5 on the same loam planting plot.

[0044] Example 2

[0045] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value.

[0046] First, the application amount of potato potassium fertilizer is determined based on soil testing and fertilization formula. In this embodiment, the application of potassium fertilizer adopts total amount control. According to the available potassium content of the soil in the planting plot of 95.6 mg / kg, according to the recommended amount in Table 1, the total amount of K2O should be 300 kg / hm 2 .

[0047] The application ratio of K2O in base fertilizer and topdressing is 1:1, and the amount of potassium chloride and potassium sulfate is calculated based on K2O.

[0048] In this example, potassium chloride is applied as basal fertilizer. 25% of K2O in the basal fertilizer is provided by potassium chloride, and the rest is provided by potassium sulfate. All K2O in the topdressing is provided by potassium sulfate. 63kg / hm2 of potassium chloride is applied as basal fertilizer. 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 28kg / hm 2 .

[0049] According to loam planting, Cl in the soil at a depth of 15-45 cm during potato seedling stage - The content has a greater impact on potato tuber formation, so the critical value of soil chlorine tolerance for potatoes provided in Table 2 is selected as 16 mg / kg.

[0050] The planting plot in this embodiment is loam and the clay content of the soil is 12.89%.

[0051] Substituting the critical value of soil chlorine tolerated by potatoes at the seedling stage, the amount of chlorine applied, and the clay content of the soil into the formula of Example 1, the irrigation amount is 154 mm. If the rainfall in the planting plot is less than 154 mm from the application of potassium chloride to the seedling stage, it needs to be supplemented to 154 mm through irrigation to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0052] Example 3

[0053] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0054] In this example, potassium chloride is applied as topdressing, the potassium in the base fertilizer is provided by potassium sulfate, 25% of the K2O in the topdressing is provided by potassium chloride, and the rest is provided by potassium sulfate. 62.5 kg / hm2 of potassium chloride is applied as topdressing 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 28.1kg / hm 2 .

[0055] According to the Cl content in the soil at a depth of 15-45 cm during the potato tuber formation period - The content has a greater impact on the formation of potato tubers, so the critical value of soil chlorine tolerated by potatoes provided in Table 2 is selected as 20 mg / kg. The critical value of soil chlorine tolerated by potato tubers during the formation period, the amount of chlorine applied, and the clay content of the soil are substituted into the formula of Example 1 to obtain an irrigation amount of 136 mm. If the rainfall from the planting plot to the tuber formation period after potassium chloride is applied is less than 136 mm, it can be supplemented to 136 mm by irrigation to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0056] Example 4

[0057] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0058] In this example, potassium chloride is applied during topdressing. The potassium in the base fertilizer is provided by potassium sulfate. 50% of the K2O in the topdressing is provided by potassium chloride, and the rest is provided by potassium sulfate. 125 kg / hm2 of potassium chloride is applied for topdressing. 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 56.3kg / hm 2 .

[0059] According to the Cl content in the soil at a depth of 15-45 cm during the potato tuber formation period - The content has a greater impact on the formation of potato tubers, so the critical value of soil chlorine tolerated by potatoes provided in Table 2 is selected as 20 mg / kg. Substituting the critical value of soil chlorine tolerated by potato tubers during the formation period, the amount of chlorine applied, and the clay content in the soil into the formula of Example 1, the irrigation amount is 154 mm. If the rainfall from the planting plot to the tuber formation period after potassium chloride is applied is less than 154 mm, it can be supplemented to 154 mm by irrigation to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0060] Example 5

[0061] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0062] In this example, potassium chloride is applied as topdressing, the potassium in the base fertilizer is provided by potassium sulfate, 75% of the K2O in the topdressing is provided by potassium chloride, and the rest is provided by potassium sulfate. 188 kg / hm2 of potassium chloride is applied as topdressing 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 84kg / hm 2 .

[0063] Substituting the critical value of soil chlorine tolerated by potatoes, the amount of chlorine applied, and the clay content of the soil into the formula of Example 1, the irrigation amount is 172 mm. If the rainfall in the planting plot is less than 172 mm after potassium chloride is applied, irrigation can be used to supplement it to 172 mm to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 2 is only that:

[0066] In this comparative example, potassium chloride was not applied as base fertilizer or topdressing, and all K2O came from potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 2 were both 154 mm to eliminate the influence of water factors on tuber yield.

[0067] Comparative Example 2

[0068] In this comparative example, potassium chloride is applied as basal fertilizer, and 50% of K2O in the basal fertilizer is provided by potassium chloride, the rest is provided by potassium sulfate, and the K2O in the topdressing is provided by potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 2 are both 154 mm to eliminate the influence of water factors on tuber yield.

[0069] Comparative Example 3

[0070] In this comparative example, potassium chloride is applied as basal fertilizer, and 75% of K2O in the basal fertilizer is provided by potassium chloride, the rest is provided by potassium sulfate, and the K2O in the topdressing is provided by potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 2 are both 154 mm to eliminate the influence of water factors on tuber yield.

[0071] Comparative Example 4

[0072] The difference between this comparative example and Example 2 is:

[0073] In this comparative example, potassium chloride is applied as basal fertilizer, and 100% of K2O in the basal fertilizer is provided by potassium chloride, and K2O in the topdressing is provided by potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 2 are both 154 mm to eliminate the influence of water factors on tuber yield.

[0074] Comparative Example 5

[0075] The difference between this comparative example and Example 2 is:

[0076] In this comparative example, chlorinating agent is applied in topdressing, K2O in base fertilizer is provided by potassium sulfate, and 100% of K2O in topdressing is provided by potassium chloride. The total rainfall and irrigation amount in this comparative example and Example 2 are both 154 mm to eliminate the influence of water factors on tuber yield.

[0077] The average potato weight, number of potatoes per plant and potato weight per plant obtained from Examples 2 to 5 and Comparative Examples 1 to 5 were statistically analyzed, and the results are shown in Table 4.

[0078] Table 4

[0079]

[0080]

[0081] As can be seen from Table 4, the average potato weight of the treatment with 50% potassium chloride as basal fertilizer reached the maximum value, and the average potato weight of the treatment with 75% potassium chloride as topdressing reached the maximum value, which was significantly higher than the control group treatment without potassium chloride application (p<0.05).

[0082] The tuber yield showed a trend of first increasing and then decreasing with the increase of potassium chloride application. The tuber yield reached the maximum value in the treatment with 25% potassium chloride as base fertilizer. As the potassium chloride application amount increased, the tuber yield began to decrease.

[0083] The tuber yield of the treatments with potassium chloride as topdressing was higher than that of the control group without potassium chloride. The tuber yield of the treatment with 75% potassium chloride was the highest, increasing by 6.99t / hm2 compared with the control group without potassium chloride. 2 .

[0084] The effect of potassium chloride application period on potato tuber yield was greater than that of potassium chloride application amount, the former reaching an extremely significant level (p<0.01) and the latter reaching a significant level (p<0.05).

[0085] Appropriate application of potassium chloride can increase potato tuber yield, and the effect of applying potassium chloride as topdressing is significantly better than that of applying potassium chloride as basal fertilizer.

[0086] The following field tests were carried out in Example 6 to Example 8 and Comparative Example 6 to Comparative Example 9 on the same sandy loam planting plot.

[0087] Example 6

[0088] This embodiment provides a field test of a method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value.

[0089] First, the application amount of potato potassium fertilizer is determined based on soil testing and fertilization formula. In this embodiment, the application of potassium fertilizer adopts total amount control. According to the available potassium content of the soil in the planting plot is 86 mg / kg, according to the recommended amount in Table 1, the total amount of potassium should be 300 kg / hm 2 .

[0090] The application ratio of K2O in base fertilizer and topdressing is 1:1, and the amount of potassium chloride and potassium sulfate is calculated based on K2O.

[0091] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0092] In this example, potassium chloride is applied as basal fertilizer. 33% of K2O in the basal fertilizer is provided by potassium chloride, and the rest is provided by potassium sulfate. All K2O in the topdressing fertilizer is provided by potassium sulfate. 83kg / hm2 of potassium chloride is applied as basal fertilizer. 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 37.5kg / hm 2 .

[0093] The planting plot in this embodiment is sandy loam, and the clay content of the soil is 4.13%.

[0094] Substituting the critical value of soil chlorine tolerated by potato seedlings in sandy loam soil (19 m / kg), the amount of chlorine applied, and the clay content of the soil into the formula of Example 1, the irrigation amount is 125 mm. If the rainfall in the planting plot is less than 125 mm after potassium chloride is applied, irrigation can be used to supplement it to 125 mm to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0095] Example 7

[0096] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0097] In this example, potassium chloride is applied during topdressing. The K2O in the base fertilizer is provided by potassium sulfate. 33% of the K2O in the topdressing is provided by potassium chloride, and the rest is provided by potassium sulfate. 83kg / hm2 of potassium chloride is applied for topdressing. 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 37.5kg / hm 2 .

[0098] The planting plot in this embodiment is sandy loam, and the clay content of the soil is 4.13%.

[0099] Substituting the critical value of soil chlorine tolerated by potato tubers in sandy loam soil during the tuber formation period (27 m / kg), the amount of chlorine applied, and the clay content of the soil into the formula of Example 1, the irrigation amount is 88 mm. If the rainfall in the planting plot is less than 88 mm after potassium chloride is applied, it can be supplemented to 88 mm through irrigation to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0100] Example 8

[0101] This embodiment provides a field test of a method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value. The difference between this embodiment and embodiment 2 is only that:

[0102] In this example, potassium chloride is applied during topdressing. The K2O in the base fertilizer is provided by potassium sulfate. 67% of the K2O in the topdressing is provided by potassium chloride, and the rest is provided by potassium sulfate. 167kg / hm2 of potassium chloride is applied for topdressing. 2 The chlorine content in potassium chloride is 45%, so the chlorine application rate is 75kg / hm 2 .

[0103] The planting plot in this embodiment is sandy loam, and the clay content of the soil is 4.13%.

[0104] Substituting the critical value of soil chlorine tolerated by potato tubers in sandy loam during the tuber formation period (27 m / kg), the amount of chlorine applied, and the clay content of the soil into the formula of Example 1, the irrigation amount is 112 mm. If the rainfall in the planting plot is less than 112 mm after potassium chloride is applied, irrigation can be used to supplement it to 112 mm to ensure that the chlorine content in the soil is lower than the critical value tolerated by potatoes.

[0105] Comparative Example 6

[0106] The difference between this comparative example and Example 8 is only that:

[0107] In this comparative example, potassium chloride was not applied as base fertilizer or topdressing, and all K2O came from potassium sulfate. In addition, the total rainfall and irrigation amount in this comparative example and Example 8 were both 125 mm to eliminate the influence of water factors on tuber yield.

[0108] Comparative Example 7

[0109] The difference between this comparative example and Example 8 is only that:

[0110] In this comparative example, potassium chloride is applied as basal fertilizer, and 67% of K2O in the basal fertilizer is provided by potassium chloride, and K2O in the topdressing is provided by potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 8 are both 125 mm to eliminate the influence of water factors on tuber yield.

[0111] Comparative Example 8

[0112] The difference between this comparative example and Example 8 is only that:

[0113] In this comparative example, potassium chloride was applied as basal fertilizer, and 100% of K2O in the basal fertilizer was provided by potassium chloride, and K2O in the topdressing was provided by potassium sulfate. The total rainfall and irrigation amount in this comparative example and Example 8 were both 125 mm to eliminate the influence of water factors on tuber yield.

[0114] Comparative Example 9

[0115] The difference between this comparative example and Example 8 is only that:

[0116] In this comparative example, chlorinating agent was applied in topdressing, K2O in base fertilizer was provided by potassium sulfate, and 100% of K2O in topdressing was provided by potassium chloride. The total rainfall and irrigation amount in this comparative example and Example 8 were both 125 mm to eliminate the influence of water factors on tuber yield.

[0117] The average potato weight, number of potatoes per plant and potato weight per plant obtained from Examples 6 to 8 and Comparative Examples 6 to 9 were statistically analyzed, and the results are shown in Table 5.

[0118] Table 5

[0119]

[0120] As can be seen from Table 5, the average potato weight of the treatment with 67% potassium chloride as basal fertilizer reached the maximum value, and the average potato weight of the treatment with 67% potassium chloride as topdressing reached the maximum value, which was significantly higher than the control group treatment without potassium chloride application (p<0.05).

[0121] The safe application method of potato potash fertilizer provided by the present invention combines the soil characteristics of different planting plots, the sensitivity of potatoes to chlorine at different growth stages, and the actual chlorine application amount and other key factors to determine the calculation model of the required irrigation amount. By dynamically monitoring the above key factors in the potato growth process and the rainfall in the planting environment, the irrigation amount is adjusted in time, which can not only reduce the chlorine content in the soil to avoid its adverse effect on the quality of potatoes, but also ensure that the potassium content in the soil can meet the needs of potatoes at different growth stages, thereby improving the yield and quality of potatoes. The present invention solves the problem that the existing application method easily causes excessive potassium chloride and has an adverse effect on the quality of potatoes, and can ensure the safe application of potash fertilizer and the high yield and high quality of potatoes.

Claims

1. A method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value, characterized in that: Potassium chloride is applied in proportion in the base fertilizer or topdressing, and then the required irrigation amount is determined based on the clay content of the soil in the planting plot, the critical value of soil chlorine tolerated by potatoes and the amount of chlorine applied. The safe application of potassium chloride in the potato cultivation process is achieved through dynamic regulation of the irrigation amount.

2. The method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value according to claim 1, characterized in that: The calculation model to determine the required irrigation amount is: I=175.8813-4.5662C+0.653F+2.5434S, Where I is the required irrigation volume, in mm; C is the critical value of soil chlorine tolerance for potatoes, in mg / kg; F is the amount of chlorine applied, in kg / hm 2 ; S is the clay content of soil, in %.

3. The method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on soil chloride critical value according to claim 1 or 2, characterized in that: When potassium chloride is applied as base fertilizer, the potassium provided by potassium chloride in the base fertilizer shall not exceed 35% of the potassium in the base fertilizer, and the rest shall be provided by potassium sulfate, and the potassium in the topdressing shall be provided by potassium sulfate; When potassium chloride is applied as top dressing, the potassium in the base fertilizer is provided by potassium sulfate, and the potassium provided by potassium chloride in the top dressing does not exceed 80% of the top dressing potassium, and the rest is provided by potassium sulfate.

4. The method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value according to claim 3, characterized in that: The application ratio of potassium in basal fertilizer and topdressing is 1:

1.

5. The method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on soil chloride critical value according to claim 4, characterized in that: The soil of the planting plot includes loam and sandy loam.

6. The method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on soil chloride critical value according to claim 5, characterized in that: The soil chlorine critical value tolerated by potatoes is the critical value of chlorine contained in loam or sandy loam at a certain depth that potatoes can tolerate during the seedling stage and tuber formation stage that are sensitive to chlorine.

7. The method for safely applying potassium chloride to potatoes by dynamically regulating irrigation volume based on soil chloride critical value according to claim 6, characterized in that: When the planting land is loam, the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the seedling stage is 18 to 35 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the seedling stage is 16 to 28 mg / kg; the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the tuber formation period is 30 to 50 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the tuber formation period is 20 to 32 mg / kg.

8. The method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on soil chloride critical value according to claim 7, characterized in that: When the planting land is sandy loam, the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the seedling stage is 9 to 37 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the seedling stage is 28 to 32 mg / kg; the critical value of soil chlorine at a depth of 15 to 30 cm that potatoes can tolerate during the tuber formation period is 27 to 40 mg / kg, and the critical value of soil chlorine at a depth of 15 to 45 cm that potatoes can tolerate during the tuber formation period is 55 to 64 mg / kg.

9. The method for achieving safe application of potassium chloride to potatoes by dynamically regulating irrigation amount based on soil chloride critical value according to claim 8, characterized in that: The required irrigation amount includes the rainfall amount and the actual irrigation amount of the planting plot after potassium chloride is applied.

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