A method for diagnosing real-time phosphorus nutrition of potato and a method for determining the amount of phosphorus fertilizer for potato

Abstract

This invention provides a method for real-time diagnosis of phosphorus nutrient deficiency in potatoes and a method for determining the application rate of phosphate fertilizer for potatoes, belonging to the field of agricultural technology. The method provided by this invention organically combines petiole diagnosis and pedicel diagnosis, more accurately determining the phosphorus nutrient status of potatoes. This enables phosphate fertilizer management to more accurately match the phosphorus requirements of potato growth and development, improves the efficiency of phosphate fertilizer utilization, and thus achieves rapid evaluation of the phosphorus nutrient status of potatoes and determines the accurate application rate of phosphate fertilizer.

Description

Technical Field

[0001] This invention belongs to the field of agricultural technology, specifically relating to a method for real-time diagnosis of phosphorus nutrient deficiency in potatoes and a method for determining the application rate of phosphate fertilizer for potatoes. Background Technology

[0002] The northern foothills of the Yinshan Mountains are one of the major potato-producing areas in China, and drip irrigation is widely used in potato cultivation in this region due to its effective water-saving advantages. However, in actual production, excessive application of phosphate fertilizer, often as a single basal fertilizer, is common in drip-irrigated potato production, failing to leverage the advantages of integrated water and fertilizer management. Due to a lack of targeted, efficient phosphate fertilizer management techniques, the phosphate fertilizer utilization efficiency of potatoes in the current season is only 11.2%, not only wasting phosphorus resources but also exacerbating the environmental risks of soil phosphorus surplus. This contradicts the green, quality-enhancing, and efficiency-improving potato industry development strategy. Therefore, precise phosphate fertilizer management to improve potato phosphate fertilizer utilization efficiency is imperative.

[0003] Currently, soil testing-based management of potato phosphate fertilizer is a common practice in many countries. However, some studies have found that phosphate application to potatoes is only effective when the available phosphorus in the soil is below 17.5 mg / kg; other studies have found that potatoes respond to phosphate fertilizer application when the available phosphorus in the soil is below 34.2 mg / kg; and some reports indicate that phosphate application increases yield when the available phosphorus in the soil is below 43.5 mg / kg, and even at 50.9 mg / kg, phosphate application still has a significant effect. Obviously, recommending potato phosphate fertilizer application based on the available phosphorus content in the soil is not very indicative and involves many uncertainties. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the purpose of this invention is to provide a method for rapidly diagnosing the phosphorus nutrient deficiency of potatoes, which can achieve rapid evaluation of the phosphorus nutrient status of potatoes and has good indicative value.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] This invention provides a method for real-time diagnosis of phosphorus nutrient abundance or deficiency in potatoes, comprising:

[0007] The critical values ​​for inorganic phosphorus concentration in potato petioles or pedicels are determined based on the emergence time when the inorganic phosphorus concentration is measured.

[0008] When the emergence time is 10 ≤ Ed ≤ 29, ΔPL4c = 46.797e 0.0679Ed ;

[0009] When the emergence time is 30 ≤ Ed ≤ 55, ΔPFc = -0.5786Ed 2 +35.182Ed +37.445;

[0010] When the emergence time is 56≤Ed≤85, ΔPL4c=26354Ed -1.2609 ;

[0011] Ed is the emergence time when the concentration of inorganic phosphorus in potato petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0012] PL4c represents the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc represents the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0013] The inorganic phosphorus concentration in potato petioles was measured 10–29 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0014] The inorganic phosphorus concentration in potato pedicels was measured 30–55 days after emergence. If PFc ≥ ΔPFc, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PFc < ΔPFc, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0015] The inorganic phosphorus concentration in potato petioles was measured 56–85 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0016] Preferably, the petiole includes the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem refers to the petiole of the fourth leaf from the top.

[0017] Preferably, the pedicel comprises a pedicel formed from the main stem of a potato.

[0018] Preferably, the inorganic phosphorus concentration includes the concentration of phosphate.

[0019] This invention provides a method for determining the application rate of phosphate fertilizer for potatoes, comprising:

[0020] After diagnosing potato phosphorus deficiency using the method described above, the amount of phosphate fertilizer to be applied is determined by combining the petiole inorganic phosphorus concentration test value and the critical value of petiole inorganic phosphorus concentration, or by combining the pedicel inorganic phosphorus concentration test value and the critical value of pedicel inorganic phosphorus concentration.

[0021] When the emergence time is 10 ≤ Ed ≤ 29, Pr = (ΔPL4c - PL4c) × (0.348e 0.013Ed );

[0022] When the emergence time is 30≤Ed≤55, Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019);

[0023] When the emergence time is 56≤Ed≤85, Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed );

[0024] Wherein, Ed is the emergence time when the inorganic phosphorus concentration in petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; PL4c is the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc is the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; and Pr is the amount of phosphate fertilizer applied, in kg / hm². 2 .

[0025] Preferably, the petiole comprises the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem is the petiole of the fourth leaf from the top.

[0026] Preferably, the pedicel comprises a pedicel formed from the main stem of a potato.

[0027] Preferably, the amount of phosphate fertilizer applied is the amount of P2O5 applied.

[0028] This invention provides the application of the method described in the above technical solution in potato fertilization.

[0029] Preferably, the application includes: improving phosphate fertilizer utilization efficiency and / or increasing potato yield.

[0030] Beneficial effects of the present invention

[0031] This invention provides a method for real-time diagnosis of phosphorus nutrient abundance or deficiency in potatoes, comprising:

[0032] The critical values ​​for inorganic phosphorus concentration in potato petioles or pedicels are determined based on the emergence time when the inorganic phosphorus concentration is measured.

[0033] When the emergence time is 10 ≤ Ed ≤ 29, ΔPL4c = 46.797e 0.0679Ed ;

[0034] When the emergence time is 30 ≤ Ed ≤ 55, ΔPFc = -0.5786Ed 2 +35.182Ed +37.445;

[0035] When the emergence time is 56≤Ed≤85, ΔPL4c=26354Ed -1.2609 ;

[0036] Ed is the emergence time when the concentration of inorganic phosphorus in potato petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0037] PL4c represents the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc represents the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0038] The inorganic phosphorus concentration in potato petioles was measured 10–29 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0039] The inorganic phosphorus concentration in potato pedicels was measured 30–55 days after emergence. If PFc ≥ ΔPFc, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PFc < ΔPFc, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0040] The inorganic phosphorus concentration in potato petioles was measured 56–85 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0041] Traditional plant phosphorus nutrition analysis requires destructive field sampling and digestion measurements based on dry weight, which is cumbersome, labor-intensive, and provides poor timeliness for fertilization guidance. This invention utilizes a reflectometer and phosphate test strips to rapidly obtain the inorganic phosphorus concentration (phosphate concentration) of potato petiole and flower stalk sap in the field. A rapid phosphorus nutrition diagnostic model combining petiole and flower stalk measurements was established, ultimately constructing a real-time, accurate, and efficient method for recommending potato phosphate fertilizer dosage. This invention measures the inorganic phosphorus concentration in petioles before and after flower stalk formation, and in flower stalks after formation, establishing a segmented continuous critical value discrimination model for real-time diagnosis of potato phosphorus nutrient abundance or deficiency. This discrimination model utilizes plant phosphorus nutrition diagnosis to establish a precise phosphate fertilizer management method suitable for the phosphorus requirements of potato growth and development. This method organically combines petiole and flower stalk diagnosis, more accurately determining the potato's phosphorus nutrition status, and enabling phosphate fertilizer management to more accurately match the phosphorus requirements of potato growth and development. The method is characterized by real-time performance, accuracy, and efficiency.

[0042] This invention also provides a method for determining the application rate of phosphate fertilizer for potatoes. Based on the real-time nutrient deficiency diagnosis method described above, this invention further determines the application rate of phosphate fertilizer for potatoes, enabling more accurate phosphate fertilizer management to match the phosphorus requirements of potato growth and development, and improving the efficiency of phosphate fertilizer utilization. Compared with traditional basal application of phosphate fertilizer, the method of determining the application rate of phosphate fertilizer for potatoes in this invention is accurate, real-time, and efficient, providing guidance for the scientific and rational application of phosphate fertilizer. Furthermore, adjusting the application rate using this method can significantly increase potato yield and improve the marketability of potatoes. In summary, the real-time diagnosis method for phosphorus nutrient deficiency in potatoes and the precise recommendation method for phosphate fertilizer provided by this invention can achieve rapid evaluation of the phosphorus nutrient status of potatoes and determine the accurate application rate of phosphate fertilizer. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 10 days after emergence.

[0045] Figure 2 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 15 days after emergence.

[0046] Figure 3 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 30 days after emergence.

[0047] Figure 4 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 45 days after emergence.

[0048] Figure 5 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 60 days after emergence.

[0049] Figure 6 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 75 days after emergence.

[0050] Figure 7 A graph showing the relationship between the concentration of inorganic phosphorus in the petioles and the total phosphorus concentration in the leaves and plants of potatoes 85 days after emergence.

[0051] Figure 8 A graph showing the relationship between phosphate concentration in the flower stalk and total phosphorus content in the plant 30 days after potato seedling emergence.

[0052] Figure 9 A graph showing the relationship between phosphate concentration in the flower stalk and total phosphorus content in the plant 40 days after potato seedling emergence.

[0053] Figure 10 A graph showing the relationship between phosphate concentration in the flower stalk and total phosphorus content of the plant 45 days after potato emergence.

[0054] Figure 11 A graph showing the relationship between phosphate concentration in the flower stalk and total phosphorus content of the plant at 55 days after potato seedling emergence.

[0055] Figure 12 Regression plot of the relationship between the 1 mg / L fertilizer application rate and the number of days after emergence of potato petiole inorganic phosphorus concentration PL4c;

[0056] Figure 13 Regression plot of the relationship between the 1 mg / L change in inorganic phosphorus concentration (PFc) in potato flower stalks and the number of days since emergence. Detailed Implementation

[0057] This invention provides a method for real-time diagnosis of phosphorus nutrient abundance or deficiency in potatoes, comprising:

[0058] The critical values ​​for inorganic phosphorus concentration in potato petioles or pedicels are determined based on the emergence time when the inorganic phosphorus concentration is measured.

[0059] When the emergence time is 10 ≤ Ed ≤ 29, ΔPL4c = 46.797e 0.0679Ed ;

[0060] When the emergence time is 30 ≤ Ed ≤ 55, ΔPFc = -0.5786Ed 2 +35.182Ed +37.445;

[0061] When the emergence time is 56≤Ed≤85, ΔPL4c=26354Ed -1.2609 ;

[0062] Ed is the emergence time when the concentration of inorganic phosphorus in potato petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0063] PL4c represents the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc represents the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L.

[0064] The inorganic phosphorus concentration in potato petioles was measured 10–29 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0065] The inorganic phosphorus concentration in potato pedicels was measured 30–55 days after emergence. If PFc ≥ ΔPFc, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PFc < ΔPFc, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0066] The inorganic phosphorus concentration in potato petioles was measured 56–85 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

[0067] In an optional embodiment of the present invention, the petiole includes the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem refers to the petiole of the fourth leaf from the top. In an optional embodiment of the present invention, the pedicel includes the pedicel formed by the potato main stem. In an optional embodiment of the present invention, the inorganic phosphorus concentration includes the concentration of phosphate. The present invention does not specifically limit the method for determining the inorganic phosphorus concentration; any conventional method in the art can be used. In an optional embodiment of the present invention, the method for determining the inorganic phosphorus concentration can be detection using a portable RQflex2 reflectometer and phosphate test strips. When determining the inorganic phosphorus concentration in the present invention, it is preferable to squeeze out the sap from the petiole and / or pedicel and dilute it to facilitate the determination of the inorganic phosphorus concentration. Finally, the inorganic phosphorus concentration obtained by direct measurement is multiplied by the dilution factor to obtain the inorganic phosphorus concentration of the petiole and / or pedicel.

[0068] As an optional embodiment of the present invention, the concentration of inorganic phosphorus PL4c in potato petioles can be detected on any day from 10 to 29 days after potato emergence, and then analyzed using ΔPL4c = 46.797e 0.0679Ed The critical value ΔPL4c of inorganic phosphorus concentration in potato petioles at the corresponding emergence time is calculated. In this invention, if PL4c ≥ ΔPL4c, it indicates that the potato has sufficient phosphorus nutrition at this time (the time when the inorganic phosphorus concentration in the potato petioles is measured); if PL4c < ΔPL4c, it indicates that the potato is deficient in phosphorus nutrition at this time (the time when the inorganic phosphorus concentration in the potato petioles is measured).

[0069] As an optional embodiment of the present invention, the inorganic phosphorus concentration (PFc) in the potato pedicel can be detected on any day between 30 and 55 days after potato emergence, and then analyzed using ΔPFc = -0.5786Ed. 2+35.182Ed+37.445 Calculate the critical value ΔPFc of inorganic phosphorus concentration in potato pedicels at the corresponding emergence time. In this invention, if PFc≥ΔPFc, the potato has sufficient phosphorus nutrition at the time when the inorganic phosphorus concentration in the potato pedicel is detected; if PFc<ΔPFc, the potato is deficient in phosphorus nutrition at the time when the inorganic phosphorus concentration in the potato pedicel is detected.

[0070] As an optional embodiment of the present invention, the concentration of inorganic phosphorus PL4c in potato petioles can be detected on any day between 56 and 85 days after potato emergence, and then analyzed using ΔPL4c = 26354Ed. -1.2609 The critical value ΔPL4c for inorganic phosphorus concentration in potato petioles at the corresponding emergence time is calculated. In this invention, if PL4c ≥ ΔPL4c, the time for detecting inorganic phosphorus concentration in potato petioles indicates sufficient phosphorus nutrition in the potato; if PL4c < ΔPL4c, the time for detecting inorganic phosphorus concentration in potato petioles indicates phosphorus deficiency in the potato.

[0071] The present invention can determine the phosphorus nutrient abundance or deficiency status of potatoes on any day from 10 to 85 days after emergence through the method described in the above technical solution, and then adjust the amount of phosphate fertilizer applied to potatoes.

[0072] This invention provides a method for determining the application rate of phosphate fertilizer for potatoes, comprising:

[0073] After diagnosing potato phosphorus deficiency using the method described above, the amount of phosphate fertilizer to be applied is determined by combining the petiole inorganic phosphorus concentration test value and the critical value of petiole inorganic phosphorus concentration, or by combining the pedicel inorganic phosphorus concentration test value and the critical value of pedicel inorganic phosphorus concentration.

[0074] When the emergence time is 10 ≤ Ed ≤ 29, Pr = (ΔPL4c - PL4c) × (0.348e 0.013Ed );

[0075] When the emergence time is 30≤Ed≤55, Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019);

[0076] When the emergence time is 56≤Ed≤85, Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed );

[0077] Wherein, Ed is the emergence time when the inorganic phosphorus concentration in petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; PL4c is the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc is the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; and Pr is the amount of phosphate fertilizer applied, in kg / hm². 2 .

[0078] In an optional embodiment of the present invention, the petiole includes the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem refers to the petiole of the fourth leaf from the top. In an optional embodiment of the present invention, the pedicel includes the pedicel formed by the potato main stem. In an optional embodiment of the present invention, the amount of phosphate fertilizer applied is the amount of P2O5 applied.

[0079] As an optional embodiment of the present invention, if the potato is confirmed to be deficient in phosphorus nutrition according to the real-time diagnosis method for potato phosphorus nutrition deficiency described in the above technical solution, and the potato emergence time is any day between 10 and 29 days, the deficiency can be diagnosed using the formula Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed ), calculate and determine the amount of potato phosphate fertilizer to be applied at the corresponding emergence time.

[0080] As an optional embodiment of the present invention, if the potato is confirmed to be deficient in phosphorus nutrition according to the method for real-time diagnosis of potato phosphorus nutrition deficiency as described in the above technical solution, and the potato emergence time is any day between 30 and 55 days, the application amount of potato phosphorus fertilizer at the corresponding emergence time can be calculated and determined by the formula Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019).

[0081] As an optional embodiment of the present invention, if potato phosphorus nutrient deficiency is confirmed according to the real-time diagnosis method for potato phosphorus nutrient deficiency described in the above technical solution, and the potato emergence time is any day between 56 and 85 days, the deficiency can be diagnosed using the formula Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed ), calculate and determine the amount of potato phosphate fertilizer to be applied at the corresponding emergence time.

[0082] This invention provides the application of the method described in the above technical solution in potato fertilization. In this invention, the application includes: improving phosphorus fertilizer utilization efficiency and / or increasing potato yield.

[0083] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0084] Example 1

[0085] 1) Feasibility of diagnosing inorganic phosphorus concentration in potato petioles and pedicels:

[0086] Field trials with different phosphate fertilizer application gradients were conducted in major potato-producing areas. The specific phosphate fertilizer application levels were: 0, 80, 160, 180, 240, and 320 kg / hm² of P₂O₅. 2 The amount of phosphate fertilizer applied is calculated as P2O5. Each treatment was replicated four times, with each plot measuring 150m². 2 Randomized arrangement, each treatment was treated with 270 kg / hm² of nitrogen. 2 K2O 300kg / hm 2 The phosphate fertilizer used in the experiment was monoammonium phosphate, containing 61 wt.% P₂O₅ and 12 wt.% N. The nitrogen content was included in the total nitrogen application, and the remaining nitrogen was supplemented with urea, which contained 46% pure N. The potassium fertilizer was potassium sulfate, containing 50 wt.% K₂O. Both phosphate and potassium fertilizers were applied as basal fertilizer in a single application. Nitrogen fertilizer was applied in six applications: 25 wt.% as basal fertilizer; 10 wt.% during the seedling stage; two applications during tuber formation, the first 10 wt.% and the second 15 wt.%; and 40 wt.% during tuber enlargement, applied in two applications of 20 wt.% each.

[0087] Determination of petiole inorganic phosphorus concentration: At 10, 15, 30, 45, 60, 75 and 85 days after emergence, 30 potato plants were randomly selected from each treatment. The petioles of the quadrangular leaflets were cut off with scissors, the leaves were removed and the petioles were kept. Juice was extracted with squeegees within a short time. The petiole juice was diluted 10 times and the inorganic phosphorus content in the petiole was determined using a Merck RQflex2 reflectometer and phosphate test strips. The petiole inorganic phosphorus concentration (mg / L) = reflectometer reading (mg / L) × dilution factor.

[0088] Determination of inorganic phosphorus concentration in flower stalks: At 30, 40, 45, and 55 days after emergence, 30 potato plants were randomly selected from each treatment. The main stem flowers were cut off with scissors, and the top flowers were removed, leaving the flower stalks. Juice was extracted using squeegees within a short time. The flower stalk juice was diluted 10 times and the inorganic phosphorus content in the flower stalks was determined using a Merck RQflex2 reflectometer and phosphate test strips. The inorganic phosphorus concentration in the flower stalks (mg / L) = reflectometer reading (mg / L) × dilution factor.

[0089] Total phosphorus concentration in plants and leaves: Nine potato plants were randomly selected from each treatment at 10, 15, 30, 40, 45, 55, 60, 75, and 85 days after emergence. The potatoes were separated into root, stem, leaf, and tuber parts. Each part was placed in an oven at 110℃ for 30 minutes to blanch, then dried at 80℃ for 48 hours, and weighed. The dried samples were pulverized, digested with H2SO4-H2O2, and then the phosphorus concentration of each part was determined using a continuous flow analyzer (SKALAR SAN++). Total phosphorus concentration in plants (%) = (root dry weight × total phosphorus concentration in roots + stem dry weight × total phosphorus concentration in stems + leaf dry weight × total phosphorus concentration in leaves + tuber dry weight × total phosphorus concentration in tubers) / (root dry weight + stem dry weight + leaf dry weight + tuber dry weight).

[0090] The inorganic phosphorus concentration in the petioles of the fourth-to-first compound leaves and the total phosphorus concentration in the plant were measured at 10, 15, 30, 45, 60, 75, and 85 days after emergence. Correlation relationships were established between the inorganic phosphorus concentration in the petioles and the total phosphorus concentration in the leaves. Significant positive correlations were found between both the inorganic phosphorus concentration in the petioles and the total phosphorus concentration in the leaves. Figures 1 to 7 That is, as the concentration of inorganic phosphorus in the petiole increases, the concentration of total phosphorus in the plant and the total phosphorus in the leaves also increase accordingly. This indicates that the concentration of inorganic phosphorus in the petiole can accurately predict the concentration of total phosphorus in the plant, and is suitable as an indicator for the diagnosis of phosphorus nutrition in potatoes.

[0091] The inorganic phosphorus concentration in the main stem pedicel and the total phosphorus concentration in the plant were measured at 30, 40, 45, and 55 days after seedling emergence. A correlation was established between the inorganic phosphorus concentration in the main stem pedicel and the total phosphorus concentration in the plant, revealing a significant positive correlation. (See [link to relevant documentation]). Figures 8-11 The result shows that as the concentration of inorganic phosphorus in the pedicel increases, the total phosphorus concentration in the plant also increases accordingly. This indicates that the concentration of inorganic phosphorus in the pedicel can accurately predict the total phosphorus concentration in the plant, making it suitable as an indicator for diagnosing phosphorus nutrition in potatoes.

[0092] 2) Response of petiole and pedicel inorganic phosphorus concentrations to phosphorus application levels

[0093] In the above experiment, the inorganic phosphorus concentration of the petiole of the four-petaled leaves obtained at 10, 15, 30, 45, 60, 75, and 85 days after seedling emergence was used to determine the corresponding phosphorus fertilizer treatments (0, 80, 160, 180, 240, and 320 P2O5 kg / hm²). 2 Correlation analysis was performed, and all results showed extremely significant correlations (see Table 1). Similarly, the concentration of inorganic phosphorus in the main stem pedicel was measured at 30, 40, 45, and 55 days after seedling emergence, and the correlations with phosphorus fertilizer treatments (0, 80, 160, 180, 240, and 320 kg / hm² P₂O₅) were obtained.2 Correlation analysis showed that both values ​​reached a highly significant level (see Table 2). Therefore, both petiole and pedicel inorganic phosphorus concentrations are highly indicative of phosphorus fertilizer supply levels. The formation of the pedicel usually signifies the transition of the plant from vegetative to reproductive growth, and phosphorus nutrients preferentially move towards the floral organs. At this time, the pedicel inorganic phosphorus concentration is more sensitive in indicating the plant's phosphorus nutrient status. Therefore, petiole inorganic phosphorus concentration can be used for diagnosis during the growth stages before pedicel formation and after flowering, while pedicel inorganic phosphorus concentration can be used during potato flowering.

[0094] Table 1. Correlation between petiole inorganic phosphorus concentration and phosphorus application rate

[0095]

[0096] Note: * indicates a significant correlation at the 0.05 level; ** indicates a significant correlation at the 0.01 level, and so on.

[0097] Table 2. Correlation between inorganic phosphorus concentration in flower stalks and phosphorus application rate.

[0098]

[0099] 3) Establishment of critical values ​​for inorganic phosphorus concentration in petioles and pedicels

[0100] In the above experiment, the inorganic phosphorus concentration of the petiole of the four-petaled leaf obtained at 10, 15, 30, 45, 60, 75, and 85 days after seedling emergence was compared with the corresponding phosphate fertilizer treatments (0, 80, 160, 180, 240, and 320 kg / hm² P₂O₅). 2 Correlation analysis was performed on the relative yields (with the highest yield in each treatment being 100%, and the percentage of other treatment yields relative to the highest yield) to determine the inflection point of the linear-platform model as the critical value of petiole inorganic phosphorus concentration PL4c, as shown in Table 3. Similarly, the concentration of inorganic phosphorus in the main stem pedicel was measured at 30, 40, 45, and 55 days after emergence and correlated with phosphorus fertilizer treatments (0, 80, 160, 180, 240, and 320 kg / hm² P₂O₅). 2 Correlation analysis was performed on the relative yields (with the highest yield in each treatment being 100%, and the percentage of other treatment yields relative to the highest yield) to determine the inflection point of the linear plus plateau model as the critical value of the inorganic phosphorus concentration PFc in the flower stalk, as shown in Table 4. The relative yields of different phosphorus application treatment groups are shown in Table 5.

[0101] Table 3. Linear plateau model and critical values ​​of petiole inorganic phosphorus concentration PL4c and relative yield.

[0102]

[0103] Note: R2 The coefficient of determination is used, and the same applies below.

[0104] Table 4. Linear plateau model and critical values ​​of inorganic phosphorus concentration (PFc) in pedicels and relative yield.

[0105]

[0106]

[0107] Table 5. Relative yields of different phosphorus application treatment groups

[0108] <![CDATA[Phosphorus application rate (kg / hm 2 )]]> 0 80 160 180 240 320 relative output 76.4％ 83.3％ 93.6％ 100％ 98.3％ 94.7％

[0109] 4) Establishing the correlation between the critical values ​​of inorganic phosphorus concentration in potato petioles and pedicels and the number of days since emergence.

[0110] Based on the critical values ​​of petiole inorganic phosphorus concentration at 10, 15, and 30 days after potato emergence (92.28 mg / L, 129.63 mg / L, and 358.51 mg / L respectively), a regression equation ΔPL4c = 46.797e can be established between the critical value of petiole inorganic phosphorus concentration and the number of days since emergence during the period of 10–29 days. 0.0679Ed Based on the critical values ​​of inorganic phosphorus concentration in flower stalks for potato seedlings at 30, 40, 45, and 55 days after emergence (573.33 mg / L, 513.33 mg / L, 454.72 mg / L, and 221.15 mg / L respectively), a regression equation ΔPFc = -0.5786Ed can be established between the critical PFc value and the number of days since emergence in the 30-55 day period. 2 +35.182Ed+37.445; Based on the critical values ​​of petiole inorganic phosphorus concentration at 45, 60, 75, and 85 days after potato emergence (225.83 mg / L, 142.91 mg / L, 116.67 mg / L, and 97.28 mg / L respectively), a regression equation ΔPL4c = 26354Ed can be established between the critical value of PL4c and the number of days after emergence in the period of 56–85 days. -1.2609 .

[0111] 5) Determination of phosphorus application rate based on a 1 mg / L variation in the inorganic phosphorus concentration test values ​​PL4c and PFc in potato petioles.

[0112] First, establish the regression relationship between the concentration of inorganic phosphorus PL4c in potato petioles and the amount of phosphorus applied at 15, 30, 45, 60, 75 and 85 days after emergence, as shown in Table 1.

[0113] Based on the formula for topdressing phosphorus fertilizer application at each growth stage, Pr = Popt - Pcon, where Popt is the total phosphorus application during the entire growth period and Pcon is the phosphorus fertilizer application amount corresponding to the petiole inorganic phosphorus concentration measured at different growth stages, combined with the regression relationship in Table 1, i.e., Pcon is the x value in the table, and the y value is used to represent x and substituted into the topdressing amount formula (Pr = Popt - Pcon), we can get Pr = Popt - ΔPct / k + b / k, where ΔPct is the petiole inorganic phosphorus concentration test value PL4c, and k and b are the coefficient of the first term and the constant of the first regression equation corresponding to different seedling emergence days in Table 1, respectively.

[0114] Therefore, by substituting ΔPct+1 and ΔPct into Pr=Popt-ΔPct / k+b / k and taking the difference, the change in phosphorus application amount when the measured value of inorganic phosphorus concentration in potato petioles PL4c changes by 1 mg / L is Pr=|1 / k|. That is, using Pr=|1 / k|, we can calculate the change in phosphorus application amount when the petiole inorganic phosphorus concentration changes by 1 mg / L. Specifically, when the measured value of inorganic phosphorus concentration in petioles increases by 1 mg / L, the phosphorus application amount needs to be reduced by 1 / k; when the measured value of inorganic phosphorus concentration in petioles decreases by 1 mg / L, the phosphorus application amount needs to be increased by 1 / k, as shown in Table 6. Similarly, the phosphorus application amount when the value of inorganic phosphorus concentration in flower stalks PFc changes by 1 mg / L can be calculated, as shown in Table 7.

[0115] The above method, which involves substituting ΔPct+1 and ΔPct into Pr = Popt - ΔPct / k + b / k, and then taking the difference, is as follows:

[0116] Assume ΔPct = m and ΔPct = n; then when ΔPct = m, Pr m =Popt-m / k+b / k; then when ΔPct=n, Pr n =Popt-n / k+b / k.

[0117] If m = ΔPct and n = ΔPct + 1, then when the measured value of inorganic phosphorus concentration in the petiole increases by 1 mg, the change in phosphorus application rate is Pr. n -Pr m =(mn) / k=(-1) / k.

[0118] That is, when the measured value of inorganic phosphorus concentration in the petiole increases by 1 mg, the change in phosphorus application rate is Pr = (-1) / k, and the change in phosphorus application rate is a decrease of 1 / k.

[0119] If m = ΔPct + 1 and n = ΔPct, then when the measured value of inorganic phosphorus concentration in the petiole decreases by 1 mg, the change in phosphorus application rate is Pr. n -Pr m = (mn) / k = 1 / k.

[0120] That is, when the measured value of inorganic phosphorus concentration in the petiole decreases by 1 mg, the change in phosphorus application rate is Pr = (-1) / k, and the change in phosphorus application rate is an increase of 1 / k.

[0121] In summary, the change in the inorganic phosphorus concentration PL4c of potato petioles by 1 mg / L is Pr = |1 / k|.

[0122] Table 6. Variation of inorganic phosphorus concentration in potato petioles; phosphorus application rate at 1 mg / L.

[0123]

[0124] Table 7. Variation of inorganic phosphorus concentration (PL4c) in potato pedicels; phosphorus application rate per 1 mg / L

[0125]

[0126]

[0127] 6) Establishing the correlation between changes in 1 mg / L of inorganic phosphorus concentration (PL4c) in potato petioles and (PFc) in flower stalks and the number of days since emergence.

[0128] Based on the above, at 10, 15, 30, 45, 60, 75, and 85 days after potato emergence, the corresponding fertilization rate for a 1 mg / L change in petiole inorganic phosphorus concentration (PL4c) is 0.3927 kg / hm². 2 0.4249 kg / hm 2 0.4980 kg / hm 2 0.6566 kg / hm 2 0.7892 kg / hm 2 0.8286 kg / hm 2 1.0994 kg / hm 2 A regression equation can be established between the variation of petiole inorganic phosphorus concentration (PL4c) by 1 mg / L fertilizer application rate and the number of days since emergence during the 15-85 day emergence period, such as... Figure 12 The equation is PeulL4 = 0.348e 0.013Ed (Ed represents emergence time, 15≤Ed≤85, PeulL4 represents the fertilization amount for a 1 mg / L change in petiole inorganic phosphorus concentration PL4c). Similarly, a regression equation was established between the fertilization amount for a 1 mg / L change in pedicel inorganic phosphorus concentration PFc and the number of emergence days during the 30-55 day emergence period: PeulF=0.5224Ln(Ed)-1.4019 (Ed represents emergence time, 30≤Ed≤55, PeulF represents the fertilization amount for a 1 mg / L change in pedicel inorganic phosphorus concentration PFc). Figure 13 .

[0129] 7) Establishment of a fertilization model for diagnosing inorganic phosphorus concentrations (PL4c) and (PFc) in potato petioles.

[0130] During the period of 10 ≤ Ed (days since emergence) ≤ 29 and 56 ≤ Ed ≤ 85, when the real-time measured petiole inorganic phosphorus concentration PL4c is greater than or equal to the critical value ΔPL4c, no additional phosphate fertilizer is needed. When the petiole inorganic phosphorus concentration PL4c is less than the critical value ΔPL4c, the difference between the critical value and the measured petiole inorganic phosphorus concentration PL4c should be calculated, and then multiplied by the phosphate application rate for a 1 mg / L change in petiole inorganic phosphorus concentration to determine the amount of phosphate fertilizer needed at that time. Similarly, during the period of 30 ≤ Ed ≤ 55, the amount of phosphate fertilizer needed at that time can also be calculated by determining the magnitude of the pedicel inorganic phosphorus concentration PFc and the critical value ΔPFc. That is, Pr = (ΔPL4c - PL4c) × PeuL4 or Pr = (ΔPFc - PFc) × PeuF. According to the formula: 10 ≤ Ed ≤ 29, Pr = (46.797e 0.0679Ed -PL4c)×(0.348e 0.013Ed );30≤Ed≤55, Pr=((-0.5786Ed 2 +35.182Ed+37.445)-PFc)×(0.5224Ln(Ed)-1.4019); 56≤Ed≤85, Pr=(26354Ed -1.2609 -PL4c)×(0.348e 0.013Ed The amount of phosphate fertilizer Pr can then be calculated.

[0131] 8) In summary, the method for rapidly diagnosing phosphorus nutrient deficiency in potatoes comprises the following steps:

[0132] The inorganic phosphorus concentration PL4c in the petioles of the fourth leaf from the top of the main stem of potatoes was measured at 10-29 days and 56-85 days after emergence; the inorganic phosphorus concentration PFc in the pedicels of the main stem of potatoes was measured at 30-55 days after emergence.

[0133] According to Formula 1, the critical value of petiole inorganic phosphorus concentration on any day between 10 and 29 days after emergence is calculated as follows: 10 ≤ Ed ≤ 29, ΔPL4c = 46.797e 0.0679Ed ;

[0134] According to Formula 2, the critical value of inorganic phosphorus concentration in the flower stalk on any day from 30 to 55 days after seedling emergence is calculated as follows: 30≤Ed≤55, ΔPFc=-0.5786Ed 2 +35.182Ed +37.445;

[0135] Based on Formula 3, the critical value of petiole inorganic phosphorus concentration on any day from 56 to 85 days after seedling emergence is calculated as follows: 56 ≤ Ed ≤ 85, ΔPL4c = 26354 Ed. -1.2609 ;

[0136] The term "Ed" refers to the emergence time of the fourth leaflet (fourth leaf from the top) and the pedicel of the potato main stem, measured in days (d). The critical values ​​for inorganic phosphorus concentration, ΔPL4c and ΔPFc, are calculated in mg / L. PL4c represents the inorganic phosphorus concentration in the petiole of the fourth leaflet (fourth leaf from the top) of the potato main stem, measured in mg / L; PFc represents the inorganic phosphorus concentration in the pedicel of the potato main stem, measured in mg / L. The fourth leaflet (fourth leaf from the top) is the fourth fully unfolded leaf from the top of the potato main stem, and the pedicel is the pedicel on the potato main stem.

[0137] The inorganic phosphorus concentration in potato petioles was measured 10–29 days after emergence; if PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition, and if PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition.

[0138] The inorganic phosphorus concentration in potato pedicels was measured 30–55 days after emergence; if PFc ≥ ΔPFc, the potato had sufficient phosphorus nutrition, and if PFc < ΔPFc, the potato was deficient in phosphorus nutrition.

[0139] The inorganic phosphorus concentration in potato petioles was measured 56–85 days after emergence; if PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition, and if PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition.

[0140] The inorganic phosphorus concentration was detected using a portable RQflex2 reflectometer and phosphate test strips.

[0141] This invention also provides a method for determining the application rate of phosphate fertilizer for potatoes. After diagnosing potato phosphorus deficiency using the above method, according to Formula 4: 10≤Ed≤29, Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed According to Formula 5: 30≤Ed≤55, Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019); According to Formula 6: 56≤Ed≤85, Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed The amount of phosphate fertilizer Pr can then be calculated.

[0142] ΔPL4c is the critical value of inorganic phosphorus concentration in the petiole of the fourth leaf from the top of the potato main stem, PL4c is the measured value of inorganic phosphorus concentration in the petiole of the fourth leaf from the top of the potato main stem, ΔPFc is the critical value of inorganic phosphorus concentration in the pedicel of the potato main stem, PFc is the measured value of inorganic phosphorus concentration in the pedicel of the potato main stem, and Ed is the emergence time of picking the petiole and pedicel of the fourth leaf from the top of the potato main stem.

[0143] The calculated application rate of phosphate fertilizer is based on the application rate of P2O5.

[0144] Example 2

[0145] Select the locally promoted potato variety "Kexin No. 1" and conduct testing according to the following steps:

[0146] 1) Detection of inorganic phosphorus concentration in petioles and pedicels

[0147] At 20, 35, and 58 days after potato emergence, 30 plants with similar growth and free from pests and diseases were randomly selected. At 20 and 58 days, the fourth fully unfolded leaf from the top of the main stem was cut off with scissors, and the leaves on the petiole were removed, leaving the petiole. At 35 days, the flower stalks on the main stem were collected. Juice was extracted from the petiole and flower stalk separately (i.e., the juice was squeezed out of the petiole and flower stalk), and the juice was diluted 10 times with distilled water (the specific dilution ratio was adjusted according to the range of inorganic phosphorus test strips of 5-120 mg / L). The concentrations were measured and recorded in real time. The actual inorganic phosphorus concentrations of the tested petiole and flower stalk were calculated based on the dilution ratio, as shown in Table 8.

[0148] Table 8 Inorganic phosphorus concentration in petioles and pedicels

[0149]

[0150] 2) Determining the nutrient abundance or deficiency of potatoes

[0151] Substituting the value of day 20 after emergence into ΔPL4c = 46.797e, 0.0679Ed In the calculation, the critical value of inorganic phosphorus concentration in petioles, ΔPL4c, was found to be 182.0 mg / L. If the concentration of inorganic phosphorus in petioles, PL4c, is greater than ΔPL4c on the 20th day after emergence, then no phosphorus fertilizer needs to be applied on the 20th day after emergence.

[0152] Substituting day 35 into ΔPFc=-0.5786Ed 2 +35.182Ed+37.445, the critical value of inorganic phosphorus ΔPFc is 560.0mg / L; if the concentration of inorganic phosphorus in the pedicel PFc is less than ΔPFc on the 35th day after emergence, then phosphate fertilizer needs to be applied on the 35th day after emergence.

[0153] Substitute day 58 after emergence into ΔPL4c = 26354Ed -1.2609 The critical value of inorganic phosphorus in petioles, ΔPL4c, was calculated to be 157.5 mg / L. If the concentration of inorganic phosphorus in petioles, PL4c, is less than ΔPL4c on the 58th day after emergence, then phosphorus fertilizer needs to be applied on the 58th day after emergence.

[0154] 3) Recommended dosage of P2O5 phosphate fertilizer for potatoes

[0155] Substituting the inorganic phosphorus concentration PL4c value (512) measured on day 35 in step 1) and the ΔPFc value (560) obtained in step 2) into the formula: Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019), the recommended phosphate fertilizer application rate Pr=21.86kg / hm 2 This means that the potato planting area needs to be fertilized with 21.86 kg / hm² of P2O5 fertilizer. 2 .

[0156] Substituting the PL4c value of 138 measured on day 58 in step 1) and the ΔPL4c value of 157.5 obtained in step 2) into formula five: Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed The calculated value of Pr is 14.42 kg / hm². 2 The recommended application rate of phosphate fertilizer is 14.42 kg / hm² for this potato planting area. 2 .

[0157] Example 3

[0158] Recommended application examples of potato phosphate fertilizer dosage

[0159] (1) In 2023, in Wuchuan County and Chayouzhong Banner, major potato-producing areas on the northern slope of the Yinshan Mountains, three models were set up: a farmer model, a phased application model of phosphate fertilizer, and a precise recommendation model of phosphate fertilizer based on petiole and pedicel diagnosis (the precise recommendation model of phosphate fertilizer protected by this invention). ， The four models are consistent in all aspects of agricultural management except for the application of phosphate fertilizer. The amount and method of applying nitrogen and potassium fertilizer are the same. In the farmer model, phosphate fertilizer is applied as a single basal application, and the application amount is shown in Table 17. In the staged application model, phosphate fertilizer is applied as a basal fertilizer of 20 wt.%, seedling stage of 20 wt.%, early tuber formation stage of 15 wt.%, late tuber formation stage of 15 wt.%, early tuber enlargement stage of 10 wt.%, late tuber enlargement stage of 10 wt.%, and starch accumulation stage of 10 wt.%. The total amount of phosphate fertilizer applied in the staged application model is shown in Table 17.

[0160] Based on the diagnosis of petiole and pedicel, the precise recommended mode for phosphate fertilizer application is 36 kg / hm² of basal phosphate fertilizer. 2 Subsequently, inorganic phosphorus concentrations were collected from the petioles of the fourth leaf from the top and the pedicels of the potato main stem at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after potato emergence, as per step 1) in Example 2, to determine the nutrient deficiency of the potato, as per step 2) in Example 2. Then, timely application of phosphate fertilizer was recommended, as per step 3) in Example 2. The total phosphate fertilizer application rate for the precise phosphate fertilizer recommendation model based on petiole and pedicel diagnosis was 36 kg / hm² as basal phosphate fertilizer. 2Adding the total recommended application rates at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after emergence, under the precise recommendation model of petiole-petal diagnosis for phosphate fertilizer, the inorganic phosphorus concentrations of petioles and pedicels at different emergence times and the actual phosphate fertilizer application rates in Chayouzhong Banner are shown in Table 9, and the total fertilization amount is shown in Table 17; under the precise recommendation model of petiole-petal diagnosis for phosphate fertilizer, the inorganic phosphorus concentrations of petioles and pedicels at different emergence times and the actual phosphate fertilizer application rates in Wuchuan County are shown in Table 10, and the total fertilization amount is shown in Table 17.

[0161] Table 9. Inorganic phosphorus concentration in petioles and pedicels at different emergence times and actual phosphate fertilizer application rates in Chayouzhong Banner.

[0162]

[0163] Table 10. Inorganic phosphorus concentration in petioles and pedicels at different emergence times and actual phosphate fertilizer application rates in Wuchuan County.

[0164]

[0165] The precise recommended phosphate fertilizer application method based on petiole diagnosis is 36 kg / hm² of basal phosphate fertilizer. 2 Subsequently, inorganic phosphorus concentrations were collected from the petioles of the fourth leaflets of the potato main stem at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after potato emergence, as per step 1) of Example 2, to determine the nutrient deficiency of potatoes, as per step 2) of Example 2. The determination of nutrient deficiency from 30 to 85 days was performed using ΔPL4c = 26354Ed. -1.2609 The critical value of inorganic phosphorus in the petiole was calculated, and then the recommended application of phosphate fertilizer was carried out in a timely manner as in step 3 of Example 2. The recommended amount of phosphate fertilizer for 30-85 days was calculated using Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed According to calculations, the total phosphate fertilizer application rate for the petiole diagnostic phosphate fertilizer precision recommendation mode is 36 kg / hm² of basal phosphate fertilizer. 2 Adding the total recommended application rates at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after emergence, Table 11 shows the petiole inorganic phosphorus concentration and actual phosphorus fertilizer application rate at different emergence times in Chayouzhong Banner under the petiole diagnostic phosphorus fertilizer precision recommendation model, and Table 17 shows the total fertilizer application rate; Table 12 shows the petiole inorganic phosphorus concentration and actual phosphorus fertilizer application rate at different emergence times in Wuchuan County under the petiole diagnostic phosphorus fertilizer precision recommendation model, and Table 17 shows the total fertilizer application rate.

[0166] Table 11. Inorganic phosphorus concentration in petioles and actual phosphate fertilizer application at different emergence times in Chayouzhong Banner.

[0167]

[0168]

[0169] Table 12. Inorganic phosphorus concentration in petioles and actual phosphate fertilizer application at different emergence times in Wuchuan County.

[0170]

[0171] (2) In 2024, in Chayouzhong Banner and Wuchuan County, major potato-producing areas on the northern slope of the Yinshan Mountains, four models were established: a phased reduction model for phosphate fertilizer application, a precise recommendation model for phosphate fertilizer based on petiole and pedicel diagnosis (the precise recommendation model for phosphate fertilizer protected by this invention), a 10wt.% reduction model for phosphate fertilizer diagnosis (the basal fertilizer application rate is the same as that of the precise recommendation model for phosphate fertilizer based on petiole and pedicel diagnosis, and 10wt.% phosphate fertilizer is reduced based on the application rate of the precise recommendation model for phosphate fertilizer based on petiole and pedicel diagnosis during topdressing), and a 10wt.% increase model for phosphate fertilizer diagnosis (the basal fertilizer application rate is the same as that of the precise recommendation model for phosphate fertilizer based on petiole and pedicel diagnosis, and 10wt.% phosphate fertilizer is increased based on the application rate of the precise recommendation model for phosphate fertilizer based on petiole and pedicel diagnosis during topdressing). Except for the phosphate fertilizer application method, the other agricultural management practices remained consistent across the four models. The application rates and methods of nitrogen and potassium fertilizers were the same, and the other agricultural management practices remained consistent with those of 2023. The phased application pattern of phosphorus fertilizer reduction is the final total amount of phosphorus fertilizer applied under the precise recommendation pattern of phosphorus fertilizer based on petiole and pedicel diagnosis in 2023. The application rate is 20 wt.% for basal fertilizer, 20 wt.% for seedling stage, 15 wt.% for early tuber formation, 15 wt.% for late tuber formation, 10 wt.% for early tuber enlargement, 10 wt.% for late tuber enlargement, and 10 wt.% for starch accumulation. The total amount of fertilizer applied under the phased application pattern of phosphorus fertilizer reduction is shown in Table 15.

[0172] Based on the diagnosis of petiole and pedicel, the precise recommended mode for phosphate fertilizer application is 36 kg / hm² of basal phosphate fertilizer. 2 Subsequently, inorganic phosphorus concentrations were collected from the petioles of the fourth leaf from the top and the pedicels of the potato main stem at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after potato emergence, as per step 1) in Example 2, to determine the nutrient deficiency of the potato, as per step 2) in Example 2. Then, timely application of phosphate fertilizer was recommended, as per step 3) in Example 2. The total phosphate fertilizer application rate for the precise phosphate fertilizer recommendation model based on petiole and pedicel diagnosis was 36 kg / hm² as basal phosphate fertilizer. 2 The total recommended application rate is added at 12, 22, 31, 38, 46, 54, 63, 72, and 82 days after emergence. Table 13 shows the inorganic phosphorus concentration in petioles and pedicels and the actual phosphorus fertilizer application rate at different emergence times in Chayouzhong Banner, and Table 17 shows the total fertilizer application rate. Table 15 shows the inorganic phosphorus concentration in petioles and pedicels and the actual phosphorus fertilizer application rate at different emergence times in Wuchuan County, and Table 17 shows the total fertilizer application rate.

[0173] The actual phosphate fertilizer application rates for the 10wt.% reduction and 10wt.% increase phosphate fertilizer application rates in Chayouzhong Banner are shown in Table 14; the actual phosphate fertilizer application rates for the 10wt.% reduction and 10wt.% increase phosphate fertilizer application rates in Wuchuan County are shown in Table 16.

[0174] Table 13. Precise Phosphate Fertilizer Recommendation Model Based on Leaf Petiole and Flower Petiole Diagnosis in Chayouzhong Banner: Inorganic Phosphate Concentration in Leaf Petiole and Flower Petiole, and Actual Phosphate Fertilizer Application.

[0175]

[0176]

[0177] Table 14 Actual Phosphate Fertilizer Application Rates in Chayouzhong Banner under the Diagnostic Model of Reduced Application of 10 wt.% and Increased Application of 10 wt.% Phosphate Fertilizer in Chayouzhong Banner

[0178]

[0179] Table 15. Precise Phosphate Fertilizer Recommendation Model Based on Petiole and Paeoniae Diagnosis in Wuchuan County: Inorganic Phosphate Concentration in Petioles and Paeoniae, and Actual Phosphate Fertilizer Application.

[0180]

[0181] Table 16 Actual Phosphate Fertilizer Application Rates in Wuchuan County under the Diagnostic Models of Reduced and Increased Application of 10wt.% Phosphate Fertilizer.

[0182]

[0183] Table 17 shows a comparison of the yield and partial productivity of phosphate fertilizer under different application modes in each experimental group in 2023 and 2024.

[0184] Table 17 Comparison of potato phosphate fertilizer yield and phosphate fertilizer partial productivity under different application modes

[0185]

[0186]

[0187] Note: ① Lowercase letters after the data in the table indicate that the differences between different patterns reach the 5% significance level; ② Significance comparisons are limited to comparisons of different patterns in the same region within the same year.

[0188] Table 17 shows the potato yield, phosphate fertilizer application, and phosphate fertilizer partial productivity data for 2023. Compared to the traditional farmer-led model, the phased phosphate fertilizer application model, and the petiole-based diagnostic phosphate fertilizer precision recommendation model, the petiole-based combined with pedicel diagnostic phosphate fertilizer precision recommendation model significantly reduced total phosphate fertilizer application (average reductions of 38.5%, 16.4%, and 10.0%, respectively) and significantly increased phosphate fertilizer partial productivity (average increases of 66.2%, 21.3%, and 11.4%, respectively), while maintaining the same yield. The marketable rate also increased by an average of 4.1, 1.3, and 1.2 percentage points, respectively. Therefore, the petiole-based combined with pedicel diagnostic phosphate fertilizer precision recommendation model is not only superior to the traditional farmer-led model and the currently promoted phased phosphate fertilizer application model, but also significantly superior to the single petiole diagnostic phosphate fertilizer precision recommendation model.

[0189] Table 17 shows the potato yield, phosphate fertilizer application, and phosphate fertilizer partial productivity obtained in 2024. It is evident that, compared to the petiole-and-flower-stalk diagnostic phosphate fertilizer precision recommendation model, directly applying the total phosphate fertilizer application obtained from the precise recommendation model to the staggered phosphate fertilizer application model would reduce potato yield. Similarly, the 10wt.% reduction in phosphate fertilizer application based on the petiole-and-flower-stalk diagnostic phosphate fertilizer precision recommendation model would also reduce potato yield. The 10wt.% increase in phosphate fertilizer application based on the petiole-and-flower-stalk diagnostic phosphate fertilizer precision recommendation model would increase phosphate fertilizer application without increasing potato yield. Compared to the staggered phosphate fertilizer application reduction model, the 10wt.% reduction model, and the 10wt.% increase model, the petiole-and-flower-stalk diagnostic phosphate fertilizer precision recommendation model achieves high yield and high marketability while minimizing phosphate fertilizer application, resulting in a higher phosphate fertilizer partial productivity. Therefore, the petiole-and-flower-stalk diagnostic phosphate fertilizer precision recommendation model achieves the synergistic goal of improving potato yield and phosphate fertilizer efficiency.

[0190] As can be seen from the above embodiments, the present invention provides a method for real-time diagnosis of phosphorus nutrient deficiency and precise recommendation of phosphate fertilizer in potatoes. By measuring the inorganic phosphorus concentration in the petiole of the fourth leaf from the top of the main stem before and after flowering, and measuring the inorganic phosphorus concentration in the pedicel after flowering, and using a portable RQflex2 reflectometer and phosphate test strips, it is possible to quickly, in real-time and conveniently measure the inorganic phosphorus concentration in potato petioles and pedicels in the field, thereby determining the phosphorus nutrient deficiency of potato plants and realizing real-time recommendation of phosphate fertilizer application, effectively solving the problem of poor timeliness in the diagnosis of potato phosphorus nutrient deficiency and phosphate fertilizer recommendation.

[0191] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for real-time diagnosis of phosphorus nutrient abundance or deficiency in potatoes, characterized in that, include: Determine the critical value of inorganic phosphorus concentration in petioles or pedicels based on the emergence time: When the emergence time is 10 ≤ Ed ≤ 29, ΔPL4c = 46.797e 0.0679Ed ; When the emergence time is 30 ≤ Ed ≤ 55, ΔPFc = -0.5786Ed 2 +35.182Ed +37.445; When the emergence time is 56≤Ed≤85, ΔPL4c=26354Ed -1.2609 ; Ed represents the emergence time when the inorganic phosphorus concentration in potato petioles or pedicels is detected, in days; ΔPL4c represents the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc represents the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L. PL4c represents the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc represents the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L. The inorganic phosphorus concentration in potato petioles was measured 10–29 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time. The inorganic phosphorus concentration in potato pedicels was measured 30–55 days after emergence. If PFc ≥ ΔPFc, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PFc < ΔPFc, the potato was deficient in phosphorus nutrition at the corresponding emergence time. The inorganic phosphorus concentration in potato petioles was measured 56–85 days after emergence. If PL4c ≥ ΔPL4c, the potato had sufficient phosphorus nutrition at the corresponding emergence time. If PL4c < ΔPL4c, the potato was deficient in phosphorus nutrition at the corresponding emergence time.

2. The method according to claim 1, characterized in that, The petiole includes the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem refers to the petiole of the fourth leaf from the top.

3. The method according to claim 1, characterized in that, The pedicel includes the pedicel formed from the main stem of the potato.

4. The method according to claim 1, characterized in that, The inorganic phosphorus concentration includes the concentration of phosphate.

5. A method for determining the application rate of phosphate fertilizer for potatoes, characterized in that, include: After diagnosing potato phosphorus deficiency using the method described in any one of claims 1 to 4, the amount of phosphate fertilizer to be applied is determined by combining the formula with the petiole inorganic phosphorus concentration test value and the petiole inorganic phosphorus concentration critical value, or with the pedicel inorganic phosphorus concentration test value and the pedicel inorganic phosphorus concentration critical value: When the emergence time is 10 ≤ Ed ≤ 29, Pr = (ΔPL4c - PL4c) × (0.348e 0.013Ed ); When the emergence time is 30≤Ed≤55, Pr=(ΔPFc-PFc)×(0.5224Ln(Ed)-1.4019); When the emergence time is 56≤Ed≤85, Pr=(ΔPL4c-PL4c)×(0.348e 0.013Ed ); Wherein, Ed is the emergence time when the inorganic phosphorus concentration in petioles or pedicels is detected, in days; ΔPL4c is the critical value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; ΔPFc is the critical value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; PL4c is the measured value of inorganic phosphorus concentration in petioles at the corresponding emergence time, in mg / L; PFc is the measured value of inorganic phosphorus concentration in pedicels at the corresponding emergence time, in mg / L; and Pr is the amount of phosphate fertilizer applied, in kg / hm². 2 .

6. The method according to claim 5, characterized in that, The petiole includes the petiole of the fourth leaf from the top of the potato main stem; the petiole of the fourth leaf from the top of the potato main stem is the petiole of the fourth leaf from the top.

7. The method according to claim 5, characterized in that, The pedicel includes the pedicel formed from the main stem of the potato.

8. The method according to claim 5, characterized in that, The amount of phosphate fertilizer applied is the amount of P2O5 applied.

9. The application of the method according to any one of claims 1 to 4 or the method according to any one of claims 5 to 8 in potato fertilization.

10. The application according to claim 9, characterized in that, The applications include: improving phosphate fertilizer utilization efficiency and / or increasing potato yield.

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