Fertilizing method for realizing simultaneous enrichment of iron, zinc and selenium in corn kernels

Abstract

The invention discloses a fertilizing method for realizing simultaneous enrichment of iron, zinc and selenium in corn kernels. Relates to the technical field of corn nutrient fertilization. Comprising the following steps: 1) applying a zinc fertilizer and an iron fertilizer; humic acid; organic fertilizer or farmyard manure; a calcium-magnesium-sulfur-silicon fertilizer; spraying fertilizer on leaf surfaces by an unmanned aerial vehicle. According to the method, through reasonable fertilization, namely reasonable matching of large, medium and trace elements (carbon, nitrogen, phosphorus, iron, zinc, selenium and the like), the yield of corn kernels and the simultaneous improvement of iron, zinc and selenium in the kernels are achieved in calcareous calcareous alkaline soil, saline-alkali soil and light soil, and the contradiction between high yield and nutrient quality of the trace elements is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of maize nutritional fertilization, and more specifically, to a fertilization method for simultaneously enriching iron, zinc, and selenium in maize grains. Background Art

[0002] Soils lack trace elements (such as zinc, iron, selenium, etc.), mainly including calcareous soils with a relatively high calcium carbonate content, saline-alkali soils with a relatively high pH value, and soils with a relatively light texture, etc. Factors such as low soil organic matter content and drought and water shortage will all lead to low available iron, zinc, and selenium contents in the soil. In addition, the increase in crop yield levels takes away more iron, zinc, and selenium from the soil. Coupled with the excessive application of phosphorus causing phosphorus-zinc / iron antagonism, it leads to the imbalance of macro, medium, and trace element nutrients, further exacerbating the risk of deficiency of trace elements such as iron, zinc, and selenium in the soil and crops, and also restricting the large-scale increase in the yield per unit area of crops such as maize.

[0003] For a long time, the application of micronutrient fertilizers such as iron, zinc, and selenium has not been fully emphasized, and there is a lack of reasonable application technical regulations in agricultural production. Farmers often apply micronutrient fertilizers blindly, resulting in improper application, such as excessive or insufficient dosage, inappropriate application period, etc., thus affecting the application effect of micronutrient fertilizers and unable to fully exert the potential of micronutrient fertilizers.

[0004] In summary, there have long been the following problems in maize production: (1) The lack of available iron, zinc, selenium, and other trace elements in the soil is serious, and the imbalance of macro, medium, and trace element nutrients restricts the large-scale increase in maize yield per unit area; (2) The iron and zinc contents in grains are generally low, with average concentrations of only 23.0 and 20.1 mg / kg, lower than the recommended values of 27.1 and 22.1 mg / kg, and the selenium content in grains is generally low, far lower than the requirement of the generally specified selenium content in grains ≥ 150 μg / kg for selenium-rich maize production; (3) There is a contradiction between high-yield varieties and high-quality micronutrient nutrition in grains. It is difficult to breed a new high-yield, high-quality, and widely adaptable variety with high yield and the concentrations of iron, zinc, and selenium in grains meeting the requirements in (2) through breeding in the short term. The breeding approach has a long cycle and slow results.

[0005] In view of the above problems of the lack of available iron, zinc, and selenium in the soil, the mismatch with the application of macronutrient fertilizers such as nitrogen and phosphorus, the imbalance of macro, medium, and trace element nutrients, the generally low concentrations of iron, zinc, and selenium in grains, and the contradiction between high-yield varieties and high-quality micronutrient nutrition in grains, the existing technical solutions mainly include the following four:

[0006] (1) Applying iron fertilizer, zinc fertilizer or selenium fertilizer to the soil alone; (2) Spraying zinc fertilizer (traditional plant protection machinery includes small sprayers, manual backpack sprayers, etc.) or selenium fertilizer (sprayed by drones) on the leaves alone; (3) Applying zinc fertilizer or selenium fertilizer alone in combination of soil and leaves; Only one micronutrient is applied in the same growing season in these three schemes. (4) Spraying a multi-element mixed solution of iron, zinc and selenium on the leaves. The operating conditions are a small sprayer / kettle, and conventional leaf spraying parameters (concentration, water carrying capacity, spraying period and frequency, etc.) are adopted. The operating efficiency is low, the yield increase range is low (<10%), and the increase range of iron concentration in grains is low (<30%); Moreover, this technical scheme is only for experimental research and has not been widely applied yet.

[0007] Therefore, the existing schemes have a relatively low yield increase range for corn, usually about 5%, and it is very difficult to exceed 10%. Moreover, it is impossible to simultaneously and significantly increase the concentrations of the three elements of iron, zinc and selenium in the grains. The increase ranges of iron and zinc, especially the iron concentration, often cannot meet the requirement of the increase range ≥ 25% stipulated in the National Food Safety Standard General Rules for Nutrition Labels of Prepackaged Foods GB 28050-2011 for the claim term "increase" when comparing the content values of nutritional components of the same kind of food well-known to consumers.

[0008] Therefore, whether it is possible to provide a fertilization method that realizes the simultaneous enrichment of iron, zinc and selenium in corn grains through reasonable fertilization and overcomes the above technical deficiencies is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0009] In view of this, the present invention provides a fertilization method for realizing the simultaneous enrichment of iron, zinc and selenium in corn grains. Through reasonable fertilization, that is, the reasonable matching of macro, medium and micro elements (such as carbon, nitrogen, phosphorus, iron, zinc and selenium), on calcareous calcareous alkaline soil, saline-alkali land and soil with relatively light texture, the yield of corn grains and the three micro elements of iron, zinc and selenium in the grains, that is, the simultaneous improvement of the four, are realized, and the contradiction between high yield and high-quality trace element nutrition is solved.

[0010] In order to achieve the above object, the present invention adopts the following technical scheme:

[0011] A fertilization method for realizing the simultaneous enrichment of iron, zinc and selenium in corn grains, comprising the following steps:

[0012] (1) Soil fertilization:

[0013] 1) Applying zinc fertilizer and iron fertilizer;

[0014] 2) Applying base fertilizer: Applying compound / mixed fertilizer, formulated fertilizer or slow / controlled release fertilizer containing low phosphorus, with the requirement that N≥20%, P 2 O 5 ≤10%, K 2 O≤12%;

[0015] Humic acid;

[0016] Organic fertilizer or farmyard manure;

[0017] Calcium-magnesium-sulfur-silicon fertilizer;

[0018] (2) Foliar fertilization by drone:

[0019] Spray the ternary mixed foliar micronutrient fertilizer of iron, zinc and selenium at the large bell-mouth stage, tasseling-silking stage, early filling stage (i.e., grain formation stage R1-R2), milk-ripening stage R2-R3 and late filling stage R3-R5 of corn respectively.

[0020] Preferably: Step 1) is specifically to apply ZnSO 4 ·7H 2 O or ZnSO 4 ·H 2 O, and the base applications are 2-3 kg / mu and 1-2 kg / mu respectively, and they are incorporated into the soil by one-time plowing before sowing; Step 2) Low-phosphorus compound / mixed fertilizer, formula fertilizer or slow / controlled-release fertilizer: The compound fertilizer N-P 4 ·7H 2 O or FeSO 4 ·H 2 O, and the ratio of N-P 2 O 5 -K 2 O is 28-5-7, 30-5-10, 25-5-8, and the amount is 40-45 kg / mu;

[0021] Humic acid with an organic matter content of 85%: 20-30 kg / mu;

[0022] Organic fertilizer 50-100 kg / mu; or, farmyard manure 300-400 kg / mu;

[0023] Calcium-magnesium-sulfur-silicon fertilizer: 10-20 kg / mu.

[0024] Preferably: The ternary mixed foliar micronutrient fertilizer of iron, zinc and selenium includes: FeSO 4 ·7H 2 O with a w / v of 3.0-6.0%, ZnSO 4 7H 2 O with a w / v of 3.0-6.0%, Na 2 SeO 3 with a w / v of 0.1-0.2%, Tween 20 with a v / v of 0.01%; the balance is water; the amount of each fertilizer application is 5-10 L / mu, and the cumulative operation is 5 times.

[0025] Preferably: For each mu and each time, FeSO 4 ·7H 2 O and ZnSO 4 7H2 The dosage of O is 150 - 300 g, and that of Na 2 SeO 3 is 5 - 10 g.

[0026] Preferably: It also includes (3) topdressing: If "variegated seedlings" (i.e., zinc deficiency symptoms) appear during the maize seedling stage, zinc fertilizer should be topdressed in a timely manner. Use 1 - 2 kg of ZnSO 4 ·7H 2 O or ZnSO 4 ·H 2 O per mu, and combine with topdressing 10 kg / mu - 15 kg / mu of urea; In addition, in areas with integrated water and fertilizer conditions, during the jointing to silking stage, topdress 1 - 2 times, each time using 0.5 kg / mu of ZnSO 4 ·7H 2 O, or apply it simultaneously with urea or water-soluble fertilizer. When the irrigation water quality is alkaline, adjust the pH value to the range of 5.5 - 6.0 before adding ZnSO 4 ·7H 2 O.

[0027] Preferably: In step (2), unmanned aerial vehicle foliar fertilizer spraying: If zinc deficiency symptoms appear during the maize seedling stage, spray ZnSO 4 ·7H 2 O, spray 1 - 2 times, with an interval of 5 d - 7 d each time; If drought, waterlogging, or high temperature during the flowering period (i.e., adversity hazards) occur during the growth period and affect the normal growth and development of the plants, spray 1 - 2 times, with an interval of 5 d - 7 d each time.

[0028] The present invention also provides the application of any of the above fertilization methods in agricultural production.

[0029] Furthermore, the ternary mixed foliar micronutrient fertilizer can be mixed and sprayed with urea solution or other foliar fertilizers with better water solubility (such as amino acid-containing and humic acid water-soluble fertilizers), drought inhibitors, and pesticides and other non-alkaline substances. The spraying concentrations of iron, zinc, and selenium should preferably use the lower limits.

[0030] Through the above technical solutions, compared with the prior art, the present invention discloses a fertilization method for simultaneously enriching iron, zinc, and selenium in maize kernels. The technical effects achieved are that the present invention clarifies the appropriate dosages of soil iron and zinc micronutrient fertilizers, the fertilization schemes for combined application with nitrogen, phosphorus, and potassium fertilizers, as well as macronutrients and micronutrients such as humic acid, organic fertilizers, and calcium-magnesium-sulfur-silicon fertilizers, determines the key technical parameters such as the spraying concentration, water carrying capacity, spraying period, and number of times of foliar micronutrient fertilizers (especially iron and zinc) that are significantly different from traditional plant protection machinery (small sprayers or knapsack sprayers) and are suitable for modern unmanned aerial vehicle operations, and innovatively forms a comprehensive soil-foliar fertilization technology for simultaneously enriching iron, zinc, and selenium in maize kernels.

[0031] Large - area foliar fertilizer spraying operations are carried out by drones. Among them, the foliar fertilizer application parameters, the spraying concentrations of zinc sulfate heptahydrate, ferrous sulfate heptahydrate, and sodium selenite are much higher than those under the operating conditions of manual backpack sprayers / small sprayers and the current spraying concentrations of foliar zinc and iron fertilizers in the "one - spray - multi - promotion" drone operations for corn (in fact, the spraying concentration parameters of zinc and iron fertilizers in "one - spray - multi - promotion" are derived from the operating experience of manual backpack sprayers / small sprayers). The water consumption is greatly reduced, which can ensure the same effect as that under the operating conditions of manual backpack sprayers / small sprayers, greatly improve the operating efficiency (time - saving and labor - saving), and has strong operability. Therefore, it breaks through the inherent cognition of traditional foliar fertilizer concentration and water consumption, realizes the optimization, update, and iterative upgrade of technical parameters, promotes the integration of agricultural machinery and agronomy, and forms a precise, efficient, and multi - element spraying technology for foliar micronutrients by drones.

[0032] Using the method of systems engineering, a comprehensive regulation technology is formed from the soil to the leaves. There is a triple coordination among soil fertility improvement, stress resistance and yield increase, and the improvement of the trace element nutritional quality of corn grains. Previous technologies only focused on the improvement of the trace element nutritional quality of grains and did not take them all into account at the same time; it maximally exerts the effect of multi - element mutual benefit and coordination among elements, maximally reduces / alleviates the antagonistic effect among elements, and realizes the multi - element coordination of macronutrients, meso - nutrients, and micronutrients.

[0033] Finally, through the coordinated regulation of macronutrients, meso - nutrients, and micronutrients, on calcareous calcareous alkaline soils, saline - alkali soils, and soils with lighter textures, while the corn grain yield increases by more than 10%, the iron and zinc concentrations in the grains increase by more than 30%, and the selenium concentration in the grains ≥ 150 μg / kg (meeting the nutritional fortification target value and the requirements for the production of selenium - rich corn); ultimately, it realizes that corn (including common grain - using, forage / silage, and fresh - eating corn) is both high - yielding and of high nutritional quality, ensuring the quantity and nutritional safety of food / feed, and improving the trace element nutritional and health levels of animals / humans. Brief Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0035] Figure 1 The drawings are the flow schematic diagrams provided by the present invention.

[0036] Figure 2 The drawings are the on - site operation demonstration diagrams provided by the present invention.

[0037] Figure 3The accompanying drawing is a field diagram of the operation demonstration provided by the present invention.

[0038] Figure 4 The accompanying drawing is a field diagram of the operation demonstration provided by the present invention. Specific embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] The embodiments of the present invention disclose a fertilization method for simultaneously enriching iron, zinc, and selenium in corn kernels (for the process schematic diagram, see Figure 1 ). Raw materials not mentioned in the embodiments are all conventional raw materials;

[0041] For example: The organic fertilizer can be selected as follows: Shandong Jiali Fertilizer Technology Co., Ltd., biological organic fertilizer, specification: effective viable bacteria count ≥ 200 million / g, organic matter ≥ 60% (execution standard: NY884 - 2012, registration certificate number: microbial fertilizer (2018) approval number (3337));

[0042] Calcium - magnesium - sulfur - silicon fertilizer: Yantai Zhongde Group Co., Ltd., brand, active silicon calcium magnesium, execution standard: NY / T 3830 - 2021; containing CaO: 25.0%, MgO: 8.0%, S: 8.0%, SiO 2 : 10.0%, Zn: 0.7%, B: 0.5%, Mo: 0.05%, functional substances: 0.05%;

[0043] Commercially available products that can meet similar planting requirements can be used;

[0044] Operating conditions and requirements

[0045] (1) Before the first spraying, it is recommended to conduct a small - area pre - experiment to ensure that the corn leaves do not show poisoning phenomena;

[0046] (2) It is advisable to carry out the spraying before 9:00 in the morning or after 16:00 in the afternoon; if it rains within 3h - 4h after spraying, it needs to be re - sprayed when it is sunny, and the spraying concentration should be appropriately reduced;

[0047] (3) When choosing a drone for spraying, the quality requirements of the drone should comply with the regulations of NY / T 3213, and the operation quality of the drone should comply with the regulations of NY / T 4259.

[0048] Supporting technologies

[0049] Adopt the whole - amount return of corn straw to return the nutrients such as carbon, nitrogen, iron, zinc, potassium, and selenium enriched in the above - ground part of corn to the soil, and other management measures are the same as those in general fields.

[0050] Example 1

[0051] A fertilization method for simultaneously enriching iron, zinc, and selenium in corn kernels (the tested corn variety is Ludan 510) includes the following steps:

[0052] (1) Soil fertilization:

[0053] 1) Apply zinc fertilizer (ZnSO 4 ·7H 2 O or ZnSO 4 ·H 2 O, in this example, it is ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O or FeSO 4 ·H 2 O, in this example, it is FeSO 4 ·7H 2 O), the base applications are 2 - 3 (2 in this example) kg / mu and 1 - 2 (1 in this example) kg / mu respectively, and they are incorporated by one - time plowing before sowing (to improve the bioavailability of trace elements iron and zinc in the soil);

[0054] 2) Apply base fertilizer: The compound fertilizer N - P 2 O 5 -K 2 O ratio is 28 - 5 - 7 (to control nitrogen and reduce phosphorus, enhance the "nitrogen - zinc synergistic effect", alleviate the "phosphorus - zinc antagonistic effect", corn is applied with compound / mixed fertilizer, formulated fertilizer or slow - controlled release fertilizer with low phosphorus content, and the requirements are N≥20%, P 2 O 5 ≤10%, K 2 O≤12%), 40 kg / mu (sowing with seed fertilizer);

[0055] Humic acid (organic matter content 85%) 20 - 30 (20 in this example) kg / mu;

[0056] Organic fertilizer 50 - 100 (50 in this example) kg / mu; (can also be replaced with 300 - 400 kg / mu of farmyard manure)

[0057] Calcium - magnesium - sulfur - silicon fertilizer 10 - 20 (10 in this example) kg / mu. (To improve soil organic matter, improve physical, chemical, and biological properties, improve the bioavailability of soil nutrients, and overall improve soil fertility)

[0058] (2) Foliar fertilization with a drone (DJI drone T30):

[0059] At the large flare stage (V12), tasseling - silking stage (VT - R1), early filling stage (grain - building stage R1 - R2), milk - ripening stage (R2 - R3), and late filling stage (pre - dough stage R3 - R5) of maize, a ternary mixed foliar micro - fertilizer of iron, zinc, and selenium was sprayed; the amount of fertilizer solution used each time was 5 - 10 (5 in this example) L / acre, and the operation was carried out 5 times in total (the operation area was fixed at 900 m 2 , 30 m×30 m. If it is used for the production of fresh - eating maize, the spraying frequency before harvest is 4 - 5 times, with an interval of 7 d - 10 d each time);

[0060] To further optimize the technical solution: The ternary mixed foliar micro - fertilizer of iron, zinc, and selenium includes: 3.0 - 6.0 (4.0 in this example)% w / v of ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O), 3.0 - 6.0 (4.0 in this example)% w / v of zinc sulfate heptahydrate (ZnSO 4 7H 2 O), 0.1 - 0.2 (0.1 in this example)% w / v of sodium selenite (Na 2 SeO 3 ), 0.01% v / v of Tween 20; the balance is water. (The amount of water can be appropriately increased according to the situation)

[0061] To further optimize the technical solution: The amount of ferrous sulfate heptahydrate and zinc sulfate heptahydrate used per acre each time is 150 - 300 (200 in this example) g, and the amount of sodium selenite used is 5 - 10 (5 in this example) g.

[0062] To further optimize the technical solution: It also includes (3) Top - dressing: If "flower - white seedlings" (zinc - deficiency symptoms) appear in the seedling stage of maize, zinc fertilizer should be promptly top - dressed, using 1 - 2 kg of ZnSO 4 ·7H 2 O or ZnSO 4 ·H 2 O per acre, combined with top - dressing 10 kg / acre - 15 kg / acre of urea; in addition, in areas with integrated water and fertilizer conditions, during the jointing to silking stage, top - dress 1 - 2 times, using 0.5 kg / acre of ZnSO 4 ·7H 2 O each time, or apply it simultaneously with urea or water - soluble fertilizer. When the irrigation water quality is alkaline, the pH value needs to be adjusted to the range of 5.5 - 6.0 before adding ZnSO 4 ·7H 2 O.

[0063] To further optimize the technical solution: For foliar fertilization with drones: If zinc deficiency symptoms appear in the seedling stage of corn, spray ZnSO 4 ·7H 2 O, spray 1 - 2 times, with an interval of 5d - 7d between each spraying; If drought, waterlogging, high temperature during the flowering period, i.e., adversity hazards, affect the normal growth and development of the plants during the growth period, spray 1 - 2 times, with an interval of 5d - 7d between each spraying.

[0064] Comparative experiment 1

[0065] Control 1: Only apply compound fertilizer N - P 2 O 5 -K 2 O with a ratio of 15 - 15 - 15, 50 kg / mu; No foliar fertilization, and other management measures are the same as those in general fields.

[0066] Control 2: Only apply compound fertilizer N - P 2 O 5 -K 2 O with a ratio of 28 - 5 - 7, 40 kg / mu; No foliar fertilization, and other management measures are the same as those in general fields.

[0067] Control 3: Apply compound fertilizer N - P 2 O 5 -K 2 O with a ratio of 28 - 5 - 7, 40 kg / mu; Zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied as basal fertilizers at 2 kg / mu and 1 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; No foliar fertilization, and other management measures are the same as those in general fields.

[0068] Control 4: Apply compound fertilizer N - P 2 O 5 -K 2 O with a ratio of 28 - 5 - 7, 40 kg / mu; Zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied as basal fertilizers at 2 kg / mu and 1 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; Apply humic acid (organic matter content 85%) at 20 kg / mu as basal fertilizer; No foliar fertilization, and other management measures are the same as those in general fields.

[0069] Control 5: Apply compound fertilizer N - P 2 O 5 -K 2 O with a ratio of 28 - 5 - 7, 40 kg / mu; Zinc fertilizer (ZnSO 4·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) were applied at 2 kg / mu and 1 kg / mu respectively as basal fertilizers, and were incorporated into the soil by one-time ploughing before sowing; 20 kg / mu of humic acid (organic matter content 85%) and 50 kg / mu of bio-organic fertilizer were applied as basal fertilizers; there was no foliar fertilizer spraying, and other management measures were the same as those in general fields.

[0070] Control 6: The basal fertilizer was compound fertilizer N-P 2 O 5 -K 2 O with a ratio of 28-5-7, 40 kg / mu; zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) were applied at 2 kg / mu and 1 kg / mu respectively as basal fertilizers, and were incorporated into the soil by one-time ploughing before sowing; 20 kg / mu of humic acid (organic matter content 85%), 50 kg / mu of bio-organic fertilizer, and 10 kg / mu of calcium-magnesium-sulfur-silicon fertilizer were applied as basal fertilizers; there was no foliar fertilizer spraying, and other management measures were the same as those in general fields.

[0071] Control 7: The basal fertilizer was compound fertilizer N-P 2 O 5 -K 2 O with a ratio of 28-5-7, 40 kg / mu; zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) were applied at 2 kg / mu and 1 kg / mu respectively as basal fertilizers, and were incorporated into the soil by one-time ploughing before sowing; 20 kg / mu of humic acid (organic matter content 85%), 50 kg / mu of bio-organic fertilizer, and 10 kg / mu of calcium-magnesium-sulfur-silicon fertilizer were applied as basal fertilizers;

[0072] Drone foliar fertilizer spraying: In the early stage of corn filling (grain formation stage R1-R2), a DJI T30 drone was used to spray a ternary mixed foliar micronutrient fertilizer of iron, zinc and selenium, ferrous sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), zinc sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), sodium selenite (Na 2 SeO 3 , 0.1%, w / v). The amount of fertilizer solution used each time was 5 L / mu, and 0.01% (v / v) Tween 20 was added; the amount of ferrous sulfate heptahydrate and zinc sulfate heptahydrate used per mu each time was 200 g, and the amount of sodium selenite used was 5 g / mu; the operation was carried out 1 time in total, and the operation area was fixed at 900 m 2(30 m × 30 m); Other management measures are the same as those in general fields.

[0073] Control 8: The compound fertilizer N-P 2 O 5 -K 2 O ratio is 28-5-7, 40 kg / mu; Zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied at the base at 2 kg / mu and 1 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; 20 kg / mu of humic acid (organic matter content 85%) and 50 kg / mu of bio-organic fertilizer and 10 kg / mu of calcium-magnesium-sulfur-silicon fertilizer are applied as base fertilizers;

[0074] UAV foliar fertilization: At the early stage of corn filling (grain formation stage R1-R2) and milk ripening stage (R2-R3), a ternary mixed foliar micronutrient fertilizer of iron, zinc and selenium is sprayed with a DJI T30 UAV. Ferrous sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), zinc sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), sodium selenite (Na 2 SeO 3 , 0.1%, w / v). The amount of fertilizer solution used each time is 5 L / mu, and 0.01% (v / v) Tween 20 is added; The amount of ferrous sulfate heptahydrate and zinc sulfate heptahydrate used per mu each time is 200 g, and the amount of sodium selenite used is 5 g / mu; The operation is carried out 2 times in total, and the operation area is fixed at 900 m 2 (30 m × 30 m); Other management measures are the same as those in general fields.

[0075] Control 9: The compound fertilizer N-P 2 O 5 -K 2 O ratio is 28-5-7, 40 kg / mu; Zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied at the base at 2 kg / mu and 1 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; 20 kg / mu of humic acid (organic matter content 85%) and 50 kg / mu of bio-organic fertilizer and 10 kg / mu of calcium-magnesium-sulfur-silicon fertilizer are applied as base fertilizers;

[0076] Drone foliar fertilization: At the early stage of corn filling (grain formation stage R1 - R2), milk ripening stage (R2 - R3), and late filling stage (before dough stage R3 - R5), a ternary mixed foliar micronutrient fertilizer of iron, zinc, and selenium was sprayed using a DJI T30 drone. Ferrous sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), zinc sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), sodium selenite (Na 2 SeO 3 , 0.1%, w / v). The amount of fertilizer solution used each time was 5 L / acre, with 0.01% (v / v) Tween 20 added; the amount of ferrous sulfate heptahydrate and zinc sulfate heptahydrate used per acre each time was 200 g, and the amount of sodium selenite used was 5 g / acre; the operation was carried out 3 times in total, and the operation area was fixed at 900 m 2 (30 m × 30 m); other management measures were the same as those in general fields.

[0077] Control 10: The compound fertilizer N - P 2 O 5 -K 2 O ratio was 28 - 5 - 7, 40 kg / acre; zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) were base - applied at 2 kg / acre and 1 kg / acre respectively, and were incorporated into the soil by plowing once before sowing; 20 kg / acre of humic acid (organic matter content 85%) and 50 kg / acre of bio - organic fertilizer and 10 kg / acre of calcium - magnesium - sulfur - silicon fertilizer were used as base fertilizers;

[0078] Drone foliar fertilization: At the tasseling - silking stage (VT - R1), early filling stage (grain formation stage R1 - R2), milk ripening stage (R2 - R3), and late filling stage (before dough stage R3 - R5) of corn, a ternary mixed foliar micronutrient fertilizer of iron, zinc, and selenium was sprayed using a DJI T30 drone. Ferrous sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), zinc sulfate heptahydrate (ZnSO 4 7H 2 O, 4.0%, w / v), sodium selenite (Na 2 SeO 3 , 0.1%, w / v). The amount of fertilizer solution used each time was 5 L / acre, with 0.01% (v / v) Tween 20 added; the amount of ferrous sulfate heptahydrate and zinc sulfate heptahydrate used per acre each time was 200 g, and the amount of sodium selenite used was 5 g / acre; the operation was carried out 4 times in total, and the operation area was fixed at 900 m 2 (30 m × 30 m); other management measures were the same as those in general fields.

[0079] During the experiment, some operation pictures can be seen in Figure 2 ; After harvest, the maize grain yield and the concentrations of iron, zinc and selenium in the grains are shown in Table 1 below:

[0080] Table 1 Effects of different fertilization treatments on maize grain yield and the concentrations of iron, zinc and selenium in the grains (Shandong)

[0081]

[0082] The experimental results show that: for the soil fertilization treatment only (Control 1 - 6), the wheat yield increase ranges from 2.5% to 9.9%, which is lower than 10%. On the basis of the optimal soil fertilization, i.e., Control 6, with the increase in the number of drone foliar micronutrient sprays (Control 7 - 10 and the present invention), the yield gradually increases. In the case of the embodiments of the present invention, the maize yield and the concentrations of iron, zinc and selenium in the grains all reach the maximum values, with increases of 15.0%, 78.6%, 197.9% and 771.7% respectively compared with Control 1, and the selenium concentration exceeds 150 μg / kg. Therefore, the present invention has good progressiveness.

[0083] Example 2

[0084] A fertilization method for simultaneously enriching iron, zinc and selenium in maize (the tested maize variety is Zheng Huang Nuo 2) grains, comprising the following steps:

[0085] (1) Soil fertilization:

[0086] 1) Apply zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O), with the base applications being 3 kg / mu and 2 kg / mu respectively, and incorporate them into the soil by one-time ploughing before sowing;

[0087] 2) Apply basal fertilizer: The compound slow-release fertilizer N-P 2 O 5 -K 2 O has a ratio of 30 - 5 - 10, 40 kg / mu (sowing with the fertilizer);

[0088] Humic acid (organic matter content 85%) 30 kg / mu;

[0089] Organic fertilizer 100 kg / mu;

[0090] Calcium-magnesium-sulfur-silicon fertilizer 20 kg / mu;

[0091] (2) Drone (DJI drone T30) foliar fertilization:

[0092] At the large bell-mouth stage (V12), tasseling-silking stage (VT-R1), early filling stage (grain formation stage R1-R2), and mid-filling stage (R2-R3) of corn, a ternary mixed foliar micro-fertilizer of iron, zinc, and selenium was sprayed; the amount of fertilizer solution used each time was 5 L / mu, and the operation was carried out 4 times in total (the operation area was fixed at 1320 m 2 , 44 m × 30 m);

[0093] To further optimize the technical solution: The ternary mixed foliar micro-fertilizer of iron, zinc, and selenium includes: ferrous sulfate heptahydrate (ZnSO 4 7H 2 O) at 4.0% w / v, zinc sulfate heptahydrate (ZnSO 4 7H 2 O) at 4.0% w / v, sodium selenite (Na 2 SeO 3 ) at 0.2% w / v, and Tween 20 at 0.01% v / v;

[0094] To further optimize the technical solution: The dosage of ferrous sulfate heptahydrate and zinc sulfate heptahydrate per mu each time is 200 g, and the dosage of sodium selenite is 10 g.

[0095] Comparative Experiment 2

[0096] Control 1: Only basal fertilizer was applied, and the basal fertilizer was only the Stanley triple superphosphate compound slow-release fertilizer with an N-P 2 O 5 -K 2 O ratio of 26-14-14, 50 kg / mu, sowing with the seed fertilizer, no topdressing in the later stage; no foliar fertilizer spraying, and other management measures were the same as those in general fields.

[0097] Control 2: Control 1 + foliar fertilizer spraying by drone (DJI drone T30) in step (2) of Example 2.

[0098] Control 3: The difference from Example 2 was only that there was no step (2), that is, only soil fertilization, no foliar fertilizer spraying, and other management measures were the same as those in general fields.

[0099] Control 4: The difference from Example 2 was only that the drone foliar fertilizer spraying in step (2) was only carried out 3 times at the large bell-mouth stage, tasseling-silking stage, and early filling stage of corn.

[0100] At the R3 stage, fresh ear samples were taken to measure the average dry weight of grains per ear and the concentrations of iron, zinc, and selenium in the grains, as shown in Table 2 below. Some operation pictures during the experiment are shown in Figure 3 ;

[0101] Table 2 Effects of Different Fertilization Treatments on the Dry Weight of Grains and the Concentrations of Iron, Zinc, and Selenium in Grains of Fresh-Eating Yellow Waxy Corn (Shandong)

[0102]

[0103] The experimental results show that only the soil fertilization scheme of the present invention combined with the drone foliar micro-fertilizer spraying a sufficient number of times can ensure that the yield increases by more than 10% compared with the control 1, and the iron, zinc and selenium concentrations in the grains reach the maximum value, which are 38.3%, 63.3% and 2887.9% higher than the control respectively, and the selenium concentration exceeds 150μg / kg.

[0104] Example 3

[0105] A fertilization method for simultaneously enriching iron, zinc and selenium in corn (the tested corn variety is Heitiannuo 631) grains, comprising the following steps:

[0106] (1) Soil fertilization:

[0107] 1) Apply zinc fertilizer (ZnSO 4 7H 2 O) and iron fertilizer (FeSO 4 7H 2 O), basal fertilizer is 3kg / mu and 2kg / mu respectively, applied once before sowing;

[0108] 2) Application of base fertilizer: compound slow / controlled release fertilizer NP 2 O 5 -K 2 O ratio is 25-5-8, 45kg / mu (seed and fertilizer sown at the same time);

[0109] Humic acid (organic matter content 85%) 30kg / mu;

[0110] Organic fertilizer 100kg / mu;

[0111] Calcium-magnesium-sulfur-silicon fertilizer 20kg / mu;

[0112] (2) UAV (DJI UAV T50) foliar fertilizer spraying:

[0113] Iron, zinc and selenium mixed foliar fertilizer was sprayed at the corn tasseling stage (V12), tasseling-silking stage (VT-R1), early grain filling stage (grain formation stage R1-R2) and mid-grain filling stage (R2-R3). The fertilizer application rate was 10L / mu each time, and the total number of operations was 4 (the operation area was fixed at 2400m 2 , 60m×40m);

[0114] To further optimize the technical solution: the iron, zinc and selenium ternary mixed foliar micro-fertilizer includes: w / v 3.0% ferrous sulfate heptahydrate (ZnSO 4 7H 2 O), w / v 3.0% zinc sulfate heptahydrate (ZnSO 4 7H2 O), sodium selenite at 0.1% w / v (Na 2 SeO 3 ), and Tween 20 at 0.01% v / v;

[0115] To further optimize the technical solution: The dosage of ferrous sulfate heptahydrate and zinc sulfate heptahydrate per mu each time is 300 g, and the dosage of sodium selenite is 10 g.

[0116] Comparison experiment 3

[0117] Control 1: Only basal fertilizer is applied, and the basal fertilizer is only compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 O ratio is 26-12-10, 50 kg / mu, sowing with fertilizer, no topdressing in the later stage; no foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0118] Control 2: Only basal fertilizer is applied, and the basal fertilizer is only compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 O ratio is 25-5-8, 45 kg / mu, sowing with fertilizer, no topdressing in the later stage; no foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0119] Control 3: Basal fertilizer is applied with compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 O ratio is 25-5-8, 45 kg / mu, sowing with fertilizer, no topdressing in the later stage; zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied as basal fertilizers at 3 kg / mu and 2 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; no foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0120] Control 4: Basal fertilizer is applied with compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 O ratio is 25-5-8, 45 kg / mu, sowing with fertilizer, no topdressing in the later stage; zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied as basal fertilizers at 3 kg / mu and 2 kg / mu respectively, and are incorporated into the soil by plowing once before sowing; basal fertilizer is applied with humic acid (organic matter content 85%) at 30 kg / mu. No foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0121] Control 5: Applying compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 The O ratio is 25-5-8, 45 kg / mu. The seed fertilizer is sown together with the seeds, and no topdressing is applied later. Zinc fertilizer (ZnSO 4 ·7H 2 O) and iron fertilizer (FeSO 4 ·7H 2 O) are applied as basal fertilizers at 3 kg / mu and 2 kg / mu respectively, and are incorporated into the soil by one-time ploughing before sowing. 30 kg / mu of humic acid (organic matter content 85%) and 100 kg / mu of organic fertilizer are applied as basal fertilizers. There is no foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0122] Control 6: Different from Example 3 in that only step (1) soil fertilization is carried out, there is no foliar fertilizer spraying, and other management measures are the same as those in general fields.

[0123] At the R3 stage, fresh ear samples are taken to measure the fresh ear yield and the concentrations of iron, zinc and selenium in dry grains. See Table 3 below. Some operation pictures during the experiment are shown in Figure 4 ;

[0124] Table 3 Effects of different fertilization treatments on the fresh ear yield and the concentrations of iron, zinc and selenium in dry grains of fresh-eating black sweet waxy corn (Shandong)

[0125]

[0126] The experimental results show that: on the basis of the conventional soil fertilization control 1, by changing the ratio of the compound slow / controlled-release fertilizer N-P 2 O 5 -K 2 O (control 2), that is, controlling nitrogen and reducing phosphorus, the yield can be increased and the concentrations of iron, zinc and selenium in corn grains can be increased. On the basis of control 2, iron fertilizer and zinc fertilizer are additionally applied to the soil (control 3), then humic acid is additionally applied (control 4), further organic fertilizer is additionally applied (control 5), and finally calcium-magnesium-sulfur-silicon fertilizer is additionally applied (control 6), continuously improving the grain yield and the concentrations of iron, zinc and selenium in corn grains. The soil fertilization treatment has the best effect under the technical integration of controlling nitrogen and reducing phosphorus + iron and zinc fertilizers + humic acid + organic fertilizer + calcium-magnesium-sulfur-silicon, that is, control 6. On the basis of control 6 of the present invention, by adding the spraying of iron, zinc and selenium ternary mixed foliar micronutrient fertilizer by drone, the grain yield of corn and the concentrations of iron, zinc and selenium in grains are further improved, and the increases compared with control 1 reach 19.9%, 34.1%, 39.4% and 2514.5% respectively, and the selenium concentration in grains exceeds 150 μg / kg.

[0127] In summary:

[0128] (1) In soil fertilization, moderately control nitrogen and reduce phosphorus in compound (mixed) / formulated / slow / controlled-release fertilizers, involving specific ratios and dosage ranges of nitrogen, phosphorus, and potassium, to enhance the "nitrogen-zinc synergistic effect" and alleviate the "phosphorus-zinc antagonistic effect";

[0129] (2) Increase the application of trace elements in soil fertilization, including the simultaneous application of zinc, iron, and selenium. The application of these three elements can be added to compound (mixed) / formulated / slow / controlled-release fertilizers or applied separately. It involves the fertilization period, method, and dosage, and generally improves the bioavailability of these three trace elements in the soil;

[0130] (3) Increase the application of humic acid, organic fertilizers (farmyard manure, commercial / bio-organic fertilizers, etc.) and other soil conditioners (calcium-magnesium-sulfur-silicon fertilizers) in soil fertilization, involving fertilizer ratios and dosages, to improve the physical-chemical-biological properties of the soil;

[0131] (4) In foliar fertilization, use modern unmanned aerial vehicle (UAV) operations for spraying, and determine the key technical parameters such as the appropriate period, concentration, water-carrying capacity, and number of sprays for the one-element, two-element, or three-element mixed spraying of iron, zinc, and selenium by UAV on a large area. These technical parameters are significantly different from those of spraying using traditional plant protection machinery (including small sprayers, knapsack sprayers, etc.), forming a precise, efficient, and multi-element spraying technology for foliar micronutrients by UAV;

[0132] (5) The present invention is a comprehensive soil-foliar nutrient management method, which is an effective integration of key individual technologies at the crop-soil system level. The above four points are indispensable and cooperate with each other. Macronutrients, secondary nutrients, and micronutrients are precisely matched, morphologically compatible, and multi-element synergistic.

[0133] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0134] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fertilization method for achieving simultaneous enrichment of iron, zinc and selenium in corn kernels, characterized in that: The following steps are involved: (1) Soil fertilization: 1) Apply zinc fertilizer and iron fertilizer; 2) Application of base fertilizer: Apply low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer, with N ≥ 20%, P2O5 ≤ 10%, K2O ≤ 12%; Humic acid; Organic fertilizer or farmyard manure; Calcium-magnesium-sulfur-silicon fertilizer; (2) UAV foliar fertilizer spraying: Spray a foliar micro-fertilizer consisting of a mixture of iron, zinc and selenium on corn during the tasseling stage, the tasseling-silking stage, the early grain filling stage (R1-R2), the milky stage (R2-R3) and the late grain filling stage (R3-R5).

2. The fertilization method according to claim 1, characterized in that: Step 1) specifically applies ZnSO4·7H2O or ZnSO4·H2O, and FeSO4·7H2O or FeSO4·H2O, with the base application being 2-3kg / mu and 1-2kg / mu respectively, and the soil is ploughed and applied once before sowing; Step 2) Low-phosphorus compound / mixed fertilizer, formula fertilizer or slow-release fertilizer: compound fertilizer N-P2O5-K2O ratio is 28-5-7, 30-5-10, 25-5-8, 40-45 kg / mu; Organic matter content 85% humic acid: 20-30kg / mu; Organic fertilizer 50-100kg / mu; or farmyard manure 300-400kg / mu; Calcium-magnesium-sulfur-silicon fertilizer: 10-20kg / mu.

3. The fertilization method according to claim 2, characterized in that: The ternary mixed foliar micro-fertilizer of iron, zinc and selenium comprises: w / v 3.0-6.0% FeSO4·7H2O, w / v 3.0-6.0% ZnSO47H2O, w / v 0.1-0.2% Na2SeO3, v / v 0.01% Tween 20; the balance is water; the amount of fertilizer used each time is 5-10L / mu, and the operation is performed 5 times in total.

4. The fertilization method according to claim 3, characterized in that: The amount of FeSO4·7H2O and ZnSO47H2O used per mu each time is 150-300g, and the amount of Na2SeO3 used is 5-10g.

5. The fertilization method according to claim 4, characterized in that: It also includes (3) topdressing: If "white seedlings" appear in the corn seedling stage, which is a symptom of zinc deficiency, zinc fertilizer should be applied in time, with 1-2 kg of ZnSO4·7H2O or ZnSO4·H2O per mu, combined with 10 kg / mu-15 kg / mu of urea. In addition, in areas with integrated water and fertilizer conditions, topdressing should be done 1-2 times from jointing to silking, with 0.5 kg / mu of ZnSO4·7H2O each time, or it can be applied simultaneously with urea or water-soluble fertilizers. When the irrigation water quality is alkaline, the pH value needs to be adjusted to the range of 5.5-6.0 before adding ZnSO4·7H2O to the fertilizer solution.

6. The fertilization method according to claim 5, characterized in that: Step (2) UAV foliar fertilizer spraying: If corn shows symptoms of zinc deficiency in the seedling stage, spray ZnSO4·7H2O on the leaves 1 to 2 times, with an interval of 5 to 7 days between each spraying. If the plant encounters drought, waterlogging, high temperature during the flowering period, or other adverse conditions that affect its normal growth and development, spray 1 to 2 times, with an interval of 5 to 7 days between each spraying.

7. Application of the fertilization method according to any one of claims 1 to 6 in agricultural production.

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