Method for precisely applying selenium to oilseed rape leaf surfaces based on dynamic regulation and control in growth period, enriching selenium, reducing cadmium and increasing yield

Abstract

The invention belongs to the technical field of modern agricultural precise planting and plant nutrition regulation and control. The invention provides a method for precisely applying selenium to oilseed rape leaf surfaces based on dynamic regulation and control in a growth period, enriching selenium, reducing cadmium and increasing yield. A sodium selenite solution is sprayed to the leaf surfaces in the key growth period of oilseed rape. The method can effectively improve the selenium content of each part of the oilseed rape, reduce the cadmium content of grains and guarantee the yield, is suitable for safe production of oilseed rape replanting in medium-light cadmium-polluted rice fields in the south of China, can be widely applied to standardized production of selenium-rich oilseed rape in main winter oilseed rape producing areas in the Yangtze River basin, and has wide application prospects. The method has important practical significance in improving agricultural quality and efficiency, guaranteeing food safety and promoting income increase of farmers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of modern agricultural precision planting and plant nutrition regulation technology, and particularly relates to a rapeseed foliar precise selenium application selenium-enrichment cadmium-reduction yield-increasing method based on dynamic regulation in growth periods. BACKGROUND

[0002] Selenium is an essential trace element for human body, and as a core component of important antioxidant enzymes such as glutathione peroxidase, it has important physiological functions such as antioxidant, immune enhancement, and prevention of Keshan disease and Kashin-Beck disease.

[0003] Rapeseed is one of the main oil crops in China, and has strong selenium enrichment capacity and cadmium tolerance. Improving the selenium content and reducing the cadmium content of rapeseed through agronomic measures is of great significance for improving human health.

[0004] In the prior art, the research on the influence of foliar selenium application on crops has the following deficiencies: 1. Most of the researches only focus on the influence of a single selenium application concentration or frequency, and lack systematic concentration and frequency combination research; 2. The influence mechanism of selenium application on the cadmium content of crops is not clear, especially the differential influence of different selenium application periods and methods on the cadmium content of different parts of rapeseed is insufficient; 3. The existing technology often only focuses on a single index of selenium content improvement or cadmium content reduction, and lacks systematic research on the synergistic improvement of yield and quality.

[0005] Therefore, it has good application prospect to research and develop a foliar selenium application method which can effectively improve the selenium content of different parts of rapeseed, reduce the cadmium content of seeds, and ensure the yield. SUMMARY

[0006] The present application aims to provide a rapeseed foliar precise selenium application selenium-enrichment cadmium-reduction yield-increasing method based on dynamic regulation in growth periods to overcome the problems of unstable selenium and cadmium regulation effect and uncertain influence on yield in the prior art.

[0007] In order to achieve the above-mentioned application purpose, the present application provides the following technical scheme:

[0008] The present application provides a rapeseed foliar precise selenium application selenium-enrichment cadmium-reduction yield-increasing method based on dynamic regulation in growth periods, which sprays sodium selenite solution on the leaves of rapeseed in the key growth period.

[0009] As a preferred, the concentration of the sodium selenite solution is 100-300 mg / L, and the spraying amount of the sodium selenite solution is 400-500 L / hm 2 .

[0010] As a preferred, the key growth period is one or several of the seedling stage, the bud stage and the initial flowering stage.

[0011] As preferred, the critical growth periods are the seedling stage, the squaring stage and the initial flowering stage.

[0012] As preferred, the interval between spraying the sodium selenite solution in the seedling stage and the squaring stage is 10-20 days, and the interval between spraying the sodium selenite solution in the squaring stage and the initial flowering stage is 10-20 days, and corresponds to the natural occurrence time of the seedling stage, the squaring stage and the initial flowering stage of the oilseed rape.

[0013] As preferred, the variety of the oilseed rape is "Ganliangyou No. 3".

[0014] As preferred, the soil amendment is used in combination with spraying the sodium selenite solution on the leaves of the oilseed rape in the critical growth periods.

[0015] As preferred, the soil amendment is biochar, lime or organic fertilizer.

[0016] As preferred, the biochar is cow dung biochar, the lime is slaked lime, and the organic fertilizer is composed of chicken manure and cow dung, and the mass ratio of the chicken manure to the cow dung is 2-4:1.

[0017] As preferred, when the soil amendment is biochar, the added amount is 1000 kg / hm 2 ;

[0018] When the soil amendment is lime, the added amount is 1500 kg / hm 2 ;

[0019] When the soil amendment is organic fertilizer, the added amount is 2000 kg / hm 2 .

[0020] The beneficial effects of the present application include the following points:

[0021] 1) The method of the present application can synergistically regulate the selenium and cadmium content distribution of each tissue of the oilseed rape and improve the yield of the oilseed rape by accurately applying selenium on the leaves of the oilseed rape in the critical growth periods.

[0022] 2) The method of the present application based on the dynamic regulation of the growth periods and the accurate application of selenium on the leaves of the oilseed rape is suitable for the safe production of the oilseed rape in the medium and light cadmium-polluted paddy fields in southern China, and can be widely applied to the standardized production of the selenium-rich oilseed rape in the main production areas of winter oilseed rape in the Yangtze River Basin, and has important practical significance for realizing agricultural quality improvement and efficiency increase, ensuring food safety and promoting farmers' income increase.

[0023] 3) The method of the present application can reduce the selenium residue in the soil, significantly reduce the cadmium content of the oilseed rape seeds, and improve the safety of agricultural products.

[0024] 4) The method for precisely applying selenium to rapeseed leaves to enrich selenium and reduce cadmium and increase yield based on dynamic regulation of the growth period described in the present invention only requires 1 to 3 sprayings to achieve the ideal effect, reduces labor costs, can be implemented using conventional spray equipment, and the cost per mu increases by no more than 20 yuan. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a bar graph showing the effects of different selenium application frequencies on selenium content, cadmium content, and yield in different parts of rapeseed in Example 1. A shows the effects of different selenium application frequencies on selenium and cadmium content in rapeseed roots, stems, and leaves; B shows the effects of different selenium application frequencies on selenium and cadmium content in rapeseed; and C shows the effects of different selenium application frequencies on rapeseed yield.

[0026] Figure 2 This is a bar graph showing the effects of different selenium concentrations on selenium content, cadmium content, and yield in different parts of rapeseed in Example 2. A shows the effects of different selenium concentrations on selenium and cadmium content in rapeseed roots, stems, and leaves; B shows the effects of different selenium concentrations on selenium and cadmium content in rapeseed; and C shows the effects of different selenium concentrations on rapeseed yield.

[0027] Figure 3 This is a bar graph showing the effects of different selenium application time intervals on selenium content, cadmium content, and yield in different parts of rapeseed in Example 3. A shows the effects of different selenium application time intervals on selenium and cadmium content in rapeseed roots, stems, and leaves; B shows the effects of different selenium application time intervals on selenium and cadmium content in rapeseed; and C shows the effects of different selenium application time intervals on rapeseed yield.

[0028] Figure 4 This is a bar graph showing the effects of selenium application combined with different soil amendments on selenium content, cadmium content, and yield in different parts of rapeseed in Example 4. A shows the effects of different soil amendments on the selenium and cadmium content in rapeseed roots, stems, and leaves; B shows the effects of different soil amendments on the selenium and cadmium content in rapeseed; and C shows the effects of different soil amendments on rapeseed yield. DETAILED DESCRIPTION

[0029] The present invention provides a method for precisely applying selenium to rapeseed leaves to enrich the leaves and reduce cadmium and increase yield based on dynamic regulation of the growth period, wherein a sodium selenite solution is sprayed on the leaves of the rapeseed during the critical growth period.

[0030] In the present invention, the concentration of the sodium selenite solution is preferably 100-300 mg / L, more preferably 150-250 mg / L, more preferably 200 mg / L, and the spraying amount of the sodium selenite solution is preferably 400-500 L / hm2. 2 , more preferably 440 to 460 L / hm 2 , more preferably 450L / hm 2 .

[0031] In the present application, the critical growth period is preferably one or several of the seedling stage, the squaring stage and the initial flowering stage.

[0032] In the present application, the critical growth period is preferably the seedling stage, the squaring stage and the initial flowering stage.

[0033] In the present application, the interval between the seedling stage and the squaring stage for spraying the sodium selenite solution is preferably 10-20 days, and more preferably 15 days; the interval between the squaring stage and the initial flowering stage for spraying the sodium selenite solution is 10-20 days, and more preferably 15 days; and the intervals correspond to the natural occurrence time of the seedling stage, the squaring stage and the initial flowering stage of the oilseed rape.

[0034] In the present application, the variety of the oilseed rape is preferably "Ganliangyou No. 3".

[0035] In the present application, the spraying of the sodium selenite solution on the leaves of the oilseed rape at the critical growth period is preferably combined with a soil conditioner.

[0036] In the present application, the soil conditioner is preferably biochar, lime or organic fertilizer.

[0037] In the present application, the biochar is preferably cow dung biochar; the lime is preferably slaked lime; and the organic fertilizer is preferably composed of chicken manure and cow dung, and the mass ratio of the chicken manure to the cow dung is preferably 2-4:1, and more preferably 3:1.

[0038] In the present application, the cow dung biochar can relieve the soil acidity of the oilseed rape, mineralize the organic carbon and promote the growth of the oilseed rape.

[0039] The slaked lime can effectively increase the soil pH value, increase the contents of soil available nitrogen, exchangeable calcium and magnesium, and thus increase the yield of the oilseed rape and promote the absorption of nitrogen, phosphorus and potassium nutrients by the oilseed rape.

[0040] The chicken manure and the cow dung can significantly increase the soil organic matter content, soil urease and phosphatase activities, and thus increase the chlorophyll content and the yield of the oilseed rape.

[0041] In the present application, when the soil conditioner is biochar, the addition amount thereof is preferably 1000 kg / hm 2 ;

[0042] When the soil conditioner is lime, the addition amount thereof is preferably 1500 kg / hm 2 ;

[0043] When the soil conditioner is organic fertilizer, the addition amount thereof is preferably 2000 kg / hm 2 .

[0044] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0045] Example 1

[0046] This example is used to illustrate the effect of the number of times of spraying sodium selenite solution at different growth stages of rapeseed on the selenium and cadmium contents and yield of rapeseed.

[0047] (1) Test conditions

[0048] 1. Variety selection and seed treatment: The rapeseed variety used for the test was “Gan Liangyou 3”, which was provided by Yichun Academy of Sciences (formerly Yichun Agricultural Science Research Institute).

[0049] 2. Field preparation: The previous crop in the experimental field was rice, and the soil type was clay loam. The basic physical and chemical properties of the soil were as follows: pH 5.11, organic matter content 24.10 g / kg, mineral nitrogen content 112.00 g / kg, available phosphorus content 79.30 g / kg, available potassium content 88.00 mg / kg, selenium content 0.24 mg / kg, and cadmium content 0.25 mg / kg. The experimental field was flat and had easy drainage and irrigation.

[0050] 3. Seeding management: Seeding on October 23, 2023, direct seeding rate 400g / 667m 2 The experimental plot is 8.0m long, 2.5m wide, and has a net area of ​​20m 2 , 27 short lines per cell, every 667m 2 The density is 38,600 plants; a 0.5m working walkway is set between the repeated plants, and protective rows are set around them. 2 Apply 40 kg of 45% Yishizhuang rapeseed fertilizer (purchased from Hubei Yishizhuang Agricultural Technology Co., Ltd.; 45% refers to the total nutrient content (N+P2O5+K2O) and the ratio (15-15-15)) as a base fertilizer. After sowing, spray 100 mL / 667 m2 of acetochlor (purchased from Hubei Chengfeng Chemical Co., Ltd.) with 30 kg of water to seal the grass.

[0051] (2) Experimental design:

[0052] Four treatment groups were set up, and the spraying rate was 450L / hm 2 , randomized block arrangement was used and repeated 3 times.

[0053] ①CSCK: spraying with clean water at the seedling stage, bud stage, and initial flowering stage, control group;

[0054] ②CS1: spray 300mg / L sodium selenite solution on the leaves at the seedling stage;

[0055] ③CS2: spray 300mg / L sodium selenite solution at the seedling and bud stages;

[0056] (4) CS3: spraying 300 mg / L sodium selenite solution at seedling stage, bud stage and initial flowering stage.

[0057] (Three) Test results

[0058] The column chart of the effects of different selenium application times on the selenium content, cadmium content and yield of different parts of rape is shown in Figure 1 , wherein A is the effect of different selenium application times on the selenium and cadmium content of rape roots, stems and leaves; B is the effect of different selenium application times on the selenium and cadmium content of rape seeds; and C is the effect of different selenium application times on the yield of rape.

[0059] It can be seen from Figure 1 that compared with the control group (CSCK), each selenium application treatment increased the selenium content of rape roots, stems, leaves and seeds. Among them, the increase of root selenium content was CS1 (370.59%) > CS3 (258.82%) > CS2 (252.94%); the increase of stem selenium content was CS3 (2000.00%) > CS1 (1533.33%) > CS2 (1500.00%); the increase of leaf selenium content was CS3 (2360.00%) > CS2 (1740.00%) > CS1 (1080.00%); and the increase of seed selenium content was CS3 (3213.33%) > CS2 (2473.33%) > CS1 (1693.33%).

[0060] Compared with CSCK, the cadmium content of each part was inconsistent, and generally showed a decreasing trend. Among them, the decrease of seed cadmium content was CS1 (44.44%) > CS2 (27.78%) > CS3 (22.22%), the cadmium content of leaves generally decreased by 17.65%, and the cadmium content of stems and roots had both increased and decreased, but the change was not significant.

[0061] Compared with CSCK, each selenium application treatment had little effect on the yield of rape (slightly decreased), and the decrease was CS3 (15.79%) > CS2 (3.51%) > CS1 (0.88%).

[0062] Example 2

[0063] This example is used to illustrate the effects of spraying different concentrations of sodium selenite solution at key growth stages of rape on the selenium and cadmium content and yield of rape.

[0064] (One) Test conditions

[0065] The same as in Example 1.

[0066] (Two) Test design

[0067] Four treatment groups were set, and the spraying amount was 450 L / hm 2, using randomized block design, repeated 3 times.

[0068] ①NDCK: spraying water on the leaves of the bud stage, control group;

[0069] ②ND1: spraying 100 mg / L sodium selenite solution on the leaves of the bud stage;

[0070] ③ND2: spraying 200 mg / L sodium selenite solution on the leaves of the bud stage;

[0071] ④ND3: spraying 300 mg / L sodium selenite solution on the leaves of the bud stage.

[0072] (Three) Test results

[0073] The column chart of the effects of different selenium application concentrations on the selenium content, cadmium content and yield of different parts of rape in this embodiment is shown in Figure 2 , wherein A is the effect of different selenium application concentrations on the selenium and cadmium contents of the roots, stems and leaves of rape; B is the effect of different selenium application concentrations on the selenium and cadmium contents of rape seeds; and C is the effect of different selenium application concentrations on the yield of rape.

[0074] It can be known from Figure 2 that: compared with the control group (NDCK), each selenium application treatment increased the selenium content of the roots, stems, leaves and seeds of rape. Among them, the increase amplitude of the root selenium content was ND2 (200%) > ND3 (166.67%) > ND1 (33.33%); the increase amplitude of the stem selenium content was ND3 (600%) > ND2 (500%) > ND1 (100%); the increase amplitude of the leaf selenium content was ND1 (1700%) > ND2 (850%) > ND3 (650%); and the increase amplitude of the seed selenium content was ND3 (557.14%) > ND2 (485.71%) > ND1 (100%);

[0075] Compared with NDCK, each selenium application treatment had no significant effect on the cadmium content of the roots and leaves of rape, although there was a difference in the cadmium content of the stems of rape, the overall effect was not great, and the cadmium content of the seeds of rape was reduced, and the reduction amplitude was ND3 (50%) > ND2 (37.5%) > ND1 (12.5%);

[0076] Compared with NDCK, each selenium application treatment increased the yield of rape, and the increase amplitude was ND2 (18.18%) > ND3 (14.35%) > ND1 (10.05%).

[0077] Example 3

[0078] This embodiment is used to illustrate the effects of the time interval of spraying sodium selenite solution on rape in the key growth period of rape on the selenium and cadmium contents and yield of rape.

[0079] (One) Test conditions

[0080] The same as example 1.

[0081] (ii) Test design

[0082] Four treatment groups were set, each of which was sprayed with 300 mg / L sodium selenite solution at the seedling stage, the bud stage and the beginning of flowering stage, and the spraying amount was 450 L / hm 2 , and the random block arrangement was adopted with 3 repetitions.

[0083] ① CSCK: the control group, which was sprayed with water at the seedling stage, the bud stage and the beginning of flowering stage;

[0084] ② T1: sprayed once at the seedling stage, sprayed the second time at the bud stage with a 10-day interval from the seedling stage, and sprayed the third time at the beginning of flowering stage with a 10-day interval from the bud stage;

[0085] ③ T2: sprayed once at the seedling stage, sprayed the second time at the bud stage with a 15-day interval from the seedling stage, and sprayed the third time at the beginning of flowering stage with a 15-day interval from the bud stage;

[0086] ④ T3: sprayed once at the seedling stage, sprayed the second time at the bud stage with a 20-day interval from the seedling stage, and sprayed the third time at the beginning of flowering stage with a 20-day interval from the bud stage.

[0087] (iii) Test results

[0088] The columnar chart of the effects of different selenium application time intervals on the selenium content, cadmium content and yield of rape is shown in Figure 3 , wherein A is the effect of different selenium application time intervals on the selenium and cadmium contents of rape roots, stems and leaves; B is the effect of different selenium application time intervals on the selenium and cadmium contents of rape seeds; and C is the effect of different selenium application time intervals on the yield of rape.

[0089] Compared with the control group (CSCK), each selenium application treatment increased the selenium content of rape roots, stems, leaves and seeds. Among them, the increase amplitude of root selenium content was T2 (280%) > T1 (250%) > T3 (220); the increase amplitude of stem selenium content was T1 (1800%) > T2 (1600%) > T3 (1400%); the increase amplitude of leaf selenium content was

[0090] T2 (2000%) > T1 (1800%) > T3 (1600%); and the increase amplitude of seed selenium content was T2 (2800%) > T1 (2500%) > T3 (2200%);

[0091] Compared with CSCK, each selenium application treatment had no significant effect on the cadmium content of rape roots and stems, and each selenium application treatment reduced the cadmium content of rape leaves and seeds. Among them, the decrease amplitude of leaf cadmium content was T2 (20%) > T1 (15%) > T3 (10%); and the decrease amplitude of seed cadmium content was T2 (20%) > T1 (15%) > T3 (10%).

[0092] Compared with CSCK, each selenium application treatment had no significant effect on the cadmium content of rape roots and stems, and each selenium application treatment reduced the cadmium content of rape leaves and seeds. Among them, the decrease amplitude of leaf cadmium content was T2 (20%) > T1 (15%) > T3 (10%); and the decrease amplitude of seed cadmium content was T2 (20%) > T1 (15%) > T3 (10%).

[0093] T1(18%) > T3(15%); the decrease range of grain cadmium content is T2(30%) > T1(25%) > T3(20%);

[0094] Compared with CSCK, each selenium treatment increased the yield of rapeseed, and the increase range is T2(5%) > T1(3%) > T3(1%).

[0095] Example 4

[0096] The preparation method of the cow dung biochar used in this example is as follows: uniformly spread the cow dung with a thickness of 8 cm on a bamboo screen, then expose it to sunlight, and turn it over 2 times a day until the water content is less than 5%; pour the dried cow dung into an air flow pulverizer and pulverize for 15 min, pass through a 60 mesh sieve, then perform carbonization reaction on the cow dung, the carbonization temperature is 600℃, the time is 4 hours, the rate of temperature rise to carbonization temperature is 10℃ / min, then cool to room temperature with the furnace, and obtain the cow dung biochar.

[0097] This example is used to illustrate the effect of spraying sodium selenite solution in the key growth period of rapeseed combined with soil improver on the selenium and cadmium content and yield of rapeseed.

[0098] (I) Test conditions

[0099] The same as example 1.

[0100] (II) Test design

[0101] Four treatment groups were set, each treatment sprayed 300mg / L sodium selenite solution at the bud stage of rapeseed, the spraying amount was 450L / hm 2 , and different amounts of soil improver were added, and the randomized block arrangement was used, and repeated 3 times.

[0102] ① CKM: no soil improver added, control group;

[0103] ② M1: add 1000kg / hm2 of cow dung biochar;

[0104] ③ M2: add 1500kg / hm2 of lime;

[0105] ④ M3: add 2000kg / hm2 of organic fertilizer (mixed by 1500kg of chicken manure and 500kg of cow dung).

[0106] (III) Test results

[0107] The column chart of the effect of selenium application combined with different soil improvers on the selenium content, cadmium content and yield of different parts of rapeseed in this example is as follows: Figure 4As shown in the figure, A is the effect of different soil amendments on the selenium and cadmium contents in rapeseed roots, stems and leaves; B is the effect of different soil amendments on the selenium and cadmium contents in rapeseed; C is the effect of different soil amendments on rapeseed yield.

[0108] Compared with the control group (CKM), all selenium treatments increased the selenium content in rapeseed roots, stems, leaves, and grains. Among them, the increase in selenium content in roots was M2 (230%) > M1 (200%) > M3 (180%); the increase in selenium content in stems was M1 (700%) > M2 (600%) > M3 (500%); the increase in selenium content in leaves was

[0109] M3 (1900%) > M1 (1700%) > M2 (1500%); the increase in grain selenium content was M1 (600%) >

[0110] M3 (550%) > M2 (500%);

[0111] Selenium application had no significant effect on the cadmium content in rapeseed roots and stems, but reduced the cadmium content in rapeseed leaves and seeds. The cadmium content in leaves decreased in the order of M2 (25%) > M1 (22%) > M3 (20%); the cadmium content in seeds decreased in the order of M2 (55%) > M1 (50%) > M3 (45%).

[0112] All selenium treatments increased rapeseed yield, with the increase rate being M1 (20%) > M3 (15%) > M2 (10%).

[0113] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for accurately applying selenium to rapeseed leaves to enrich selenium and reduce cadmium and increase yield based on dynamic regulation of the growth period, characterized in that: Spray sodium selenite solution on the leaves during the critical growth period of rapeseed.

2. The method according to claim 1, characterized in that The concentration of the sodium selenite solution is 100-300 mg / L, and the spraying amount of the sodium selenite solution is 400-500 L / hm2. 2 .

3. The method according to claim 1, characterized in that The key growth period is one or more periods among the seedling stage, bud stage and initial flowering stage.

4. The method according to claim 3, characterized in that The key growth periods are the seedling stage, bud stage and initial flowering stage.

5. The method according to claim 4, characterized in that The interval between spraying sodium selenite solution during the seedling and bud stages is 10 to 20 days, and the interval between spraying sodium selenite solution during the bud stage and early flowering stage is 10 to 20 days, which corresponds to the natural occurrence time of the seedling stage, bud stage and early flowering stage of rapeseed.

6. The method according to claim 4 or 5, characterized in that The rapeseed variety is "Gan Liangyou No. 3".

7. The method according to claim 1, characterized in that When spraying sodium selenite solution on the leaves of rapeseed during its critical growth period, use soil conditioners in combination.

8. The method according to claim 7, characterized in that The soil conditioner is biochar, lime or organic fertilizer.

9. The method according to claim 8, characterized in that The biochar is cow dung biochar; the lime is slaked lime; and the organic fertilizer is composed of chicken dung and cow dung, with the mass ratio of chicken dung to cow dung being 2 to 4:

1.

10. The method according to claim 8 or 9, characterized in that When the soil conditioner is biochar, its addition amount is 1000kg / hm 2 ; When the soil conditioner is lime, the addition amount is 1500kg / hm2 2 ; When the soil conditioner is organic fertilizer, the addition amount is 2000kg / hm 2 .

Images