A rice selenium-enriched cadmium-reducing foliar control agent and its application method

Abstract

The invention discloses a rice selenium-enriched cadmium-reducing foliar barrier and an application method thereof. The selenium-enriched cadmium-reducing foliar barrier is prepared by compounding husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds, wherein the mass ratio is 15%-20% of sodium silicate, 10%-15% of zinc sulfate, 20%-40% of selenium compounds, and the balance is husk wood vinegar. The selenium-enriched cadmium-reducing foliar barrier is sprayed at the tillering stage and the booting stage of rice respectively. Compared with the rice selenium-enriched cadmium-reducing foliar barrier sprayed with the same amount of clear water and other formulas, the selenium-enriched cadmium-reducing foliar barrier of the invention significantly reduces the cadmium content in brown rice and increases the selenium content in brown rice. The invention has the advantages of simple operation, easy acquisition of raw materials, and conversion of waste into treasure. Several barrier components cooperate with each other to jointly play the role of selenium-enriched cadmium-reducing in rice, and has a strong promotion and application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a rice selenium-enriched cadmium-reducing foliar control agent and an application method thereof. Background Art

[0002] Rice is an important global food resource, providing the main source of calories for more than 50% of the world's population. Rice requires a large number of elements such as nitrogen, phosphorus, and potassium during its growth, as well as trace elements such as silicon, magnesium, boron, and cadmium. Although these trace elements account for a small proportion of all the elements required for the rice growth cycle, they play an important role in the growth and development of rice.

[0003] Cadmium (Cd) is one of the most biologically toxic heavy metals and is currently the most common heavy metal pollution element in cultivated land. Rice is very easy to accumulate heavy metal cadmium and is the major cereal crop with the strongest ability to absorb cadmium. It also poses a potential threat to human health through the food chain. Rice has become the main source of heavy metal cadmium intake for the human body. Cadmium is a non-essential element for the human body and is toxic to humans, animals and plants. Long-term low-dose cadmium exposure caused by eating "cadmium rice" has the triple effects of carcinogenicity, teratogenicity and mutagenicity, which seriously threatens food production safety and human health.

[0004] In order to reduce the risk of cadmium pollution in rice to human health, my country's food safety standard (GB2762-2012) stipulates that the limit of cadmium in rice is 0.2 mg kg -1 .

[0005] Selenium is an essential trace nutrient for the human body. It has the functions of removing peroxides, preventing cell damage, delaying cell aging, anti-cancer, and preventing cardiovascular diseases. Selenium deficiency can cause a variety of diseases in the human body. 72% of the counties and cities in China have varying degrees of selenium deficiency in the soil, and people in these areas often have insufficient selenium intake. Even in some soils with high selenium content, the selenium content in the food produced is also low. Spraying selenium-containing foliar fertilizer is an effective way to produce selenium-rich rice. In cadmium-contaminated areas, the research and development of foliar fertilizer that takes into account both selenium-enriched rice and reducing the cadmium content of rice is of great significance to rice production. Studies have shown that selenium and cadmium have antagonistic effects, and selenium in the soil can inhibit the absorption of cadmium by rice roots.

[0006] Therefore, how to provide a foliar inhibitor that can enrich rice with selenium and reduce cadmium and its application method is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0007] The invention aims to overcome the disadvantages of the prior art and provides a rice selenium-enriched cadmium-reducing foliar barrier and an application method thereof. The selenium-enriched cadmium-reducing foliar barrier is prepared by compounding husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds, wherein the mass ratio is 15%-20% of sodium silicate, 10%-15% of zinc sulfate, 20%-40% of selenium compounds, and the balance is husk wood vinegar. The selenium-enriched cadmium-reducing foliar barrier is sprayed at the tillering stage and the booting stage of rice respectively. Compared with the rice selenium-enriched cadmium-reducing foliar barrier sprayed with the same amount of clear water and other formulas, the selenium-enriched cadmium-reducing foliar barrier of the invention significantly reduces the cadmium content in rice brown rice and increases the selenium content in rice brown rice. The invention has the advantages of simple operation, easy acquisition of raw materials, and transformation of waste into treasure. Several barrier components cooperate with each other to jointly play the role of rice selenium-enriched cadmium-reducing, and has a strong prospect for promotion and application.

[0008] In order to achieve the above technical effects, the following technical solutions are adopted:

[0009] A rice selenium-enriched cadmium-reducing foliar control agent comprises the following components:

[0010] Husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds;

[0011] The selenium compound is one or more of sodium selenite, sodium selenate and potassium selenate.

[0012] Further, the preparation method of the rice husk wood vinegar is:

[0013] In the drying stage, the temperature is 20-60°C, during which the rice is completely dried;

[0014] In the hulling stage, the husk is separated from the brown rice by a rice mill;

[0015] In the fermentation stage, the husks are piled up for fermentation, and the fermentation temperature is controlled at 70-150°C. During this process, the husks begin to decompose, and the gaseous wood vinegar components produced in this process are cooled and recovered by a condenser to form a wood vinegar stock solution;

[0016] Separation and refining: The wood vinegar stock solution is collected and stored in a sedimentation tank, and is separated and refined by standing for more than 3 months to obtain the entire wood vinegar stock solution.

[0017] Furthermore, the mass ratio of the rice husk wood vinegar, sodium silicate, zinc sulfate and selenium compound is:

[0018] Sodium silicate 15%-20%, zinc sulfate 10%-15%, selenium compound 20%-40%, and the balance is rice husk wood vinegar.

[0019] A method for applying a rice selenium-enriched cadmium-reducing foliar control agent comprises the following steps:

[0020] The sodium silicate, zinc sulfate and selenium compound in the rice selenium-enriched cadmium-reducing foliar control agent are dissolved in proportion in the husk wood vinegar solution, and the mixture is evenly mixed to obtain the foliar control agent, which is then diluted with a diluent and sprayed evenly on the rice leaves during the rice growth process.

[0021] Furthermore, the diluent of the foliar barrier agent is water.

[0022] Furthermore, the dilution multiple of the foliar barrier agent is 500-800 times.

[0023] Furthermore, the rice growth process is the tillering stage and / or the booting stage.

[0024] Furthermore, the dosage of the foliar barrier agent before dilution is 3-4 L / hectare.

[0025] Furthermore, the foliar barrier agent is sprayed before 10 am and after 4 pm on a sunny or cloudy day, the suitable temperature range is 15-30°C, and the spraying site is the rice leaf surface.

[0026] Furthermore, the foliar barrier agent is sprayed 1-3 times during the tillering stage and the booting stage.

[0027] The beneficial effects of the present invention are:

[0028] The invention discloses a rice selenium-enriched cadmium-reducing foliar barrier and an application method thereof. The selenium-enriched cadmium-reducing foliar barrier is prepared by compounding husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds, wherein the mass ratio is 15%-20% of sodium silicate, 10%-15% of zinc sulfate, 20%-40% of selenium compounds, and the balance is husk wood vinegar. The selenium-enriched cadmium-reducing foliar barrier is sprayed at the tillering stage and the booting stage of rice respectively. Compared with the rice selenium-enriched cadmium-reducing foliar barrier sprayed with the same amount of clean water and other formulas, the selenium-enriched cadmium-reducing foliar barrier of the invention significantly reduces the cadmium content in rice brown rice and increases the selenium content in rice brown rice. The invention has the advantages of simple operation, easy acquisition of raw materials, and transformation of waste into treasure. Several barrier components cooperate with each other to jointly play the role of rice selenium-enriched cadmium-reducing, and has a strong prospect for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in the following description are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0030] Figure 1 This is a diagram of the preparation process of the cadmium-reducing leaf surface control agent provided by an embodiment of the present invention;

[0031] Figure 2 This is a diagram of the application process of the cadmium-reducing foliar inhibitor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0035] Embodiment 1:

[0036] Comparison of the dissolution state of selenium-rich cadmium-reducing foliar inhibitors with and without husk wood vinegar:

[0037] 1. Dissolve 200g sodium silicate, 150g zinc sulfate and 400g sodium selenate in 250g rice husk wood vinegar:

[0038] With husk wood vinegar as the component, sodium silicate 20%, zinc sulfate 15%, sodium selenate 40% were added. Due to the color of husk wood vinegar itself (dark brown), no precipitation was observed in the solution system and on the surface. Microwave oscillation for 24 hours, after standing for 24 hours, no precipitation reaction was observed. After filtration, the filter paper surface was dark brown, and after weighing, the filter paper weight increased by 10.42g.

[0039] 2. Replace the husk wood vinegar with distilled water, that is, dissolve 200g of sodium silicate, 150g of zinc sulfate, and 400g of sodium selenate in 250g of distilled water:

[0040] When distilled water is used as a component, precipitation is easily generated after the system is mixed. After microwave vibration for 24 hours, most of the precipitation has not been eliminated after standing for 24 hours. This is because sodium silicate and zinc sulfate react in distilled water to form zinc silicate precipitation.

[0041] After filtering the microwave-oscillated system, the surface of the filter paper turned green-yellow, and the weight of the filter paper increased by 104.32 g.

[0042] The rice husk wood vinegar of the invention can make sodium silicate, zinc sulfate and sodium selenate coexist in the system, so that they can jointly and synergistically reduce the cadmium and enrich the selenium of rice in the subsequent spraying process.

[0043] Embodiment 2:

[0044] like Figure 1 As shown, 200 g of sodium silicate, 150 g of zinc sulfate, and 400 g of selenium compound (sodium selenate) are dissolved in 250 g of rice husk wood vinegar to obtain the selenium-rich cadmium-reducing foliar control agent, hereinafter referred to as this material.

[0045] Spraying period effect verification test: Field plot tests of late rice were carried out at three different periods: tillering period, heading period, and booting period. The test process is as follows:

[0046] like Figure 2 As shown, use a measuring cylinder to take 200 mL of selenium-rich cadmium-reducing foliar inhibitor, add clean water (i.e. 100 L of water) at a ratio of 1:500, and spray it on the rice with a back sprayer at a dosage of 3 L of cadmium-reducing foliar inhibitor stock solution per hectare according to the planned time. The control is sprayed with an equal amount of clean water.

[0047] Test location: Penghu Village, Zhushan Town, Yushui District, Xinyu City

[0048] Trial time: 2023 late rice season

[0049] Experimental setup: 1 plot per treatment, 4 replicates per treatment. The plot area is 15 square meters (i.e. 4.5 mL of cadmium-reducing foliar inhibitor stock solution per plot, i.e. 2250 mL of water diluted cadmium-reducing foliar inhibitor and sprayed, the control group is the same amount of clean water), 25 cm of space is left between plots, and no ridges are set. All plots are in the same field, and the growth environment is completely the same.

[0050] Experimental fields: total cadmium content in the soil was 0.57 mg / kg, pH was 5.43, effective cadmium content was 0.27 mg / kg, and the rice varieties were uniform and were the main cultivated varieties locally.

[0051] Experimental treatment 1: When the late rice is in the tillering stage, take 4.5 mL of this material, dilute it with 500 times of water, and spray it on the rice leaves using a manual backpack sprayer; the control is directly sprayed with an equal amount of clean water.

[0052] Experimental treatment 2: When rice is at heading stage, take 4.5 mL of this material, dilute it with 500 times of water, and spray it on rice leaves using a manual backpack sprayer; the control is directly sprayed with an equal amount of clean water.

[0053] Experimental treatment three: When the rice is in the booting stage, take 4.5 mL of this material, dilute it with 500 times of water, and spray it on the rice leaves using a manual backpack sprayer; the control is directly sprayed with an equal amount of clean water.

[0054] Experimental treatment 4: During the tillering stage and booting stage of rice, take 4.5 mL of this material, dilute it with 500 times of water, and spray it on the rice leaves using a manual backpack sprayer; the control is to directly spray an equal amount of clean water at the same time.

[0055] Sample collection: During the rice maturity period (early November), rice grains were collected and threshed.

[0056] The test results show that compared with spraying an equal amount of clean water, spraying the selenium-enriched cadmium-reducing foliar inhibitor of the present invention significantly reduced the cadmium content in brown rice and increased the selenium content in brown rice. Among them, spraying 4.5 mL each during the tillering stage and the booting stage had the most significant effect. Compared with spraying an equal amount of clean water during each period, the cadmium reduction effect was 75.68%, and the selenium-enriching effect was 7.0 times.

[0057]

[0058]

[0059] Compared with Example 2:

[0060] Comparative Example 1:

[0061] 350 g of zinc sulfate and 400 g of selenium compound (sodium selenate) were dissolved in 250 g of rice husk wood vinegar to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 1.

[0062] Comparative Example 2:

[0063] 350 g of sodium silicate and 400 g of selenium compound (sodium selenate) were dissolved in 250 g of rice husk wood vinegar to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 2.

[0064] Comparative Example 3:

[0065] Dissolve 200 g of sodium silicate and 150 g of zinc sulfate in 250 g of rice husk wood vinegar to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 3.

[0066] Comparative Example 4:

[0067] 200 g of sodium silicate, 150 g of zinc sulfate, and 400 g of a selenium compound (sodium selenate) were dissolved in 250 g of acetic acid to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 4.

[0068] Comparative Example 5:

[0069] Since sodium silicate and zinc sulfate cannot coexist in water, 325g of sodium silicate and 200g of selenium compound (sodium selenate) were taken and mixed evenly to obtain the selenium-rich cadmium-reducing foliar barrier a in Comparative Example 5; 275g of zinc sulfate and 200g of selenium compound (sodium selenate) were mixed evenly to obtain the selenium-rich cadmium-reducing foliar barrier b in Comparative Example 5; 4.5mL of selenium-rich cadmium-reducing foliar barrier a was taken with a measuring cylinder during the tillering period, and clean water (i.e. 2250mL of water) was added at a ratio of 1:500 and sprayed on the rice with a back sprayer. After an interval of 2 days, the mixture was sprayed with a sprayer. Take 4.5mL of selenium-rich cadmium-reducing foliar inhibitor b with a measuring cylinder, add clean water (i.e. 2250mL of water) at a ratio of 1:500, and spray it on the rice with a back sprayer. At the booting stage, take 4.5mL of selenium-rich cadmium-reducing foliar inhibitor a with a measuring cylinder, add clean water (i.e. 2250mL of water) at a ratio of 1:500, and spray it on the rice with a back sprayer. After an interval of 2 days, take 4.5mL of selenium-rich cadmium-reducing foliar inhibitor b with a measuring cylinder, add clean water (i.e. 2250mL of water) at a ratio of 1:500, and spray it on the rice with a back sprayer.

[0070] Comparative Example 6:

[0071] 400 g of selenium compound (sodium selenate) was dissolved in 600 g of rice husk wood vinegar to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 6.

[0072] Comparative Example 7:

[0073] Take 600 g of sodium silicate and 400 g of selenium compound (sodium selenate) to obtain the selenium-rich cadmium-reducing foliar inhibitor in Comparative Example 7.

[0074] Comparative Example 8:

[0075] Take 600 g of zinc sulfate and 400 g of a selenium compound (sodium selenate) to obtain the selenium-rich cadmium-reducing foliar control agent in Comparative Example 8.

[0076] Comparative Example 9:

[0077] Take 400 g of selenium compound (sodium selenate) to obtain the selenium-rich cadmium-reducing foliar inhibitor in Comparative Example 9.

[0078] Effect verification test during spraying period: The foliar control agents in comparative examples 1-9 were tested in late rice field plots at the tillering stage and the booting stage. The test process is as follows:

[0079] During the tillering stage, use a measuring cylinder to take each selenium-rich cadmium-reducing foliar inhibitor, add clean water (i.e. 2250 mL of water) at a ratio of 1:500, and spray it on the rice with a back sprayer. During the booting stage, use a measuring cylinder to take 4.5 mL of each selenium-rich cadmium-reducing foliar inhibitor, add clean water (i.e. 2250 mL of water) at a ratio of 1:500, and spray it on the rice with a back sprayer.

[0080] Test location: Penghu Village, Zhushan Town, Yushui District, Xinyu City

[0081] Trial time: 2023 late rice season

[0082] Experimental setup: The above comparative examples 1-9 were treated in one plot, and each treatment was repeated 4 times. The plot area was 15 square meters (i.e., 4.5 mL of each cadmium-reducing foliar barrier agent stock solution was applied to each plot, i.e., 2250 mL of water was used to dilute the cadmium-reducing foliar barrier agent and then sprayed, and the control group was sprayed with the same amount of clean water). A 25 cm space was left between the plots, and no ridges were set. All plots were in the same field, and the growth environment was completely the same.

[0083] Experimental fields: total cadmium content in the soil was 0.57 mg / kg, pH was 5.43, effective cadmium content was 0.27 mg / kg, and the rice varieties were uniform and were the main cultivated varieties locally.

[0084] Spraying period: Spray once during the tillering stage and the booting stage of late rice.

[0085] Sample collection: During the rice maturity period (early November), rice grains were collected and threshed.

[0086] The test results show that the differences between Comparative Examples 1 to 9 and the embodiments are described below.

[0087]

[0088]

[0089] According to the experimental results of the above embodiments, the sodium silicate, zinc sulfate, husk wood vinegar and selenium compound components of the present invention can cooperate with each other, and through their joint action, the cadmium content in rice brown rice can be significantly reduced, and the selenium content in rice brown rice can be significantly increased. A foliar barrier agent that can enrich rice with selenium and reduce cadmium and an application method thereof are provided. Compared with other barrier agent formulations, the foliar barrier agent of the present invention only needs to be sprayed once each at the tillering stage and the booting stage, and has an extremely outstanding selenium-enriching and cadmium-reducing effect, which solves the technical problem that rice cannot be quickly enriched with selenium and reduced with cadmium by using foliar barrier agents in the prior art.

[0090] In summary, the invention discloses a rice selenium-rich cadmium-reducing foliar barrier and an application method thereof. The selenium-rich cadmium-reducing foliar barrier is prepared by compounding husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds, wherein the mass ratio is 15%-20% of sodium silicate, 10%-15% of zinc sulfate, 20%-40% of selenium compounds, and the balance is husk wood vinegar. The selenium-rich cadmium-reducing foliar barrier is sprayed at the tillering stage and the heading stage of rice respectively. Compared with the rice selenium-rich cadmium-reducing foliar barrier sprayed with the same amount of clean water and other formulas, the selenium-rich cadmium-reducing foliar barrier of the invention significantly reduces the cadmium content in rice brown rice and increases the selenium content in rice brown rice. The invention has the advantages of simple operation, easy acquisition of raw materials, and transformation of waste into treasure. Several barrier components cooperate with each other to jointly play the role of rice selenium-rich cadmium-reducing, and has a strong prospect for promotion and application.

[0091] At this point, those skilled in the art recognize that, although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A rice selenium-enriched cadmium-reducing foliar control agent, characterized in that: The foliar barrier agent is composed of the following components: Husk wood vinegar, sodium silicate, zinc sulfate and selenium compounds; The selenium compound is a selenious acid or selenic acid compound; The mass ratio of the rice husk wood vinegar, sodium silicate, zinc sulfate and selenium compound is: Sodium silicate 15%-20%, zinc sulfate 10%-15%, selenium compound 20%-40%, the balance is rice husk wood vinegar; The selenium compound is one or more of sodium selenite, sodium selenate, and potassium selenate; The preparation method of the rice husk wood vinegar is: In the drying stage, the temperature is 20-60°C, during which the rice is completely dried; In the hulling stage, the husk is separated from the brown rice by a rice mill; In the fermentation stage, the husks are piled up for fermentation, and the fermentation temperature is controlled at 70-150°C. During this process, the husks begin to decompose, and the gaseous wood vinegar components produced in this process are cooled and recovered by a condenser to form a wood vinegar stock solution; Separation and refining: The wood vinegar stock solution is collected and stored in a sedimentation tank, and is separated and refined by standing for more than 3 months to obtain the entire wood vinegar stock solution.

2. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 1, characterized in that: The application method comprises the following steps: The sodium silicate, zinc sulfate and selenium compound in the rice selenium-enriched cadmium-reducing foliar control agent are dissolved in proportion in the husk wood vinegar solution, and the mixture is evenly mixed to obtain the foliar control agent, which is then diluted with a diluent and sprayed evenly on the rice leaves during the rice growth process.

3. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The diluent of the foliar barrier agent is water.

4. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The dilution multiple of the foliar barrier agent is 500-800 times.

5. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The rice growth process is the tillering stage and / or the booting stage.

6. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The dosage of the foliar control agent before dilution is 3-4 L / hectare.

7. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The foliar barrier agent is sprayed on the rice leaves before 10 am and after 4 pm on a sunny or cloudy day, with a suitable temperature range of 15-30°C.

8. The method for applying the rice selenium-enriched cadmium-reducing foliar control agent as claimed in claim 2, characterized in that: The foliar barrier agent is sprayed 1 to 3 times during the tillering stage and the booting stage.

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