Selenium-rich fresh corn and production method thereof

Abstract

The invention discloses selenium-rich fresh corn and a production method thereof, and relates to the field of functional agriculture. The selenium content in the fresh grains of the selenium-rich fresh corn is 0.15 mg / kg-4 mg / kg, so that the requirements of the national selenium-rich nutrition claim are met, and the risk of excessive selenium intake is avoided under the conventional eating condition. The production method of the selenium-rich fresh corn comprises two steps of preparing the selenium-rich leaf fertilizer special for the fresh corn and applying the selenium-rich leaf fertilizer, wherein the special selenium-rich leaf fertilizer comprises the following components in parts by weight: 0.1-0.3 part of a selenium source (in terms of selenium), 0.3-0.6 part of phosphoric acid, 1.5-2 parts of sulfate and 0.1-0.5 part of a surfactant; the application method comprises the step of spraying the prepared special selenium-rich foliar fertilizer at one time from the flowering stage to the filling stage of corn according to the dosage of 1-2 L / mu. Compared with the prior art, the production method provided by the invention has the characteristics of strong specificity, multiple nutrients and good absorptivity, the application method is simple and convenient, the fertilizer consumption can be reduced, the cost can be reduced, the return flight frequency of the plant protection unmanned aerial vehicle can be reduced, and the working efficiency can be improved.

Description

Technical Field

[0001] The invention relates to the field of functional agriculture, and in particular to selenium-enriched fresh corn and a production method thereof. Background Art

[0002] Selenium is one of the essential trace elements for the human body. It has antioxidant, anti-aging and normal physiological function maintaining the immune system. Studies have shown that low selenium intake is related to a variety of malignant diseases such as cancer, liver disease, low immunity, cardiovascular and cerebrovascular diseases.

[0003] Fresh corn refers to corn whose green and tender cobs or kernels are used as edible or processed materials. It has the characteristics of unique taste and rich nutrition, and is widely favored by the public. Fresh corn is divided into sweet, sticky and sweet and sticky types. The average growing period is 90 days. It enters the milky stage 15 to 25 days after flowering, which is the best time to harvest fresh corn. my country's fresh corn planting area exceeds 25 million mu. The selenium-rich fresh corn produced by biofortification technology can solve the "hidden hunger" problem caused by insufficient selenium intake in some people.

[0004] Fresh corn after primary processing is a pre-packaged food. Therefore, for selenium-rich fresh corn, according to GB28050-2011 "General Rules for Nutrition Labeling of Pre-packaged Foods", it is necessary to label selenium-rich products in the form of nutrition claims. GB 28050 states in its Table C1 (page 9) that if the content of a certain mineral in every 100 g of solid product is ≥30% NRV, it can be claimed on the label that it is rich in this mineral. As a mineral, selenium has an NRV value of 50 μg (Appendix A, page 5 of GB 28050), that is, the selenium content in the solid product must be ≥30%*50μg / 100g=0.15 mg / kg before it can be claimed to be "selenium-rich".

[0005] In the prior art, there have been reports on the use of selenium-rich foliar fertilizers in the production of various agricultural products. However, there are several problems in the prior art: first, the selenium-rich corn on the market generally refers to corn with a final dry weight corn kernel selenium content of 0.15 mg / kg, and its fresh weight is generally around 0.01 mg / kg, which does not meet the requirements for fresh corn to be selenium-rich; second, the existing selenium-rich foliar fertilizers are generally developed and produced for the above-mentioned selenium-rich corn. According to the commonly used usage and dosage, the requirement of a fresh weight selenium content of more than 0.15 mg / kg cannot be achieved. If the dosage is increased, not only will repeated spraying of fertilizers require additional labor, but excessive spraying of selenium will often cause seedling burn. For example, CN201310593495.9 discloses a high-selenium corn cultivation method, which requires three consecutive sprayings of selenium-containing fertilizers, and each spraying amount is as high as 800-1000 kg / hectares, and the operation is cumbersome; thirdly, although CN201510144395.7 discloses a method for preparing a selenium-rich bio-organic fertilizer for fresh corn, and although the selenium content of selenium-rich corn produced by this method can reach about 50 mg / kg, this method applies a large amount of selenium-containing ingredients in the soil, and there may be a risk of selenium residues.

[0006] Therefore, for the selenium-rich fresh corn that is becoming increasingly popular in the market, not only is it necessary to have a fresh weight selenium content of more than 0.15 mg / kg, but it also requires a production method that is simple in process and has no risk of burning seedlings. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide fresh corn that meets the claims of selenium-rich nutrition and a production method thereof, which can effectively increase the selenium content in fresh corn without causing toxicity to corn plants, and is easy to use and cost-effective.

[0008] The technical solution adopted by the present invention is: A selenium-enriched fresh corn, characterized in that the selenium content in the fresh corn kernels is 0.15 mg / kg-4 mg / kg.

[0009] Preferably, the selenium content in the fresh corn kernels is 0.15 mg / kg-0.3 mg / kg.

[0010] The present invention also provides a method for producing fresh corn, the steps of which include: preparing a special selenium-rich foliar fertilizer for fresh corn, and spraying it once at 1-2 liters per mu from the flowering stage to the grain filling stage of the corn.

[0011] Among them, the ratio of special selenium-rich foliar fertilizer is: 0.1-0.3 parts of selenium source (calculated as selenium), 0.3-0.6 parts of phosphoric acid, 1.5-2 parts of sulfate, and 0.1-0.5 parts of surfactant.

[0012] Preferably, a selenium-rich foliar fertilizer specifically for fresh corn may contain, in addition to 0.1-0.3 parts of a selenium source (calculated as selenium), 0.3-0.6 parts of phosphoric acid, 1.5-2 parts of sulfate, and 0.1-0.5 parts of a surfactant, 8 parts of ammonium molybdate, 1.7 parts of dipotassium hydrogen phosphate, 0.4 parts of boric acid, 0.2 parts of chitosan oligosaccharides, and 3-6 parts of a microbial fermentation extract.

[0013] Preferably, the components of the special selenium-rich foliar fertilizer are 0.1 parts of selenium source (calculated as selenium), 5 parts of phosphoric acid, 1.5 parts of sulfate, 0.3 parts of surfactant, 8 parts of ammonium molybdate, 1.7 parts of dipotassium hydrogen phosphate, 0.4 parts of boric acid, 0.2 parts of chitosan oligosaccharide, and 5 parts of microbial fermentation extract.

[0014] Preferably, the selenium source in the above-mentioned special selenium-enriched foliar fertilizer set is one or a combination of any of selenite, selenate, and selenoamino acid.

[0015] Preferably, the selenium source in the above-mentioned special selenium-enriched foliar fertilizer set is selenoamino acid.

[0016] Preferably, the microbial fermentation extract is prepared by extracting corn stalks after transformation by selenium-loving microorganisms, and includes two or more amino acids, polypeptides, polysaccharides and selenium chelates.

[0017] Preferably, the surfactant is one or more of sodium lauryl sulfate, fatty acid glyceride, and quaternary ammonium salt.

[0018] The preferred method of using the special selenium-rich foliar fertilizer is to take 1-2 liters of foliar fertilizer per mu, dilute it with water more than 10 times, and spray it evenly; the application time is from the flowering stage to the filling stage of corn.

[0019] The preferred method of using the special selenium-rich foliar fertilizer is to take 1-2 liters of foliar fertilizer per mu, dilute it 10-20 times with water, and spray it evenly with a drone; the application time is 3-5 days before and after the corn heading period, and strong light exposure should be avoided during application.

[0020] Compared with the prior art, the advantages of the present invention are: 1. The selenium content of the selenium-enriched fresh corn provided by the present invention is 0.15 mg / kg-4 mg / kg, which not only meets the requirements of the national selenium-enriched nutrition claim, but also does not have the risk of excessive selenium intake under normal consumption conditions (the edible part of each cob of fresh corn is about 100 grams on average, and according to the selenium content of 4 mg / kg, it can increase 400 micrograms of selenium, which does not exceed the recommended upper limit of selenium intake).

[0021] 2. The selenium-rich foliar fertilizer for fresh corn provided by the present invention uses a combination of phosphate, sulfate, and surfactants in combination with selenium, achieving the effect of high-dose spraying without burning seedlings during spraying. The principle is that selenium shares sulfate transporters and phosphate transporters with phosphates and sulfates during absorption and utilization by corn plants. Through the proportion configuration of the present invention, the absorption of selenium can be dispersed to avoid excessive selenium and poisoning due to local high concentrations; while the surfactant helps the fertilizer to be evenly dispersed and attached to the plant leaves, it also makes the phosphate, sulfate, and selenium source more evenly distributed, and avoids excessive local concentrations.

[0022] 3. The application method of the selenium-rich foliar fertilizer for fresh corn of the present invention is simple and convenient, with a low dilution multiple, and does not require multiple applications, thereby reducing fertilizer usage and costs. At the same time, the use of plant protection drones for spraying can reduce the frequency of returns and improve work efficiency. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with embodiments: A corn planting experiment was carried out using the selenium-rich foliar fertilizer specially used for fresh corn of the present invention. The experimental location was Suzhou City. The experimental corn varieties were Su Yunuo No. 5, Su Kenuo No. 10, and Su Kenuo 1804. The water and fertilizer management of the experimental plots was consistent, and other planting conditions were the same.

[0024] The preparation method of selenium-rich foliar fertilizer for fresh corn is 0.1 parts of selenoamino acids (calculated as selenium), 5 parts of phosphoric acid, 1.5 parts of sulfate, 0.3 parts of fatty acid glyceride, 8 parts of ammonium molybdate, 1.7 parts of dipotassium hydrogen phosphate, 0.4 parts of boric acid, 0.2 parts of chitosan oligosaccharides, and 5 parts of microbial fermentation extract.

[0025] The implementation land area is 4 mu, each mu is divided into 12 small plots, and every 4 plots are randomly divided into a group, and then divided into 3 small groups. Every 3 small groups constitute a large group of corn varieties. In each large group, the special selenium-enriched foliar fertilizer for fresh corn is applied according to the method described in Examples 1 to 3, and they are recorded as treatment groups 1 to 3. A plot that is not applied with the special selenium-enriched foliar fertilizer for fresh corn is selected as the implementation control group. Example

[0026] The method for applying selenium-rich foliar fertilizer for fresh corn comprises the following steps: 1. Take 1 liter of the above-mentioned selenium-rich foliar fertilizer for fresh corn and dilute it to 10 liters with water.

[0027] 2. Use a plant protection drone to evenly spray the diluted foliar fertilizer onto treatment group 1. Example

[0028] The method for applying selenium-rich foliar fertilizer for fresh corn comprises the following steps: 1. Take 1 liter of the above-mentioned selenium-rich foliar fertilizer for fresh corn and dilute it to 20 liters with water.

[0029] 2. Use a plant protection drone to evenly spray the diluted foliar fertilizer onto treatment group 2. Example

[0030] The method for applying selenium-rich foliar fertilizer for fresh corn comprises the following steps: 1. Take 2 liters of the above-mentioned selenium-rich foliar fertilizer for fresh corn and dilute it to 20 liters with water.

[0031] 2. Use a plant protection drone to evenly spray the diluted foliar fertilizer onto treatment group 3.

[0032] Fresh ear samples were collected at the milky stage. Five fresh ear samples were randomly collected from each plot from treatment groups 1 to 3 and the control group. Corn yield and selenium content in fresh ears were measured. The statistical results are shown in Table 1.

[0033] Table 1: Corn yield and selenium content in fresh ears in the planting experiment

[0034] The detection limit of selenium content is 0.02㎍ / kg.

[0035] It can be seen from the experimental groups 1-3 and the control group that the selenium-rich foliar fertilizer specially used for fresh corn of the present invention can improve the growth and yield of corn when used in the critical period of corn, with the yield increased by more than 8% and the selenium content being stable.

[0036] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A selenium-enriched fresh corn, characterized in that The selenium content in fresh corn kernels is between 0.15 mg / kg and 4 mg / kg.

2. The selenium-enriched fresh corn according to claim 1, characterized in that The selenium content in the fresh corn kernels is 0.15 mg / kg-0.3 mg / kg.

3. The method for producing selenium-enriched fresh corn according to claim 1-2, characterized in that It includes two steps: preparing special selenium-rich foliar fertilizer for fresh corn and applying it: the ratio of the special selenium-rich foliar fertilizer is: 0.1-0.3 parts of selenium source (in terms of selenium), 0.3-0.6 parts of phosphoric acid, 1.5-2 parts of sulfate, and 0.1-0.5 parts of surfactant; The method of use is to spray the above-mentioned special selenium-rich foliar fertilizer at a dosage of 1-2 L / mu from the flowering stage to the filling stage of corn.

4. The method for producing selenium-enriched fresh corn according to claim 3, characterized in that The selenium-rich foliar fertilizer contains, in addition to 0.1-0.3 parts of selenium source (calculated as selenium), 0.3-0.6 parts of phosphoric acid, 1.5-2 parts of sulfate, and 0.1-0.5 parts of surfactant, 8 parts of ammonium molybdate, 1.7 parts of dipotassium hydrogen phosphate, 0.4 parts of boric acid, 0.2 parts of chitosan oligosaccharide, and 3-6 parts of microbial fermentation extract.

5. The method for producing selenium-enriched fresh corn according to claim 3, characterized in that The selenium-rich foliar fertilizer comprises 0.1 parts of a selenium source (in terms of selenium), 5 parts of phosphoric acid, 1.5 parts of sulfate, 0.3 parts of a surfactant, 8 parts of ammonium molybdate, 1.7 parts of dipotassium hydrogen phosphate, 0.4 parts of boric acid, 0.2 parts of chitosan oligosaccharide, and 5 parts of a microbial fermentation extract.

6. The method for producing selenium-enriched fresh corn according to claim 3, characterized in that The selenium source in the above-mentioned special selenium-rich foliar fertilizer group is one of selenite, selenate, and selenoamino acid, or any combination thereof; the biological fermentation extract is prepared by extracting corn stalks after transformation by selenium-loving microorganisms, and includes two or more of amino acids, polypeptides, polysaccharides, and selenium chelates; the surfactant is one of sodium dodecyl sulfate, fatty acid glycerides, and quaternary ammonium salts, or any combination thereof.

7. The method for producing selenium-enriched fresh corn according to claim 3, characterized in that The method of using the special selenium-rich foliar fertilizer is to take 1-2 liters of foliar fertilizer per mu, dilute it with water more than 10 times, and spray it evenly; the application time is from the flowering stage to the filling stage of corn.

8. The method for producing selenium-enriched fresh corn according to claim 3, characterized in that The method of using the selenium-rich foliar fertilizer is to take 1-2 liters of foliar fertilizer per mu, dilute it 10-20 times with water, and spray it evenly with a drone; the application time is 3-5 days before and after the corn heading period, and strong light exposure should be avoided during application.

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