Production method of selenium-rich medical stone sweet potatoes

Abstract

The invention discloses a production method of selenium-rich medical stone sweet potatoes. The method comprises the following steps: planting sweet potatoes in a land environment containing a selenium-rich fertilizer; the selenium-enriched fertilizer is prepared from 0.5 to 1 part of selenium-enriched saccharomycetes, 5 to 10 parts of medical stone, 5 to 10 parts of soybean meal, 5 to 8 parts of wheat bran, 0.05 to 0.08 part of molasses, 5 to 10 parts of sodium selenite and 1 to 5 parts of sweet potato peel; a selenium-rich fertilizer diluent is applied in the middle stage of sweet potato planting, and the selenium-rich fertilizer diluent is prepared by mixing a selenium-rich fertilizer with water with the volume being 40-50 times that of the selenium-rich fertilizer. The selenium-rich fertilizer is prepared by converting selenium-rich saccharomycetes into inorganic selenium, and the selenium-rich saccharomycetes have very high activity, can be massively propagated in the fermentation process, have very strong selenium conversion capability and can fully convert the inorganic selenium in the raw materials; the medical stone is added into the selenium-rich fertilizer, various elements including selenium can be separated out through the medical stone, a selenium source is provided for selenium-rich saccharomycetes, meanwhile, rich nutrition is provided for growth of the sweet potatoes, and in addition, the medical stone can improve soil and promote healthy growth of the sweet potatoes.

Description

Technical Field

[0001] The present invention belongs to the technical field of agriculture, and in particular relates to a production method of selenium-rich medical stone sweet potatoes. Background Art

[0002] Selenium is one of the essential trace elements in the human body and plays a variety of important physiological functions in organisms. Many studies have shown that selenium has antioxidant and anti-cancer effects, can antagonize heavy metal poisoning, improve the body's immune capacity, regulate the absorption and utilization of vitamins, and effectively prevent various diseases including cardiovascular and cerebrovascular diseases. The recommended selenium intake for adults by the Chinese Nutrition Society is 50-250 μg / day, and for key populations such as cancer, kidney disease, and liver disease patients, the daily selenium intake needs to reach more than 200 μg. However, according to the survey and statistics, about 72% of the land in China has varying degrees of selenium deficiency, and the problem of selenium deficiency in the population deserves high attention. Selenium deficiency in the human body can lead to various diseases such as diabetes, cardiovascular diseases, and acute myocarditis. The risk of endemic diseases such as Keshan disease and goiter also increases significantly in selenium-deficient areas. Selenium cannot be stored in the human body, and the required selenium is mainly obtained through diet. Therefore, selenium-rich foods have received more and more attention in recent years.

[0003] Medical stone is an active mineral medicine stone containing a large amount of macro and trace elements required by the human body. It has strong adsorption, dissolution, and biological activities, and has broad application prospects in the agricultural field. When medical stone dissolves in water, it can precipitate various elements including silicon, iron, magnesium, calcium, zinc, potassium, copper, phosphorus, selenium, etc. Therefore, using its leaching solution can effectively supply various nutrient elements required for plant growth and reproduction. Medical stone is loose and porous, has a large specific surface area, and has extremely strong physical adsorption ability. It can not only adsorb harmful heavy metals such as chromium, arsenic, and lead, but also adsorb pathogenic bacteria such as Staphylococcus aureus and Shigella dysenteriae and has a certain killing effect on them. In addition, medical stone can also improve the physical and chemical properties of the soil, regulate the pH value of the soil, adsorb residual pesticides, etc. Its wide application is conducive to promoting the sustainable development of agricultural ecology.

[0004] Sweet potatoes, also known as red potatoes, sweet potatoes, and mountain yams, are rich in starch, cellulose, various vitamins, linoleic acid, as well as elements such as potassium, iron, copper, and calcium. In particular, they contain a large amount of lysine, effectively solving the problem of the lack of this component in staple foods, and are a crop with relatively high nutritional value. Combining with the current situation of selenium deficiency in the Chinese population, the production technology of selenium-rich sweet potatoes has been rapidly promoted and developed. Currently, selenium-rich fertilizers are mainly divided into two types: one is mineral selenium fertilizer, which is a fertilizer processed from natural selenium-containing minerals; the other is chemical selenium fertilizer, which is further divided into inorganic selenium fertilizer and organic selenium fertilizer. Inorganic selenium fertilizer is mainly complexes of inorganic selenium such as sodium selenite, potassium selenite, and ammonium selenite, and organic selenium fertilizer is a fertilizer converted from inorganic selenium, such as through the fermentation process of microorganisms. Starting from the development of new selenium-rich fertilizers and continuously innovating the production technology of selenium-rich sweet potatoes can not only increase the selenium content of sweet potatoes but also achieve higher added value and economic benefits. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a production method for selenium-rich melilotus sweet potatoes.

[0006] The technical solution adopted by the present invention is: a production method for selenium-rich melilotus sweet potatoes, which plants sweet potatoes in a land environment containing selenium-rich fertilizer; the selenium-rich fertilizer includes 0.5 - 1 part of selenium-rich yeast, 5 - 10 parts of medical stone, 5 - 10 parts of soybean meal, 5 - 8 parts of wheat bran, 0.05 - 0.08 part of molasses, 5 - 10 parts of sodium selenite, and 1 - 5 parts of sweet potato peel.

[0007] Preferably, a diluted selenium-rich fertilizer solution is applied during the middle stage of sweet potato planting. The diluted selenium-rich fertilizer solution is made by diluting the selenium-rich fertilizer with 40 - 50 times the volume of water.

[0008] Preferably, a base fertilizer and a selenium-rich fertilizer are applied to the land environment for planting sweet potatoes. The application amount of the base fertilizer is 100 - 150 kg / mu, and the application amount of the selenium-rich fertilizer is 30 - 50 kg / mu.

[0009] Preferably, the base fertilizer is a mixture of nitrogen, phosphorus, and potassium compound fertilizer and organic fertilizer in a weight ratio of 1:8 - 10; the nitrogen, phosphorus, and potassium content ratio of the nitrogen, phosphorus, and potassium compound fertilizer is 1:1:2; the organic fertilizer is made by retting 30 - 45 parts of sweet potato leaves and 45 - 60 parts of livestock and poultry manure by weight.

[0010] Preferably, a diluted selenium-rich fertilizer solution is top-dressed during the middle stage of sweet potato planting, once every 20 days, 150 - 200 kg each time, and the application is stopped 20 days before harvesting;

[0011] 60 - 80 days after the transplanting of spring sweet potatoes or 40 - 70 days after the transplanting of summer sweet potatoes is the middle stage of sweet potato planting.

[0012] A selenium-rich sweet potato fertilizer, comprising 0.5 - 1 part of selenium-rich yeast, 5 - 10 parts of medical stone, 5 - 10 parts of soybean meal, 5 - 8 parts of wheat bran, 0.05 - 0.08 part of molasses, 5 - 10 parts of sodium selenite, and 1 - 5 parts of sweet potato peel.

[0013] Preferably, the preparation method includes:

[0014] Weigh and mix medical stone, soybean meal, and sweet potato peel according to the weight ratio, and crush and sieve through a 10-mesh sieve to obtain a mixture;

[0015] Dry and crush sodium selenite, and sieve through a 100-mesh sieve;

[0016] After the selenium-rich yeast is cultured in a medium at 40 °C for 2 h for activation, mix it with the mixture, sodium selenite, wheat bran, and molasses, and build a pile for fermentation;

[0017] After 22 - 25 days of fermentation, dry, crush, and sieve through a 100-mesh sieve to obtain the selenium-rich fertilizer.

[0018] Preferably, the selenium-rich yeast medium includes 40 g of glucose, 20 g of tryptone, 10 g of yeast extract powder, and pH 5.4.

[0019] Preferably, the fermentation temperature is 35 - 38 °C.

[0020] Preferably, the fermented selenium-rich fertilizer is dried at 35 - 38 °C until the water content is less than 8%.

[0021] Beneficial effects

[0022] The advantages and positive effects of the present invention are:

[0023] 1. The selenium-rich fertilizer used is made by converting inorganic selenium with selenium-rich yeast. The selenium-rich yeast has high activity, can multiply in large numbers during the fermentation process, and has strong selenium conversion ability, which can fully convert the inorganic selenium in the raw materials. The selenium content of the sweet potatoes produced by using the present invention reaches about 49 μg / kg, while the selenium content of the sweet potatoes produced by using the conventional method is only about 5 μg / kg. The selenium content is significantly increased by about 10 times, and the selenium-rich effect is obvious.

[0024] 2. Add medical stone to the selenium-rich fertilizer. Medical stone can precipitate various elements including selenium, provide a selenium source for selenium-rich yeast, and provide rich nutrients for the growth of sweet potatoes. In addition, medical stone can also improve the soil and promote the healthy growth of sweet potatoes.

[0025] 3. In addition, the present invention reuses sweet potato waste such as sweet potato peel and sweet potato leaves to make fertilizer, which can realize the recycling of resources. Specific embodiments

[0026] The present invention discloses a production method of selenium-rich melon-seeded sweet potatoes, which involves planting sweet potatoes in a land environment containing selenium-rich fertilizer. Before transplanting the sweet potato seeds, a basal fertilizer and a selenium-rich fertilizer are applied first. The application amount of the basal fertilizer is 100 - 150 kg / mu, and the application amount of the selenium-rich fertilizer is 30 - 50 kg / mu. The basal fertilizer is a mixture of a nitrogen-phosphorus-potassium ternary compound fertilizer and an organic fertilizer in a weight ratio of 1:8 - 10. The nitrogen, phosphorus, and potassium content ratio of the nitrogen-phosphorus-potassium ternary compound fertilizer is 1:1:2. The organic fertilizer is prepared by retting 30 - 45 parts of sweet potato leaves and 45 - 60 parts of livestock and poultry manure by weight. The selenium-rich fertilizer includes 0.5 - 1 part of selenium-rich yeast, 5 - 10 parts of medical stone, 5 - 10 parts of soybean meal, 5 - 8 parts of wheat bran, 0.05 - 0.08 part of molasses, 5 - 10 parts of sodium selenite, and 1 - 5 parts of sweet potato peel.

[0027] During the mid-term of sweet potato planting, a diluted selenium-rich fertilizer solution is applied. The diluted selenium-rich fertilizer solution is made by diluting the selenium-rich fertilizer with 40 - 50 times the volume of water. It is applied once every 20 days, 150 - 200 kg each time, and the application is stopped 20 days before harvesting. The specific planting method can be carried out according to the following steps.

[0028] (1) Selecting strong seedlings: Select sweet potato seeds with long, plump, smooth skin, no pest and disease spots and scars as seeds, and select strong seedlings 2 months before transplanting and planting. Before seedling raising, soak the sweet potato seeds in a saline solution with a mass fraction of 15 - 25% for 28 - 48 h, and the soaking temperature is 25 - 28 °C, and then carry out greenhouse breeding.

[0029] (2) Land preparation and fertilization: Select a plot with deep soil layer, good air permeability, and good water seepage and water storage performance for planting; Select a sunny day for fine land preparation, plow about 30 cm deep, apply the basal fertilizer and the selenium-rich fertilizer, and then plow again, rake the soil to be broken and flat to make the soil and fertilizer evenly mixed; After the land is deeply plowed and leveled, ridges are formed. The ridge height is 30 - 40 cm, the ridge width is 90 - 100 cm, the ditch width is 20 - 30 cm, and the ditch depth is 15 - 20 cm.

[0030] The application amounts of the basal fertilizer and the selenium-rich fertilizer are 100 - 150 kg / mu and 30 - 50 kg / mu respectively; Among them, the basal fertilizer is a mixture of a nitrogen-phosphorus-potassium ternary compound fertilizer and an organic fertilizer in a weight ratio of 1:8 - 10. The nitrogen, phosphorus, and potassium content ratio of the nitrogen-phosphorus-potassium ternary compound fertilizer is 1:1:2. The organic fertilizer is prepared by retting 30 - 45 parts of sweet potato leaves and 45 - 60 parts of livestock and poultry manure by weight. Among them, the selenium-rich fertilizer is prepared from the following raw materials by weight: 0.5 - 1 part of selenium-rich yeast, 5 - 10 parts of medical stone, 5 - 10 parts of soybean meal, 5 - 8 parts of wheat bran, 0.05 - 0.08 part of molasses, 5 - 10 parts of sodium selenite, and 1 - 5 parts of sweet potato peel;

[0031] (3) Transplanting and planting: Spring sweet potatoes are transplanted from late April to early May, and summer sweet potatoes are transplanted from late May to early June. When the seedlings bred in the greenhouse grow to about 15 cm, they are transplanted and planted on the ridges in step (2). The seedlings are inserted 5 - 10 cm deep, and the plant spacing is kept at 30 - 35 cm. After transplantation, sufficient root-fixing water is promptly watered.

[0032] (4) Field management: In the early stage (60 days after spring sweet potato transplantation and 40 days before summer sweet potato transplantation), check and supplement seedlings in a timely manner, and supplement strong seedlings in the places where there are missing seedlings. Cultivate and loosen the soil every 10 - 15 days to keep the soil loose and breathable. In the middle stage (60 - 80 days after spring sweet potato transplantation and 40 - 70 days after summer sweet potato transplantation), top-dress the diluted selenium-rich fertilizer solution. The diluted selenium-rich fertilizer solution is made by mixing selenium-rich fertilizer with 40 - 45 times the volume of water, once every 20 days, 150 - 200 kg each time, and stop applying 20 days before harvesting. In the later stage (after 80 days of spring sweet potato transplantation and 70 days of summer sweet potato transplantation until harvesting), strengthen the management of fertilizer and water to prevent the premature senescence of the plants.

[0033] (5) Pest and disease control: The main pests of sweet potatoes include Spodoptera litura, sweet potato hawkmoth, etc. Before the egg masses hatch into 3rd instar larvae, spray 4000 times the liquid of 15% indoxacarb suspension concentrate, 1500 times the liquid of 0.5% emamectin benzoate EC, etc. The main disease is black spot disease, spray 500 times the liquid of 70% thiophanate-methyl.

[0034] (6) Harvest in due time: Start harvesting in the 5th month after transplanting and planting or when the temperature drops to 15°C. Select to harvest on sunny days. After the sweet potatoes are unearthed, remove the soil and fibrous roots on the surface, dry the surface moisture, and store them away from light.

[0035] The present invention also discloses a selenium-rich fertilizer for sweet potatoes, which can be used for the above-mentioned sweet potato production. The selenium-rich fertilizer for sweet potatoes includes 0.5 - 1 part of selenium-rich yeast, 5 - 10 parts of medical stone, 5 - 10 parts of soybean meal, 5 - 8 parts of wheat bran, 0.05 - 0.08 part of molasses, 5 - 10 parts of sodium selenite, and 1 - 5 parts of sweet potato peel. The specific preparation method is as follows:

[0036] Step 1: Weigh and mix medical stone, soybean meal, and sweet potato peel according to the weight ratio, and crush them through a 10-mesh sieve to obtain a mixture.

[0037] Step 2: Dry and crush sodium selenite, and pass it through a 100-mesh sieve.

[0038] Step 3: After the selenium-rich yeast is cultured and activated in a medium (pH 5.4) with a formula of 40 g of glucose, 20 g of tryptone, and 10 g of yeast extract powder at 40°C for 2 h, mix it with the mixture, sodium selenite, wheat bran, and molasses, and build a pile for fermentation. The fermentation temperature is 35 - 38°C.

[0039] Step 4: After 22 - 25 days of fermentation, dry at 35 - 38°C until the water content is less than 8%, then crush and pass through a 100 - mesh sieve to obtain the selenium - rich fertilizer.

[0040] The selenium - rich fertilizer used in the present invention is made by converting inorganic selenium with selenium - rich yeast. The selenium - rich yeast has high activity, can multiply in large numbers during the fermentation process, and has strong selenium - conversion ability, which can fully convert the inorganic selenium in the raw materials. Adding medical stone to the selenium - rich fertilizer, the medical stone can release various elements including selenium, providing a selenium source for the selenium - rich yeast, and at the same time providing rich nutrients for the growth of sweet potatoes. In addition, the medical stone can also improve the soil and promote the healthy growth of sweet potatoes. In addition, the present invention re - uses sweet potato waste such as sweet potato peels and sweet potato leaves to make fertilizers, which can realize the recycling of resources.

[0041] The following is an illustration of the present invention with specific embodiments.

[0042] Example 1: Preparation of selenium - rich sweet potato fertilizer

[0043] The selenium - rich fertilizer is made from the following raw materials by weight: 0.5 parts of selenium - rich yeast, 5 parts of medical stone, 5 parts of soybean meal, 5 parts of wheat bran, 0.05 parts of molasses, 5 parts of sodium selenite, and 1 part of sweet potato peel.

[0044] 1.1 Weigh the medical stone, soybean meal, and sweet potato peel according to the weight ratio, crush and pass through a 10 - mesh sieve, and mix to obtain a mixture.

[0045] 1.2 Wash, dry, crush the sodium selenite, and pass through a 100 - mesh sieve for later use.

[0046] 1.3 After the selenium - rich yeast is activated by culturing in a medium (pH 5.4) with a formula of 40 g of glucose, 20 g of tryptone, and 10 g of yeast extract powder at 40°C for 2 h, mix it with the mixture, sodium selenite, wheat bran, and molasses, build a heap and ferment for 22 days at a fermentation temperature of 35°C; after fermentation, dry at 35°C until the water content is less than 8%; crush and pass through a 100 - mesh sieve to obtain the selenium - rich sweet potato fertilizer.

[0047] Example 2: Production of selenium - rich medical stone sweet potatoes

[0048] 2.1 Select strong seedlings: Select seed potatoes with long, plump, smooth skin, no pest and disease spots and scars as seeds, and select strong seedlings 2 months before transplanting and planting; before seedling raising, soak the sweet potato seeds in a 15% salt water solution at 25°C for 28 h, and then carry out greenhouse breeding.

[0049] 2.2 Land preparation and fertilization: Choose a plot with deep soil layer, good air permeability, and good water infiltration and water storage for planting; choose to do fine land preparation on a sunny day, plow deeply about 30cm, apply base fertilizer and selenium-rich fertilizer, the application amount of base fertilizer and selenium-rich fertilizer is 100kg / mu and 30kg / mu respectively, and then plow deeply again, harrow and level the soil to make the soil and fertilizer evenly mixed; after deep plowing and leveling the land, ridges are formed, with a ridge height of 30cm, a ridge width of 90cm, a ditch width of 20cm, and a ditch depth of 15cm;

[0050] The base fertilizer is a mixture of nitrogen, phosphorus and potassium ternary compound fertilizer and organic fertilizer in a weight ratio of 1:8, the nitrogen, phosphorus and potassium content ratio of the nitrogen, phosphorus and potassium ternary compound fertilizer is 1:1:2, and the organic fertilizer is made by fermenting 30 parts of sweet potato leaves and 45 parts of livestock and poultry manure and urine in weight; the selenium-rich fertilizer is prepared by Example 1;

[0051] 2.3 Transplanting and planting: Spring potatoes are transplanted in late April to early May, and summer potatoes are transplanted in late May to early June. When the seedlings grown in the greenhouse grow to about 15 cm, they are transplanted to the ridges in step 2.2. The seedlings are planted 5 cm deep and the spacing between plants is kept at 30 cm. After transplanting, water them in time to ensure that they can take root.

[0052] 2.4 Field management: In the early stage (60 days after spring potato transplanting and 40 days before summer potato transplanting), timely check and supplement seedlings, and replenish strong seedlings in places where seedlings are missing; till and loosen the soil once every 10 days to keep the soil loose and breathable; in the middle stage (60-80 days after spring potato transplanting and 40-70 days after summer potato transplanting), apply selenium-rich fertilizer dilution, which is made of selenium-rich fertilizer and 40 times the volume of water, once every 20 days, 150kg each time, and stop applying 20 days before harvest; in the late stage (80 days after spring potato transplanting and 70 days after summer potato transplanting until harvest), strengthen fertilizer and water management to prevent and control premature aging of plants;

[0053] 2.5 Disease and pest control: The main pests of sweet potatoes are Spodoptera litura and Sextus hornbilus. Before the eggs hatch into the third-instar larvae, spray 4000 times of 15% indoxacarb suspension or 1500 times of 0.5% emamectin benzoate emulsifiable concentrate. The main disease is black spot, spray 500 times of 70% thiophanate methyl solution.

[0054] 2.6 Harvest at the right time: Start harvesting in the 5th month after transplanting or when the temperature drops to 15℃; choose to harvest on a sunny day. After the sweet potatoes emerge from the soil, remove the soil and fibrous roots on the surface, dry the surface moisture, and store away from light.

[0055] The unearthed sweet potatoes were tested and the average selenium content of the sweet potatoes produced by the production method of the present invention reached 49 μg / kg, which meets the standard requirements of selenium-enriched agricultural products and has a good selenium-enriched effect.

[0056] The above has described the embodiments of the present invention in detail, but the above content is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A production method of selenium-rich melon seeds and stones sweet potatoes, characterized in that: plant sweet potatoes in a land environment containing selenium-rich fertilizer; the selenium-rich fertilizer includes 0.5-1 part of selenium-rich yeast, 5-10 parts of medical stone, 5-10 parts of soybean meal, 5-8 parts of wheat bran, 0.05-0.08 part of molasses, 5-10 parts of sodium selenite, and 1-5 parts of sweet potato peel.

2. The production method of selenium-rich melon seeds and stones sweet potatoes according to claim 1, characterized in that: apply the diluted solution of selenium-rich fertilizer during the middle stage of sweet potato planting, and the diluted solution of selenium-rich fertilizer is made by mixing selenium-rich fertilizer with 40-50 times the volume of water.

3. The production method of selenium-rich melon seeds and stones sweet potatoes according to claim 2, characterized in that: apply base fertilizer and selenium-rich fertilizer in the land environment for planting sweet potatoes, the application amount of base fertilizer is 100-150 kg / mu, and the application amount of selenium-rich fertilizer is 30-50 kg / mu.

4. The production method of selenium-rich melon seeds and stones sweet potatoes according to claim 3, characterized in that: the base fertilizer is mixed by nitrogen, phosphorus and potassium ternary compound fertilizer and organic fertilizer according to the weight ratio of 1:8-10; the content ratio of nitrogen, phosphorus and potassium in the nitrogen, phosphorus and potassium ternary compound fertilizer is 1:1:2; the organic fertilizer is made by retting 30-45 parts of sweet potato leaves and 45-60 parts of livestock and poultry manure according to the weight parts.

5. The production method of selenium-rich melon seeds and stones sweet potatoes according to any one of claims 2-4, characterized in that: topdress the diluted solution of selenium-rich fertilizer during the middle stage of sweet potato planting, once every 20 days, 150-200 kg each time, and stop applying 20 days before harvesting; 60-80 days after transplanting of spring sweet potatoes or 40-70 days after transplanting of summer sweet potatoes is the middle stage of sweet potato planting.

6. A sweet potato selenium-rich fertilizer, characterized in that: including 0.5-1 part of selenium-rich yeast, 5-10 parts of medical stone, 5-10 parts of soybean meal, 5-8 parts of wheat bran, 0.05-0.08 part of molasses, 5-10 parts of sodium selenite, and 1-5 parts of sweet potato peel.

7. The sweet potato selenium-rich fertilizer according to claim 6, characterized in that: the preparation method includes: weigh and mix medical stone, soybean meal, and sweet potato peel according to the weight ratio, and crush and sieve through a 10-mesh sieve to obtain a mixture; dry and crush sodium selenite, and sieve through a 100-mesh sieve; after activating selenium-rich yeast in a culture medium at 40 °C for 2 h, mix it with the mixture, sodium selenite, wheat bran, and molasses, and build a pile for fermentation; after 22-25 days of fermentation, dry, crush, and sieve through a 100-mesh sieve to obtain selenium-rich fertilizer.

8. The sweet potato selenium-rich fertilizer according to claim 7, characterized in that: the selenium-rich yeast culture medium includes 40 g of glucose, 20 g of tryptone, 10 g of yeast extract powder, and pH 5.

4.

9. The sweet potato selenium-rich fertilizer according to claim 7, characterized in that: the fermentation temperature is 35-38 °C.

10. The sweet potato selenium-rich fertilizer according to claim 7, characterized in that: the fermented selenium-rich fertilizer is dried at 35-38 °C until the water content is less than 8%.