A fully degradable pre-seeded rice seedling pot tray and preparation method thereof

Abstract

The invention discloses a fully degradable pre-sowing rice pot seedling tray and a preparation method thereof, comprising a seedling tray body, nutrient soil in the seedling tray body and a degradable film above the nutrient soil; the seedling tray body comprises rice straw, cow dung, a degradable adhesive and corn starch, the nutrient soil comprises peat soil, vermiculite and compound micro-fertilizer, and the degradable film is a polyvinyl alcohol film; the seedling tray body of the invention replaces most of the soil with rice straw, which not only reduces soil collection and reduces costs, but also the plant fibers of the straw provide better physical strength for the seedling tray body, and under the bonding effect of the degradable adhesive and corn starch, the firmness of the seedling tray body is stronger and the stability is higher; and the moisture content of the seedling tray body and the nutrient soil of the invention is between 10-12%, which not only ensures the vitality of the seeds, but also facilitates the storage of the seedling tray after preparation, and has high economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural production, and relates to a rice pot body seedling tray, and specifically relates to a fully degradable pre-seeded rice pot body seedling tray and a preparation method thereof. Background Art

[0002] Rice pot cultivation technology is widely used in my country and is a very effective way to improve rice quality and yield. Traditional seedling trays mainly use blanket seedlings, whose roots are tangled into blanket-like seedling blocks. When transplanting, the seedlings need to be cut into blocks, which will damage the root system of the seedlings and seriously affect the quality and yield of rice. The yield increase of early rice, double-season late rice and short-growing rice using blanket seedling machine is not obvious.

[0003] Moreover, the seedling growing medium used for rice blanket seedlings is mainly soil, with hard plastic seedling trays as carriers. The seeds are germinated in advance, then sown and darkened through an assembly line, and then placed in greenhouses or paddy fields to grow into seedlings. This type of seedling tray is not only difficult to degrade and will pollute the environment, but also requires consumption of a large amount of surface soil every year, which is labor-intensive and time-consuming.

[0004] Patent CN105237141A discloses a straw biomatrix seedling tray and a preparation method thereof, comprising a seedling tray and a matrix located inside the seedling tray and a bottom film underneath, wherein the matrix comprises plant straw, auxiliary agents and water, and the straw biomatrix is ​​used instead of plastic to reduce the pollution of plastic to the environment; however, this scheme cannot realize pre-seeding of seeds, and requires farmers to sow manually, which is costly, and the yield increase effect is not obvious due to insufficient manual sowing technology.

[0005] Patent CN108323356A discloses a multifunctional biomass degradable rice seedling tray and a preparation method thereof, which includes rice seeds, a nutrient matrix and a covering matrix. The matrix and seeds are bonded together by a biodegradable adhesive to form a plate-shaped culture matrix to replace the soil. This scheme adds adhesive to crop straw to prepare the matrix, and the covering matrix also uses adhesive, and after the preparation is completed, the seedling tray is pressed to obtain the covering matrix above and below the rice seeds, resulting in the physical strength of the covering matrix above and below the rice seeds being too high, affecting the activity of the seeds during storage, and being unfavorable for germination and rooting of the seeds after germination. However, if the bonding strength is too low, the seedling tray will fall apart during seedling cultivation and cannot be transplanted by a rice machine.

[0006] Since rice seedling cultivation is highly seasonal, they need to be planted immediately after cultivation. When the service scale of a seedling nursery reaches thousands or tens of thousands of acres, faced with the expanded rice seedling transportation radius, different regions, different crops, different cultivation habits, different varieties, as well as sudden weather changes, pests and diseases and other events, it is simply impossible for a seedling nursery to achieve a one-to-one digital correspondence with thousands of households, resulting in disordered, untimely and inadequate planting; and a large number of seedlings will slow down or die after planting, affecting the normal growth of rice.

[0007] Therefore, the rice seedling trays prepared by the current prior art cannot avoid the risk of scale-up, and there is no fully degradable pre-sown rice seedling tray and its preparation method, which has a relatively stable tray body during storage and seedling raising and does not affect the germination rate of rice seeds. Summary of the invention

[0008] One of the purposes of the present invention is to provide a fully degradable pre-seeded rice seedling pot tray;

[0009] The technical problem to be solved is: how to improve the stability of the seedling tray body in the storage state and the seedling raising state;

[0010] The second object of the present invention is to provide a method for preparing a fully degradable pre-seeded rice seedling pot tray;

[0011] The technical problem to be solved is: to extend the storage time of seedling trays under the premise of ensuring seed activity.

[0012] The present invention enhances the stability of the seedling tray body in the storage state by adding a degradable adhesive only in the seedling tray body, and improves the stability in the seedling raising state by the bonding effect produced by cross-linking the starch in the seedling tray body after the dissolution of the covering degradable film.

[0013] The purpose of the present invention can be achieved through the following technical solutions:

[0014] A fully degradable pre-seeded rice seedling tray, comprising a seedling tray body, nutrient soil in the seedling tray body, and a degradable film above the nutrient soil;

[0015] The seedling tray body includes the following raw materials in parts by weight: 80-120 parts of rice straw, 40-60 parts of cow dung, 15-25 parts of degradable adhesive, and 20-30 parts of corn starch;

[0016] The nutrient soil contains the following raw materials in parts by weight: 20-30 parts of peat soil, 10-20 parts of vermiculite, and 0.8-1 part of compound micro-fertilizer;

[0017] The degradable adhesive is plant protein glue;

[0018] The degradable film is a polyvinyl alcohol film.

[0019] Furthermore, the steps for preparing the seedling tray body are as follows:

[0020] The rice straw is crushed into a particle size of ≤2mm and then mixed with cow dung for fermentation for 30-40 days. After the fermentation is completed, corn starch and plant protein glue are added to the fermentation product, and the mixture is stirred and mixed evenly, and then pressed into shape. After demolding, the mixture is baked at a constant temperature of 40-50°C to a moisture content of 10-12% to obtain the seedling tray body.

[0021] Furthermore, the seedling tray body is rectangular, and a bowl-shaped hole array is arranged inside. The hole depth of the seedling tray body is 1.2-1.5 cm. The seedling tray body is 58.0 cm long, 28.0 cm wide, and 1.8 cm high. There are 14-18 holes arranged in the width direction and 31-36 holes arranged in the length direction. The number of holes in the seedling tray body is 434-648 holes.

[0022] Further, the preparation steps of nutrient soil are as follows:

[0023] After mixing peat soil and vermiculite and sterilizing them at high temperature, add compound micro-fertilizer, mix and sieve, and dry to a moisture content of 10-12% to obtain nutrient soil.

[0024] Furthermore, the compound micro-fertilizer includes the following fertilizers in parts by weight:

[0025] 30-35 parts of potassium chloride, 30-35 parts of urea, 15-20 parts of monoammonium phosphate, 8-10 parts of borax, 2-5 parts of superphosphate, 2-5 parts of magnesium sulfate, and 2-5 parts of silicon dioxide.

[0026] Further, the preparation steps of the polyvinyl alcohol film are as follows:

[0027] Dissolve ethylene glycol, Tween 80 and sodium dodecyl sulfate in deionized water in a flask, add carboxy polyvinyl alcohol into the flask, seal the flask and heat to 65-75° C. to swell the carboxy polyvinyl alcohol for 1.5-2.5 hours, cast the swollen carboxy polyvinyl alcohol using a solution casting machine and dry at 65-75° C. to obtain a polyethylene film.

[0028] Furthermore, the mass ratio of carboxypolyvinyl alcohol, ethylene glycol, Tween 80, sodium lauryl sulfate and deionized water is 8-12: 0.8-1: 0.8-1: 1.2-1.5: 85-90.

[0029] Furthermore, a method for using a fully degradable pre-seeded rice seedling tray is as follows:

[0030] S1, using a punching machine to press the seedling tray body into a rectangular tray with pot-shaped holes;

[0031] S2, sowing rice seeds in the holes of the seedling tray body with a seeder, 2-3 seeds per hole of hybrid rice and 4-6 seeds per hole of conventional rice;

[0032] S3, fill the holes of the seedling tray with 1.2-1.5cm thick nutrient soil;

[0033] S4. Cover the nutrient soil with a layer of 25-30 μm thick degradable film to cover all the holes;

[0034] S5. Use an edge wrapping machine to wrap the four sides of the degradable film on the sides of the seedling tray body and fix the edges.

[0035] A method for preparing a fully degradable pre-seeded rice seedling pot tray comprises the following steps:

[0036] Step 1: Press the seedling tray body into a rectangular tray with pot-shaped holes;

[0037] Step 2: Fill the holes of the seedling tray with 1.2-1.5 cm thick nutrient soil;

[0038] Step 3: Cover the nutrient soil with a layer of 25-30 μm thick degradable film to cover all the holes;

[0039] Step 4: Use an edge wrapping machine to wrap the four sides of the degradable film around the sides of the seedling tray body to fix the edges, so as to obtain a fully degradable pre-sowing rice pot seedling tray.

[0040] Furthermore, after the step 1 is completed, the rice seeds are sown in the holes of the seedling tray body, and then the subsequent steps are completed to realize the pre-sowing of seeds.

[0041] Furthermore, the fully degradable pre-seeded rice seed pot seedling tray is placed on a flat and compacted bedside seedling raising ground or cement drying ground, and sufficient water is poured to keep it moist to complete the seedling raising.

[0042] Beneficial effects of the present invention:

[0043] 1. The seedling tray body of the present invention replaces most of the soil with rice straw, which not only reduces the cost of soil removal, but also the plant fiber of the straw provides better physical strength for the seedling tray body. Under the bonding effect of plant protein glue and corn starch, the seedling tray is more firm and more stable during storage; and the moisture content of the seedling tray body and the nutrient soil is between 10-12%, and a layer of degradable film is covered on the nutrient soil, which not only ensures the vitality of the seeds, but also facilitates the storage of the seedling tray after preparation.

[0044] 2. The degradable film of the present invention is a polyvinyl alcohol film, which is prepared from carboxypolyvinyl alcohol. The water solubility and fluidity of the degradable film after dissolution are improved, so that the degradable film on the surface of the seedling tray body can quickly dissolve and infiltrate into the nutrient soil and the seedling tray body during seedling cultivation, and form a sticky complex with the starch in the seedling tray body, providing adhesion to compensate for the reduced viscosity of the seedling tray body caused by the hydrolysis of plant protein glue, so that the seedling tray body maintains good firmness and stability during seedling cultivation, so as to facilitate the rice machine to take the seedling tray body for transplanting, reduce mechanical damage to the rice root system, and improve the production efficiency of the transplanter.

[0045] 3. The rice seedling tray of the present invention only adds a degradable adhesive into the seedling tray body, which will not affect the nutrient soil above the rice seeds. After the degradable film dissolves, it cross-links in the seedling tray body to form a complex, which will only enhance the bonding strength of the seedling tray body, so that the nutrient soil can maintain a loose structure, has little inhibitory effect on seed germination, and is convenient for rice seeds to germinate.

[0046] 4. The preparation method of the present invention can realize the large-scale year-round production of rice pot seedling trays through the prefabrication of the seedling tray body and the pre-sowing of seeds, which can not only extend the production time but also ensure product quality. In addition, the prefabrication production can be carried out according to different regions and rice varieties, thereby improving the factory's seedling supply capacity.

[0047] 5. The fully degradable pre-seeded rice seedling tray of the present invention can be directly placed on a flat and compacted rice seedling raising field or a cement drying field. After being watered and kept moist, the rice seedlings can sprout and emerge. The rice seedling raising is simple, and farmers can arrange the planting time by themselves, which can effectively reduce the cost of rice seedling raising and transplanting for farmers, and has high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a comparison chart of the seedling raising effects of the fully degradable pre-seeded rice pot seedling tray prepared by the present invention and the seedling raising tray prepared by ordinary substrate;

[0049] Figure 2 It is a growth diagram of rice seedlings grown in the fully degradable pre-seeded rice pot seedling tray prepared by the present invention and rice seedlings grown in common substrates; DETAILED DESCRIPTION

[0050] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] A fully degradable pre-seeded rice seedling tray, comprising a seedling tray body, nutrient soil in the seedling tray body, and a degradable film above the nutrient soil;

[0053] The seedling tray body includes the following raw materials in parts by weight: 80 kg of rice straw, 40 kg of cow dung, 15 kg of plant protein glue, and 20 kg of corn starch.

[0054] The steps for preparing the seedling tray body are as follows:

[0055] The rice straw was crushed into a particle size of ≤2mm and then mixed with cow dung for fermentation for 30 days. The compost was turned during the fermentation period to control the moisture content of the fermentation product to 20%. After the fermentation was completed, corn starch and plant protein glue were added to the fermentation product, stirred and mixed evenly, and then pressed into shape. After demolding, the product was baked at a constant temperature of 40°C to a moisture content of 10% to obtain the seedling tray body.

[0056] The rice straw and cow dung are fermented to make the seedling tray, which can promote the growth of seedlings and increase the accumulation of dry matter. The seedlings are strong, neat and uniform, with tight roots, and the seedlings are not easy to break. There are fewer missing seeds during the planting process.

[0057] There are many highly hydrophilic hydroxyl functional groups on the main chain of straw fiber molecules, and the surface of corn starch also has hydroxyl functional groups. The hydroxyl groups combine with each other to form hydrogen bonds, which enhance the adhesion of plant protein glue and help stabilize the structure of the seedling tray.

[0058] The structure of the seedling tray body is:

[0059] The external dimensions of the seedling tray body are 28.0×58.0×1.8cm, the hole depth is 1.5cm, there are 14 holes in a horizontal row and 31 holes in a vertical row, totaling 434 holes, which is convenient for cooperation with the rice transplanter.

[0060] The nutrient soil contains the following raw materials in parts by weight: 20 kg of peat soil, 10 kg of vermiculite, and 0.8 kg of compound micro-fertilizer.

[0061] The steps for preparing nutrient soil are as follows:

[0062] After mixing peat soil and vermiculite and sterilizing them at high temperature, add compound micro-fertilizer, mix and sieve, and dry to a moisture content of 10% to obtain nutrient soil.

[0063] Compound micronutrient fertilizers include the following fertilizers by mass:

[0064] 300g potassium chloride, 300g urea, 150g monoammonium phosphate, 80g borax, 20g superphosphate, 20g magnesium sulfate, and 20g silicon dioxide.

[0065] The degradable film is a polyvinyl alcohol film, and the preparation steps are as follows:

[0066] In a flask, 8 g of ethylene glycol, 8 g of Tween 80 and 12 g of sodium dodecyl sulfate were dissolved in 850 mL of deionized water, 80 g of carboxy polyvinyl alcohol was added to the flask, the flask was sealed and the temperature was raised to 65° C. to swell the carboxy polyvinyl alcohol for 1.5 h, the swollen carboxy polyvinyl alcohol was cast using a solution casting machine and dried at 65° C. to obtain a polyethylene film;

[0067] The introduction of carboxyl groups reduces the crystallinity of polyvinyl alcohol, increases the water solubility rate of polyvinyl alcohol, and improves the fluidity of polyvinyl alcohol after dissolution, which helps to quickly dissolve the film on the surface of the nutrient soil, increase the oxygen content in the nutrient soil, and increase the germination rate of rice seeds.

[0068] A method for preparing a fully degradable pre-seeded rice seedling pot tray comprises the following steps:

[0069] Step 1: Press the seedling tray body into a rectangular tray with pot-shaped holes;

[0070] Step 2: Fill the holes of the seedling tray with 1.5 cm thick nutrient soil;

[0071] Step 3: Cover the nutrient soil with a 25 μm thick biodegradable film to cover all the holes;

[0072] Step 4: Use an edge wrapping machine to wrap the four sides of the degradable film around the sides of the seedling tray body to fix the edges, so as to obtain a fully degradable pre-sowing rice pot seedling tray.

[0073] Example 2

[0074] A fully degradable pre-seeded rice seedling tray, comprising a seedling tray body, nutrient soil in the seedling tray body, and a degradable film above the nutrient soil;

[0075] The seedling tray body includes the following raw materials in parts by weight: 100 kg of rice straw, 50 kg of cow dung, 20 kg of plant protein glue, and 25 kg of corn starch.

[0076] The steps for preparing the seedling tray body are as follows:

[0077] The rice straw was crushed into a particle size of ≤2mm and then mixed with cow dung for fermentation for 35 days. The compost was turned during the fermentation period to control the moisture content of the fermentation product to 25%. After the fermentation was completed, corn starch and plant protein glue were added to the fermentation product, stirred and mixed evenly, and then pressed into shape. After demolding, the product was baked at a constant temperature of 45°C to a moisture content of 11% to obtain the seedling tray body.

[0078] The structure of the seedling tray body is:

[0079] The outer dimensions of the seedling tray body are 28.0×58.0×1.8cm, the hole depth is 1.3cm, there are 18 holes in a horizontal row and 34 holes in a vertical row, for a total of 612 holes in the seedling tray body.

[0080] The nutrient soil contains the following raw materials in parts by weight: 25 kg of peat soil, 15 kg of vermiculite, and 0.9 kg of compound micro-fertilizer.

[0081] The steps for preparing nutrient soil are as follows:

[0082] Peat soil and vermiculite are mixed and sterilized at high temperature, then compound micro-fertilizer is added, the mixture is sieved, and dried to a moisture content of 11% to obtain nutrient soil.

[0083] Compound micronutrient fertilizers include the following fertilizers by mass:

[0084] 325g potassium chloride, 325g urea, 175g monoammonium phosphate, 90g borax, 35g superphosphate, 35g magnesium sulfate, and 35g silicon dioxide.

[0085] The degradable film is a polyvinyl alcohol film, and the preparation steps are as follows:

[0086] In a flask, 9 g of ethylene glycol, 9 g of Tween 80 and 13 g of sodium dodecyl sulfate were dissolved in 875 mL of deionized water, 100 g of carboxy polyvinyl alcohol was added to the flask, the flask was sealed and the temperature was raised to 70° C. to swell the carboxy polyvinyl alcohol for 2 h, the swollen carboxy polyvinyl alcohol was cast using a solution casting machine and dried at 70° C. to obtain a polyethylene film;

[0087] A method for preparing a fully degradable pre-seeded rice seedling pot tray comprises the following steps:

[0088] Step 1: Press the seedling tray body into a rectangular tray with pot-shaped holes;

[0089] Step 2: Fill the holes of the seedling tray with 1.3 cm thick nutrient soil;

[0090] Step 3: Cover the nutrient soil with a 25 μm thick biodegradable film to cover all the holes;

[0091] Step 4: Use an edge wrapping machine to wrap the four sides of the degradable film around the sides of the seedling tray body to fix the edges, so as to obtain a fully degradable pre-sowing rice pot seedling tray.

[0092] Example 3

[0093] A fully degradable pre-seeded rice seedling tray, comprising a seedling tray body, nutrient soil in the seedling tray body, and a degradable film above the nutrient soil;

[0094] The seedling tray body includes the following raw materials in parts by weight: 120 kg of rice straw, 60 kg of cow dung, 25 kg of plant protein glue, and 30 kg of corn starch.

[0095] The steps for preparing the seedling tray body are as follows:

[0096] The rice straw was crushed into a particle size of ≤2mm and then mixed with cow dung for fermentation for 40 days. The compost was turned during the fermentation period to control the moisture content of the fermentation product to 30%. After the fermentation was completed, corn starch and plant protein glue were added to the fermentation product, stirred and mixed evenly, and then pressed into shape. After demolding, the product was baked at a constant temperature of 50°C to a moisture content of 12% to obtain the seedling tray body.

[0097] The structure of the seedling tray body is:

[0098] The outer dimensions of the seedling tray body are 28.0×58.0×1.8cm, the hole depth is 1.2cm, there are 18 holes in a horizontal row and 36 holes in a vertical row, for a total of 648 holes in the seedling tray body.

[0099] The nutrient soil contains the following raw materials in parts by weight: 30 kg of peat soil, 20 kg of vermiculite, and 1 kg of compound micro-fertilizer.

[0100] The steps for preparing nutrient soil are as follows:

[0101] Peat soil and vermiculite are mixed and sterilized at high temperature, then compound micro-fertilizer is added, the mixture is sieved, and dried to a moisture content of 12% to obtain nutrient soil.

[0102] Compound micronutrient fertilizers include the following fertilizers by mass fraction:

[0103] 350g potassium chloride, 350g urea, 200g monoammonium phosphate, 100g borax, 50g superphosphate, 50g magnesium sulfate, and 50g silicon dioxide.

[0104] The degradable film is a polyvinyl alcohol film, and the preparation steps are as follows:

[0105] In a flask, 10 g of ethylene glycol, 10 g of Tween 80 and 15 g of sodium dodecyl sulfate were dissolved in 900 mL of deionized water, 120 g of carboxy polyvinyl alcohol was added to the flask, the flask was sealed and the temperature was raised to 75° C. to swell the carboxy polyvinyl alcohol for 2.5 hours, the swollen carboxy polyvinyl alcohol was cast using a solution casting machine and dried at 75° C. to obtain a polyethylene film;

[0106] A method for preparing a fully degradable pre-seeded rice seedling pot tray comprises the following steps:

[0107] Step 1: Press the seedling tray body into a rectangular tray with pot-shaped holes;

[0108] Step 2: Fill the holes of the seedling tray with 1.2 cm thick nutrient soil;

[0109] Step 3: Cover the nutrient soil with a 30 μm thick biodegradable film to cover all the holes;

[0110] Step 4: Use an edge wrapping machine to wrap the four sides of the degradable film around the sides of the seedling tray body to fix the edges, so as to obtain a fully degradable pre-sowing rice pot seedling tray.

[0111] Plant protein glue was purchased from Shandong Pingju Biotechnology Co., Ltd.;

[0112] Potassium chloride and superphosphate were purchased from Jinan Yuanfang Chemical Co., Ltd.;

[0113] Monoammonium phosphate was purchased from Zhejiang Yicun Biotechnology Co., Ltd.;

[0114] Urea was purchased from Shandong Zhuoan Chemical Co., Ltd.;

[0115] Borax was purchased from the American Borax Group (boron content 21%);

[0116] Tween 80 was purchased from Hai'an Petrochemical Plant, Jiangsu Province;

[0117] Magnesium sulfate, silica, ethylene glycol, and sodium dodecyl sulfate were purchased from Sigma-Aldrich;

[0118] Carboxy polyvinyl alcohol was purchased from Guangzhou Qihua Chemical Co., Ltd.;

[0119] Example 4

[0120] The difference from Example 1 is that the seedling tray is placed for 120 days after preparation.

[0121] Comparative Example 1

[0122] The commercially available ordinary pot-shaped blanket-shaped plastic seedling tray was purchased from Anhui Jusheng Technology Co., Ltd.

[0123] Comparative Example 2

[0124] The difference from Example 4 is that no degradable film is included.

[0125] Comparative Example 3

[0126] The difference from Example 1 is that corn starch is not included.

[0127] The fully degradable pre-seeded rice pot seedling trays prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were pre-seeded and then used for seedling raising experiments in a seedling raising greenhouse. The tested rice variety was Zaoxian 616. The seedling raising results are shown in FIG. Figure 1 , Figure 2 As shown, on the ninth day of seedling raising, the five-point method was used to sample and take the average value to calculate the germination rate per unit area and the integrity of the seedling tray holes. The experimental results are shown in Table 1:

[0128] Table 1

[0129] project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Seedling rate 93.6% 93.1% 92.8% 90.3% 81.2% 72.4% 90.7% The integrity of the holes in the seedling tray 98.2% 98.5% 97.8% 96.7% 99.9% 74.5% 81.2%

[0130] See also Figure 1 As shown, Figure 1 The straw matrix in the middle is the fully degradable pre-sown rice seedling pot tray prepared by the present invention. As can be seen from the figure, the rice seedlings grown in the rice seedling tray prepared by the present invention have more developed root systems and more root systems;

[0131] See also Figure 2 As shown, the rice seedlings grown in the fully degradable pre-seeded rice pot seedling tray prepared by the present invention (right picture) grow significantly better than the rice seedlings grown in the ordinary substrate (traditional seedling tray mainly composed of soil, left picture), and have whiter roots and stronger vitality.

[0132] As can be seen from the data in Table 1, the emergence rates of Examples 1 to 3 of the present invention are much higher than those of Comparative Examples 1 and 3, all reaching more than 92%, and the integrity of the seedling tray holes all reaching more than 97%, indicating that the seedling tray body prepared by the present invention can also ensure the structural stability of the seedling tray body during seedling cultivation; in Comparative Example 1, due to the poor air permeability and excessive water retention of the plastic seedling tray, the emergence rate of seeds is affected, indicating that the present invention has a greater improvement in the emergence rate than the traditional plastic seedling tray; in Comparative Example 3, due to the absence of corn starch, the firmness of the seedling tray body is lower than that of Examples 1 to 3, and the bonding effect of the degradable film on the seedling tray body is less improved after dissolution, resulting in loose and cracked holes of some seedling tray bodies, resulting in a low integrity of the seedling tray holes, thereby affecting the emergence rate of rice seeds;

[0133] The germination rate of Example 4 is much higher than that of Comparative Example 2 because Comparative Example 2 does not have a degradable film covering the nutrient soil. Long-term storage causes part of the seeds in the seedling tray to become inactive, resulting in a low germination rate. In addition, the reduction in water content in the seedling tray body causes the seedling tray body to become brittle, and the holes are easily loosened and cracked after watering again. Therefore, the integrity of the holes in the seedling tray body of Comparative Example 2 is relatively low.

[0134] 120 days after transplanting rice seedlings using the rice transplanter in Example 1-Example 4, the area of ​​the randomly selected unit area of ​​25 cm long and 20 cm wide was greater than 2 cm 2 The rice pot body seedling tray body fragments were washed and dried, and then the rice pot body seedling tray body fragments were weighed. Each group was measured three times and the average value was taken to calculate the degradation rate of the rice pot body seedling tray body. The calculation results are shown in Table 2:

[0135] Table 2

[0136] project Example 1 Example 2 Example 3 Example 4 Degradation rate 71.3% 72.5% 71.8% 70.1%

[0137] It can be seen from the data in Table 2 that the degradation rates of the rice pot body seedling tray embodiments 1 to 4 prepared by the present invention in the rice field are all higher than 70% after 120 days, indicating that the rice pot body seedling tray prepared by the present invention has good degradability and high environmental protection.

[0138] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0139] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fully degradable pre-seeded rice seedling pot tray, characterized in that: It includes a seedling tray body, nutrient soil in the seedling tray body, and a degradable film above the nutrient soil; The seedling tray body comprises the following raw materials in parts by weight: 80-120 parts of rice straw, 40-60 parts of cow dung, 15-25 parts of degradable adhesive, and 20-30 parts of corn starch; The nutrient soil comprises the following raw materials in parts by weight: 20-30 parts of peat soil, 10-20 parts of vermiculite, and 0.8-1 part of compound micro-fertilizer; The degradable adhesive is plant protein glue; The degradable film is a polyvinyl alcohol film; The steps for preparing the seedling tray body are as follows: The rice straw is crushed to a particle size of ≤2 mm and then mixed with cow dung for fermentation for 30-40 days. After the fermentation is completed, corn starch and plant protein glue are added to the fermentation product, and after stirring and mixing evenly, the mixture is pressed into shape. After demoulding, the mixture is baked at a constant temperature of 40-50° C. to a moisture content of 10-12% to obtain a seedling tray body. The polyvinyl alcohol film is prepared by the following steps: Dissolve ethylene glycol, Tween 80 and sodium dodecyl sulfate in deionized water in a flask, add carboxy polyvinyl alcohol into the flask, seal the flask and heat to 65-75° C. to swell the carboxy polyvinyl alcohol for 1.5-2.5 hours, cast the swollen carboxy polyvinyl alcohol using a solution casting machine and dry at 65-75° C. to obtain a polyethylene film.

2. A fully degradable pre-seeded rice seedling tray according to claim 1, characterized in that: The nutrient soil is prepared by the following steps: After mixing peat soil and vermiculite and sterilizing them at high temperature, add compound micro-fertilizer, mix and sieve, and dry to a moisture content of 10-12% to obtain nutrient soil.

3. The fully degradable pre-seeded rice seedling tray according to claim 1, characterized in that: The compound micro-fertilizer comprises the following fertilizers in parts by mass: 30-35 parts of potassium chloride, 30-35 parts of urea, 15-20 parts of monoammonium phosphate, 8-10 parts of borax, 2-5 parts of superphosphate, 2-5 parts of magnesium sulfate, and 2-5 parts of silicon dioxide.

4. The fully degradable pre-seeded rice seedling tray according to claim 1, characterized in that: The mass ratio of the carboxypolyvinyl alcohol, ethylene glycol, Tween 80, sodium lauryl sulfate and deionized water is 8-12: 0.8-1: 0.8-1: 1.2-1.5: 85-90.

5. The fully degradable pre-seeded rice seedling tray according to claim 1, characterized in that: The method of using the seedling tray is: S1, using a punching machine to press the seedling tray body into a rectangular tray with pot-shaped holes; S2, sowing rice seeds in the holes of the seedling tray body with a seeder, 2-3 seeds per hole of hybrid rice and 4-6 seeds per hole of conventional rice; S3, filling the holes of the seedling tray with nutrient soil; S4. Cover the nutrient soil with a layer of biodegradable film to cover all the holes; S5. Use an edge wrapping machine to wrap the four sides of the degradable film on the sides of the seedling tray body and fix the edges.

6. The method for preparing a fully degradable pre-seeded rice seedling pot tray according to claim 1, characterized in that: The preparation method comprises the following steps: Step 1: Press the seedling tray body into a rectangular tray with pot-shaped holes; Step 2: Fill the holes of the seedling tray with 1.2-1.5 cm thick nutrient soil; Step 3: Cover the nutrient soil with a layer of 25-30 μm thick degradable film to cover all the holes; Step 4: Use an edge wrapping machine to wrap the four sides of the degradable film on the sides of the seedling tray body and fix the edges to obtain a fully degradable pre-sown rice seedling tray.

7. The method for preparing a fully degradable pre-seeded rice seedling pot tray according to claim 6, characterized in that: The seedling tray body is rectangular, with bowl-shaped holes arranged in an array inside the rectangle, the hole depth is 1.2-1.5 cm, the seedling tray body is 58.0 cm long, 28.0 cm wide, and 1.8 cm high, with 14-18 holes arranged in the width direction and 31-36 holes arranged in the length direction, and the number of holes in the seedling tray body is 434-648 holes.

Images