Wet-formed rice seedling raising substrate sheet as well as preparation method and application thereof

Abstract

The invention provides a wet-formed rice seedling raising substrate sheet as well as a preparation method and application thereof, and belongs to the technical field of rice cultivation. The preparation method comprises the following steps: mixing livestock manure with a mixture of rice bran and husk, adding a nutritional agent and active bacteria into the mixture, and sequentially performing primary fermentation and secondary fermentation to obtain a completely decomposed fermented material; mixing the fermented material, straw fibers, crushed rice hulls and sodium bentonite to prepare slurry, and carrying out wet slurry fishing and suction, pressing, suction filtration forming and drying to obtain the substrate sheet. According to the method, breeding manure and agricultural straw resources are comprehensively utilized, and the high-nutrition disease-resistant rice seedling raising substrate sheet is prepared. When the rice seedling raising substrate sheet is used for rice seedling raising, the seedling raising preparation period can be shortened by 80%, and the comprehensive cost is reduced by 30%; the seedlings are neat and strong, root systems are developed, damping-off is avoided, and the seedling protection rate is 90% or above.

Description

Technical Field

[0001] The invention relates to the technical field of rice cultivation, and in particular to a wet-formed rice seedling-raising substrate sheet and a preparation method and application thereof. Background Art

[0002] With the development of rice cultivation technology, rice machine transplanting technology has gradually replaced manual transplanting technology, greatly improving labor efficiency and saving labor. For machine transplanting technology, cultivating rice seedlings that meet the standards is the key to rice machine transplanting. At this stage, rice transplanters require rice seedlings to grow in modular seedling trays, and have high requirements for the age and morphological indicators of the seedlings (such as uniform and neat growth of seedlings, appropriate seedling height, developed root system, bright green leaves and no diseases, etc.). The morphological indicators of seedlings are closely related to the seedling culture medium.

[0003] At present, the main substrates for raising rice seedlings in my country are natural soil, nutrient soil and organic substrates for raising rice seedlings. Among them, the use of nutrient soil accounts for a large proportion. Although the commercially available powdered substrate can replace part of the nutrient soil, it cannot solve the dependence on nutrient soil and realize soilless rice seedling raising. At present, most of the nutrient soil is made by growers or rice seedling raising organizations, and a small part is produced by factories. There are mainly problems such as quality not meeting the requirements, cumbersome preparation process, and high labor intensity. It can no longer meet the needs of large-scale centralized rice seedling raising, which restricts the promotion and application of mechanical transplanting. In addition, due to the different soil fertility and fertilization standards used as bed soil in various places, the bed soil after fertilization is not thoroughly disinfected, which is easy to cause soil-borne diseases, bringing harm to rice seedling raising. Therefore, both natural soil and nutrient soil are no longer suitable for the requirements of machine transplanting technology for rice seedling raising. It is necessary to develop a rice seedling raising substrate product that is more suitable for machine transplanting technology to replace traditional natural soil or nutrient soil. Summary of the invention

[0004] In view of the problems of damage to cultivated land and vegetation, long production preparation time, high labor consumption, soil-borne diseases, etc. caused by traditional rice seedling raising, the present invention provides a wet-formed rice seedling raising substrate sheet and a preparation method thereof. The preparation method comprises mixing poultry and livestock manure with bran, adding nutrients and active bacteria for composting and fermentation, and then mixing the obtained fermented material with straw fiber and rice husk crushed to make pulp, and then performing the steps of wet-process slurry suction, pressing, suction filtration and forming, and drying to obtain the substrate sheet. The method achieves the purpose of comprehensively utilizing livestock manure and agricultural straw resources to prepare a rice seedling raising substrate sheet with comprehensive nutrition and resistance to diseases, while shortening the rice seedling raising process, saving labor consumption, and reducing the cost of rice seedling raising.

[0005] Specifically, the present invention adopts the following technical solutions to achieve the above objectives: A method for preparing a wet-formed rice seedling raising substrate sheet comprises the following steps: S1, mixing poultry and livestock manure with bran to obtain a mixed material A; adding nutrients and active bacteria to the mixed material A, mixing them evenly, to obtain a mixed material B; subjecting material B to primary fermentation and secondary fermentation in sequence to obtain a fermented material; the nutrient is a mixture of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate; The straw is prepared into straw fibers with a length of ≤5 mm; preparing the dry rice husk into rice husk crumbs with a particle size of ≤5 mm; S2, the fermentation material, the straw fiber, the rice husk crushed and the sodium bentonite are uniformly mixed according to their respective dry weight mass ratios of (55-65):(30-35):(5-8):(3-5), and then water is added to prepare a slurry with a solid content of 1.2wt%-2.4wt%, and the pH of the slurry is adjusted to 5.0-6.5; S3, conveying the slurry prepared in step S2 to the slurry pool of the molding machine, scooping and sucking the slurry through a standard mold, extruding, filtering and sucking to form, and then drying to obtain a rice seedling substrate sheet.

[0006] In a preferred embodiment, the mass ratio of livestock manure to bran in step S1 is (50-80):(20-50).

[0007] In a preferred embodiment, the water content of the livestock manure is ≤75wt%.

[0008] In a preferred embodiment, the moisture content of the bran is ≤15wt%.

[0009] In a preferred embodiment, the livestock manure includes at least one of cow manure, sheep manure and pig manure.

[0010] In a preferred embodiment, the active bacterial agent is Bacillus subtilis.

[0011] In a preferred embodiment, the amount of the nutrient agent is 0.2% to 0.5% of the mass of the mixed material A.

[0012] In a preferred embodiment, the amount of the active bacteria is 0.1% to 0.2% of the mass of the mixed material A.

[0013] In a preferred embodiment, the water content of the mixed material B is controlled at 50wt%~65wt%.

[0014] In a preferred embodiment, the carbon-nitrogen mass ratio in the mixed material B is (25-30):1.

[0015] In a preferred embodiment, the nutrient agent is mixed with monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of (30~50):(10~15):(3~8):(5~10):(5~8):(1.5~2.5):(0.5~1.5):(0.5~1):(0.01~0.1).

[0016] In a preferred embodiment, the steps of fermenting the mixed material B are as follows: putting the mixed material B into a fermentation tank, controlling the pile height in the fermentation tank to be ≤2 meters; supplying oxygen through the aeration pipe of the fermentation tank, and the oxygen concentration is 15%~20%; when the material core temperature in the fermentation tank rises to 50~65°C, starting to turn the pile, and after continuing fermentation for 25~30 days, obtaining the intermediate fermentation material C.

[0017] In a further preferred embodiment, the steps of secondary fermentation of the mixed material B are as follows: the intermediate fermentation material C is transported to an aging workshop, and secondary fermentation is carried out by natural stacking and ventilation, the pile height is controlled to be 3 to 6 meters, the pile is turned over every 5 to 7 days, and after 20 to 25 days of secondary fermentation, particles with a particle size of 5 mm or more are screened out to obtain a fermentation material with a moisture content ≤30wt%.

[0018] In a preferred embodiment, the drying temperature in step S3 is 180-220° C., and the drying time is 45-60 minutes.

[0019] The present invention also provides a rice seedling raising substrate sheet prepared according to any one of the above schemes.

[0020] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) The rice seedling raising substrate sheet provided by the present invention is used for raising rice seedlings, which can be used immediately after purchase. Compared with the existing substrate or field soil for raising rice seedlings, it saves more than 50% of manpower, shortens the rice seedling raising preparation period by 80%, and reduces the overall cost by 30%.

[0021] (2) The rice seedling cultivation substrate sheet of the present invention has comprehensive nutrients. The rice seedlings cultivated by using the substrate sheet are uniform, strong, have a well-developed root system, and are free from damping-off disease. The seedling survival rate is above 90%. After transplanting, the seedlings grow quickly and have more tillers, which can promote rice yield increase.

[0022] (3) The preparation method of the rice seedling substrate sheet provided by the present invention realizes the whole process of modern factory production from ingredient preparation, fermentation to pulping, molding and drying, making the quality of the rice seedling substrate sheet more stable and reliable, thereby improving the quality and safety of rice seedlings, and greatly promoting the development of centralized rice seedling cultivation and mechanical transplanting technology.

[0023] (4) The preparation method of the rice seedling substrate sheet provided by the present invention comprehensively utilizes livestock and poultry manure and agricultural straw, effectively realizes energy conservation and emission reduction in agricultural breeding and planting, promotes the development of an ecological agricultural breeding and farming cycle, and provides a new and effective way for the green circular economy of agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart for preparing the rice seedling raising substrate sheet in this application. DETAILED DESCRIPTION

[0025] The following content is combined with the embodiments to clearly and completely describe the technical solution of the present application so that those skilled in the art can fully understand the present application. Obviously, the described embodiments are only some preferred embodiments of the present application, rather than all embodiments. Any equivalent transformation or substitution made to the following implementation modes by those of ordinary skill in the art without creative work belongs to the protection scope of the present application.

[0026] The calcium magnesium phosphate fertilizer used in the following examples is a commercially available product that meets the GB / T 20412-2021 "Calcium Magnesium Phosphate Fertilizer" standard. The viable count of Bacillus subtilis is 10 billion CFU / g. The whole bran is composed of rice bran and rice husk powder in a mass ratio of 2-3:7-8. The various components in the nutrient are common products on the market.

[0027] The product quality inspection standards of the rice seedling substrate sheet prepared in this application are shown in Table 1.

[0028] Table 1 Quality standards for rice seedling substrate sheets

[0029] Reference Figure 1 The specific embodiment of the present invention provides a method for preparing a wet-formed rice seedling raising substrate sheet, comprising the following steps: A method for preparing a wet-formed rice seedling raising substrate sheet comprises the following steps: S1. Preparation of fermentation materials, straw fiber and rice husk fragments In terms of mass, 50-80 parts of livestock manure with a moisture content of ≤75wt% are mixed with 20-50 parts of bran with a moisture content of ≤15wt% to obtain a mixed material A. Add 0.2%-0.5% of the mass of nutrients and 0.1%-0.2% of the mass of active bacteria to the mixed material A, mix them evenly, and obtain a mixed material B with a moisture content of 50wt%-65wt% and a carbon-nitrogen mass ratio of (25-30):1. Put the mixed material B into a fermentation tank, and control the pile height in the fermentation tank to be ≤2 meters. Oxygen is supplied through the aeration pipe of the fermentation tank, and the oxygen supply concentration is 15%-20%. When the material core temperature in the fermentation tank rises to 50-65°C, turn the pile, and continue fermentation for 25-30 days to obtain an intermediate fermentation material C. The intermediate fermentation material C is transported to the aging workshop, and secondary fermentation is carried out by natural stacking and ventilation. The pile height is controlled to be 3-6 meters, and the pile is turned every 5-7 days (for example, 5 days, 6 days or 7 days). After 20-25 days (for example, 20 days, 21 days, 22 days, 23 days or 25 days) of secondary fermentation, the larger particles are removed by a 5mm drum screen to obtain a fermentation material with a moisture content of ≤30wt%. Among them, the poultry and livestock manure is one or more of cow manure, sheep manure or pig manure. The nutrient agent is a mixture of monoammonium phosphate (diammonium phosphate), potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of (30-50):(10-15):(3-8):(5-10):(5-8):(1.5-2.5):(0.5-1.5):(0.5-1):(0.01-0.1). The active bacterial agent is Bacillus subtilis.

[0030] The straw with a moisture content of ≤15wt% is crushed to a length of ≤5cm by a crusher, and then sent to a high-concentration pulping machine. Water needs to be added during the pulping. After the straw crushed material is ground by the high-concentration pulping machine, straw fibers with a length of ≤5mm are obtained. The straw is generally selected from one or more of rice straw, wheat straw, and corn straw.

[0031] The dry rice husk with a moisture content of ≤10wt% is sent to a thread rolling machine for crushing and kneading, and the rice husk crumbs with a particle size of ≤5mm are obtained after processing.

[0032] S2. Pulping The fermented material, straw fiber, rice husk crushed and nano-bentonite prepared in step S1 are mixed evenly according to their respective dry weight mass ratios of (55~65):(30~35):(5~8):(3~5) and added to the metering bin, and then conveyed to the feeding belt after being measured by the belt scale of the metering bin, and then conveyed to the pulping machine via the feeding belt. The materials enter the pulping machine in batches, and tap water is added to make a slurry with a solid content of 3wt%~8wt%. The pulping machine pulps in batches, and the slurry prepared in each batch is sent to the slurry stirring tank through a pipeline. The slurry stirring tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. The slurry in the slurry stirring tank is conveyed to the slurry supply tank by a slurry pump, diluted with water to a solid content of 1.2wt%~2.4wt%, and an appropriate amount of concentrated sulfuric acid is added to adjust the pH of the slurry to 5.0~6.5. The slurry supply tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. Repeating the slurrying step can achieve continuous slurry supply.

[0033] S3, drying and molding The slurry in the slurry supply tank is pumped into the slurry tank of the molding machine. The slurry in the slurry tank of the molding machine is stirred by compressed air. The lower mold of the molding machine is deep into the liquid surface. After holding for 3 to 5 seconds, the slurry is fished out. During the slurry fishing process of the lower mold, the vacuum pump is kept to suck and filter out part of the water in the slurry. After the lower mold moves up to the set position, it is molded with the upper mold, and the filtration is carried out for 3 to 5 seconds. The vacuum suction valve of the lower mold is closed, and the upper mold is kept sucking and moved up to obtain the formed matrix sheet wet blank. The wet blank is transferred to the chain plate tray of the dryer and sent to the drying box via the chain plate tray. The drying box is continuously heated by a boiler or a hot air furnace to maintain the drying temperature in the dryer at 180~220℃. The chain tray in the drying box is divided into six layers from top to bottom, and the residence time of the matrix sheet wet blank is 45~60 minutes. The tail end of the dryer is equipped with a circulating fan, which circulates 80% of the low-temperature hot air from the lower air chamber to the upper air chamber to mix with the heat supplied by the boiler for recycling. The remaining 20% ​​of the low-temperature hot air is discharged to the heat exchanger to heat the slurry pumped out of the slurry mixing tank to achieve heat recovery. After drying, the matrix sheets are sent out from the lower layer of the drying box and introduced into the baler belt through a mechanical device. After the baler automatically stacks them into piles, they are packaged by manual bagging. Repeating the above steps can achieve continuous production of matrix sheet wet blanks and continuous drying processes.

[0034] After the wet blank is dried, a matrix sheet product with a size of (575±5) mm×(275±5) mm, a thickness of 8-10 mm, a single sheet weight of 300-350 g, and a moisture content of 5%-8% is obtained.

[0035] In this application, the moisture content of livestock manure is controlled to be ≤75wt%, and the moisture content of bran is ≤15wt%. Bran can effectively balance excess water, which is conducive to the fermentation raw materials to quickly reach the optimal fermentation moisture content. The straw is ground into fibers with a length of ≤5mm by a pulping machine, which is the key material for product molding in this application, can ensure the adhesion and molding of various raw material tissues, and maintain the structural strength, looseness and stability of the product. Rice husk crushed rice husk is obtained by grinding and crushing rice husk, which improves its water absorption performance, can effectively improve the air permeability of the product in the matrix sheet, and can appropriately reduce the water holding capacity of the product, thereby controlling the moisture content of the wet blank during the suction filtration of the molding machine to reduce the energy consumption of product drying. The matrix sheet is dried by hot air at 180℃-220℃, and the drying time is 45~60 minutes, which can effectively kill material pests and diseases, mature the fibers, and greatly reduce the adverse factors of the seedling cultivation process on the growth of seedlings.

[0036] As an example, the number of portions of livestock manure in step S1 is 50 portions, 55 portions, 56 portions, 60 portions, 62 portions, 65 portions, 68 portions, 70 portions, 75 portions, and 80 portions, but is not limited to the aforementioned examples.

[0037] As examples, the number of portions of bran in step S1 is 20 portions, 22 portions, 25 portions, 30 portions, 36 portions, 40 portions, 45 portions, and 50 portions, but is not limited to the aforementioned examples.

[0038] As an example, the mass ratios of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in step S1 are 40:10:6:8:6:2:1:0.7:0.05, 30:12:4:10:7:1.5:0.5:0.5:0.1, 35:15:5:10:8:2.5:1.5:1:0.01, 50:14:8:6:5:2.3:0.9:0.8:0.08, and 45:13:3:5:5:1.8:1.1:0.9:0.06, but are not limited to the aforementioned examples.

[0039] As examples, the moisture content in the mixed material B is 50wt%, 51wt%, 55wt%, 58wt%, 60wt%, and 65wt%, but is not limited to the aforementioned examples.

[0040] As an example, the carbon-nitrogen mass ratio in the mixed material B is 25:1, 26:1, 27:1, 28:1, 29:1, and 30:1, but is not limited to the aforementioned examples.

[0041] As an example, the material core temperature in the fermentation tank is 50~52℃, 51~53℃, 52~55℃, 55~56℃, 56~57℃, 57~58℃, 60~62℃, 63~65℃; the fermentation time is 25 days, 26 days, 27 days, 28 days, 29 days or 30 days; but it is not limited to the aforementioned examples.

[0042] As an example, the dry weight ratios of fermentation materials, straw fibers, rice husks and nano-bentonite are 55:30:5:3, 55:40:5:3.5, 58:35:7:4, 60:35:5:4.5 and 65:32:8:5, but are not limited to the aforementioned examples.

[0043] As examples, the solid content of the slurry in the pulping machine is 3wt%, 4wt%, 5wt%, 5.5wt%, 6wt%, 7wt%, and 8wt%, but is not limited to the aforementioned examples.

[0044] As examples, the solid content of the diluted slurry in the slurry supply tank is 1.2wt%, 1.3wt%, 1.4wt%, 1.6wt%, 1.8wt%, 2.0wt%, and 2.4wt%, but is not limited to the aforementioned examples.

[0045] Example 1 A method for preparing a wet-formed rice seedling raising substrate sheet comprises the following steps: S1. Preparation of fermentation materials, straw fiber and rice husk fragments 60 parts of cow dung with a moisture content of 72wt% and 20 parts of bran with a moisture content of 10wt% were mixed to obtain a mixed material A. 0.4% of the mass of the nutrient and 0.1% of the mass of the active bacteria (the number of active bacteria was 10 billion CFU / g of Bacillus subtilis) were added to the mixed material A, and mixed evenly to obtain a mixed material B with a moisture content of 56.5wt% and a carbon-nitrogen mass ratio of 26:1. The mixed material B was put into the fermentation tank, and the pile height in the fermentation tank was controlled to be ≤2 meters. Oxygen was supplied through the aeration pipe of the fermentation tank, and the oxygen supply concentration was 18%. When the core temperature of the material in the fermentation tank rose to 60~65℃, the pile was turned over. After continuous fermentation for 28 days, the intermediate fermentation material C was obtained. The intermediate fermentation material C was transported to the aging workshop, and secondary fermentation was carried out by natural stacking and ventilation. The pile height was 5 meters, and the pile was turned over once every 5 days. After 25 days of secondary fermentation, larger particles were removed through a 5mm drum screen to obtain a fermentation material with a moisture content of 20wt%. Among them, the nutrient agent is a mixture of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of 40:10:6:8:6:2:1:0.7:0.05.

[0046] The rice straw with a moisture content of 12wt% is crushed to a length of ≤5cm by a crusher, and then sent to a high-concentration refiner. Water needs to be added during the refining. After the rice straw crushed material is ground by the high-concentration refiner, straw fibers with a length of ≤5mm and a moisture content of 45wt% are obtained.

[0047] The dry rice husk with a moisture content of 8wt% was sent to a thread rolling machine for crushing and kneading, and after processing, rice husk crumbs with a particle size of ≤5mm and a moisture content of 42wt% were obtained.

[0048] S2. Pulping The fermented material, straw fiber, rice husk crushed and sodium bentonite prepared in step S1 are mixed evenly according to their respective dry weight ratios of 60:35:5:5, and then added to the metering bin, and then conveyed to the feeding belt after being measured by the belt scale of the metering bin, and then conveyed to the pulping machine via the feeding belt. The materials enter the pulping machine in batches, and tap water is added to make a slurry with a solid content of 5wt%. The pulping machine pulps in batches, and the slurry prepared in each batch is sent to the slurry stirring tank through a pipeline. The slurry stirring tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. The slurry in the slurry stirring tank is transported to the slurry supply tank by a slurry pump, diluted with water to a solid content of 1.5wt%, and an appropriate amount of concentrated sulfuric acid is added to adjust the pH of the slurry to 5. The slurry supply tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. Repeating the slurrying step can achieve continuous slurry supply.

[0049] S3, drying and molding The slurry in the slurry supply tank is pumped into the slurry tank of the molding machine. The slurry in the slurry tank of the molding machine is stirred by compressed air. The lower mold of the molding machine is deep into the liquid surface. After holding for 3 to 5 seconds, the slurry is fished out. During the slurry fishing process of the lower mold, the vacuum pump is kept to suck and filter out part of the water in the slurry. After the lower mold moves up to the set position, it is molded with the upper mold and filtered for 3 to 5 seconds. The vacuum suction valve of the lower mold is closed, and the upper mold is kept sucking and moved up to obtain the formed matrix sheet wet blank (575mm×275mm×10mm). The wet blank is transferred to the chain plate tray of the dryer and sent to the drying box via the chain plate tray. The drying box is continuously heated by a boiler or a hot air furnace to keep the drying temperature in the dryer at 200℃. The chain tray in the drying box is divided into six layers from top to bottom, and the residence time of the matrix sheet wet blank is 50 minutes. The tail end of the dryer is equipped with a circulating fan, which circulates 80% of the low-temperature hot air from the lower air chamber to the upper air chamber to mix with the heat supplied by the boiler for recycling. The remaining 20% ​​of the low-temperature hot air is discharged to the heat exchanger to heat the slurry pumped out of the slurry mixing tank to achieve heat recovery. After drying, the matrix sheets are sent out from the lower layer of the drying box and introduced into the baler belt through a mechanical device. After the baler automatically stacks them into piles, they are packaged by manual bagging. Repeating the above steps can achieve continuous production of matrix sheet wet blanks and continuous drying processes.

[0050] After testing, the prepared matrix sheet had a moisture content of 7wt%, a weight of 313g, a size of 573mm×271mm×9.0mm, an organic matter content of 55%, a pH of 6.8, a conductivity of 0.578mS / cm, and a total nutrient content of 5.5wt%, and the limit indicators met the requirements.

[0051] Example 2 A method for preparing a wet-formed rice seedling raising substrate sheet comprises the following steps: S1. Preparation of fermentation materials, straw fiber and rice husk fragments 70 parts of pig manure with a moisture content of 75wt% were mixed with 30 parts of bran with a moisture content of 10wt% to obtain a mixed material A. 0.25% of the mass of the nutrient and 0.1% of the mass of the active bacteria (the number of active bacteria was 10 billion CFU / g of Bacillus subtilis) were added to the mixed material A, and mixed evenly to obtain a mixed material B with a moisture content of 55.5wt% and a carbon-nitrogen mass ratio of 25:1. The mixed material B was put into the fermentation tank, and the pile height in the fermentation tank was controlled to be ≤2 meters. Oxygen was supplied through the aeration pipe of the fermentation tank, and the oxygen supply concentration was 15%. When the core temperature of the material in the fermentation tank rose to 60~65℃, the pile was turned over. After continuous fermentation for 30 days, the intermediate fermentation material C was obtained. The intermediate fermentation material C was transported to the aging workshop, and secondary fermentation was carried out by natural stacking and ventilation. The pile height was 6 meters, and the pile was turned over every 5 days. After 25 days of secondary fermentation, larger particles were removed through a 5mm drum screen to obtain a fully decomposed fermentation material with a moisture content of 25wt%. Among them, the nutrient agent is a mixture of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of 30:12:4:10:7:1.5:0.5:0.5:0.1.

[0052] The wheat straw with a moisture content of 10wt% is crushed to a length of ≤5cm by a crusher, and then sent to a high-concentration refiner. Water needs to be added during the refining. After the wheat straw crushed material is ground by the high-concentration refiner, straw fibers with a length of ≤5mm and a moisture content of 45wt% are obtained.

[0053] The dry rice husk with a moisture content of 8wt% was sent to a thread rolling machine for crushing and kneading, and after processing, rice husk crumbs with a particle size of ≤5mm and a moisture content of 42wt% were obtained.

[0054] S2. Pulping The fermented material, straw fiber, rice husk crushed and sodium bentonite prepared in step S1 are mixed evenly according to their respective dry weight ratios of 58:35:7:3.5, and then added to the metering bin, and then conveyed to the feeding belt after being measured by the belt scale of the metering bin, and then conveyed to the pulping machine via the feeding belt. The materials enter the pulping machine in batches, and tap water is added to make a slurry with a solid content of 5wt%. The pulping machine pulps in batches, and the slurry prepared in each batch is sent to the slurry stirring tank through a pipeline. The slurry stirring tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. The slurry in the stirring tank is pumped to the slurry supply tank, diluted with water to a solid content of 1.8wt%, and an appropriate amount of concentrated sulfuric acid is added to adjust the pH of the slurry to 5. The slurry supply tank is equipped with a stirrer to prevent the material from settling and causing uneven concentration. Repeating the slurrying step can achieve continuous slurry supply.

[0055] S3, drying and molding The slurry in the slurry supply tank is pumped into the slurry tank of the molding machine. The slurry in the slurry tank of the molding machine is stirred by compressed air. The lower mold of the molding machine is deep into the liquid surface. After holding for 3 to 5 seconds, the slurry is fished out. During the slurry fishing process of the lower mold, the vacuum pump is kept to suck and filter out part of the water in the slurry. After the lower mold moves up to the set position, it is molded with the upper mold, and the filtration is carried out for 3 to 5 seconds. The vacuum suction valve of the lower mold is closed, and the upper mold is kept sucking and moved up to obtain the formed matrix sheet wet blank (575mm×275mm×10mm). The wet blank is transferred to the chain plate tray of the dryer, and sent to the drying box through the chain plate tray. The drying box is continuously heated by a boiler or a hot air furnace to keep the drying temperature in the dryer at 180℃. The chain tray in the drying box is divided into six layers from top to bottom, and the residence time of the matrix sheet wet blank is 60 minutes. The tail end of the dryer is equipped with a circulating fan, which circulates 80% of the low-temperature hot air from the lower air chamber to the upper air chamber to mix with the heat supplied by the boiler for recycling. The remaining 20% ​​of the low-temperature hot air is discharged to the heat exchanger to heat the slurry pumped out of the slurry mixing tank to achieve heat recovery. After drying, the matrix sheets are sent out from the lower layer of the drying box and introduced into the baler belt through a mechanical device. After the baler automatically stacks them into piles, they are packaged by manual bagging. Repeating the above steps can achieve continuous production of matrix sheet wet blanks and continuous drying processes.

[0056] After testing, the prepared matrix sheet had a water content of 8wt%, a weight of 325g, a size of 572mm×272mm×9.5mm, an organic matter content of 52%, a pH of 6.65, a conductivity of 0.655mS / cm, and a total nutrient content of 6.2wt%, and the limit indicators met the requirements.

[0057] Example 3 A method for preparing a wet-formed rice seedling raising substrate sheet comprises the following steps: S1. Preparation of fermentation materials, straw fiber and rice husk fragments Mix 25 parts of cow dung with a moisture content of 70wt%, 50 parts of pig dung with a moisture content of 75wt% and 25 parts of bran with a moisture content of 10wt% to obtain a mixed material A. Add 0.35% of the mass of nutrients and 1‰ of active bacteria (the number of active bacteria is 10 billion CFU / g Bacillus subtilis) to the mixed material A, mix them evenly, and obtain a mixed material B with a moisture content of 60wt% and a carbon-nitrogen mass ratio of 28:1. Put the mixed material B into the fermentation tank, and control the pile height in the fermentation tank to ≤2 meters. Oxygen is supplied through the aeration pipe of the fermentation tank, and the oxygen supply concentration is 20%. When the core temperature of the material in the tank rises to 60~65℃, turn the pile and continue fermentation for 30 days to obtain the intermediate fermentation material C. The intermediate fermentation material C is transported to the aging workshop, and secondary fermentation is carried out by natural stacking and ventilation. The pile is 3 meters high and turned over every 5 days. After 25 days of secondary fermentation, the larger particles are removed by a 5mm drum screen to obtain a fully decomposed fermentation material with a moisture content of 28wt%. Among them, the nutrient agent is a mixture of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of 35:15:5:10:8:2.5:1.5:1:0.01.

[0058] The corn stalks with a moisture content of 10wt% are crushed into a length of ≤5cm by a crusher, and then sent to a high-concentration refiner. Water needs to be added during the refining. After the corn stalk crushed material is ground by the high-concentration refiner, straw fibers with a length of ≤5mm and a moisture content of 45wt% are obtained.

[0059] The dry rice husk with a moisture content of 10wt% was sent to a thread rolling machine for crushing and kneading, and after processing, rice husk crumbs with a particle size of ≤5mm and a moisture content of 42wt% were obtained.

[0060] S2. Pulping The fermented material, straw fiber, rice husk crushed and sodium bentonite prepared in step S1 are mixed evenly according to their respective dry weight ratios of 55:40:5:4, and then added to the metering bin, and then conveyed to the feeding belt after being measured by the belt scale of the metering bin, and then conveyed to the pulping machine via the feeding belt. The materials enter the pulping machine in batches, and tap water is added to make a slurry with a solid content of 5wt%. The pulping machine pulps in batches, and each batch of prepared slurry is placed in a stirring tank. The slurry in the stirring tank is pumped to the slurry supply tank, diluted with water to a solid content of 1.5wt%, and an appropriate amount of concentrated sulfuric acid is added to adjust the pH of the slurry to 5. The slurry supply tank is equipped with a stirrer to prevent material precipitation and cause uneven concentration. Repeating the slurrying step can achieve continuous slurry supply.

[0061] S3, drying and molding The slurry in the slurry supply tank is pumped into the molding machine, and the slurry in the slurry tank of the molding machine is stirred by compressed air. The lower mold of the molding machine is deep into the liquid surface, and after holding for 3 to 5 seconds, the slurry is fished out. During the slurry fishing process of the lower mold, the vacuum pump is kept to suck and filter out part of the water in the slurry. After the lower mold moves up to the set position, it is molded with the upper mold, and the filtration is carried out for 3 to 5 seconds. The vacuum suction valve of the lower mold is closed, and the upper mold is kept sucking and moved up to obtain the formed matrix sheet wet blank (575mm×275mm×11mm). The wet blank is transferred to the chain plate tray of the dryer, and sent to the drying box via the chain plate tray. The drying box is continuously heated by a boiler or a hot air furnace to keep the drying temperature in the dryer at 220℃. The chain tray in the drying box is divided into six layers from top to bottom, and the residence time of the matrix sheet wet blank is 45 minutes. The tail end of the dryer is equipped with a circulating fan, which circulates 80% of the low-temperature hot air from the lower air chamber to the upper air chamber to mix with the heat supplied by the boiler for recycling. The remaining 20% ​​of the low-temperature hot air is discharged to the heat exchanger to heat the slurry pumped out of the slurry mixing tank to achieve heat recovery. After drying, the matrix sheets are sent out from the lower layer of the drying box and introduced into the baler belt through a mechanical device. After the baler automatically stacks them into piles, they are packaged by manual bagging. Repeating the above steps can achieve continuous production of matrix sheet wet blanks and continuous drying processes.

[0062] After testing, the prepared matrix sheet had a water content of 8wt%, a weight of 330g, a size of 570mm×271mm×10mm, an organic matter content of 52%, a pH of 6.5, a conductivity of 0.695mS / cm, and a total nutrient content of 4.5wt%, and the limit indicators met the requirements.

[0063] Comparative Example 1 The seedling raising substrate sheet in this comparative example is prepared as follows: a commercially available rice seedling raising substrate and dry fine garden soil are mixed in a mass ratio of 1:1 to form a rice seedling raising bed soil, which is then loaded into a standard rice seedling raising tray (580mm×280mm), with each tray containing 3±0.5 kg of rice seedling raising bed soil, and the bed soil is evenly spread on the rice seedling raising tray with a thickness of 1.8~2cm. Among them, the main technical indicators of the commercially available rice seedling raising substrate are as follows: pH value is 5.5~7.0 (for example, pH is 6.0), total porosity is 50%~80% (for example, total porosity is 65%), moisture content is <30wt% (for example, moisture content is 25wt%), and bulk density is 0.3~0.6g / cm 3 (For example, the bulk density is 0.5g / cm 3 ), organic matter content>40wt% (for example, organic matter content is 48wt%), total nitrogen, phosphorus and potassium content>2wt% (for example, total nitrogen, phosphorus and potassium content is 3wt%). The emergence rate of rice sprouts after sowing is>85%. The heavy metal limit index should meet the requirements of NY / T 525-2021 "Organic Fertilizer". The components are mixed evenly, without mildew, odor or caking.

[0064] Comparative Example 2 The difference between the preparation method of the rice seedling raising substrate sheet in this comparative example and that in comparative example 1 is that the commercially available rice seedling raising substrate in comparative example 1 is replaced with a commercially available organic fertilizer that meets the NY / T 525-2021 "Organic Fertilizer" standard.

[0065] Comparative Example 3 The method for preparing the seedling raising substrate sheet in this comparative example is as follows: the surface planting soil of the farmland is used as the rice seedling raising bed soil after being crushed, sieved through 5-10 meshes (for example, 7 meshes), disinfected with carbendazim, and adjusted to pH 5.5-6.5 (for example, pH is adjusted to 6.0), and then loaded into a standard seedling raising tray (580 mm×280 mm), each tray being loaded with 3±0.5 kg of rice seedling raising bed soil, and the bed soil is evenly spread on the seedling raising tray with a thickness of 1.8-2 cm.

[0066] Verification of seedling raising effect Referring to the method in NY / T3245-2018 "Technical Specifications for Rice Stacked Tray Seedling Raising", the method for raising rice seedlings using the seedling raising substrate sheet prepared in this application includes the following steps: P1. Place the rice seedling substrate sheet into a universal seedling tray (standard 9-inch seedling tray); sprinkle water on the substrate sheet in the tray, spraying 600-800mL of water per tray, until there is no dripping from the bottom of the tray, the tray surface is even and there is no water accumulation, the substrate sheet is completely wet, and water can seep out when gently pressed.

[0067] P2. The sowing rate of double-season conventional rice is 90-120g / tray of dry grain, the sowing rate of double-season hybrid rice is 70-100g / tray of dry grain, and the sowing rate of single-season hybrid rice is 60-90g / tray of dry grain. Sprinkle the rice seeds that have been soaked and germinated in advance evenly on the substrate sheet and cover them with a layer of soil 0.3-0.56cm thick.

[0068] P3. After covering the soil, cover the tray with a layer of non-woven fabric or plastic film to keep warm and moist.

[0069] P4. Seedbed management: a) Temperature management: The temperature of the seedling raising environment should be controlled at 22-30℃. When the temperature is low, the ambient temperature should be kept above 15℃ and ventilation should be maintained; b) Water management: water less or not at all before the first leaf and the first core grow out, so that the seedbed is kept in a dry state; after the first leaf and the first core grow out, keep the seedbed moist and not white, and the seedlings upright. If there is little or no water spitting out from the leaf tips in the morning, or if the heart leaves curl up at noon, water should be added in time and watered thoroughly at one time; c) Fertilization: When the seedlings are growing weakly, apply urea.

[0070] P5. Reel transplanting: When removing seedlings, directly roll up the seedlings of appropriate age and transport them for transplanting. If the seedling blanket is too dry, you can add water to facilitate smooth transplanting of the seedlings.

[0071] The matrix sheets prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were respectively subjected to a rice seedling raising experiment under the same conditions according to the above method. Each matrix sheet was placed in a rice seedling raising tray of the same standard, watered thoroughly, and sown. The sowing amount was 100 g of seeds / tray, the soil thickness was 0.5 cm, and a plastic film or non-woven fabric was covered. The plastic film or non-woven fabric was removed after the seedlings emerged. The seedling growth period was 30 days, and the seedling height, root length, root number, leaf width, survival rate and morbidity of the seedlings were measured. The specific results are shown in Table 2.

[0072] Table 2 Growth of rice seedlings obtained by using different substrate sheets for rice seedling cultivation

[0073] As can be seen from Table 2, compared with the matrix sheet prepared in the comparative example, the matrix sheet prepared in the present application has obvious advantages in terms of rice seed germination rate, rice seedling growth (seedling height, root number, survival rate) and disease resistance. This shows that the rice seedling raising matrix sheet provided in the present application can fully meet the nutritional requirements of the rice seedling raising process, and also has good disease resistance.

[0074] The above-described embodiments are only preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. For any person skilled in the art, the present application may have various changes and modifications. Any simple equivalent changes and modifications made based on the scope of protection of the present application and the contents of the specification should be included in the scope of protection of the present application.

Claims

1. A method for preparing a wet-formed rice seedling raising substrate sheet, characterized in that: The following steps are involved: S1, mixing poultry and livestock manure with bran to obtain a mixed material A; adding nutrients and active bacteria to the mixed material A, mixing them evenly, to obtain a mixed material B; subjecting material B to primary fermentation and secondary fermentation in sequence to obtain a fermented material; the nutrient is a mixture of monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate; The straw is prepared into straw fibers with a length of ≤5 mm; preparing the dry rice husk into rice husk crumbs with a particle size of ≤5 mm; S2, the fermentation material, the straw fiber, the rice husk crushed, and the sodium bentonite are uniformly mixed according to their respective dry weight ratios of (55-65):(30-35):(5-8):(3-5), and then water is added to prepare a slurry with a solid content of 1.2wt% to 2.4wt%, and the pH of the slurry is adjusted to 5.0 to 6.5; S3, conveying the slurry prepared in step S2 to the slurry pool of the molding machine, scooping and sucking the slurry through a standard mold, extruding, filtering and sucking to form, and then drying to obtain a rice seedling substrate sheet.

2. The preparation method according to claim 1, characterized in that: The water content of the livestock manure is ≤75wt%; or / and the water content of the bran is ≤15wt%.

3. The preparation method according to claim 1, characterized in that: The livestock manure includes at least one of cow manure, sheep manure and pig manure; or / and the active bacterial agent is Bacillus subtilis.

4. The preparation method according to claim 1, characterized in that: The amount of the nutrient agent is 0.2% to 0.5% of the mass of the mixed material A; or / and the amount of the active bacteria is 0.1% to 0.2% of the mass of the mixed material A.

5. The preparation method according to claim 1, characterized in that: The carbon-nitrogen mass ratio in the mixed material B is (25-30):1; or / and the nutrient agent is formed by mixing monoammonium phosphate, potassium sulfate, magnesium sulfate, humic acid, calcium magnesium phosphate, sodium silicate, zinc sulfate, ferrous sulfate, and sodium borate in a mass ratio of (30-50):(10-15):(3-8):(5-10):(5-8):(1.5-2.5):(0.5-1.5):(0.5-1):(0.01-0.1).

6. The preparation method according to claim 1, characterized in that: The steps of fermenting the mixed material B are as follows: putting the mixed material B into a fermentation tank, controlling the pile height in the fermentation tank to be ≤2 meters; supplying oxygen through the aeration pipe of the fermentation tank, and the oxygen concentration is 15%~20%; when the material core temperature in the fermentation tank rises to 50~65°C, starting to turn the pile, and after continuing fermentation for 25~30 days, obtaining the intermediate fermentation material C.

7. The preparation method according to claim 6, characterized in that: The steps of secondary fermentation of the mixed material B are as follows: the intermediate fermentation material C is transported to the aging workshop, and secondary fermentation is carried out by natural stacking and ventilation, the pile height is controlled to be 3-6 meters, the pile is turned over every 5-7 days, and after 20-25 days of secondary fermentation, particles with a particle size of more than 5 mm are screened out to obtain a fermentation material with a moisture content of ≤30wt%.

8. The preparation method according to claim 1, characterized in that: In step S1, the mass ratio of livestock manure to bran is (50-80):(20-50); or / and, in step S3, the drying temperature is 180-220° C., and the drying time is 45-60 minutes.

9. A rice seedling raising substrate sheet prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the rice seedling raising substrate sheet according to claim 9 in rice seedling raising.

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