Simple and fertilizer-saving seedling raising method

Abstract

The invention belongs to the field of seedling raising, and discloses a light and simple fertilizer-saving seedling raising method, which comprises the following steps: laying a supporting substance: laying matrix cotton in a seedling tray as lower-layer matrix cotton under the condition that the tray exists, spraying water to enable the matrix cotton to fully absorb water to form a water layer with the seedling tray, and fully contacting with the seedling tray; under the condition that no disc exists, the substrate cotton is directly laid on the horizontal hard ground to serve as lower-layer substrate cotton, or a mulching film is laid in the field firstly, and then the substrate cotton is laid on the mulching film to serve as the lower-layer substrate cotton; paving the controlled-release fertilizer on the wet lower-layer substrate cotton; paving matrix cotton as upper-layer matrix cotton, and spraying water to fully wet the upper-layer matrix cotton and fully contact the upper-layer matrix cotton with the lower-layer matrix cotton; sowing, darkening and accelerating germination, seedling lifting and transplanting with fertilizer. According to the method, the seedling quality is improved; compared with a conventional substrate seedling raising method, the tray seedling raising method and the tray-free seedling raising method have the advantages that the cost is saved by 28.5% and 43.3% respectively, the labor cost is saved by 31.8%, the mechanical transplanting efficiency is improved by 19.4%, and meanwhile, the use amount of a base tillering nitrogen fertilizer is reduced.

Description

Technical Field

[0001] This invention belongs to the field of seedling cultivation and relates to a simple and fertilizer-saving seedling cultivation method. Background Technology

[0002] Existing seedling raising methods in China all use plastic seedling trays as the base and soil or new substrates as the medium. However, this approach presents several problems in practice: First, the seedling trays filled with seedling soil or substrate weigh approximately 5 kg, making transportation difficult. Second, the processes of lifting and transporting seedlings, as well as preparing, mixing, and storing the seedling soil, all require significant manpower and can easily damage the seedlings. Third, the uniform 28cm×58cm size of the seedling trays necessitates frequent loading of seedlings into the transplanter, resulting in numerous loading cycles, prolonged processing time, and consequently limiting the transplanter's efficiency (CN101828498A; CN103348858A; CN104054493A).

[0003] In order to further liberate labor and improve work efficiency, Japanese scholars have tried the long-mat seedling raising technology with soilless cultivation as its core (Kohei TASATA. Raising and Transplanting Technology for Long Mat with Hydroponically Grown Rice Seedlings.). Compared with the traditional nutrient soil (substrate) seedling raising technology, the long-mat seedling raising technology has the following main characteristics: (1) Water-rolled seedling raising is lighter; (2) Hydroponic seedling raising is more fertilizer-saving; (3) Machine transplanting is more efficient and labor-saving; (4) Non-woven fabric is used as the seedling raising medium, and the formation of seedling blocks is not affected by the root force (seeding amount), which is expected to solve the problem of machine transplanting of hybrid rice and promote the application of hybrid rice; (5) Only a small amount of corresponding equipment needs to be added to the existing transplanting machinery before it can be put into use; (6) Existing facilities and greenhouses are fully utilized without occupying arable land. However, its seedling raising device is made of aluminum alloy, and the cost of the seedling raising device is relatively large (CN202456016U).

[0004] To address key issues in Japan's long-mat seedling raising technology, domestic scholars have developed a series-connected water-rolled seedling raising technology. This technology uses a series of seedling trays with enclosed pots as a base, replacing the long strip seedbed. Hemp film, rice husks, and seeds are then laid on the trays (CN111374038A). However, this new seedling raising method is still time-consuming and labor-intensive in laying the rice husks, and since the rice husks themselves do not provide nutrients, manual fertilization is required, which can easily lead to uneven fertilization and affect seedling growth. The practical application of the series-connected water-rolled seedling tray is not yet mature; the high cost of the seedling trays and low farmer acceptance have prevented the technology from being widely adopted. Therefore, a simplified seedling raising method that ensures high seedling quality while being labor-saving, cost-effective, and environmentally friendly is needed. Summary of the Invention

[0005] The purpose of this invention is to address existing problems by providing a simple and fertilizer-saving seedling raising method. For the first time, it eliminates the limitations of seedling trays and uses controlled-release fertilizer as seedling fertilizer to provide nutrients to seedlings. At the same time, it improves seedling quality, reduces seedling raising costs, simplifies seedling raising operations, reduces labor, and enables transplanting with fertilizer, thereby increasing yield and fertilizer utilization rate, and thus improving economic benefits.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A simplified and fertilizer-saving seedling raising method includes the following steps:

[0008] Step (1) Laying the substrate: If there is a tray, lay the substrate cotton in the seedling tray as the lower substrate cotton, spray water to make the substrate cotton fully absorb water and form a water layer between it and the seedling tray, and make full contact; if there is no tray, lay the substrate cotton directly on the horizontal hard ground as the lower substrate cotton, or first lay the mulch film in the field, and then lay the substrate cotton on the mulch film as the lower substrate cotton.

[0009] Step (2), spreading fertilizer: spread the controlled-release fertilizer evenly on the moist lower substrate cotton;

[0010] Step (3): Lay down the substrate cotton as the upper substrate cotton, so that the upper substrate cotton covers the controlled-release fertilizer, and spray water to fully moisten the upper substrate cotton and make full contact with the lower substrate cotton.

[0011] Step (4), sowing: Sow moist seedlings evenly on the upper substrate cotton;

[0012] Step (5), Darkening and germination: Spread a layer of seedling substrate on the wet seedlings, spray water to fill the gaps in the seedling substrate with water, and wait for the seedlings to grow.

[0013] Step (6), seedling raising and transplanting with fertilizer: When the seedlings grow to 3 leaves and 1 heart, roll the long strips of seedlings into seedling rolls and place them on the rice transplanter for field transplanting. The unreleased fertilizer is coiled in the seedling roots and randomly transplanted into the field, which can improve fertilizer utilization and reduce the amount of base fertilizer used in the field.

[0014] In step (1), according to the rice variety, reserve hard land or field area. For conventional rice varieties, reserve enough seedling raising space at a seedling-to-plant ratio of 1:80 to 1:100, and for hybrid rice, reserve enough seedling raising space at a seedling-to-plant ratio of 1:120 to 1:130.

[0015] Before laying the substrate, the substrate is cut to the required length. In some specific implementations, the substrate is cut to the appropriate length on a level, hard surface.

[0016] When seedling trays are available, cut the substrate cotton as needed and place it in the trays for seedling cultivation. When seedling trays are unavailable, if seedlings are being cultivated on level, hard ground, cut the substrate cotton as needed and place it directly on the ground for seedling cultivation. If seedlings are being cultivated in the field, a plastic film should be laid to prevent the roots from sinking into the soil and making it difficult to lift the seedlings. Then, cut the substrate cotton as needed and place it directly on the plastic film for seedling cultivation.

[0017] The seedling tray mentioned is a rice seedling tray or a water-rolled seedling tray.

[0018] The width of the seedling tray is 28cm.

[0019] The rice seedling raising hard disk has a length of 58cm, a width of 28cm, and a height of 3cm. There are 392 circular water-permeable holes with a diameter of 3mm evenly distributed on the bottom of the rice seedling raising hard disk.

[0020] The water roll seedling tray is composed of seedling trays connected in series.

[0021] The aforementioned tandem seedling tray is the tandem seedling tray disclosed in Chinese Patent CN111374038A.

[0022] Specifically, the tandem seedling tray includes a U-shaped seedling trough. Multiple inverted truncated pyramidal water storage holes are evenly distributed at the bottom of the trough. The side panels of the seedling trough are "┌" shaped, with ribs on the outer sides. Wedge-shaped connectors and wedge-shaped connecting ports that mate with the wedge-shaped connectors are respectively provided at both ends of the two side panels of the seedling trough. Along the length of the seedling trough, the wedge-shaped connectors extend beyond the outermost water storage holes. Adjacent seedling trays are connected via the wedge-shaped connectors / wedge-shaped connecting ports / wedge-shaped connecting ports. A wedge-shaped connector allows two seedling trays to be connected in series. Along the length of the seedling trough, a first baffle in the shape of a "┌" is located at the wedge-shaped connector end of the seedling tray, and a vertical second baffle is located at the wedge-shaped connector end. The upper edge of the first baffle is 3mm higher than the water storage hole, and the upper edge of the second baffle is 1.5mm higher than the water storage hole. When two adjacent seedling trays are connected in series, the top plane of the first baffle covers the top of the second baffle of the adjacent seedling tray, forming a horizontal channel between the top plane of the first baffle and the top of the second baffle of the adjacent seedling tray. A single series-connected seedling tray is 58cm long, 28cm wide, and 3cm high on the two long side walls. The water storage hole is 1.5cm wide at the top, 1cm wide at the bottom, and 0.7-0.8cm deep. A single series-connected seedling tray has a total of 648 water storage holes: 36 on the long side and 18 on the short side.

[0023] The width of the substrate cotton is 28cm.

[0024] The substrate cotton has a thickness of 20 mm and a density of 70-80 kg / m³.

[0025] Preferably, the thickness of the substrate cotton is 20 mm and the density is 80 kg / m³ (i.e., specification 20 / 80).

[0026] The lower and upper substrate cotton layers of this invention have the same specifications.

[0027] In step (2), the controlled-release fertilizer is a resin-coated compound fertilizer with a release period of 2 months, N-P2O5-K2O: 15%-15%-15%; the amount of controlled-release fertilizer used is 80-100g per 28cm×58cm.

[0028] When a tray is used, the controlled-release fertilizer is applied at a rate of 80-100g per tray. When a tray is not used, the controlled-release fertilizer is applied at a rate of 80-100g per 28cm x 58cm area.

[0029] In step (4), before sowing, the rice seeds undergo selection, germination test, soaking, and germination to obtain wet sprouted grains, which are then evenly sown onto the substrate cotton. For specific steps, please refer to Chinese patent application CN103959956A.

[0030] The sowing method described is mechanical sowing, specifically using a simple seeder to evenly sow moist seedlings on the upper substrate cotton.

[0031] The present invention uses hard ground micro-sprinkler irrigation equipment for water management throughout the seedling raising process, and no additional fertilizer is required except for controlled release fertilizer.

[0032] In step (5), the thickness of the seedling substrate is 0.5 to 0.8 cm.

[0033] The seedling substrate mentioned is a professional seedling substrate for machine transplanting of rice, which can be obtained by purchasing commercially available products.

[0034] In step (6), water management is carried out in the seedling raising stage. No additional fertilizer is needed except for controlled-release fertilizer. The seedlings are hardened off by removing the film in real time when the seedlings have 2 leaves and 1 heart. When the seedlings grow to the 3-leaf and 1-heart stage, the seedling blocks are cut into seedling blocks of the required length with scissors. The long seedling blocks are rolled into seedling rolls using a seedling roller.

[0035] When transplanting seedlings with fertilizer, any unreleased fertilizer is randomly introduced into the field and placed in the root zone of the seedlings, 2-3 cm below the soil surface.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] The substrate cotton used in this invention is mainly composed of natural minerals and gravel, making it environmentally friendly. As an inert substrate, it possesses excellent physical properties such as light weight, breathability, and good water retention, enabling precise control of the crop root environment and widespread application in soilless cultivation. The fiber structure of the substrate cotton can be considered as a combination of gas and solid substances, with fibers distributed in a bridging pattern to form micropores. With a porosity exceeding 95%, it effectively absorbs and anchors water and fertilizer, achieving water retention and fertilizer conservation. Simultaneously, the numerous pores provide a favorable environment for plant growth, promoting root development, advancing the greening time after rice transplanting, and advancing the mechanized transplanting of rice and other crops. Furthermore, the substrate cotton effectively improves soil moisture content, electrical conductivity, and other soil physicochemical properties, alleviating the effects of salt and cadmium stress, thus demonstrating significant potential in agricultural production.

[0038] Compared to traditional machine-transplanted rice seedling raising using hard disk substrate, this invention uses substrate cotton as the seedling raising medium. It allows for seedling raising with or without trays. When using trayless seedling raising, it eliminates the limitations of trays, and the low cost of substrate cotton reduces seedling raising costs. The weight of the seedling block is nearly half that of the substrate seedling block, and the length of the seedling block can be adjusted according to the size of the site, reducing labor during seedling transportation and improving machine transplanting efficiency. This invention uses "substrate cotton + seedling fertilizer" as the medium, eliminating the need for additional topdressing during seedling raising. Daily water management is sufficient, achieving cost savings and increased efficiency. Furthermore, the fertilizer in the seedling block can be carried into the field during transplanting, reducing the need for fertilizer in the field and improving fertilizer utilization.

[0039] This invention involves evenly spreading controlled-release fertilizer on a moist lower layer of substrate cotton, covering the controlled-release fertilizer with an upper layer of substrate cotton, and spraying water to fully moisten the upper layer of substrate cotton and ensure full contact with the lower layer of substrate cotton, so as to ensure that the fertilizer does not come into direct contact with the seeds and prevent seedling burn.

[0040] The method of this invention improves the quality of seedlings; compared with conventional substrate seedling raising methods, the tray-based and trayless simplified fertilizer-saving seedling raising methods save 28.5% and 43.3% of costs respectively, reduce labor costs by 31.8%, and increase machine transplanting efficiency by 19.4%, effectively saving labor and reducing the amount of nitrogen fertilizer used for field tillers. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the use of a seedling tray; in the diagram, 1-seedling substrate, 2-wet seedling grain, 3-controlled release fertilizer, 41-upper layer substrate cotton, 42-lower layer substrate cotton, 5-seedling tray.

[0042] Figure 2 This is a schematic diagram of the trayless usage state; in the diagram, 1-seedling substrate, 2-wet seedling grain, 3-controlled release fertilizer, 41-upper substrate cotton, 42-lower substrate cotton, 6-hard ground (mulch film).

[0043] Figure 3 This is a schematic diagram of seedling blocks under the screening and optimization treatment of substrate cotton seedling raising process; where A is the seedling block obtained by water roll seedling tray raising method, B is the seedling block obtained by hard disk seedling raising method, C is the seedling block obtained by trayless seedling raising method, and D is the seedling block of control group (CK).

[0044] Figure 4 To compare the effects of different seedling raising methods on seedling rooting capacity.

[0045] Figure 5 To compare the weight of seedlings and seedling blocks under different seedling raising methods.

[0046] Figure 6 A schematic diagram of long rolled seedlings under optimized treatment of substrate cotton; where A represents long rolled seedlings obtained by water-rolled seedling tray cultivation method, and B represents long rolled seedlings obtained by trayless hard disk cultivation method. Detailed Implementation Plan

[0047] The present invention will be further described below with reference to the embodiments. Experimental methods not specified in the embodiments are generally carried out in accordance with known means in the art.

[0048] Example 1

[0049] A simple and fertilizer-saving seedling raising method is a tray seedling raising method ( Figure 1 The process includes the following steps:

[0050] Step (1): Based on the area of ​​hard ground or field reserved according to the selected rice variety Jingjingxiang No. 8, reserve enough seedling raising space at a seedling-to-plant ratio of 1:100.

[0051] Use hard disks or water roll seedling trays as seedling trays 5 for seedling cultivation;

[0052] Hard disk: The hard disk is specially designed for machine-transplanted rice seedling raising. It is made of polypropylene (PP) or polyethylene (PE), which has good toughness, corrosion resistance and durability, and can adapt to various environmental conditions during the seedling raising process. The dimensions of a single hard disk are 58cm×28cm and 3cm high. There are 3mm diameter circular permeable holes evenly distributed on the bottom of the disk. The number of permeable holes is generally 392 to ensure good water permeability and air permeability, which is conducive to the growth and development of seedling roots.

[0053] The water-rolled seedling tray is composed of a series of seedling trays connected in series. See Chinese Patent (CN111374038A) Embodiment 1 for the series seedling tray. The series seedling tray includes a U-shaped seedling trough. Multiple inverted truncated pyramid-shaped water storage holes are evenly distributed at the bottom of the seedling trough. The side panels of the seedling trough are "┌" shaped, and ribs are provided on the outer side of the side panels. Wedge-shaped connectors and wedge-shaped connecting ports that mate with the wedge-shaped connectors are respectively provided at both ends of the two side panels of the seedling trough. Along the length of the seedling trough, the wedge-shaped connectors extend beyond the outermost water storage holes. Two adjacent seedling trays... Two seedling trays are connected in series using wedge-shaped connectors / wedge-shaped openings. Along the length of the seedling trough, a first baffle in the shape of a "┌" is located at the wedge-shaped connector end of the seedling tray, and a vertical second baffle is located at the wedge-shaped opening end. The upper edge of the first baffle is 3mm higher than the water storage hole, and the upper edge of the second baffle is 1.5mm higher than the water storage hole. When two adjacent seedling trays are connected in series, the top plane of the first baffle covers the top of the second baffle of the adjacent seedling tray, forming a horizontal channel between them. A single series-connected seedling tray measures 58cm × 28cm, with two long side walls 3cm high. The water storage hole is 1.5cm wide at the top, 1cm wide at the bottom, and 0.7-0.8cm deep. A single series-connected seedling tray has a total of 648 water storage holes: 36 on the long side and 18 on the short side. Before assembly, clean the connection ports of the tandem seedling trays to ensure there are no obstructions. Assemble the seedling trays in long strips (each row width is the same as the seeder width), ensuring the seedling trays are roughly level. The length of each row can be adjusted according to the size of the seedling raising site. Two adjacent seedling trays in each strip are connected in series with wedge-shaped connectors and wedge-shaped connection ports. The top surface of the first baffle covers the top surface of the second baffle of the adjacent seedling tray.

[0054] Step (2), laying the supporting material: cut the substrate cotton as needed on a level, hard surface; cut the substrate cotton to a thickness of 20mm and a density of 80kg / m³. 3 (20 / 80) of substrate cotton is laid in the seedling tray 5 as the lower layer of substrate cotton 42; water is sprayed to allow the substrate cotton to fully absorb water and form a water layer between it and the seedling tray, ensuring full contact.

[0055] Step (3), spreading fertilizer: spread controlled-release fertilizer 3 (resin-coated compound fertilizer with a release cycle of 2 months, N-P2O5-K2O: 15%-15%-15%) evenly on the moist lower substrate cotton. The amount of controlled-release fertilizer is 80g / plate.

[0056] Step (4): Lay the surface with a thickness of 20mm and a density of 80kg / m³. 3 (20 / 80) of the substrate cotton is used as the upper substrate cotton 41 to cover the controlled-release fertilizer 3. Water is sprayed to fully moisten the upper substrate cotton and make full contact with the lower substrate cotton.

[0057] Step (5), Mechanical sowing: Use a simple seeder to evenly sow wet sprouted grain 2 on the upper substrate cotton, with a sowing amount of 150g of wet sprouted grain per tray;

[0058] Step (6), Darkening and germination: Spread a 0.5cm thick layer of seedling substrate 1 (brand: Hailifeng, Hainan Hailifeng Agricultural Development Co., Ltd.) on the wet seedling valley 2, spray water to fill the gaps in the substrate with water, and wait for the seedlings to grow.

[0059] Step (7), seedling raising and transplanting with fertilizer: Water management is carried out during the seedling raising stage. No additional fertilizer is needed except for controlled-release fertilizer. When the seedlings have 2 leaves and 1 heart, the film is removed in time to harden the seedlings. When the seedlings grow to 3 leaves and 1 heart, the seedling blocks are cut into the required length with scissors. The seedling blocks are rolled into seedling rolls using a seedling roller and placed on the rice transplanter. The unreleased fertilizer is coiled in the root system of the seedlings and randomly transplanted into the field. The fertilizer is in the root zone of the seedlings, 2-3 cm away from the soil surface, which can improve the fertilizer utilization rate and reduce the amount of base fertilizer used in the field.

[0060] Example 2

[0061] A simple and fertilizer-saving seedling raising method is a trayless seedling raising method. Figure 2 The process includes the following steps:

[0062] Step (1): Based on the area of ​​hard ground or field reserved according to the selected rice variety Jingjingxiang No. 8, reserve enough seedling raising space at a seedling-to-plant ratio of 1:100.

[0063] Step (2), laying the support substrate: If the seedlings are raised on a level hard ground, the substrate cotton (58cm long, 28cm wide, 20mm thick, and 80kg / m³ (20 / 80)) is laid directly on the level hard ground as the lower substrate cotton 42. Spray water to make the substrate cotton fully absorb water and form a water layer between it and the level hard ground, so that they are in full contact.

[0064] If seedlings are raised in the field, a plastic film should be laid first, and then a 20 / 80 (mm / kg / m³) substrate cotton should be laid directly on the plastic film as the lower substrate cotton 42 to prevent the roots from getting stuck in the soil and making it difficult to lift the seedlings.

[0065] Step (3), spreading fertilizer: spread controlled-release fertilizer 3 (resin-coated compound fertilizer with a release cycle of 2 months, N-P2O5-K2O: 15%-15%-15%) evenly on the moist lower substrate cotton. The amount of controlled-release fertilizer is 80g / (58cm×28cm).

[0066] Step (4): Lay the surface with a thickness of 20mm and a density of 80kg / m³. 3 (20 / 80) of the substrate cotton is used as the upper substrate cotton to cover the controlled-release fertilizer 3. Spray water to fully moisten the upper substrate cotton and make full contact with the lower substrate cotton.

[0067] Step (5), Mechanical sowing: Use a simple seeder to evenly sow wet sprouted rice 2 on the upper substrate cotton, with a sowing amount of 150g wet sprouted rice / (58cm×28cm);

[0068] Step (6), Darkening and germination: Spread a 0.5cm thick layer of seedling substrate 1 (brand: Hailifeng, Hainan Hailifeng Agricultural Development Co., Ltd.) on the wet seedling valley 2, spray water to fill the gaps in the substrate with water, and wait for the seedlings to grow.

[0069] Step (7), seedling raising and transplanting with fertilizer: Water management is carried out during the seedling raising stage. No additional fertilizer is needed except for controlled-release fertilizer. When the seedlings have 2 leaves and 1 heart, the film is removed in time to harden the seedlings. When the seedlings grow to 3 leaves and 1 heart, the seedling blocks are cut into the required length with scissors. The seedling blocks are rolled into seedling rolls using a seedling roller and placed on the rice transplanter. The unreleased fertilizer is coiled in the root system of the seedlings and randomly transplanted into the field. The fertilizer is in the root zone of the seedlings, 2-3 cm away from the soil surface, which can improve the fertilizer utilization rate and reduce the amount of base fertilizer used in the field.

[0070] Example 3

[0071] Screening and optimization of substrate cotton seedling raising technology

[0072] In March 2025, the inventors conducted seedling raising experiments at the Batou Experimental Base in Yazhou Town, Sanya City, Hainan Province (109°15′E, 18°35′N).

[0073] The tested variety was Jingjingxiang No. 8.

[0074] The impact of different specifications of substrate cotton on seedling quality

[0075] Treatment group: The seedling raising method using a hard disk in Example 1 was adopted, only the substrate cotton of different specifications was used as the upper and lower layers of substrate cotton, and the specifications of the upper and lower layers of substrate cotton were the same; substrate cotton specifications: 20mm thickness, density 64kg / m³ (20 / 64); 20mm thickness, density 80kg / m³ (20 / 80); 15mm thickness, density 64kg / m³ (15 / 64); 20mm thickness, density 80kg / m³ (20 / 80); 10mm thickness, density 100kg / m³ (10 / 100).

[0076] The experimental results are shown in Table 1. They indicate that seedlings raised using substrate cotton with a thickness of 20mm and a density of 80kg / m³ (20 / 80) exhibited higher stem base width, aboveground dry weight, and a stronger seedling index. While seedlings raised using other substrate cotton specifications showed significantly higher leaf age, plant height, SPAD, and aboveground dry weight compared to the control (CK) treatment, insufficient substrate cotton thickness resulted in insufficient space for root development, reduced medium volume, and decreased water and fertilizer retention, leading to inhibited growth. Furthermore, excessively low density resulted in high porosity, poor water and fertilizer retention, and increased susceptibility to environmental influences, resulting in lower seedling quality. Therefore, substrate cotton with a thickness of 20mm and a density of 80kg / m³ (20 / 80) was selected for further investigation. The control group (CK) used commercially available organic seedling substrate (brand: Hailifeng, Hainan Hailifeng Agricultural Development Co., Ltd.) and followed traditional seedling raising methods, including laying the base soil on a machine-transplanted rice-specific hard disk, watering, sowing, covering the seeds, and seedling management.

[0077] Table 1. Effects of different specifications of substrate cotton on seedling quality in machine-transplanted rice under hard disk conditions.

[0078] <![CDATA[Thickness / Density (mm / kg / m 3 )]]> Ye Ling Plant height (cm) Stem base width (mm) SPAD Dry weight of aerial parts (mg) Seedling survival rate (%) <![CDATA[Degree of filling (mg·cm -1 )]]> <![CDATA[Strong seedling index (mm·mg·cm -1 )]]> 20 / 64 3.03ab 15.76b 1.88b 33.79a 14.09b 88.37c 0.90bc 1.69b 20 / 80 3.23a 17.08a 2.0a 33.82a 18.16a 92.67a 1.07a 2.13a 15 / 64 3.34a 17.77a 1.86b 32.37a 16.39a 94.14a 0.92b 1.71b 15 / 80 3.14ab 17.98a 1.8b 34.96a 16.23a 91.90a 0.90bc 1.62b 10 / 100 3.06ab 17.69a 1.91ab 31.96a 13.77b 92.47ab 0.78c 1.62b CK 2.90b 10.90c 1.83b 28.37b 12.37b 89.20bc 1.13a 2.08a

[0079] Note: Different letters in the same column indicate significant differences, and the same applies below.

[0080] The impact of different tray environments on seedling quality

[0081] Treatment group: Substrate cotton specifications: thickness 20mm, density 80kg / m³ (20 / 80); Different seedling tray types: machine-transplanted rice special seedling tray (Example 1), water roll seedling tray (Example 1), trayless (Example 2); Fertilizer type: resin-coated compound fertilizer with a release period of 2 months (N-P2O5-K2O: 15%-15%-15%).

[0082] Control group (CK): Commercial organic seedling substrate (Hainan Hailifeng Agricultural Development Co., Ltd.) was used. Traditional seedling raising methods were adopted, including laying the base soil, watering, sowing, covering the seeds and managing the seedlings on a special hard disk for machine-transplanted rice.

[0083] Table 2. Effects of different tray environments on seedling quality

[0084] Seedling tray type Ye Ling Plant height (cm) Stem base width (mm) SPAD Dry weight of aerial parts (mg) Seedling survival rate (%) <![CDATA[Degree of filling (mg·cm -1 )]]> <![CDATA[Seedling vigor index (mm·mg·cm -1 )]]> Water roll seedling tray 3.0b 17.14a 1.90a 32.01b 17.58a 92.71a 1.03ab 1.96ab harddisk 3.15ab 17.08a 1.85a 35.01a 15.89a 91.53a 0.93b 1.72bc diskless 3.34a 17.54a 1.92a 33.11ab 13.71b 91.49a 0.79c 1.51c CK 2.90b 10.90b 1.83a 28.37c 12.37b 89.20a 1.13a 2.08a

[0085] The test results are shown in Table 2. Figure 3 , Figure 4 and Figure 5The results indicate that there was no significant difference in seedling quality between different tray environments (including tray-based and trayless). Seedlings treated with resin-coated compound fertilizer with a 2-month release period showed significantly higher seedling quality than those in the control (CK) treatment. There was no significant difference in seedling growth between different tray environments, but the aboveground condition of seedlings treated with substrate cotton was superior to that in the CK treatment. Figure 3 The rooting force of the trayless seedling treatment was 3.2 times that of the CK treatment, and the seedling blocks met the requirements for machine transplanting. Figure 4 The weight of seedling blocks treated without trays is only 53% of that of the control group (CK), effectively reducing labor costs. Figure 5 Therefore, the best seedling quality is achieved when using a substrate cotton with a thickness of 20mm and a density of 80kg / m³ (20 / 80) in combination with a resin-coated compound fertilizer with a release period of 2 months.

[0086] Example 4

[0087] Optimization of substrate cotton long-rolled seedlings

[0088] In June 2025, the inventors conducted seedling raising experiments at the Batou Experimental Base in Yazhou Town, Sanya City, Hainan Province (109°15′E, 18°35′N).

[0089] The tested variety was Jingjingxiang No. 8.

[0090] Treatment group: Example 1 is a tray-based seedling raising method, using water-rolled seedling trays with a length of 174cm, which consists of 4 trays connected in series; Example 2 is a trayless seedling raising method; Substrate cotton specifications: thickness 20mm, density 80kg / m³ (20 / 80); Fertilizer type: resin-coated compound fertilizer with a release period of 2 months (N-P2O5-K2O: 15%-15%-15%).

[0091] Control group: Commercial organic seedling substrate (brand: Hailifeng, Hainan Hailifeng Agricultural Development Co., Ltd.) was used. Traditional seedling raising methods were adopted, including laying the base soil, watering, sowing, covering the seeds and managing the seedlings on a special hard disk for machine-transplanted rice.

[0092] Table 3. Effects of different seedling tray types on the quality of long-rolled rice seedlings

[0093] deal with Ye Ling Plant height (cm) Stem base width (mm) SPAD Number of roots Dry weight of aerial parts (mg) Seedling survival rate (%) <![CDATA[Degree of filling (mg·cm -1 )]]> <![CDATA[Seedling vigor index (mm·mg·cm -1 )]]> Water roll seedling tray 4.0ab 18.7a 2.4a 32.5b 12a 21.9a 82a 1.17a 2.84a diskless 4.0a 18.8a 2.4a 34.9a 12a 21.1a 83a 1.12a 2.73a CK 3.8b 12.8b 1.8b 24.1c 11.7a 13.3b 80a 1.04b 1.84b

[0094] The test results are shown in Table 3. Figure 6 The results indicate that there was no significant difference in seedling quality between the trayless treatment and the tray-treated water-rolled seedlings. Both treatments showed significantly better results than the control (CK) treatment in terms of plant height, stem base width, SPAD (spider root diameter), and aboveground dry weight. There was no significant difference in aboveground growth between the tray-treated and trayless seedlings; both exhibited good growth, with long, rolled seedlings that could be lifted without breaking, and good root holding capacity. Figure 6 ).

[0095] Example 5

[0096] A comparison of the cost and efficiency of the simplified and fertilizer-saving rice seedling raising method of the present invention (Example 1: hard disk seedling raising, Example 2: diskless seedling raising) with the machine-transplanted rice hard disk seedling raising method (CK).

[0097] The main methods for machine-transplanted rice seedling raising in trays include seed treatment, precision sowing, dark germination, and scientific water management. Specifically: Seed treatment: Sun-dry seeds for 1 day to enhance vitality, select seeds with clean water to remove empty or shriveled grains, then dark-soak seeds in a seed soaking agent for 2 days (stirring appropriately during this time), wash off the agent, and then dark-germinate seeds under high temperature and humidity for 1 day; Precision sowing: First, lay a 2cm layer of substrate at the bottom and water thoroughly, then sow at a rate of 110g of dry rice per tray, cover with a 0.5cm layer of substrate, and moisten the top; Dark germination: Stack the seedling trays 20-25 cm high. Layer (place empty trays with soil on top), seal with black film to keep warm, moist, and opaque. Place the trays when 80% of the seeds have sprouted 1cm from the soil after 2-3 days. Scientific water management: keep moist before the seedlings have 2 leaves and 1 heart (you can cover them with non-woven fabric). For seedlings raised on hard ground, the substrate must be moist but not waterlogged. After the seedlings have 2 leaves and 1 heart, manage the water during dry season (quickly irrigate and drain water in the evening, and briefly spray to cool down when the temperature is high). Micro-sprinkler irrigation is preferred. Before the seedlings are laid in the field, water them to check that the surface is level and then flatten it into a paste. Use 25-30 seedling trays per mu (unit of land area) and tie them with ropes to ensure that they are tightly attached without gaps or gaps.

[0098] 1. Material Costs

[0099] (1) Machine-transplanted rice trays: The unit price of the tray is 4.5 yuan, and the usage time is calculated as 5 years, that is, the price of each tray is 4.5 / 5=0.9 yuan;

[0100] (2) Seedling substrate: The unit price of a 50L conventional seedling substrate is 25 yuan. Each bag can raise 6 trays of seedlings. The bottom layer accounts for 80% and the seed covering accounts for 20%. That is, the price per tray is 25 / 6=4.17 (yuan). The price of the substrate covering the seed per tray is 4.17*20%=0.834 (yuan).

[0101] (3) Matrix cotton: The market price of matrix cotton is 0.8 yuan / roll;

[0102] (4) Controlled-release fertilizer: A resin-coated compound (N-P2O5-K2O: 15%-15%-15%) with a release period of 2 months is used. The market price of this controlled-release fertilizer is 9.35 yuan / kg, and the cost per batch is 9.35 / 1000*80=0.748 yuan.

[0103] (5) Seeds: The market price of the experimental seed Jingjingxiang No. 8 is 10 yuan / kg. The amount of seeds sown per tray is 110g of dry rice, which means the price of seeds per tray is 1.1 yuan.

[0104] Table 4. Impact of different seedling raising methods on seedling raising costs (yuan / tray)

[0105] deal with Seedling tray matrix substrate cotton Controlled-release fertilizer seed Total cost CK 0.90 4.10 0 0 1.10 6.10 Substrate cotton (hard drive) 0.90 0.82 0.80 0.74 1.10 4.36 Substrate cotton (without discs) 0 0.82 0.80 0.74 1.10 3.46

[0106] As shown in Table 4, the conventional substrate seedling raising method has a higher total cost due to the higher substrate input. The substrate cotton can achieve trayless seedling raising due to its material properties, and its total cost is the lowest. Therefore, in the case of tray seedling raising, the cost saving compared to the conventional substrate seedling raising method is (6.10-4.36) / 6.10=28.5%; in the case of trayless seedling raising, the cost saving compared to CK is (6.10-3.46) / 6.10=43.3%.

[0107] 2. Labor costs

[0108] The method of raising rice seedlings in hard trays by machine transplanting mainly includes the preparation of seeds, seedling trays, substrate and seedbed. The labor input per mu of seedling field is 1200 yuan. Based on the ratio of seedling field to paddy field of 1:100, the labor cost of raising seedlings per mu of paddy field by machine transplanting is 14.8 yuan.

[0109] The simplified and fertilizer-saving seedling raising method mainly includes the preparation of seeds, seedling trays, seedbeds, sowing, and fertilization (fertilization only needs to be done once before sowing). The labor input per mu of seedling field is 880 yuan. Based on the ratio of seedling field to field is 1:100, the labor cost of raising seedlings per mu of machine-transplanted field is 10.1 yuan.

[0110] Therefore, it can be seen that the manual input of the seedling raising method of the present invention is reduced compared with the special machine-transplanted rice hard disk seedling raising method. The simple and fertilizer-saving seedling raising method saves 31.8% compared with the special machine-transplanted rice hard disk seedling raising method.

[0111] 3. Planting efficiency

[0112] Specialized machine-transplanted rice hard disk seedling raising method: machine transplanting efficiency 0.36 hm / h, 3 people to operate each transplanter and 1 person to drive;

[0113] Simplified and fertilizer-saving seedling raising method: machine transplanting efficiency is 0.43 hm / h, each rice transplanter requires 2 people to operate and 1 person to drive.

[0114] Therefore, it can be seen that the machine transplanting efficiency of the simplified and fertilizer-saving rice seedling raising method of the present invention is 19.4% higher than that of the dedicated machine transplanting rice hard disk seedling raising method, and it also saves labor input.

Claims

1. A simplified and fertilizer-saving method for seedling cultivation, characterized in that: Includes the following steps: Step (1) Laying the substrate: If there is a tray, lay the substrate cotton in the seedling tray as the lower layer of substrate cotton, spray water so that the substrate cotton can fully absorb water and form a water layer between it and the seedling tray, and make full contact. In the absence of a tray, the substrate cotton can be laid directly on a level, hard surface as the lower substrate cotton, or a plastic film can be laid in the field first, and then the substrate cotton can be laid on the plastic film as the lower substrate cotton. Step (2), spreading fertilizer: spread the controlled-release fertilizer evenly on the moist lower substrate cotton; Step (3): Lay down the substrate cotton as the upper substrate cotton, so that the upper substrate cotton covers the controlled-release fertilizer, and spray water to fully moisten the upper substrate cotton and make full contact with the lower substrate cotton. Step (4), sowing: Sow moist seedlings evenly on the upper substrate cotton; Step (5), Darkening and germination: Spread a layer of seedling substrate on the wet seedlings, spray water to fill the gaps in the seedling substrate with water, and wait for the seedlings to grow. Step (6), seedling raising and transplanting with fertilizer: When the seedlings grow to 3 leaves and 1 heart, roll the long strips of seedlings into seedling rolls, place the rolls on the rice transplanter for field transplanting, and the unreleased fertilizer is coiled in the seedling root system and randomly transplanted into the field.

2. The simplified and fertilizer-saving seedling raising method according to claim 1, characterized in that: Based on the rice variety, reserve sufficient hard ground or field area. For conventional rice varieties, reserve sufficient seedling raising space at a seedling-to-plant ratio of 1:80 to 1:100, and for hybrid rice, reserve sufficient seedling raising space at a seedling-to-plant ratio of 1:120 to 1:

130.

3. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: The seedling tray is a rice seedling raising hard disk or a water-rolled seedling tray; the width of the seedling tray is 28cm.

4. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: The water-rolled seedling trays are composed of interconnected seedling trays; each interconnected seedling tray includes a U-shaped seedling trough, with multiple inverted truncated pyramidal water storage holes evenly distributed at the bottom of the trough. The side panels of the seedling trough are "┌" shaped, with ribs provided on the outer side of the side panels. Wedge-shaped connectors and wedge-shaped connecting ports that mate with the wedge-shaped connectors are respectively provided at both ends of the two side panels of the seedling trough. Along the length of the seedling trough, the wedge-shaped connectors extend beyond the outermost water storage holes. Adjacent seedling trays are connected by wedge-shaped connectors / wedges. The wedge-shaped connector / wedge-shaped head allows for the series connection of two seedling trays. Along the length of the seedling trough, a "┌"-shaped first baffle is located at the wedge-shaped connector end of the seedling tray, and a vertical second baffle is located at the wedge-shaped connector end. The upper edge of the first baffle is 3mm higher than the water storage hole, and the upper edge of the second baffle is 1.5mm higher than the water storage hole. When two adjacent seedling trays are connected in series, the top plane of the first baffle covers the top of the second baffle of the adjacent seedling tray, forming a horizontal channel between the top plane of the first baffle and the top of the second baffle of the adjacent seedling tray. A single series-connected seedling tray is 58cm long, 28cm wide, and has two long side walls that are 3cm high.

5. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: The substrate cotton has a width of 28cm; the substrate cotton has a thickness of 20mm and a density of 70-80kg / m³. 3 .

6. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1 or 5, characterized in that: The substrate cotton has a thickness of 20 mm and a density of 80 kg / m³. 3 .

7. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: The controlled-release fertilizer is a resin-coated compound fertilizer with a release period of 2 months, and the N-P2O5-K2O ratio is 15%-15%-15%. The dosage of the controlled-release fertilizer is 80-100g per 28cm×58cm.

8. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: The thickness of the seedling substrate is 0.5–0.8 cm.

9. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: Water management is carried out during the seedling raising stage, and no additional fertilizer is needed except for controlled-release fertilizer. The seedlings are hardened off by removing the film in time when they have two leaves and one heart. When the seedlings grow to the three-leaf and one-heart stage, the seedling blocks are cut into seedling blocks of the required length with scissors, and the long seedling blocks are rolled into seedling rolls using a seedling roller.

10. The method for raising rice seedlings in cotton substrate by machine transplanting according to claim 1, characterized in that: When transplanting seedlings with fertilizer, any unreleased fertilizer is randomly inserted into the field and placed in the root zone of the seedlings, 2-3 cm from the soil surface.

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