A method for improving the quality of rice in southern China

Abstract

This invention relates to the field of rice cultivation, specifically to a method for improving the quality of rice cultivation in southern regions. The method includes: 1) sowing and seedling raising, spraying seedling fertilizer after the rice seedlings reach the two-leaf and four-leaf stages respectively, and preparing for transplanting to the field at the six-leaf stage; 2) before transplanting, preparing the field by tilling and creating planting pits to control rice planting density, pre-filling the pits with slow-release fertilizer, and maintaining soil moisture content through shallow irrigation. One to two days before transplanting, the water layer is drained before transplanting, followed by routine field management; 3) harvesting the rice when it matures, with full, golden-yellow, drooping ears. This invention improves rice planting density while ensuring optimal rice development; increases rice yield per acre; improves fertilizer utilization efficiency; enhances rice quality; and is environmentally friendly, maintaining the purity of reservoir water resources and avoiding human-caused pollution of water sources.

Description

Technical Field

[0001] This invention relates to the field of rice cultivation, and more specifically to a method for improving the quality of rice cultivation in southern regions. Background Technology

[0002] Rice is one of my country's most important food crops, holding a vital position in the national economy. Its sown area, total output, and yield per unit area all rank first among food crops, highlighting its importance. However, existing organic rice cultivation methods result in relatively low yields. While improvements in rice varieties have yielded some success, addressing the root causes of yield deficiencies through changes in cultivation methods has not yet yielded the desired improvement.

[0003] Furthermore, the environment in the south results in a relatively limited area for single-plot rice cultivation, mostly consisting of small fields or terraces, with a limited area per unit paddy field. This is one of the key factors limiting rice production in the south. Summary of the Invention

[0004] To address the problems that existing rice cultivation techniques generally fail to effectively contribute to yield, and that low planting density leads to limited actual rice yield and quality, as well as relatively low fertilizer utilization, this invention provides a method for improving the quality of rice cultivation in southern regions.

[0005] The purpose of this invention is:

[0006] First, ensure a high rice germination rate when planted in southern soils;

[0007] II. Increase rice yield per mu;

[0008] Third, improve the effective utilization rate of fertilizers and improve the quality of rice.

[0009] To achieve the above objectives, the present invention adopts the following technical solution.

[0010] A method for improving the quality of rice in southern China.

[0011] The method includes:

[0012] 1) Sow and raise seedlings. Spray seedling fertilizer when the rice seedlings reach the two-leaf stage and the four-leaf stage respectively. When the seedlings reach the six-leaf stage, prepare to transplant them to the field.

[0013] 2) Before transplanting, prepare the field by tilling and creating pits, dig pits to control the rice planting density, pre-fill the pits with slow-release fertilizer, and maintain soil moisture by shallow water irrigation. After draining the water layer 1-2 days before transplanting, transplant the rice into the pits and carry out daily field management.

[0014] 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down.

[0015] As a preferred option

[0016] Step 1) involves pre-sowing seed treatment, which includes:

[0017] Soaking: First, pre-soak in water for 10-12 hours, then soak in soaking solution for 10-12 hours. After soaking in the soaking solution, rinse with water and drain. Then soak in water again for 10-12 hours to complete the soaking process.

[0018] The soaking solution contains 13–17 wt% uronic acid, 20–25 wt% sodium hypochlorite solution, 0.8–1.2 wt% proline, and the remainder is water.

[0019] As a preferred option

[0020] The components of the seedling fertilizer mentioned in step 1) are:

[0021] Chitosan oligosaccharides 1-5 wt%, EDTA chelated iron 1-2 wt%, humic acid 9-15 wt%, soybean meal 20-35 wt%, potassium chloride 1-5 wt%, balance water;

[0022] When spraying seedling fertilizer at the two-leaf and four-leaf stages, the fertilizer should be applied at a ratio of 800-1200 g per square meter.

[0023] As a preferred option

[0024] Step 2) The purpose of preparing the paddy field is to ensure that there are no weeds, debris, or floating scum in the paddy field, and that the topsoil is fine on top and coarse on the bottom, and that the topsoil is soft and the bottom is firm. After the paddy field is leveled, it needs to be compacted appropriately. Sandy soil should be compacted for 12-36 hours, loam for 24-48 hours, and clay for 48-72 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep the water level low.

[0025] As a preferred option

[0026] Step 2) The pit density is 12-15×12-15 cm, the pit opening diameter is controlled to be 8-10 cm, and the pit depth is 15-17 cm.

[0027] As a preferred option

[0028] Step 2) The slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer filled in the pit from bottom to top;

[0029] The deep fertilizer layer is 5-7 cm thick and is composed of 22-30 wt% soybean meal, 45-60 wt% potassium-rich organic potassium fertilizer, and the remainder sand.

[0030] The middle layer of fertilizer is 3-4 cm thick and is composed of 20-30 wt% soybean powder, 14-20 wt% organic phosphorus and calcium fertilizer, 7-15 wt% organic potassium fertilizer, 10-20 wt% citrate-soluble silicon fertilizer and the remainder sand.

[0031] The surface fertilizer layer is 3-4 cm thick and is composed of 10-20 wt% urea, 15-25 wt% dipotassium hydrogen phosphate, 7-12 wt% diammonium phosphate, 6-10 wt% potassium chloride, 10-20 wt% citrate-soluble silicon fertilizer, 3-6 wt% paclobutrazol, and the remainder sand.

[0032] As a preferred option

[0033] When prefilling slow-release fertilizer, first fill the deep layer fertilizer, and then lay a fine mesh with a pore size of 7-9 mm on the surface of the deep layer fertilizer and against the side wall of the pit.

[0034] The fine mesh is then filled with a middle layer of fertilizer, and a coarse mesh with a mesh size of 18-22 mm is laid on the surface of the middle layer of fertilizer, adhering to the side wall of the pit.

[0035] As a preferred option

[0036] Step 2) The number of clumps transplanted per acre is 30,000 to 40,000;

[0037] When transplanting, control the transplanting depth to 2-3 cm.

[0038] As a preferred option

[0039] Step 2) The routine field management includes basal application, seedling establishment, topdressing, and shallow irrigation.

[0040] As a preferred option

[0041] The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing is controlled at 560–580 kg·hm². -2 115~130 kg∙hm -2 490~500 kg∙hm -2 ;

[0042] The ratio of nitrogen fertilizer application during the basal and topdressing processes is 2:(2.8-3.2), the ratio of potassium fertilizer application is 3:(4.8-5.2), and all phosphorus fertilizer is applied during the basal application process.

[0043] The core of this invention lies in increasing crop planting density to improve rice yield per acre. Simultaneously, the method of pre-fertilizing in pits enhances fertilizer utilization and improves rice quality. Conventional southern hybrid rice is planted at 12,000 to 15,000 clumps per acre, with some high-density planting reaching 18,000 to 20,000 clumps. However, this high-density planting typically leads to a decline in rice quality. Generally, when high-density planting exceeds 30,000 clumps, rice quality will significantly decrease, with actual yield sometimes falling below that of 12,000 clumps, and fertilizer utilization is low with significant waste.

[0044] This is because high-density planting leads to competition for limited nutrients, resulting in unequal development among plants. Some plants with developmental advantages maintain their advantage for a long time, while insufficient fertilizer causes plants with competitive disadvantages to remain at a disadvantage.

[0045] However, this invention is not merely about increasing planting density, but also about coordinating and controlling the general growth trend of rice. To this end, this invention also includes improvements in fertilization methods.

[0046] In terms of fertilization, this invention uses pit fertilization combined with delayed application of base fertilizer for regulation. Usually, after rice transplanting, the rice root system prioritizes the development of vertical roots, and throughout the entire growth period of rice, the development of vertical roots is prioritized. The development of vertical roots is driven by two factors: firstly, the application of base fertilizer before transplanting results in a greater nutrient depth, and in order to obtain more nutrients, the rice will continuously develop vertical roots, and nutrients will continuously settle in the soil, thus maintaining the trend of vertical root development; secondly, it is to ensure stable rooting and rapid root development.

[0047] However, this invention employs pit application and delayed basal application, enabling rice seedlings in the pits to effectively obtain direct, shallow fertilizer nutrients after transplanting. This firstly suppresses factors that promote vertical root development in rice. Combined with the coarse netting laid on the surface of the intermediate fertilizer layer, the vertical root development of rice is relatively significantly restricted. Rice roots can effectively obtain nutrients by establishing shallow roots. At the same time, the slow application of basal fertilizer allows the soil to accumulate certain nutrients in the circumferential direction of the pits, thereby promoting horizontal root development under the combined effect of both methods.

[0048] The development of vertical roots in high-density planting will lead to increased competition for nutrients, while the development of horizontal roots will have a positive effect in the micro-ecological environment, prompting rice to prioritize the supply of nutrients to the ovules closer to the stem, thereby increasing the fullness of the grains per panicle. Furthermore, due to the shallow root system, the paclobutrazol in the shallow fertilizer used in this invention has the effect of inhibiting seedling elongation and promoting tillering, which can increase the chlorophyll content of seedlings, enhance enzyme activity, and facilitate metabolism; potassium dihydrogen phosphate can increase the root respiration substrate, improve root vitality, and facilitate the absorption and utilization of nutrients in the soil by rice, while also controlling excessive ineffective tillering in rice; citrate-soluble silicon fertilizer has a significant impact on the yield and quality of rice. Rice stems and leaves contain 10% to 20% silicon dioxide. Applying silicon fertilizer can increase the thickness of vascular bundles and thick-walled tissues in the pseudostem of rice, thereby increasing the lodging resistance of rice and playing a role in increasing yield; nitrogen sources will stimulate the branching of plant roots, enabling the roots to capture nitrogen in the soil environment, while promoting the lateral growth of accessory roots to form lateral roots and secondary roots, providing anchoring support for rice and forming an independent support system, which can support the outward expansion of stems and leaves of rice during the growth process to obtain more sunlight and space. This method prioritizes the lateral development of both the above-ground and below-ground parts of the rice plant, thereby increasing the actual effective light-receiving area of ​​the rice plant in a single planting pit. For high-density planting techniques, this can effectively improve the early survival rate of rice and the utilization rate of basal nutrients.

[0049] Furthermore, high-density rice cultivation effectively suppresses barnyard grass growth because rice has a nutrient competitive advantage over barnyard grass. Therefore, in this invention, high-density rice cultivation and improved fertilization methods alter the growth trend of the rice crop, resulting in higher nutrient utilization by the rice and preventing barnyard grass from obtaining sufficient nutrients. Consequently, this invention almost completely eliminates the need for weeding in daily field management, reducing the harm caused by herbicides to rice growth.

[0050] As rice grows and develops, and the nutrients from the basal fertilizer gradually settle, the rice root system, after early horizontal root development, transitions back to vertical root development. The taproot slowly extends through the coarse netting into the intermediate layer of fertilizer. This intermediate layer fertilizer is composed of slow-release organic fertilizer, which requires decomposition to form nutrients available for the rice crop, thus preventing loss during early growth. Simultaneously, the organic fertilizer in the intermediate layer stimulates the auxin transport function of NRT1.1 in the roots, preventing auxin accumulation in lateral root primordia and inhibiting further lateral root growth. It also induces the activation of the CLE peptide in CLAVATA1 signaling, thus inhibiting the growth of lateral root primordia. Furthermore, it induces the expression of nitrogen-responsive genes, including NRT2.1 and NRT1.1, thereby promoting taproot growth and the absorption of other micronutrients from the surrounding environment, such as Fe. 3+ The absorption of organic fertilizer is enhanced; when the main root grows into the middle layer, the seedling is in the spikelet growth stage, and the organic fertilizer also acts as a flower-promoting fertilizer, increasing the number of spikelets per spike, preventing spikelet degeneration, and increasing the accumulation of storage substances in the stem sheath.

[0051] During the mid-layer fertilization stage, rice root development is more rapid, leading to faster nutrient accumulation. In the deep-layer fertilization stage, organic fertilizer is used to improve rice maturity and plumpness. From the perspective of improving rice commercial quality, excessive application of long-term nitrogen fertilizers such as urea is not advisable. Using organic fertilizer plays a crucial role in prolonging root vitality, maintaining stem maturity, preventing lodging, improving seedling survival rate, and enhancing quality. Simultaneously, this invention applies more potassium-rich organic potassium fertilizer in the deep-layer fertilization stage. Common organic potassium fertilizers include dried banana peels soaked in a saturated potassium chloride solution for at least 12 hours, allowing for full absorption of potassium chloride and fixation within the banana peel. This potassium slowly decomposes and releases a significant amount of potassium after the rice roots develop to the deep-layer fertilization stage, promoting grain development and nutrient accumulation, and improving grain quality. As with this invention, both basal and topdressing applications adhere to the principle of early application of phosphorus and later application of potassium to ensure a balance between rice development and grain quality.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1) While increasing the planting density of rice, the development effect of rice was ensured;

[0054] 2) Increase rice yield per mu;

[0055] 3) Improve the effective utilization rate of fertilizers and enhance rice quality;

[0056] 4) Environmentally friendly. This characteristic can maintain the purity of reservoir water resources, thereby avoiding human-caused pollution of water sources. Detailed Implementation

[0057] The present invention will be further described clearly and in detail below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0058] Unless otherwise specified, all raw materials used in the embodiments of the present invention are commercially available or obtainable by those skilled in the art; unless otherwise specified, all methods used in the embodiments of the present invention are methods mastered by those skilled in the art.

[0059] Unless otherwise specified, the potassium-rich organic potassium fertilizer used in the embodiments of the present invention is made by soaking dried banana peels in a saturated potassium chloride solution for 12 hours to allow them to fully absorb potassium chloride and fix it in the dried banana peels. Then, the peels are filtered out and sun-dried until dry for storage and use.

[0060] Unless otherwise specified, the rice variety used in the embodiments and comparative examples of this invention is the commercially available "Shenliangyou 534" rice.

[0061] Unless otherwise specified, all embodiments and comparative examples of this invention were conducted in experimental fields, and all data such as yield per mu were obtained through conversion. Example 1

[0062] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0063] 1) Soak seeds, sow seeds and raise seedlings in sequence. When the rice seedlings grow to the two-leaf stage and the four-leaf stage, spray seedling fertilizer at a ratio of 800 g per square meter. When the seedlings reach the six-leaf stage, prepare to transplant them to the field.

[0064] The soaking process involves first pre-soaking the seeds in water for 12 hours, then soaking them in a 50-fold diluted soaking solution for 12 hours. After soaking in the solution, the seeds are rinsed with water and drained, and then soaked in water again for 12 hours to complete the soaking process.

[0065] The seed soaking solution contained 15 wt% uronic acid, 22 wt% sodium hypochlorite solution, 1.0 wt% proline, and the balance was water.

[0066] The seedling fertilizer consists of 3 wt% chitosan oligosaccharides, 1 wt% EDTA chelated iron, 12 wt% humic acid, 25 wt% soybean meal, 3 wt% potassium chloride, and the remainder is water.

[0067] 2) Before transplanting, the paddy field should be prepared and plowed until there are no weeds, debris, or floating scum. The topsoil should be fine on top and coarse on the bottom, and the soil should be soft on top and firm on the bottom. After leveling the paddy field, it needs to be compacted appropriately. Sandy soil should be compacted for 24 hours, loam for 47 hours, and clay for 48 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep a thin layer of water at a depth of 1 cm. Dig cylindrical pits at a density of 12×12 cm, with a pit opening diameter of 8 cm and a pit depth of 15 cm. Pre-fill the pits with slow-release fertilizer.

[0068] Slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer that are filled in the pit from bottom to top;

[0069] The deep fertilizer layer is 5 cm thick and is composed of 22 wt% soybean powder, 45 wt% potassium-rich organic potassium fertilizer and the remainder sand. The surface of the deep fertilizer layer is covered with a fine mesh with an 8 mm aperture, which adheres to the side wall of the pit.

[0070] The middle layer of fertilizer is 3 cm thick and is made of 20 wt% soybean powder, 14 wt% chicken bone powder, 7 wt% dried banana peel, 10 wt% sodium metasilicate and the remainder sand. The surface of the middle layer of fertilizer is covered with a coarse mesh with a 20 mm aperture, which adheres to the side wall of the pit.

[0071] The surface fertilizer layer is 3 cm thick and is composed of 10 wt% urea, 15 wt% dipotassium hydrogen phosphate, 7 wt% diammonium phosphate, 6 wt% potassium chloride, 10 wt% sodium metasilicate, 3 wt% paclobutrazol, and the remainder sand.

[0072] Maintain soil moisture content with shallow water irrigation with a 1 cm water layer. Drain the water layer 1 day before transplanting and transplant the seedlings into the holes at a ratio of 30,000 clumps per acre, controlling the transplanting depth to 2 cm. Carry out daily field management, including basal application, seedling establishment, and topdressing, while maintaining shallow water irrigation with a depth of 1.0 cm.

[0073] The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing was 570 kg∙hm. -2 120 kg∙hm -2 490kg∙hm -2 ;

[0074] The ratio of nitrogen fertilizer application during the basal application and topdressing process is 2:3, the ratio of potassium fertilizer application is 3:5, and all phosphorus fertilizer is applied during the basal application process. Among them, nitrogen-phosphorus-potassium compound fertilizer is used as basal fertilizer, and urea and potassium chloride are used as topdressing.

[0075] 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down.

[0076] Quality testing: imperfect grains, effective ears, yield, thousand-grain weight, and potassium content of grains.

[0077] Imperfect grains: Samples for impurity testing are divided into large and small samples. Large samples are used to test for impurities in the large sample, including large impurities on the upper sieve and the undersize material on the lower sieve. Small samples are small portions taken from the sample that has been tested for large impurities, testing for impurities and imperfect grains similar in size to the grain grains. Samples are taken to the specified mass according to GB / T 5491. From the average sample, a large sample mass (m1) is taken, accurate to g, and screened twice according to the screening method specified in GB / T 5491 (four screenings for extra-large grains and oilseeds). Then, large impurities on the upper sieve (grain husks removed and classified as impurities) and the undersize material from the lower sieve are combined and weighed (m1), accurate to 0.01 g. From the sample that has been tested for large-scale impurities, aliquot the sample to a minimum mass (m2) according to GB / T 5491. For a minimum mass of 100 g, measure to the nearest 0.01 g; for a minimum mass of 100 g, measure to the nearest 0.1 g. Pour the sample into an analytical pan, remove impurities according to the quality standard, and weigh (m2) to the nearest 0.01 g. Simultaneously with the testing of the small-scale impurities, remove imperfect particles according to the quality standard and weigh (m3) to the nearest 0.01 g.

[0078] The test results are shown in the table below.

[0079]

[0080] The above-described detection and characterization clearly demonstrate that the high-density rice cultivation method of this invention effectively solves the problems of poor cultivation results and low nutrient utilization in traditional high-density planting methods. It achieves unexpectedly high yields and high-quality grains, making it effective for producing high-quality rice. Example 2

[0081] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0082] 1) Soak seeds, sow seeds and raise seedlings in sequence. When the rice seedlings grow to the two-leaf stage and the four-leaf stage, spray seedling fertilizer at a ratio of 800 g per square meter. When the seedlings reach the six-leaf stage, prepare to transplant them to the field.

[0083] The soaking process involves first pre-soaking the seeds in water for 12 hours, then soaking them in a 50-fold diluted soaking solution for 12 hours. After soaking in the solution, the seeds are rinsed with water and drained, and then soaked in water again for 12 hours to complete the soaking process.

[0084] The seed soaking solution contained 15 wt% uronic acid, 22 wt% sodium hypochlorite solution, 1.0 wt% proline, and the balance was water.

[0085] The seedling fertilizer consists of 3 wt% chitosan oligosaccharides, 1 wt% EDTA chelated iron, 12 wt% humic acid, 25 wt% soybean meal, 3 wt% potassium chloride, and the remainder is water.

[0086] 2) Before transplanting, the paddy field should be prepared and plowed until there are no weeds, debris, or floating scum. The topsoil should be fine on top and coarse on the bottom, and the soil should be soft on top and firm on the bottom. After leveling the paddy field, it needs to be compacted appropriately. Sandy soil should be compacted for 24 hours, loam for 47 hours, and clay for 48 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep a shallow layer of water at a depth of 1 cm. Dig cylindrical pits at a density of 15×15 cm, with a pit opening diameter of 10 cm and a pit depth of 17 cm. Pre-fill the pits with slow-release fertilizer.

[0087] Slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer that are filled in the pit from bottom to top;

[0088] The deep fertilizer layer is 7 cm thick and is composed of 30 wt% soybean powder, 60 wt% potassium-rich organic potassium fertilizer and the remainder sand. The surface of the deep fertilizer layer is covered with a fine mesh with an 8 mm aperture, which adheres to the side wall of the pit.

[0089] The middle layer of fertilizer is 4 cm thick and is made of 30 wt% soybean powder, 20 wt% chicken bone powder, 15 wt% dried banana peel, 20 wt% sodium metasilicate and the remainder sand. The surface of the middle layer of fertilizer is covered with a coarse mesh with a 20 mm aperture, which adheres to the side wall of the pit.

[0090] The surface fertilizer layer is 4 cm thick and is composed of 20 wt% urea, 25 wt% dipotassium hydrogen phosphate, 12 wt% diammonium phosphate, 10 wt% potassium chloride, 20 wt% sodium metasilicate, 6 wt% paclobutrazol, and the remainder sand.

[0091] Maintain soil moisture content with shallow water irrigation with a 1 cm water layer. Drain the water layer 1 day before transplanting and transplant the plants into holes at a ratio of 40,000 clumps per acre, controlling the transplanting depth to 3 cm. Carry out daily field management, including basal application, seedling establishment, and topdressing, while maintaining shallow water irrigation with a 1.0 cm depth.

[0092] The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing was 570 kg∙hm. -2 120 kg∙hm -2 490kg∙hm -2 ;

[0093] The ratio of nitrogen fertilizer application during the basal application and topdressing process is 2:3, the ratio of potassium fertilizer application is 3:5, and all phosphorus fertilizer is applied during the basal application process. Among them, nitrogen-phosphorus-potassium compound fertilizer is used as basal fertilizer, and urea and potassium chloride are used as topdressing.

[0094] 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down.

[0095] Quality testing: imperfect grains, effective ears, yield, thousand-grain weight, and potassium content of grains.

[0096] Imperfect grains: Samples for impurity testing are divided into large and small samples. Large samples are used to test for impurities in the large sample, including large impurities on the upper sieve and the undersize material on the lower sieve. Small samples are small portions taken from the sample that has been tested for large impurities, testing for impurities and imperfect grains similar in size to the grain grains. Samples are taken to the specified mass according to GB / T 5491. From the average sample, a large sample mass (m1) is taken, accurate to g, and screened twice according to the screening method specified in GB / T 5491 (four screenings for extra-large grains and oilseeds). Then, large impurities on the upper sieve (grain husks removed and classified as impurities) and the undersize material from the lower sieve are combined and weighed (m1), accurate to 0.01 g. From the sample that has been tested for large-scale impurities, aliquot the sample to a minimum mass (m2) according to GB / T 5491. For a minimum mass of 100 g, measure to the nearest 0.01 g; for a minimum mass of 100 g, measure to the nearest 0.1 g. Pour the sample into an analytical pan, remove impurities according to the quality standard, and weigh (m2) to the nearest 0.01 g. Simultaneously with the testing of the small-scale impurities, remove imperfect particles according to the quality standard and weigh (m3) to the nearest 0.01 g.

[0097] The test results are shown in the table below.

[0098]

[0099] The above-described detection and characterization clearly demonstrate that the high-density rice cultivation method of this invention effectively solves the problems of poor cultivation results and low nutrient utilization in traditional high-density planting methods. It achieves unexpectedly high yields and high-quality grains, making it effective for producing high-quality rice. Example 3

[0100] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0101] 1) Soak seeds, sow seeds and raise seedlings in sequence. When the rice seedlings grow to the two-leaf stage and the four-leaf stage, spray seedling fertilizer at a ratio of 800 g per square meter. When the seedlings reach the six-leaf stage, prepare to transplant them to the field.

[0102] The soaking process involves first pre-soaking the seeds in water for 12 hours, then soaking them in a 50-fold diluted soaking solution for 12 hours. After soaking in the solution, the seeds are rinsed with water and drained, and then soaked in water again for 12 hours to complete the soaking process.

[0103] The seed soaking solution contained 15 wt% uronic acid, 22 wt% sodium hypochlorite solution, 1.0 wt% proline, and the balance was water.

[0104] The seedling fertilizer consists of 3 wt% chitosan oligosaccharides, 1 wt% EDTA chelated iron, 12 wt% humic acid, 25 wt% soybean meal, 3 wt% potassium chloride, and the remainder is water.

[0105] 2) Before transplanting, the paddy field should be prepared and plowed until there are no weeds, debris, or floating scum. The topsoil should be fine on top and coarse on the bottom, and the soil should be soft on top and firm on the bottom. After leveling the paddy field, it needs to be compacted appropriately. Sandy soil should be compacted for 24 hours, loam for 47 hours, and clay for 48 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep a shallow layer of water at a depth of 1 cm. Dig cylindrical pits at a density of 12×12 cm, with a pit opening diameter of 8 cm and a pit depth of 16 cm. Pre-fill the pits with slow-release fertilizer.

[0106] Slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer that are filled in the pit from bottom to top;

[0107] The deep fertilizer layer is 5 cm thick and is composed of 25 wt% soybean powder, 50 wt% potassium-rich organic potassium fertilizer and the remainder sand. The surface of the deep fertilizer layer is covered with a fine mesh with an 8 mm aperture, which adheres to the side wall of the pit.

[0108] The middle layer of fertilizer is 4 cm thick and is made of 25 wt% soybean powder, 16 wt% chicken bone powder, 11 wt% dried banana peel, 15 wt% sodium metasilicate and the remainder sand. The surface of the middle layer of fertilizer is covered with a coarse mesh with a 20 mm aperture, which adheres to the side wall of the pit.

[0109] The surface fertilizer layer is 3 cm thick and is composed of 15 wt% urea, 22 wt% dipotassium hydrogen phosphate, 10 wt% diammonium phosphate, 6.5 wt% potassium chloride, 15 wt% sodium metasilicate, 5 wt% paclobutrazol, and the remainder sand.

[0110] Maintain soil moisture content with shallow water irrigation with a 1 cm water layer. Drain the water layer 1 day before transplanting and transplant the plants into holes at a ratio of 40,000 clumps per acre, controlling the transplanting depth to 3 cm. Carry out daily field management, including basal application, seedling establishment, and topdressing, while maintaining shallow water irrigation with a 1.0 cm depth.

[0111] The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing was 570 kg∙hm. -2 120 kg∙hm -2 490kg∙hm -2 ;

[0112] The ratio of nitrogen fertilizer application during the basal application and topdressing process is 2:3, the ratio of potassium fertilizer application is 3:5, and all phosphorus fertilizer is applied during the basal application process. Among them, nitrogen-phosphorus-potassium compound fertilizer is used as basal fertilizer, and urea and potassium chloride are used as topdressing.

[0113] 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down.

[0114] Quality testing: imperfect grains, effective ears, yield, thousand-grain weight, and potassium content of grains.

[0115] Imperfect grains: Samples for impurity testing are divided into large and small samples. Large samples are used to test for impurities in the large sample, including large impurities on the upper sieve and the undersize material on the lower sieve. Small samples are small portions taken from the sample that has been tested for large impurities, testing for impurities and imperfect grains similar in size to the grain grains. Samples are taken to the specified mass according to GB / T 5491. From the average sample, a large sample mass (m1) is taken, accurate to g, and screened twice according to the screening method specified in GB / T 5491 (four screenings for extra-large grains and oilseeds). Then, large impurities on the upper sieve (grain husks removed and classified as impurities) and the undersize material from the lower sieve are combined and weighed (m1), accurate to 0.01 g. From the sample that has been tested for large-scale impurities, aliquot the sample to a minimum mass (m2) according to GB / T 5491. For a minimum mass of 100 g, measure to the nearest 0.01 g; for a minimum mass of 100 g, measure to the nearest 0.1 g. Pour the sample into an analytical pan, remove impurities according to the quality standard, and weigh (m2) to the nearest 0.01 g. Simultaneously with the testing of the small-scale impurities, remove imperfect particles according to the quality standard and weigh (m3) to the nearest 0.01 g.

[0116] The test results are shown in the table below.

[0117]

[0118] The above-described detection and characterization clearly demonstrate that the high-density rice cultivation method of this invention effectively solves the problems of poor cultivation results and low nutrient utilization in traditional high-density planting methods. It achieves unexpectedly high yields and high-quality grains, making it effective for producing high-quality rice. Example 4

[0119] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0120] 1) Soak seeds, sow seeds and raise seedlings in sequence. When the rice seedlings grow to the two-leaf stage and the four-leaf stage, spray seedling fertilizer at a ratio of 800 g per square meter. When the seedlings reach the six-leaf stage, prepare to transplant them to the field.

[0121] The soaking process involves first pre-soaking the seeds in water for 12 hours, then soaking them in a 50-fold diluted soaking solution for 12 hours. After soaking in the solution, the seeds are rinsed with water and drained, and then soaked in water again for 12 hours to complete the soaking process.

[0122] The seed soaking solution contained 15 wt% uronic acid, 22 wt% sodium hypochlorite solution, 1.0 wt% proline, and the balance was water.

[0123] The seedling fertilizer consists of 3 wt% chitosan oligosaccharides, 1 wt% EDTA chelated iron, 12 wt% humic acid, 25 wt% soybean meal, 3 wt% potassium chloride, and the remainder is water.

[0124] 2) Before transplanting, the paddy field should be prepared and plowed until there are no weeds, debris, or floating scum. The topsoil should be fine on top and coarse on the bottom, and the soil should be soft on top and firm on the bottom. After leveling the paddy field, it needs to be compacted appropriately. Sandy soil should be compacted for 24 hours, loam for 47 hours, and clay for 48 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep a shallow layer of water at a depth of 1 cm. Dig cylindrical pits at a density of 15×15 cm, with a pit opening diameter of 10 cm and a pit depth of 15 cm. Pre-fill the pits with slow-release fertilizer.

[0125] Slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer that are filled in the pit from bottom to top;

[0126] The deep fertilizer layer is 5 cm thick and is composed of 25 wt% soybean powder, 50 wt% potassium-rich organic potassium fertilizer and the remainder sand. The surface of the deep fertilizer layer is covered with a fine mesh with an 8 mm aperture, which adheres to the side wall of the pit.

[0127] The middle layer of fertilizer is 4 cm thick and is made of 25 wt% soybean powder, 16 wt% chicken bone powder, 11 wt% dried banana peel, 15 wt% sodium metasilicate and the remainder sand. The surface of the middle layer of fertilizer is covered with a coarse mesh with a 20 mm aperture, which adheres to the side wall of the pit.

[0128] The surface fertilizer layer is 4 cm thick and is composed of 15 wt% urea, 22 wt% dipotassium hydrogen phosphate, 10 wt% diammonium phosphate, 6.5 wt% potassium chloride, 15 wt% sodium metasilicate, 5 wt% paclobutrazol, and the remainder sand.

[0129] Maintain soil moisture content with shallow water irrigation with a 1 cm water layer. Drain the water layer 1 day before transplanting and transplant the plants into holes at a ratio of 40,000 clumps per acre, controlling the transplanting depth to 3 cm. Carry out daily field management, including basal application, seedling establishment, and topdressing, while maintaining shallow water irrigation with a 1.0 cm depth.

[0130] The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing was 570 kg∙hm. -2 120 kg∙hm-2 490kg∙hm -2 ;

[0131] The ratio of nitrogen fertilizer application during the basal application and topdressing process is 2:3, the ratio of potassium fertilizer application is 3:5, and all phosphorus fertilizer is applied during the basal application process. Among them, nitrogen-phosphorus-potassium compound fertilizer is used as basal fertilizer, and urea and potassium chloride are used as topdressing.

[0132] 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down.

[0133] Quality testing: imperfect grains, effective ears, yield, thousand-grain weight, and potassium content of grains.

[0134] Imperfect grains: Samples for impurity testing are divided into large and small samples. Large samples are used to test for impurities in the large sample, including large impurities on the upper sieve and the undersize material on the lower sieve. Small samples are small portions taken from the sample that has been tested for large impurities, testing for impurities and imperfect grains similar in size to the grain grains. Samples are taken to the specified mass according to GB / T 5491. From the average sample, a large sample mass (m1) is taken, accurate to g, and screened twice according to the screening method specified in GB / T 5491 (four screenings for extra-large grains and oilseeds). Then, large impurities on the upper sieve (grain husks removed and classified as impurities) and the undersize material from the lower sieve are combined and weighed (m1), accurate to 0.01 g. From the sample that has been tested for large-scale impurities, aliquot the sample to a minimum mass (m2) according to GB / T 5491. For a minimum mass of 100 g, measure to the nearest 0.01 g; for a minimum mass of 100 g, measure to the nearest 0.1 g. Pour the sample into an analytical pan, remove impurities according to the quality standard, and weigh (m2) to the nearest 0.01 g. Simultaneously with the testing of the small-scale impurities, remove imperfect particles according to the quality standard and weigh (m3) to the nearest 0.01 g.

[0135] The test results are shown in the table below.

[0136]

[0137] The above-described detection and characterization clearly demonstrate that the high-density rice cultivation method of this invention effectively solves the problems of poor cultivation results and low nutrient utilization in traditional high-density planting methods. It achieves unexpectedly high yields and high-quality grains, making it effective for producing high-quality rice.

[0138] Comparative Example 1

[0139] The same period saw the industrialized cultivation of Shenliangyou 534 rice (planting density of 15,000 clumps per mu).

[0140] The planting and cultivation data are shown in the table below.

[0141]

[0142] A comparison of the above results with Examples 1-4 clearly shows that, while the yield increase is not directly proportional to the number of clumps, the yield of this invention is significantly improved despite the generally increased number of clumps. Regarding the thousand-grain weight data, the rice grains cultivated using this invention are slightly smaller than those obtained using conventional methods. However, in terms of nutritional value, this invention exhibits a higher potassium content in the grains. Potassium content is a crucial factor in evaluating the nutritional quality of rice grains, and this invention shows an increase of approximately 20% in potassium content, demonstrating a significant improvement in nutritional quality and resulting in high-quality refined rice grains.

[0143] Comparative Example 2

[0144] Shenliangyou 534 rice was planted at a high density in the experimental field using conventional planting methods (planting density of 25,000 clumps per mu).

[0145] The planting and cultivation data are shown in the table below.

[0146]

[0147] Shenliangyou 534 rice was planted at an ultra-high density in the experimental field using conventional planting methods (planting density of 35,000 clumps per mu).

[0148] The planting and cultivation data are shown in the table below.

[0149]

[0150] The results above, compared with Comparative Example 1 and Examples 1-4, clearly show that conventional planting methods are not suitable for high-density or even ultra-density (over 30,000 plants / acre) rice cultivation. Both high-density and ultra-density planting significantly impact rice quality and growth. For example, in high-density planting, the density increased by approximately 66.7%, but the yield only increased by about 10%, and the thousand-grain weight and potassium content decreased significantly. This demonstrates that high-density planting using common methods leads to severe grain shrinkage and an inability to effectively accumulate nutrients, resulting in a significant decline in nutritional quality. Conversely, ultra-density planting resulted in a very significant decrease in yield, with further reductions in thousand-grain weight and potassium content. Therefore, conventional planting methods are not suitable for high-density and ultra-density rice cultivation.

[0151] Comparative Example 3

[0152] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0153] The specific planting and cultivation methods and testing characteristics are the same as in Example 3, except that fine and coarse nets are not set on the surface of the deep and middle layers of fertilizer when the slow-release fertilizer is pre-filled in the pit.

[0154]

[0155] The above-mentioned testing and characterization revealed that the presence or absence of coarse and fine netting significantly impacts the actual planting and cultivation results. The inventors believe this impact is primarily due to the fact that without coarse and fine netting to regulate root development and nutrient absorption in rice, the roots prematurely undergo vertical development. This results in the pre-applied slow-release fertilizer being less effective than expected, with potassium fertilizer being absorbed too early. Although the number of effective panicles increases, the yield does not, and there is a slight decrease in grain size. However, the most significant impact is on grain potassium content. The premature absorption of potassium-rich organic potassium fertilizer prevents the grains from obtaining sufficient potassium nutrients during development, leading to a very significant decrease in grain potassium content. This greatly weakens the cultivation effect and fails to effectively obtain high-quality, high-nutritional-value rice grains.

[0156] Comparative Example 4

[0157] A method for improving the quality of rice cultivation in southern China was developed, and the method was validated in experimental fields. The specific steps include:

[0158] The specific planting and cultivation methods and testing characteristics are the same as in Example 3, except that the planting density is further increased to 45,000 clumps per acre.

[0159]

[0160] Through the above-described tests, it is evident that while the planting method of this invention can achieve high-density planting, further increases in planting density result in insufficient nutrition for some seedlings. The intense competition among multiple seedlings for limited nutrients exceeds the self-regulation limits of the micro-ecological environment, leading to vicious competition. Compared to Example 3, the yield per acre not only fails to increase but actually decreases, resulting in poor planting and cultivation effects. Therefore, it is evident that the maximum planting density applicable to the planting scheme of this invention should not exceed 40,000 seedlings per acre.

Claims

1. A method for improving the quality of rice grown in southern regions, characterized in that, The method includes: 1) Sow and raise seedlings. Spray seedling fertilizer when the rice seedlings reach the two-leaf stage and the four-leaf stage respectively. When the seedlings reach the six-leaf stage, prepare to transplant them to the field. 2) Before transplanting, prepare the field by tilling and creating pits, dig pits to control the rice planting density, pre-fill the pits with slow-release fertilizer, and maintain soil moisture by shallow water irrigation. After draining the water layer 1-2 days before transplanting, transplant the rice into the pits and carry out daily field management. 3) Harvest the rice when it is mature, with plump, golden-yellow grains hanging down. Step 2) The pit density is 12-15×12-15 cm, the pit opening diameter is controlled to be 8-10 cm, and the pit depth is 15-17 cm; Step 2) The slow-release fertilizer includes deep fertilizer, middle fertilizer and surface fertilizer filled in the pit from bottom to top; The deep fertilizer layer is 5-7 cm thick and is composed of 22-30 wt% soybean meal, 45-60 wt% potassium-rich organic potassium fertilizer, and the remainder sand. The middle layer of fertilizer is 3-4 cm thick and is composed of 20-30 wt% soybean powder, 14-20 wt% organic phosphorus and calcium fertilizer, 7-15 wt% organic potassium fertilizer, 10-20 wt% citrate-soluble silicon fertilizer and the remainder sand. The surface fertilizer layer is 3-4 cm thick and is composed of 10-20 wt% urea, 15-25 wt% dipotassium hydrogen phosphate, 7-12 wt% diammonium phosphate, 6-10 wt% potassium chloride, 10-20 wt% citrate-soluble silicon fertilizer, 3-6 wt% paclobutrazol, and the remainder sand. When prefilling slow-release fertilizer, first fill the deep layer fertilizer, and then lay a fine mesh with a pore size of 7-9 mm on the surface of the deep layer fertilizer and against the side wall of the pit. The fine mesh is then filled with a middle layer of fertilizer, and a coarse mesh with a mesh size of 18-22 mm is laid on the surface of the middle layer of fertilizer, adhering to the side wall of the pit. Step 2) The number of clumps transplanted per acre is 30,000 to 40,000; When transplanting, control the transplanting depth to 2-3 cm.

2. The method for improving the quality of southern rice according to claim 1, characterized in that, Step 1) involves pre-sowing seed treatment, which includes: Soaking: First, pre-soak in water for 10-12 hours, then soak in soaking solution for 10-12 hours. After soaking in the soaking solution, rinse with water and drain. Then soak in water again for 10-12 hours to complete the soaking process. The soaking solution contains 13–17 wt% uronic acid, 20–25 wt% sodium hypochlorite solution, 0.8–1.2 wt% proline, and the remainder is water.

3. The method for improving the quality of southern rice according to claim 1, characterized in that, The components of the seedling fertilizer mentioned in step 1) are: Chitosan oligosaccharides 1-5 wt%, EDTA chelated iron 1-2 wt%, humic acid 9-15 wt%, soybean meal 20-35 wt%, potassium chloride 1-5 wt%, balance water; When spraying seedling fertilizer at the two-leaf and four-leaf stages, the fertilizer should be applied at a ratio of 800-1200 g per square meter.

4. The method for improving the quality of southern rice according to claim 1, characterized in that, Step 2) The purpose of preparing the paddy field is to ensure that there are no weeds, debris, or floating scum in the paddy field, and that the topsoil is fine on top and coarse on the bottom, and that the topsoil is soft and the bottom is firm. After the paddy field is leveled, it needs to be compacted appropriately. Sandy soil should be compacted for 12-36 hours, loam for 24-48 hours, and clay for 48-72 hours. When the mud has settled, the topsoil is of moderate softness and hardness and will not sink the machine, keep the water level low.

5. The method for improving the quality of southern rice according to claim 1, characterized in that, Step 2) The routine field management includes basal application, seedling establishment, topdressing, and shallow irrigation.

6. The method for improving the quality of southern rice according to claim 5, characterized in that, The total amount of nitrogen, phosphorus, and potassium fertilizer applied as basal and top dressing is controlled at 560–580 kg·hm². -2 115~130 kg∙hm -2 490~500 kg∙hm -2 ; The ratio of nitrogen fertilizer application during the basal and topdressing processes is 2:(2.8-3.2), the ratio of potassium fertilizer application is 3:(4.8-5.2), and all phosphorus fertilizer is applied during the basal application process.

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