Rice straw cutting, burying and returning method

Abstract

The invention discloses a rice straw cutting, burying and returning method, and belongs to the technical field of agriculture, and the method comprises the following steps: when a rice field is dried in autumn until flowers reach water, carrying out longitudinal cutting treatment on rice straws to obtain longitudinally cut straws; obtaining the soil organic matter content of the rice field region, and determining the feeding amount of longitudinally-cut straws in different regions based on the soil organic matter content; based on the feeding amount of the longitudinally-cut straw, the feeding amount of a corrosion promoting agent is obtained; longitudinally-cut straw and a corrosion promoting agent are put into the rice field to be subjected to field returning treatment; and performing shallow slurrying operation on the rice field in spring of the next year. The problems that in the prior art, the straw returning effect cannot be reasonably kept, and the resource consumption and complexity of straw returning operation are too high are solved. And the obtaining effect of straw returning operation is fully improved, so that the rice yield is increased based on straw returning.

Description

Technical Field

[0001] This application belongs to the field of agricultural technology, and in particular relates to a method for cutting and burying rice straw back into the field. Background Technology

[0002] The black soil region of Northeast my country is a crucial rice production base, with an annual planting area of ​​nearly 80 million mu (approximately 5.3 million hectares) and rice output accounting for 18% of the national total. It holds significant strategic importance for ensuring my country's absolute food security. However, in recent years, the soil fertility of paddy fields in Northeast China has been declining, becoming a major factor restricting the increase of rice yield per unit area.

[0003] Returning rice straw to the field is an important measure to improve the soil fertility of paddy fields. However, the rate of full straw return in the black soil region of Northeast China is low. After shallow tillage and deep plowing in spring, the straw residue tends to float, and repeated mulching and burying of straw in spring damages the soil aggregate structure, affecting rice transplanting and root development. In addition, the peak of straw decomposition often coincides with the rice seedling establishment and tillering stage. Harmful substances produced during decomposition are detrimental to rice root growth and may even lead to yield reduction. This is a major reason why straw return to the field is difficult to promote and why the topsoil layer of paddy fields becomes thinner, less fertile, and harder. Therefore, increasing the rate of rice straw burial, advancing the rapid decomposition period of rice straw, and reducing the damage to soil structure caused by repeated mulching are of great significance for cultivating and utilizing black soil in paddy fields effectively.

[0004] Temperature and moisture are crucial factors affecting straw decomposition. Studies show that in Northeast China, the effective accumulated temperature in autumn and winter accounts for over 30% of the total annual effective accumulated temperature. Returning rice straw to the field in autumn can fully utilize the effective accumulated temperature of autumn and winter to advance the straw decomposition period. Using water-based tillage for returning straw to the field can further saturate the straw, fully leveraging the decomposition by microorganisms and the tearing effect of freeze-thaw cycles to achieve efficient straw decomposition during the fallow period. Currently, the autumn pulping and returning technology used in some parts of Northeast China, while utilizing the temperature and moisture resources of autumn and winter, results in shallow straw burial depth. To improve straw burial depth, multiple pulping processes are required, severely damaging the soil aggregate structure, increasing soil bulk density, and reducing soil permeability and aeration, which is detrimental to the normal growth of rice roots and the protection of paddy field soil fertility. Therefore, innovating a method for promoting the decomposition of rice straw in autumn and returning it to the field, achieving full burial of rice straw in a single operation, is essential and of great significance for cultivating and utilizing black soil effectively and ensuring the normal growth of rice.

[0005] Chinese invention patent 202110201461.5 discloses a method for returning rice straw to the field in autumn in cold regions. The method involves mixing rice straw with paddy field soil after rice harvest; watering to soak the straw while keeping the soil moist; after 10-15 days, collecting the decomposed straw and placing it in a cellulose liquid culture medium to obtain a mixed bacterial stock solution; adding the mixed bacterial stock solution to the cellulose liquid culture medium for further culture to obtain a mixed bacterial solution; spraying the mixed bacterial solution onto the surface of the crushed and soaked straw, simultaneously spreading organic fertilizer, tilling to a depth of 15-20 cm, and watering again. The disadvantages of this method are that it requires manual watering, soaking the straw requires a large amount of water, and the preparation of the mixed bacterial solution requires certain technical skills and a high level of operational expertise. Chinese invention patent 202110579018.1 discloses a method for returning rice straw to the field in autumn using water-plowing and slurry. The method involves harvesting and crushing rice straw after the autumn rice harvest and before the topsoil freezes, then evenly spreading the crushed straw in the field; flooding the field for 3-5 days; and rotary tilling to a depth of at least 20 cm to mix the rice straw with the slurry. The disadvantage of this method is that the flooding period wastes effective accumulated heat, and in the cold regions of Northeast China, river water supply stops during the rice harvest season, making irrigation difficult. Chinese invention patent 202210297497.2 discloses a method for returning rice straw to the field in cold regions in autumn using slurry. The method involves harvesting rice straw after the paddy field has dried out to a waterlogged state in autumn, spreading the straw on the surface of the paddy field, applying a straw decomposition promoter, and then slurrying and leveling the field to a depth of 10 cm. The advantage of this method is that it eliminates the need for artificial watering, but the pulping depth is shallow, requiring multiple pulping processes to increase the straw burial rate, which increases the soil bulk density and is not conducive to the rooting of rice.

[0006] In summary, the above invention patents demonstrate that methods for returning rice straw to the field in autumn in the cold regions of Northeast China either require manual irrigation or multiple pulping processes, which are detrimental to soil fertility. Therefore, developing a method that ensures effective straw return while reducing the complexity of the process is a pressing technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the problems existing in current rice straw return-to-field technologies, this application discloses a method for cutting and burying rice straw for return to the field. The aim is to provide a straw return-to-field technology that utilizes residual water in the paddy field, longitudinally cutting the straw and then horizontally pressing and burying it in the soil. This significantly improves the straw burial rate and fully utilizes the water, light, and heat resources available before the soil freezes in winter for initial decomposition of the straw. The alternating freeze-thaw action in winter and spring breaks up the straw, accelerating decomposition and improving soil fertility, thus ensuring smooth rice production. Specifically: A method for cutting and burying rice straw back into the field, the method comprising: When the rice paddies are dry in autumn and the water level reaches the flower stage, the rice straw is longitudinally cut to obtain longitudinally cut straw. The soil organic matter content of the paddy field area was obtained, and the longitudinally cut straw application amount in different areas was determined based on the soil organic matter content. Based on the amount of longitudinally cut straw applied, the amount of composting agent applied is obtained; Longitudinal chopped straw and decomposition promoters are applied to paddy fields for returning straw to the field. The following spring, shallow slurry preparation was carried out on the aforementioned paddy field.

[0008] Optionally, the process of longitudinally cutting the rice straw when the paddy field is dried out in autumn to obtain longitudinally cut straw includes: The depth of the water layer in the Huadashui area is 1~2cm; The stubble height for rice should be 25-35cm. The longitudinal cutting depth of rice straw should not be less than 20cm.

[0009] Optionally, obtaining the soil organic matter content of the paddy field area and determining the longitudinally cut straw application amount for different areas based on the soil organic matter content includes: Obtain the soil organic matter content of all areas within the paddy field; Based on the soil organic matter content, the paddy fields were divided into areas for the longitudinal cutting of straw. Based on the area of ​​the longitudinally cut straw placement area and the soil organic matter content, the amount of longitudinally cut straw placed in different areas is obtained.

[0010] Optionally, obtaining the amount of composting agent based on the amount of longitudinally cut straw includes: To obtain the decomposition rate of longitudinally cut straw by different types of decomposition accelerators, and to select the type of decomposition accelerator; The amount of composting agent applied is determined based on the decomposition rate of the type of composting agent and the amount of longitudinally cut straw applied.

[0011] Optionally, the process of applying longitudinally chopped straw and a decomposition accelerator to the paddy field for returning the straw to the field includes: According to the amount of longitudinally cut straw to be applied, longitudinally cut straw is applied to different areas of the paddy field; According to the dosage of the accelerator, spray the accelerator onto the longitudinally cut straw to obtain longitudinally cut straw after accelerating the decay. The paddy field was rotary treated, and the longitudinally cut straw after decomposition was buried in the soil; The soil in the paddy field was leveled.

[0012] Optionally, spraying the composting agent onto the longitudinally cut straw according to the prescribed dosage to obtain composted longitudinally cut straw includes: The longitudinally cut straw is evenly dispersed to ensure that it is evenly distributed. Spray the composting agent evenly onto the longitudinally cut straw to ensure that the composting agent is evenly distributed on the longitudinally cut straw.

[0013] Optionally, the process of rotary tillage of the paddy field and burying the longitudinally chopped straw after decomposition in the soil includes: The depth of the paddy field rotary treatment shall not be less than 20cm; The longitudinally cut straw, after being accelerated to decompose, is evenly buried in the deepest part of the soil layer treated by rotary soil.

[0014] Optionally, the shallow slurry preparation operation carried out on the paddy field in the following spring includes: The shallow slurry preparation depth is 0~5cm.

[0015] Optional, also includes: Prioritize rice straw cutting and burying operations based on the organic matter content of paddy fields; Based on the priority of rice straw cutting and burying operations, the rice varieties selected for the paddy fields include: When the priority of rice straw cutting and burying operations is high, the selected rice variety is an early-maturing rice variety; when the priority of rice straw cutting and burying operations is not high, the selected rice variety is any available rice variety.

[0016] The beneficial effects of this application include: 1. Eliminates the limitation on straw stubble height. In the technical solution of this application, the straw is longitudinally cut, and the parameters of the longitudinally cut straw can be adjusted according to the requirements of returning to the field. In this process, there is no need to pay attention to the stubble height, only to adjust the parameters such as the straw burial depth.

[0017] 2. Full use of existing resources. In the technical solution of this application, straw is buried during the autumn flowering and watering stage, lasting from autumn to the following spring. The straw decomposes again during the freeze-thaw cycle in winter, reducing the problems of straw floating and harmful gas generation that exist under conventional straw return measures. At the same time, it utilizes the water, light and heat resources of the soil in Northeast China before freezing, and uses lime nitrogen to adjust the soil carbon-nitrogen ratio to promote straw decomposition.

[0018] 3. It avoids the problem of soil quality degradation. Autumn straw is returned to the field, and in winter, the rice paddies freeze to form an ice layer, reducing the problem of soil thinning caused by strong winter and spring winds in Northeast China. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the embodiments of this application or the prior art will be briefly introduced below. Obviously, the following description is only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the following detailed description to explain this disclosure, but do not constitute a limitation of this disclosure. In the drawings: Figure 1 A flowchart illustrating a method for cutting and burying rice straw back into the field, provided as an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, in the embodiments of this application, "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0021] Current methods for returning rice straw to the field include pulping, crushing, and autumn water-harrowing. These techniques often fail to protect the soil, leading to the loss of organic matter. Furthermore, they require a high level of skill, increasing the investment of manpower and resources. To address these issues, this application discloses a method for cutting and burying rice straw for returning to the field, such as... Figure 1 The diagram shown is a flowchart of a method for cutting and burying rice straw back into the field, as disclosed in an embodiment of this application. Specifically: A method for cutting and burying rice straw back into the field, the method comprising: S110. When the rice paddies are dried up in autumn and the water level reaches the bottom, the rice straw is longitudinally cut to obtain longitudinally cut straw.

[0022] S120. Obtain the soil organic matter content of the paddy field area, and determine the amount of longitudinally cut straw to be applied in different areas based on the soil organic matter content.

[0023] S130. Based on the amount of longitudinally cut straw applied, obtain the amount of composting agent applied.

[0024] S140. Apply longitudinally chopped straw and a decomposition accelerator to the paddy field for returning to the field.

[0025] S150. In the following spring, shallow slurry preparation was carried out on the paddy field.

[0026] The purpose of all the above steps is to determine the amount of longitudinally chopped straw to be returned to the field in each area, in addition to using longitudinally chopped straw, and to implement corresponding application operations based on the determined amount. This is especially important considering that large-scale paddy fields suitable for harvesting with large agricultural machinery will inevitably have uneven soil organic matter content. Therefore, it is necessary to rationally determine the amount of straw to be applied based on the organic matter content. The beneficial effects, besides enabling proper straw return to the field, include supplementing areas with low organic matter content with more straw to better increase organic matter content, and conversely, reducing the amount of straw applied to areas with high organic matter content to conserve resources.

[0027] The following will provide a detailed explanation of all the steps above: As described in step S110, the purpose of this step is to make reasonable use of the residual water resources in the paddy fields during autumn to promote the effect of straw return to the field. Specifically: The depth of the water layer in the Huadashui area is 1~2cm; The stubble height for rice should be 25-35cm. The longitudinal cutting depth of rice straw should not be less than 20cm.

[0028] As described in step S120, the purpose of this step is to support the planting of different types of rice in different areas of large-scale paddy fields. These rice varieties have different organic matter consumption levels, and the natural environment of the paddy fields themselves also leads to differences in organic matter content. It is unreasonable to use the same straw return method for soils with different organic matter contents. Therefore, in specific treatments, it is necessary to determine the amount of straw to be applied based on soil organic matter content testing. Specifically: Obtain the soil organic matter content of all areas within the paddy field; Based on the soil organic matter content, the paddy fields were divided into areas for the longitudinal cutting of straw. Based on the area of ​​the longitudinally cut straw placement area and the soil organic matter content, the amount of longitudinally cut straw placed in different areas is obtained.

[0029] In monitoring the organic matter content of soil, a monitoring sensor can be set up to directly measure the organic matter content, and then the organic matter content data at the location of the sensor can be obtained.

[0030] Among them, areas with similar or identical organic matter content data are obtained, and based on the obtained regional values, the rice fields are divided into areas for longitudinally cut straw placement.

[0031] The area of ​​the obtained deployment area can be determined directly based on the sensor placement.

[0032] The application rate is determined based on the organic matter content that straw can release into the paddy field during the straw return period from autumn to spring. The equation for determining the application rate is: ; in, W i Indicates the first i The weight of longitudinally cut straw to be placed in each area of ​​the paddy field; W di Indicates the first i Organic matter requirements of each paddy field area; w p This indicates the organic matter content provided per unit weight of longitudinally cut straw.

[0033] Once the area of ​​different regions is determined, the burial thickness of the longitudinally cut straw can be determined by combining the obtained weight of the longitudinally cut straw.

[0034] The beneficial effect of step S120 is that it fully considers the possible differences in organic matter content in different areas under the condition of large-area paddy fields, and determines the paddy field area based on the difference parameter. Based on the organic matter content parameter of the paddy field area, it determines the amount of longitudinally cut straw to be applied in different areas, thus realizing personalized application of longitudinally cut straw in paddy fields.

[0035] As described in step S130, the purpose of this step is to screen the types of composting agents used in straw returning operations, and at the same time, determine the dosage of composting agents based on the amount of longitudinally cut straw applied in different areas of the paddy field. Specifically: To obtain the decomposition rate of longitudinally cut straw by different types of decomposition accelerators, and to select the type of decomposition accelerator; The amount of composting agent applied is determined based on the decomposition rate of the type of composting agent and the amount of longitudinally cut straw applied.

[0036] The study analyzed the effects of preservatives, including key parameters such as the decomposition rate after application and environmental requirements.

[0037] In the use of decomposition accelerators, the accelerators need to be sprayed evenly onto the longitudinally cut straws in different areas of the paddy field to ensure that all the longitudinally cut straws can decompose under the action of the accelerators.

[0038] The final selected decomposition accelerator in this application is calcium cyanamide, which can ensure a high decomposition rate while reducing the accumulation of harmful substances.

[0039] The determination of the dosage of the composting accelerator should be based on the required dosage of the accelerator and the amount of longitudinally cut straw used. As described in step S140, the purpose of this step is to return the treated longitudinally chopped straw to the field to ensure that the straw can decompose after being returned. Specifically: According to the amount of longitudinally cut straw to be applied, longitudinally cut straw is applied to different areas of the paddy field; According to the dosage of the accelerator, spray the accelerator onto the longitudinally cut straw to obtain longitudinally cut straw after accelerating the decay. The paddy field was rotary treated, and the longitudinally cut straw after decomposition was buried in the soil; The soil in the paddy field was leveled.

[0040] During the straw return process, it is necessary to ensure that the longitudinally chopped straw used decomposes at a consistent rate after being placed in the paddy field. Therefore, it is essential to spray the decomposition accelerator evenly. Specifically: The longitudinally cut straw is evenly dispersed to ensure that it is evenly distributed. Spray the composting agent evenly onto the longitudinally cut straw to ensure that the composting agent is evenly distributed on the longitudinally cut straw.

[0041] For straw return to the field, the longitudinally chopped straw needs to be rotary tilled before being placed in the soil. To ensure the straw is buried at a suitable depth, the tilling depth needs to be set before the straw is returned to the field. Specifically: The depth of the paddy field rotary treatment shall not be less than 20cm; The longitudinally cut straw, after being accelerated to decompose, is evenly buried in the deepest part of the soil layer treated by rotary soil.

[0042] As described in step S150, the purpose of this step is to ensure the effectiveness of straw return to the field. After the longitudinally cut straw is returned to the field in autumn, the paddy field needs further treatment the following spring to allow oxygen and other substances to enter the soil, thus promoting decomposition. Simultaneously, it is necessary to avoid disrupting the stratification formed by the buried longitudinally cut straw. Specifically: The shallow slurry preparation depth is 0~5cm.

[0043] The purpose of returning straw to the field is to increase the organic matter content of the soil in the paddy field, which is then used to select rice varieties. To ensure the effectiveness of straw returning, a method can be adopted that the need for straw returning in a specific area is determined based on the soil organic matter content. This selection should be based on priority. Furthermore, to guarantee the effectiveness of straw returning, it is necessary to ensure that the operation can be carried out from autumn to the following spring to ensure the treatment effect. Specifically: Prioritize rice straw cutting and burying operations based on the organic matter content of paddy fields; Based on the priority of rice straw cutting and burying operations, the rice varieties selected for the paddy fields include: When the priority of rice straw cutting and burying operations is high, the selected rice variety is an early-maturing rice variety; when the priority of rice straw cutting and burying operations is not high, the selected rice variety is any available rice variety.

[0044] The priority for straw return to the field is determined by the method that the lower the organic matter content of the paddy field, the higher the priority of straw return to the field.

[0045] When straw return to the field is given a high priority, it is necessary to ensure the effectiveness of the straw return operation. A key method is to ensure the decomposition time of the straw. Therefore, early-maturing rice varieties are used to ensure the decomposition time.

[0046] The priority for straw return to the field can be determined by setting an organic matter content threshold. That is, if the straw content is below the set threshold, the priority is high; if it is above the threshold, the priority is low. The organic matter content threshold can be set based on the experience of technical personnel, or the average soil organic matter content of the entire paddy field area can be used as the threshold.

[0047] The beneficial effect of step S150 is that, based on the priority of rice straw return to the field, rice varieties are selected, and by using early-maturing rice varieties, the decomposition time is extended, thereby improving the straw return to the field effect.

[0048] To further illustrate the overall technical solution and the technical effects achievable in this application, and based on the implementation method of the technology, this application provides four comparative examples and two experimental examples. By comparing the cultivation results, the effects achieved by the embodiments of this application are determined. Specifically: Comparative Example 1 This case study was conducted in Alaxin Village, Daxing Town, Tailai County, Qiqihar City, Heilongjiang Province (the experiment began in 2021). The village belongs to the mid-latitude continental monsoon climate zone, characterized by dry and windy springs, hot and dry summers, windy and highly variable autumns, and cold and snowless winters. The average annual accumulated temperature is 2930.6 degrees Celsius, the average annual temperature is 4.9 degrees Celsius, the average annual frost-free period is 145 days, the average annual sunshine duration is 2908.8 hours, and the average annual precipitation is 392.6 mm. The village has a complete irrigation and drainage system. The tested soil was submerged paddy soil. The physicochemical properties of the topsoil were: organic matter 16.2 g·kg⁻¹, total nitrogen 2.28 g·kg⁻¹, hydrolyzable nitrogen 198 mg·kg⁻¹, available phosphorus 42 mg·kg⁻¹, and available potassium 166 mg·kg⁻¹.

[0049] This comparative method of straw return to the field involves full-volume spring rotary tillage. Specific procedures are as follows: ① During the later stages of rice growth, when the soil naturally dries to field capacity, harvest the rice using a semi- (full)-feed combine harvester, chopping and crushing the straw into 5-10 cm pieces. A straw diffuser is installed below the chopper to ensure even distribution of the chopped straw, preventing clogging or ridging. ② No land preparation is performed in autumn, allowing the straw to remain on the soil surface throughout the winter. ③ During the spring thawing period (mid-April), use a rotary tiller to prepare the land and return the straw to the field to a depth of 10-15 cm, burying all the straw underground. ④ During the spring planting period (mid-May), soak the field to a depth of 3-5 cm, then use a pulper to shallowly pulp the soil to a depth of 5-10 cm, preparing for transplanting. Other management practices are the same as in the local area. The rice variety used in the trial was Zhongkefa 5. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1m² quadrat was harvested at each point, and 10 holes were randomly selected from each quadrat to measure the effective tillers and thousand-grain weight of the rice.

[0050] Comparative Example 2 The experimental site for Comparative Example 2 was located next to that of Comparative Example 1, and the soil properties were the same. The difference was that the straw return method was half-volume spring rotary tillage. Specific procedures were as follows: ① When the rice plants naturally dried to field capacity during the later stages of their growth, a combine harvester with half (full) feed was used to harvest the rice. ② All the straw discharged by the harvester was bundled and removed from the field, leaving only the straw stubble on the ground. ③ During the spring soil thawing period (mid-April), a rotary tiller was used for land preparation and straw return operations to a depth of 10-15 cm, burying all the straw stubble underground. ④ During the spring planting period (mid-May), the field was soaked to a depth of 3-5 cm, and a pulping machine was used for shallow pulping to a depth of 5-10 cm, preparing for transplanting. Other management practices were the same as in the local area, and the rice variety used in the experiment was Zhongkefa No. 5. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m2 quadrat was harvested at each point, and 10 holes were randomly selected from each quadrat to measure the effective tillers and thousand-grain weight of the rice.

[0051] Comparative Example 3 The experimental site for Comparative Example 3 was located next to that of Comparative Example 1, and the soil properties were the same. The difference was that the straw return method was full-volume autumn straw slurry return. Specific procedures were as follows: ① During the later stages of rice growth, when the soil naturally dried to field capacity, a half- (full-)-feed combine harvester was used to harvest the rice, chopping and crushing the straw into 5-10 cm pieces. A straw diffuser was installed below the chopper to ensure even spreading of the chopped straw, preventing clogging or ridging. ② The straw was then rotary tilled to a depth of 10-15 cm using a straw slurry machine, utilizing residual water in the paddy field to form a slurry that fully coated the straw. ③ During the spring thawing period (mid-April), a rotary tiller was used for land preparation and straw return to the field, with a tillage depth of 10-15 cm. ④ During the spring planting period (mid-May), the field was flooded to a depth of 3-5 cm, and then shallowly slurried to a depth of 5 cm using a slurry machine, preparing for transplanting. Other management practices were the same as in the local area, and the rice variety used in the experiment was Zhongkefa 5. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m2 quadrat was harvested at each point, and 10 holes were randomly selected from each quadrat to measure the effective tillers and thousand-grain weight of the rice.

[0052] Comparative Example 4 This case study was conducted in the Tailai County Industrial Park, Qiqihar City, Heilongjiang Province (the experiment began in 2022). The park belongs to the mid-latitude continental monsoon climate zone, characterized by dry and windy springs, hot and dry summers, windy and highly variable autumns, and cold and snowless winters. The annual average accumulated temperature is 2930.6 degrees Celsius, the annual average temperature is 4.9 degrees Celsius, the annual average frost-free period is 145 days, the annual average sunshine duration is 2908.8 hours, and the annual average precipitation is 392.6 mm. The park has a complete irrigation and drainage system. The tested soil was meadow paddy soil. The physicochemical properties of the topsoil were: organic matter 15.9 g·kg⁻¹, total nitrogen 0.82 g·kg⁻¹, hydrolyzable nitrogen 77 mg·kg⁻¹, available phosphorus 9 mg·kg⁻¹, and available potassium 120 mg·kg⁻¹.

[0053] This comparative method for straw return to the field involves returning all straw to the field via autumn rotary tillage. Specific procedures are as follows: ① During the later stages of rice growth, when the soil naturally dries to field capacity, harvest the rice using a semi- (full)-feed combine harvester, chopping and crushing the straw into 5-10 cm pieces. Install a straw diffuser below the chopper to ensure even distribution of the chopped straw, preventing clogging or ridging. ② Use a rotary tiller for land preparation and straw return to the field, working to a depth of 10-15 cm, burying all the straw in the soil. ③ During the spring thawing period (mid-April), use a rotary tiller for land preparation and straw return to the field, working to a depth of 10-15 cm. ④ During the spring planting period (mid-May), flood the field to a depth of 3-5 cm, then use a pulper for shallow pulping to a depth of 5 cm, preparing for transplanting. Other management practices are the same as in the local area. The rice variety used in the trial was Tai Rong No. 1. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m² quadrat was harvested at each point, and 10 hills were randomly selected from each quadrat to measure the effective tillering and thousand-grain weight of the rice. The experiment began in the autumn of 2022, and the straw decomposition rate was measured using a nylon mesh bag method after full straw return to the field in autumn, before planting in the spring of 2023, and after the autumn rice harvest.

[0054] Comparative Example 5 Comparative Example 5 was located next to Comparative Example 4, with identical soil properties. The difference lay in the method of straw return: full-volume straw was returned to the field during autumn plowing. Specific procedures were as follows: ① During the later stages of rice growth, when the soil naturally dried to field capacity, a half- (full-)-feed combine harvester was used to harvest the rice, chopping the straw into 5-10 cm pieces. A straw diffuser was installed below the chopper to ensure even distribution of the chopped straw, preventing clogging or ridging. ② Deep plowing and straw return were performed using a moldboard plow paired with a tractor, to a depth of 20-25 cm, burying all the straw in the soil. ③ During the spring thawing period (mid-April), a rotary tiller was used for further tilling and straw return, to a depth of 10-15 cm. ④ During the spring planting period (mid-May), the field was flooded to a depth of 3-5 cm, followed by shallow slurrying using a slurry machine to a depth of 5 cm, preparing for transplanting. Other management practices were the same as in the local area. The rice variety used in the experiment was Tai Rong No. 1. After the rice matured, the aboveground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m² quadrat was harvested at each point to measure grain biomass, and 10 plots were randomly selected to measure effective tillering and thousand-grain weight. The experiment began in the autumn of 2022, using a nylon mesh bag method to determine the straw decomposition rate after full straw return to the field in autumn, before planting in spring 2023, and after rice harvest in autumn.

[0055] Experimental Example 1 The experimental site for Example 1 was located next to that of Comparative Example 1, and the soil properties were the same. The difference was that the straw return method involved applying calcium cyanamide and then cutting and burying all the straw in the autumn. Specific procedures were as follows: ① During the later stages of rice growth, when the soil naturally dried to field capacity, a half- (full-)-feed combine harvester was used to harvest the rice, chopping and crushing the straw into 5-10 cm pieces. A straw diffuser was installed below the chopper to ensure the chopped straw was evenly spread without piling or ridging. ② The soil was deep-loosened using a tiller to a depth of 15-20 cm, followed by longitudinal cutting of the straw stubble, rotary tillage, and leveling using a new type of pulper to evenly mix the rice straw into the soil layer and level the surface. ③ During the spring thawing period (mid-April), a rotary tiller was used for land preparation and straw return to the field to a depth of 10-15 cm. ④ During the spring planting season (mid-May), the paddy fields were soaked to a depth of 3-5 cm, and then shallowly pulped to a depth of 5 cm using a pulping machine, in preparation for transplanting. Other management practices were the same as in the local area. The rice variety used for the test was Zhongkefa No. 5. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m2 quadrat was harvested at each point, and 10 hills were randomly selected from each quadrat to measure the effective tillers and thousand-grain weight of the rice.

[0056] Experiment Example 2 The experimental site for Example 2 was located next to that of Comparative Example 4, and the soil properties were the same. The difference was that the straw return method involved applying calcium cyanamide and then cutting and burying all the straw in the autumn. Specific procedures were as follows: ① During the later stages of rice growth, when the soil naturally dried to field capacity, a half- (full-)-feed combine harvester was used to harvest the rice, and the straw was chopped into 5-10 cm pieces. A straw diffuser was installed below the chopped straw to ensure even distribution and prevent clogging or ridging. ② The soil was deep-loosened using a tiller to a depth of 15-20 cm, followed by longitudinal cutting of the straw stubble, rotary tillage, and leveling using a new type of pulper to evenly mix the rice straw into the soil layer and level the surface. ③ During the spring thawing period (mid-April), a rotary tiller was used for land preparation and straw return to the field to a depth of 10-15 cm. ④ During the spring planting season (mid-May), the fields were soaked to a depth of 3-5 cm, and then shallowly pulped to a depth of 5 cm using a pulping machine, in preparation for transplanting. Other management practices were the same as in the local area. The rice variety used in the experiment was Tai Rong No. 1. After the rice matured, the above-ground parts of the rice were harvested along the soil surface in each plot using a 3-point sampling method to measure the total nitrogen, total phosphorus, total potassium, organic matter, available nitrogen, available potassium, and available phosphorus in the soil. A 1 m2 quadrat was harvested at each point, and 10 hills were randomly selected from each quadrat to measure the effective tillering and thousand-grain weight of the rice. The experiment began in the autumn of 2022, and the straw decomposition rate was measured using the nylon mesh bag method after all the straw was cut and buried in the field in the autumn, before the spring planting in 2023, and after the autumn rice harvest.

[0057] Table 1 shows the yield data for different treatments at the experimental site in Daxing Town, Tailai County. The yield was measured using a mechanical harvesting method. Impurities and empty grains were removed, and the grains were weighed on-site. The moisture content was then determined, and the yield results after conversion to standard moisture content (14.5%) are shown in Table 1. The yield measurement shows that Experimental Example 1 yielded 658.9 kg per mu, representing increases of 17.7%, 10.2%, and 3.2% compared to full-amount straw spring rotary return, half-amount straw spring rotary return, and full-amount straw autumn pulping and return.

[0058] ; Table 2 shows the yield data for different treatments at the experimental site in Tailai County. The yield was measured using a mechanical harvesting method. Impurities and empty grains were removed, and the grains were weighed on-site. The moisture content was then determined, and the yield results after conversion to standard moisture content (14.5%) are shown in Table 2. The yield measurement shows that Experimental Example 2 yielded 448.9 kg per mu, representing increases of 4.84% and 5.28% compared to full straw autumn rotary tillage and full straw autumn plowing, respectively.

[0059] ; Table 3 shows the straw burial rate data for different treatments at the experimental site in Tailai County. The results show that after one autumn operation, the straw burial rate of Experiment 2 was 95%, which was 35.71% and 46.15% higher than that of returning all straw to the field in autumn and returning all straw to the field in autumn, respectively.

[0060] ; Table 4 shows the straw decomposition rate data of different treatments at the experimental site in Tailai County. The results show that the straw decomposition rate of rice at the harvest time in Experiment Example 2 was 74.96%, which was 6.37% and 8.90% higher than that of returning all straw to the field in autumn and returning all straw to the field in autumn, respectively.

[0061] ; The results above show that the technical solution of this application can significantly improve the implementation effect of straw return to the field, thereby ensuring that the yield of rice can be fully increased based on the effective straw return operation after the implementation of the technical solution.

[0062] The beneficial effects of this application include: 1. Eliminates the limitation on straw stubble height. In the technical solution of this application, the straw is longitudinally cut, and the parameters of the longitudinally cut straw can be adjusted according to the requirements of returning to the field. In this process, there is no need to pay attention to the stubble height, only to adjust the parameters such as the straw burial depth.

[0063] 2. Full use of existing resources. In the technical solution of this application, straw is buried during the autumn flowering and watering stage, lasting from autumn to the following spring. The straw decomposes again during the freeze-thaw cycle in winter, reducing the problems of straw floating and harmful gas generation that exist under conventional straw return measures. At the same time, it utilizes the water, light and heat resources of the soil in Northeast China before freezing, and uses lime nitrogen to adjust the soil carbon-nitrogen ratio to promote straw decomposition.

[0064] 3. It avoids the problem of soil quality degradation. Returning straw to the field in autumn and allowing it to freeze over in winter to form an ice layer cover the paddy fields reduces the thinning of the soil layer caused by strong winter and spring winds in Northeast China. Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to computer program instructions. The aforementioned computer program can be stored in a non-volatile storage medium, and when executed, it performs the steps of the above method embodiments. Alternatively, if the integrated unit of the present invention is implemented as a software functional module and sold or used as an independent product, it can also be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a non-volatile storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, network device, etc.) to execute all or part of the methods described in the various embodiments of the present invention.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for cutting and burying rice straw back into the field, characterized in that, The method includes: When the rice paddies are dry in autumn and the water level reaches the flower stage, the rice straw is longitudinally cut to obtain longitudinally cut straw. The soil organic matter content of the paddy field area was obtained, and the longitudinally cut straw application amount in different areas was determined based on the soil organic matter content. Based on the amount of longitudinally cut straw applied, the amount of composting agent applied is obtained; Longitudinal chopped straw and decomposition promoters are applied to paddy fields for returning straw to the field. The following spring, shallow slurry preparation was carried out on the aforementioned paddy field.

2. The method for cutting and burying rice straw back into the field according to claim 1, characterized in that, The process of longitudinally cutting rice straw during the autumn when the paddy field is dried out and the water level reaches the flowering stage, to obtain longitudinally cut straw, includes: The depth of the water layer in the Huadashui area is 1~2cm; The stubble height for rice should be 25-35cm. The longitudinal cutting depth of rice straw should not be less than 20cm.

3. The method for cutting and burying rice straw back into the field according to claim 1, characterized in that, The process of obtaining the soil organic matter content of the paddy field area and determining the longitudinally cut straw application amount for different areas based on the soil organic matter content includes: Obtain the soil organic matter content of all areas within the paddy field; Based on the soil organic matter content, the paddy fields were divided into areas for the longitudinal cutting of straw. Based on the area of ​​the longitudinally cut straw placement area and the soil organic matter content, the amount of longitudinally cut straw placed in different areas is obtained.

4. The method for cutting and burying rice straw back into the field according to claim 1, characterized in that, The step of obtaining the amount of composting agent based on the amount of longitudinally cut straw applied includes: To obtain the decomposition rate of longitudinally cut straw by different types of decomposition accelerators, and to select the type of decomposition accelerator; The amount of composting agent applied is determined based on the decomposition rate of the type of composting agent and the amount of longitudinally cut straw applied.

5. The method for cutting and burying rice straw back into the field according to claim 1, characterized in that, The process of applying longitudinally chopped straw and a decomposition accelerator to the paddy field for returning the straw to the field includes: According to the amount of longitudinally cut straw to be applied, longitudinally cut straw is applied to different areas of the paddy field; According to the dosage of the accelerator, spray the accelerator onto the longitudinally cut straw to obtain longitudinally cut straw after accelerating the decay. The paddy field was rotary treated, and the longitudinally cut straw after decomposition was buried in the soil; The soil in the paddy field was leveled.

6. A method for cutting and burying rice straw back into the field according to claim 5, characterized in that, The step of spraying the composting agent onto the longitudinally cut straw according to the prescribed dosage to obtain composted longitudinally cut straw includes: The longitudinally cut straw is evenly dispersed to ensure that it is evenly distributed. Spray the composting agent evenly onto the longitudinally cut straw to ensure that the composting agent is evenly distributed on the longitudinally cut straw.

7. A method for cutting and burying rice straw back into the field according to claim 5, characterized in that, The process of rotary tillage of paddy fields and burying the longitudinally chopped straw after decomposition into the soil includes: The depth of the paddy field rotary treatment shall not be less than 20cm; The longitudinally cut straw, after being accelerated to decompose, is evenly buried in the deepest part of the soil layer treated by rotary soil.

8. A method for cutting and burying rice straw back into the field according to claim 1, characterized in that, The shallow slurry preparation operation carried out on the paddy field in the following spring includes: The shallow slurry preparation depth is 0~5cm.

9. A method for cutting and burying rice straw back into the field according to any one of claims 1 to 8, characterized in that, Also includes: Prioritize rice straw cutting and burying operations based on the organic matter content of paddy fields; Based on the priority of rice straw cutting and burying operations, the rice varieties selected for the paddy fields include: When the priority of rice straw cutting and burying operations is high, the selected rice variety is an early-maturing rice variety; when the priority of rice straw cutting and burying operations is not high, the selected rice variety is any available rice variety.

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