Full-amount straw returning seeding method for high yield of rice and emission reduction of rice field

Abstract

The invention relates to the technical field of sowing methods, and provides a full-amount straw returning sowing method for high rice yield and rice field emission reduction, which can realize the uniform penetration rate of straws to more than 90%, promote the increase of oxygen content in a plough layer and rhizosphere, effectively promote the oxidation of rice field methane, reduce methane emission and relieve the poison of reducing substances to rice roots. The method effectively relieves the problems of early-stage runt seedlings and later-stage withering of rice under straw returning, saves cost, realizes rice yield increase, and comprises the following steps: 7-10 days before rice harvesting, draining water in a rice field, and adopting a harvester with a straw crushing function and a throwing device for harvesting during harvesting, the method comprises the following steps: chopping straws, uniformly scattering the chopped straws in a field, turning over as soon as possible after rice is harvested, soaking the field in shallow water of 1-2 cm on the field surface for half a day before rice transplanting, performing rotary-tillage-free soil preparation and stubble burying, selecting a rice variety suitable for local climate and soil conditions for seeding, and performing field management and strengthening field disease and pest monitoring after seeding.

Description

Technical Field

[0001] The invention relates to the technical field of sowing methods, and in particular to a sowing method for returning all the straw to the field for high rice yield and reduced rice field emissions. Background Art

[0002] Returning straw to fields is an efficient agricultural production method. It can achieve efficient utilization of straw, while improving soil fertility and reducing methane emissions from paddy fields. In order to support the application of returning straw to fields in southern rice-growing areas, we propose a method of returning all straw to fields for high rice yields and reduced rice field emissions. On the one hand, it can increase soil organic matter and enhance soil carbon sinks. On the other hand, it can increase the carbon source of methane-producing bacteria in rice fields and increase methane production in rice fields.

[0003] After searching, the invention patent with Chinese patent publication number CN115925489A discloses a method for returning the full amount of straw to the field based on field composting of organic fertilizer under the corn conservation tillage mode in Northeast China. The method generally includes the following steps: taking a field with a unit area of ​​not less than 2ha as the straw collection area, selecting autumn harvest straw and leaving high stubble for ground covering, mixing 1 / 3 of the crushed straw with an appropriate amount of livestock and poultry manure and a low-temperature bacterial agent of specific components for on-site composting to make organic fertilizer, and returning the straw to the field through row fertilization, thereby achieving the full return of straw to the field.

[0004] The most common application of returning straw to the fields is returning corn straw to the fields. For example, a method of returning all straw to the fields based on field composting of organic fertilizer under the corn conservation tillage model in the Northeast is also a method of returning corn straw to the fields. The area of ​​rice-growing areas in the south is also very large. Therefore, how to achieve high rice yields and reduce methane emissions from rice fields under the premise of returning all straw to the fields is the key and main problem that needs to be solved urgently. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for returning the entire amount of straw to the field for sowing to increase rice yields and reduce emissions from rice fields. The method can achieve a uniform straw penetration rate of more than 90%, promote an increase in oxygen content in the plow layer and the rhizosphere, effectively promote methane oxidation in rice fields, and reduce methane emissions. At the same time, it can eliminate the toxicity of reducing substances (such as H2S) to the rice root system, effectively alleviate the problems of early rice seedling stunting and late rice seedling greed under the condition of returning straw to the field, save costs, and achieve increased rice production.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for returning all the straw to the field for high rice yield and reduced rice field emissions, comprising the following steps:

[0007] S1. Pre-harvest straw treatment: About 7-10 days before rice harvest, drain the water in the rice field, control water, increase oxygen and promote root growth, improve methane oxidation capacity, achieve methane emission reduction, and facilitate the harvester to enter the operation and subsequent straw treatment;

[0008] S2. Return the straw to the field. Use a harvester with a straw crushing function and a spreading device to harvest. Chop the straw and evenly spread it on the field to ensure that the straw is evenly covered to avoid piles and local over-thickness. Spread 2 kg of straw compost evenly per mu.

[0009] S3. Soil preparation: ploughing should be carried out as soon as possible after rice harvest. Use a three-share plow or rotary tiller for dry tillage or dry rotary tillage once. The tillage depth is 20cm-25cm and the rotary tillage depth is 12cm-15cm. When ploughing, the straw and soil are fully mixed, which is conducive to the decomposition of the straw and the release of nutrients. Before transplanting rice, the field surface is kept in 1cm-2cm of shallow water for half a day, and the field surface is not required to be tilled and the stubble is buried, which reduces the floating of straw and root stubble on the field surface. The field is flat and uniform around, so as to achieve the purpose of dry tillage to increase oxygen in rice fields and shallow water tillage to bury stubble;

[0010] S4. Rice variety selection: select high-quality and high-yield rice varieties that are suitable for local climate and soil conditions, with high harvest index, strong aerenchyma, strong root vitality and strong stress resistance. After the selection is completed, the seeds are selected, disinfected and soaked to improve the seed germination rate and uniformity of seedling emergence. Fungicides and insecticides can be used to disinfect the seeds to prevent the occurrence of diseases and insect pests;

[0011] S5. Rice sowing. After the rice seedlings are cultivated, they are sown by transplanting. Transplanting is done by machine or manual transplanting to ensure the quality and transplanting density of the seedlings. To achieve high-yield cultivation, the spacing between seedlings is reduced to increase the planting density by 20%. The ratio of nitrogen fertilizer application in the early and late stages of rice is adjusted with reference to the carbon-nitrogen ratio of soil microorganisms to coordinate the nutrient competition between rice and soil microorganisms.

[0012] S6. Field management after sowing. After transplanting, use furrows and ridges to control water, promote root growth and strengthen stalks, improve the quality of the seedling population, and increase the oxygen supply of rice plants. After planting, shallow water is used to protect the seedlings. After the seedlings have recovered, the fields are exposed to the sun for 3-5 days to increase the oxygen content in the soil and promote root growth. After that, the field surface is kept moist to promote early growth of the seedlings and methane oxidation, enhance the vitality of the seedling root system and oxygen secretion capacity. The seedlings are inspected and the fields are exposed to the sun before and after the critical leaf age for effective tillering. Shallow water is needed to protect the flowers during the heading and flowering stages. After the heading is complete, dry and wet are alternated. According to the soil fertility and the growth needs of the seedlings, base fertilizer, tillering fertilizer and ear fertilizer are reasonably applied;

[0013] S7. Strengthen the monitoring of field pests and diseases, timely discover and prevent pests and diseases, give priority to biological and physical control methods, adopt chemical control methods when necessary, reduce the use of chemical pesticides, and give priority to high-efficiency, low-toxicity and low-residue pesticides to ensure the quality and safety of agricultural products.

[0014] Preferably, in step S2, when the harvester is harvesting, the stubble height is ≤15 cm, and the straw crushing length is ≤10 cm.

[0015] Preferably, step S2 ensures uniform crushing of the straw and uniform spreading of the straw composting agent to promote rapid decomposition of the straw and reduce greenhouse gas emissions.

[0016] Preferably, before the step S2, the specific conditions of the previous crop of pests and weeds in the field should be checked. For fields with serious pests and weeds in the previous crop, the straw should be piled up on the spot and returned to the field, and the straw should be treated harmlessly away from the field when necessary.

[0017] Preferably, in step S3, the field surface leveling standard is that there is no obvious unevenness, and a paddy field harrow and a laser leveler are used to assist in the leveling operation.

[0018] Preferably, before tilling the land in step S3, it is necessary to ensure that the moisture content of the field soil is ≤30%. If there is continuous rainfall before land preparation, the water on the field surface needs to be drained and wet tillage and wet preparation should be carried out. The yield and emission reduction effects of this technology in depressions or fields with poor drainage may be affected, and technical adjustments should be made according to actual conditions.

[0019] Preferably, the rice variety selection in step S4 should take into account the growth period of the rice variety to ensure that it can mature in a local suitable season.

[0020] Preferably, in step S6, the amount of nitrogen fertilizer applied is appropriately reduced to avoid nitrogen deficiency in rice due to nitrogen fixation during straw decomposition, and organic fertilizer and phosphorus and potassium fertilizer are increased to improve soil fertility and rice stress resistance.

[0021] Compared with the prior art, the present invention provides a method for returning all the straw to the field for high rice yield and reduced rice field emissions, which has the following beneficial effects:

[0022] (1) In the present invention, by introducing the straw return operation, the rice stalks are fully utilized, which is not only beneficial to soil fertilization and reduction of chemical fertilizer application, but also helps to achieve high rice yield.

[0023] (2) In the present invention, the post-care treatment of the seedlings formed by cooperating with the straw return operation promotes the reasonable growth of the seedlings and promotes the increase of rice yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example

[0027] See also Figure 1 A method for returning all the straw to the field for high rice yield and reduced rice field emissions, comprising the following steps: treating the straw before harvesting, draining the water in the rice field about 7-10 days before rice harvesting, controlling water, increasing oxygen and promoting rooting, improving the methane oxidation capacity, achieving methane emission reduction, and facilitating the entry of the harvester for operation and subsequent straw treatment, and returning the straw to the field. Before the operation, the specific conditions of the previous crop of pests and weeds in the field should be checked. For the fields with serious pests and weeds in the previous crop, the straw should be piled up on the spot and returned to the field. When necessary, carry out harmless treatment of straw off the field, verify that there is no disease, insect or weed in the previous crop or the disease, insect and weed are not serious, use a harvester with straw crushing function and spreading device to harvest, complete the straw chopping and evenly spread the straw in the field after crushing, ensure that the straw is evenly covered, avoid piles and local excessive thickness, when the harvester is harvesting, the stubble height is ≤15cm, the straw crushing length is ≤10cm, and 2kg of straw composting agent is evenly applied per mu to ensure that the straw is evenly crushed and the straw is not thick. The straw composting agent is spread evenly to promote the rapid decomposition of straw and reduce greenhouse gas emissions. For soil preparation, plowing should be carried out as soon as possible after rice harvest. Before tilling, the moisture content of the field soil must be ensured to be ≤30%. If there is continuous rainfall before land preparation, the field surface water must be drained and wet tillage and wet preparation must be carried out. The yield and emission reduction effect of this technology in depressions or fields with poor drainage may be affected. Technical adjustments should be made according to actual conditions. Use a three-furrow plow or rotary tiller for dry tillage or dry rotary tillage once, and the tillage depth is 20c m-25cm, rotary tillage depth 12cm-15cm, the straw and soil are fully mixed during plowing, which is beneficial to the decomposition of the straw and the release of nutrients. Before transplanting rice, the field surface is kept in 1cm-2cm of shallow water for half a day, and rotary tillage and burying of stubble are avoided to reduce the floating of straw and stubble on the field surface. The field is flat and uniform around to achieve the purpose of dry farming to increase oxygen in rice fields and shallow water tillage to bury stubble. The field surface flatness standard is that there is no obvious unevenness, and paddy field harrows and laser levelers are used to assist in leveling operations.

[0028] It should be further explained that, for rice variety selection, high-quality and high-yield rice varieties with high harvest index, strong aeration tissue, strong root vitality and strong stress resistance suitable for local climate and soil conditions should be selected. After the selection is completed, the seeds should be selected, disinfected and soaked to improve the germination rate and uniformity of seedling emergence. Bactericides and insecticides can be used to disinfect the seeds to prevent the occurrence of diseases and insect pests. The growth period of rice varieties should be considered in the selection of rice varieties to ensure that they can mature in the local suitable season. After rice sowing and rice seedling cultivation, they are sown by transplanting. Transplanting is done by machine transplanting or manual transplanting to ensure the quality of the seedlings and the transplanting density. In order to achieve high-yield cultivation, the planting density is increased by 20% by reducing the seedling spacing. The soil microbial carbon-nitrogen ratio is used as a reference to adjust the nitrogen fertilizer application ratio in the early and late stages of rice, coordinate the nutrient competition between rice and soil microorganisms, reduce the nitrogen in the ear fertilizer (20% of the total nitrogen), and adjust the ratio of base fertilizer: tillering fertilizer: ear fertilizer to 37.5%:50%:12.5%. Field management after sowing, water control with furrows and ridges after transplanting, root strengthening, improving the quality of the seedling group, and increasing the oxygen supply of the rice plant. After planting, shallow water is used to protect the seedlings. After the seedlings have recovered, the fields are exposed to the sun for 3-5 days to increase the oxygen content in the soil and promote root growth. After that, the field surface is kept moist to promote early growth of the seedlings and methane oxidation, enhance the vitality of the seedling root system and oxygen secretion capacity. The seedlings are inspected and the fields are dried before and after the critical leaf age for effective tillering. Shallow water is needed to protect the flowers during the heading and flowering stages. After the heading is complete, dry and wet alternately. According to the soil fertility and seedling growth needs , apply base fertilizer, tillering fertilizer and ear fertilizer reasonably, appropriately reduce the application of nitrogen fertilizer, avoid nitrogen deficiency of rice due to nitrogen fixation during straw decomposition, increase the application of organic fertilizer and phosphorus and potassium fertilizers, improve soil fertility and rice stress resistance, strengthen field pest and disease monitoring, timely detect and prevent pests and diseases, give priority to biological and physical control methods, adopt chemical control methods when necessary, reduce the use of chemical pesticides, give priority to high-efficiency, low-toxic and low-residue pesticides, and ensure the quality and safety of agricultural products.

[0029] It is also necessary to further explain that other rice field emission reduction measures include: scientific formula fertilization, reducing excessive application of nitrogen fertilizer, reducing nitrogen loss and greenhouse gas emissions, using slow-release fertilizers, organic fertilizers to replace part of chemical fertilizers, etc., to improve fertilizer utilization rate, using water-saving irrigation techniques such as intermittent irrigation and wet irrigation, etc., to reduce rice field drainage and methane emissions, avoid long-term deep water irrigation, maintain soil aeration, inhibit methane production, and plant green manures such as astragalus or alfalfa after rice harvest or before sowing to increase soil organic matter content and improve soil structure. After returning green manure to the field, it can reduce the application of chemical fertilizers and reduce carbon emissions from rice fields.

[0030] To sum up, the full amount of straw returning to the field sowing method for high rice yield and reduced rice field emissions is centered on dry tillage, wet preparation, aerobic farming, density increase, water control and oxygen increase cultivation, and is equipped with high-yield and low-emission rice varieties and carbon-nitrogen mutual straw returning technology, which achieves high and stable rice yields and reduced methane emissions from rice fields. The full amount of straw returning to the field sowing method for high rice yield and reduced rice field emissions has been demonstrated in Dianjiang County, Jiangjin District and Tongliang District of Chongqing. Combined with the data feedback from the demonstration area, the full amount of straw returning to the field sowing method for high rice yield and reduced rice field emissions can achieve a uniform straw penetration rate of more than 90%, and the oxygen content in the plow layer and rhizosphere is significantly increased, which can be used It effectively promotes methane oxidation in rice fields and reduces methane emissions. At the same time, it can eliminate the toxicity of reducing substances (such as H2S) to rice roots, effectively alleviate the problems of early rice seedling stunting and late rice greed under straw return to the field, save costs, and achieve increased rice production. Testing has shown that soil organic matter increased by 0.3g / kg to 0.4g / kg, significantly improved soil nitrogen supply capacity and soil potassium content, and achieved a 4.1%-8.8% increase in rice production, an average increase of 38.9kg / mu, a 31.7%-75.7% reduction in methane emissions, and a cost saving and increased income of 103.5 yuan / mu. The effects of high yield, reduced emissions, increased efficiency and increased income are significant.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for returning all the straw to the field for high rice yield and reduced rice field emissions, characterized in that: The steps include: S1. Pre-harvest straw treatment: 7-10 days before rice harvest, drain the water in the rice field, control water, increase oxygen and promote root growth, improve methane oxidation capacity, achieve methane emission reduction, and facilitate the harvester to enter the operation and subsequent straw treatment; S2. Return the straw to the field. Use a harvester with a straw crushing function and a spreading device to harvest. Chop the straw and evenly spread it on the field to ensure that the straw is evenly covered to avoid piles and local over-thickness. Spread 2 kg of straw compost evenly per mu. S3. Soil preparation: ploughing should be carried out as soon as possible after rice harvest. Use a rotary tiller to till the soil once at a depth of 12cm-15cm. The straw and soil should be fully mixed during tilling, which is conducive to the decomposition of the straw and the release of nutrients. Before transplanting rice, the field surface should be kept in a shallow water of 1cm-2cm for half a day, and the field surface should be prepared and buried without rotary tillage to reduce the floating of straw and stubble on the field surface. The field should be flat and uniform around to achieve the purpose of dry tillage to increase oxygen in rice fields and shallow water tillage to bury stubble. S4. Rice variety selection: select high-quality and high-yield rice varieties that are suitable for local climate and soil conditions, with high harvest index, strong aerenchyma, strong root vitality and strong stress resistance. After the selection is completed, the seeds are selected, disinfected and soaked to improve the seed germination rate and uniformity of seedling emergence. Use fungicides and pesticides to disinfect the seeds to prevent the occurrence of diseases and insect pests; S5. Rice sowing. After the rice seedlings are cultivated, they are sown by transplanting to ensure the quality and transplanting density of the seedlings. To achieve high-yield cultivation, the spacing between seedlings is reduced and the planting density is increased by 20%. The ratio of nitrogen fertilizer application in the early and late stages of rice is adjusted based on the soil microbial carbon-nitrogen ratio to coordinate the nutrient competition between rice and soil microorganisms. S6. Field management after sowing. After transplanting, use furrows and ridges to control water, promote root growth and strengthen stalks, improve the quality of the seedling population, and increase the oxygen supply of rice plants. After planting, shallow water is used to protect the seedlings. After the seedlings have recovered, the fields are exposed to the sun for 3-5 days to increase the oxygen content in the soil and promote root growth. After that, the field surface is kept moist to promote early growth of the seedlings and methane oxidation, enhance the vitality of the seedling root system and oxygen secretion capacity. The seedlings are inspected and the fields are exposed to the sun before and after the critical leaf age for effective tillering. Shallow water is needed to protect the flowers during the heading and flowering stages. After the heading is complete, dry and wet are alternated. According to the soil fertility and the growth needs of the seedlings, base fertilizer, tillering fertilizer and ear fertilizer are reasonably applied; S7. Strengthen the monitoring of field pests and diseases, timely discover and prevent pests and diseases, give priority to biological and physical control methods, adopt chemical control methods when necessary, reduce the use of chemical pesticides, and give priority to high-efficiency, low-toxicity and low-residue pesticides to ensure the quality and safety of agricultural products.

2. A rice yield-enhancing and rice field emission-reducing method for returning all the straw to the field according to claim 1, characterized in that: In step S2, when the harvester is harvesting, the stubble height is ≤15 cm, and the straw crushing length is ≤10 cm.

3. A rice yield-enhancing and rice field emission-reducing method for returning all the straw to the field according to claim 2, characterized in that: The step S2 ensures that the straw is evenly crushed and the straw composting agent is evenly spread, so as to promote rapid decomposition of the straw and reduce greenhouse gas emissions.

4. A method for returning all the straw to the field for high rice yield and reduced rice field emissions according to claim 3, characterized in that: Before the step S2 is performed, the specific conditions of the previous crop of pests and weeds in the field should be checked. For fields with serious pests and weeds in the previous crop, the straw should be piled up on the spot and returned to the field. If necessary, the straw should be treated harmlessly away from the field.

5. A method for returning all the straw to the field for high rice yield and reduced rice field emissions according to claim 4, characterized in that: In step S3, the field surface is leveled to have no obvious unevenness, and a paddy field harrow and a laser leveler are used to assist in the leveling operation.

6. A method for returning all the straw to the field for high rice yield and reduced rice field emissions according to claim 5, characterized in that: Before the tillage operation in step S3, it is necessary to ensure that the moisture content of the field soil is ≤30%.

7. A method for returning all the straw to the field for high rice yield and reduced rice field emissions according to claim 6, characterized in that: The rice variety selection in step S4 should take into account the growth period of the rice variety to ensure that it can mature in a suitable season locally.

8. The method for returning all the straw to the field for high rice yield and reduced rice field emissions according to claim 7, characterized in that: In step S6, the amount of nitrogen fertilizer applied is appropriately reduced to avoid nitrogen deficiency in rice due to nitrogen fixation during straw decomposition, and organic fertilizer and phosphorus and potassium fertilizer are increased to improve soil fertility and rice stress resistance.

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