Paddy rice yield increasing method for no-tillage returning of weeds to field and combined application of nitrogen fertilizer in slack winter

Abstract

The invention relates to the technical field of agriculture, and discloses a rice yield increasing method for no-tillage returning of winter slack weeds and combined application of nitrogenous fertilizer, which comprises the following steps: crushing and tiling the winter slack weeds, and spraying a microbial agent containing signal secretion flora; coating urea with a coating solution containing signal response microorganisms to prepare a slow-release nitrogen fertilizer; slow-release nitrogen fertilizer is applied to a weed layer, and a reaction substrate is formed through shallow layer operation and mixing; matrix moisture is regulated and controlled to conduct signal molecules and activate microorganisms to start release; and transplanting the rice into the substrate, and carrying out whole-growth-period cultivation by utilizing nutrients of the rice. An integrated synergistic reaction matrix is constructed, so that a weed decomposition system and a fertilizer response system are tightly coupled in physical space and mutually promoted in function, a biological signal is provided for fertilizer release in the weed decomposition process, and a decomposition product can be used as a carbon source of microorganisms in a slow-release shell; metabolite of microorganisms can reversely promote decomposition of weeds, and the resource efficiency of weed returning and the overall efficiency of the system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural technology, in particular to a winter idle weed no-tillage returning field nitrogen fertilizer application rice yield increasing method. BACKGROUND

[0002] Nitrogen is an essential macronutrient for rice growth, and its supply level directly determines the final yield of rice. In rice field agricultural production, how to efficiently apply nitrogen fertilizer and scientifically handle the field weeds during the winter idle period are two technical links related to production cost, resource utilization efficiency and ecological environmental benefits.

[0003] In the prior art, the mainstream treatment method for winter idle weeds includes chemical agent removal or mechanical plowing and deep burying. In terms of nitrogen fertilizer application, the base fertilizer + topdressing mode is generally adopted, and the quick-acting nitrogen fertilizer is applied in the field in several times. In order to solve the problem of easy loss of quick-acting nitrogen fertilizer, the coated controlled / slow-release fertilizer technology has been developed, which forms a physical barrier film on the surface of the fertilizer particles to slow down the release rate of the internal nutrients, and the release behavior is mainly affected by environmental factors such as soil temperature and moisture.

[0004] However, the treatment method of plowing and deep burying of weeds in the prior art makes the weeds slowly anaerobically decomposed in the deep soil, and the nutrient release period is too long to synchronize with the growth demand of the current season rice, resulting in waste of biomass resources. The management mode of base fertilizer + topdressing not only increases the labor input, but also causes the soil nitrogen concentration to be too high instantaneously after single application, which is easy to be lost through leaching, volatilization and other ways, resulting in low nitrogen fertilizer utilization rate. And the passive release mode of the existing controlled / slow-release fertilizer based on the physical model is preset and relatively fixed, which is difficult to respond to the dynamic physiological demand of crops at different growth stages. Therefore, the present application provides a winter idle weed no-tillage returning field nitrogen fertilizer application rice yield increasing method to solve the problems in the prior art. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a winter idle weed no-tillage returning field nitrogen fertilizer application rice yield increasing method, which solves the problems of slow decomposition of weed returning field, uncontrollable nutrient release, low utilization rate of traditional nitrogen fertilizer and the need for multiple topdressing.

[0006] To achieve the above purpose, the present application realizes the following technical scheme: the present application provides a winter idle weed no-tillage returning field nitrogen fertilizer application rice yield increasing method, comprising the following steps: S1, the winter idle weeds in the rice field are mechanically pulverized and treated to make them evenly spread on the surface of the field to form a weed layer. Then, a directional induction type composite microbial agent is sprayed on the surface of the weed layer. The agent contains a specific type of signal secreting bacteria group that produces and releases specific signal molecules during the process of decomposing and metabolizing components such as cellulose, hemicellulose and lignin in weeds.

[0007] Preferably, the directional induction type composite microbial agent can also include a rapid decomposition bacteria group to accelerate the initial decomposition process of weeds. The rapid decomposition bacteria group can be Trichoderma reesei or Streptomyces thermophilus. The signal secreting bacteria group can be Rhizobium strain or Pseudomonas strain.

[0008] S2, a predetermined coating liquid is used to coat the granular urea to form a coating layer with specific functions on the surface of the urea particles, thereby obtaining a dual-response type slow-release nitrogen fertilizer. The coating liquid is composed of chitosan, sodium alginate, polyvinyl alcohol, calcium carbonate and slow-release endomicrobes. Among them, the slow-release endomicrobes are selected microorganisms that can produce physiological responses to the specific signal molecules.

[0009] Preferably, the step of coating the urea particles can further include: Chitosan, sodium alginate, polyvinyl alcohol, calcium carbonate and the slow-release endomicrobes are uniformly mixed in an aqueous solvent according to the weight parts of chitosan 2-5 parts, sodium alginate 2-5 parts, polyvinyl alcohol 1-3 parts, calcium carbonate 0.5-2 parts and slow-release endomicrobes 1-4 parts to prepare the coating liquid.

[0010] The urea particles are placed in a coating device (such as a fluidized bed or a coating pot), and the prepared coating liquid is uniformly sprayed to the surface of the urea particles through an atomizing nozzle under the condition that the particles keep rolling or fluidizing.

[0011] The urea particles treated by spraying are dried at low temperature to make the coating liquid dehydrate and solidify on the surface of the urea particles to form a coating layer with a predetermined thickness. The thickness of the coating layer can be controlled to be 5%-15% of the diameter of the urea particles.

[0012] Preferably, the slow-release endomicrobes can be Bacillus agri or Lactobacillus agri. Such microorganisms are in a dormant or low-activity state under normal conditions, and their proliferation and metabolic activity are activated after receiving the specific signal molecules.

[0013] S3, the prepared dual-response type slow-release nitrogen fertilizer is applied to the surface of the treated weed layer. Then, the dual-response type slow-release nitrogen fertilizer and the weed layer are mechanically mixed in the surface soil by shallow operation to form a structure-integrated synergistic reaction matrix.

[0014] Preferably, the mode of the shallow operation can further include: The dual-response slow-release nitrogen fertilizer is uniformly spread on the surface of the weed layer according to a predetermined application amount.

[0015] The dual-response slow-release nitrogen fertilizer spread on the surface of the weed layer is mixed with the weed layer and uniformly mixed in the surface soil within a depth range of 5-15 cm by using an agricultural machine such as a rotary cultivator or a disc harrow.

[0016] S4, when the water in the field is managed, the constructed synergistic reaction matrix is water regulated. Water acts as a conducting medium in this process, and the specific signal molecules released from the weed layer are migrated from the weed decomposition site to the surface of the coating layer of the dual-response slow-release nitrogen fertilizer. The specific signal molecules contact the slow-release shell microorganisms in the coating layer, thereby activating the physiological activity of the microorganisms, and then starting the change of the coating layer structure and the release of the internal nitrogen.

[0017] Preferably, the water regulating step can further include: After the rice is sown or transplanted, the synergistic reaction matrix is first saturated irrigation to ensure the initial continuity of water as a conducting medium, triggering the initial and concentrated migration of specific signal molecules.

[0018] After the first saturated irrigation is completed, the water content of the synergistic reaction matrix is maintained within a range of 60%-80% of the field water holding capacity to ensure the sustained and stable migration of specific signal molecules and the physiological activity of the slow-release shell microorganisms.

[0019] S5, the rice seedlings are sown or transplanted in the synergistic reaction matrix. During the entire growth period of the rice, the synergistic reaction matrix continuously provides the nitrogen nutrients required for the growth of the rice, without any additional nitrogen fertilizer application operation.

[0020] The present application provides a winter idle weed no-tillage and nitrogen fertilizer application rice yield increasing method. Has the following beneficial effects: 1, the present application constructs an integrated synergistic reaction matrix, which tightly couples the weed decomposition system and the fertilizer response system in physical space and promotes each other in function. In the matrix, the weed decomposition process not only provides biological signals for fertilizer release, but also provides carbon sources for slow-release shell microorganisms, and the metabolic products of microorganisms can promote the decomposition of weeds in reverse, thereby forming an internal cycle of matter and information, improving the resource utilization efficiency of weed returning and the overall efficiency of the system.

[0021] 2, The application utilizes specific signal molecules generated in the process of weed decomposition as a biological trigger mechanism, activates the microorganisms in the dormant state in the slow-release shell in the double-response type slow-release nitrogen fertilizer coating layer through water mediation, and then starts and regulates the release of nitrogen, directly links the nutrient supply rate with the field biological degradation process, so that the release dynamics of nitrogen has higher matching degree with the nutrient demand law in the early growth period of crops.

[0022] 3, The application can realize the continuous and stable supply of nitrogen in the whole growth period of rice through one-time synergistic reaction matrix construction and fertilization operation, so that the split fertilization operation in the traditional cultivation mode is not needed. The free-fertilization cultivation mode reduces the labor input and field management complexity in agricultural production, reduces the nutrient leaching or volatilization loss in the crop nutrient demand trough period due to the coupling of nitrogen release and biological signals, and thus improves the agronomic utilization rate of nitrogen fertilizer. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The method flow chart of the application is shown in the figure; Figure 2 The curve graph of the dynamic change of soil available nitrogen content of the application is shown in the figure; Figure 3 The column chart of the yield of rice and nitrogen fertilizer utilization rate of the application is shown in the figure. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the specification of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0025] The sources and specifications of the main raw materials and reagents used in the following examples and comparative examples are as follows, and the reagents not specifically described are commercially available analytical pure or higher grade products.

[0026] Chitosan, CAS No. 9012-76-4; Sodium alginate, CAS No. 9005-38-3; Polyvinyl alcohol, CAS No. 9002-89-5; Thermophilic streptomyces, accession No. CICC 21728; Trichoderma reesei, accession No. CICC 13052; Rhizobium, accession No. CICC 10914; Pseudomonas, accession No. CICC 10910; The present application is prepared by the present inventors, and see Preparation Example 1. The present application is prepared by the present inventors, and see Preparation Example 2.

[0027] Preparation Example 1-2: Preparation Example 1: The preserved Trichoderma reesei and Streptomyces thermophilus strains were inoculated on potato dextrose agar (PDA) medium plates and cultured at 28°C for 5-7 days for activation. Then, well-grown colonies were inoculated in potato dextrose broth (PDB) liquid medium and cultured at 28°C, 150 rpm / min in a shaker for 72 hours to prepare a bacterial suspension, with an effective viable bacterial count of not less than 1.0×10 8 CFU / mL.

[0028] The preserved Rhizobium and Pseudomonas strains were inoculated on beef extract peptone agar medium plates and cultured at 30°C for 48 hours for activation. Then, single colonies were inoculated in beef extract peptone liquid medium and cultured at 30°C, 180 rpm / min in a shaker for 36 hours to prepare a bacterial suspension, with an effective viable bacterial count of not less than 1.0×10 9 CFU / mL.

[0029] The four bacterial suspensions prepared in the above steps were uniformly mixed according to the volume ratio of Trichoderma reesei: Streptomyces thermophilus: Rhizobium strain: Pseudomonas strain 1:1:1:1. Glycerol was added to the mixed bacterial solution as a protective agent at a final concentration of 10% (v / v), and after uniform stirring, the finished product of the directional induction type composite microbial agent was obtained. The total effective viable bacterial count of the finished product is not less than 2.0×10 9 CFU / mL, and it is stored at 4°C for standby use.

[0030] Preparation Example 2: 100 parts by weight of deionized water as a solvent; 2.0 parts by weight of polyvinyl alcohol (PVA-1788) was added to the solvent, heated to 90°C and stirred until it was completely dissolved, and then cooled to 40°C to obtain a PVA solution; In the cooled PVA solution, 3.5 parts by weight of chitosan, 3.5 parts by weight of sodium alginate and 1.0 parts by weight of calcium carbonate were added in sequence, and high-speed shearing stirring was carried out for 30 minutes to make them uniformly dispersed; Finally, 2.5 parts by weight of Bacillus subtilis freeze-dried bacterial powder (effective viable bacterial count ≥1.0×10 11CFU / g), continue to stir at low speed for 20 minutes to obtain a uniform and stable coating liquid. The solid content of the coating liquid is 11.1wt%, and the apparent viscosity at 25℃ is 350mPa·s.

[0031] A fluidized bed coating machine was used, and 100kg of agricultural grade urea particles with a particle size of 2.0-4.0mm were added to the fluidized bed as a base material; The process parameters were set as follows: the inlet air temperature was 75℃, the material temperature was controlled at 45±2℃, the fluidization air speed was 1.8m / s, the coating liquid spraying rate set by the peristaltic pump was 250mL / min, and the atomization pressure was 0.2MPa; After starting the equipment, when the urea particles were in a stable fluidized state, the prepared coating liquid was sprayed through the top spray gun to the surface of the particles until the coating liquid was completely sprayed.

[0032] After stopping the liquid spraying, the coated urea particles were further fluidized and dried at an inlet air temperature of 40℃ for 2 hours to ensure complete curing of the coating layer; The finished product was cooled and screened to obtain the dual-response slow-release nitrogen fertilizer. The detection showed that the coating layer thickness of the finished product accounted for 10.5% of the average diameter of the particles, the total nitrogen content was ≥44.2%, the effective viable bacterial count of soil bacillus was ≥1.5×10 7 CFU / g.

[0033] Please refer to the attached Figure 1 , Examples 1-3: Example 1: S1, the field weeds were crushed on site using a weed crusher, so that the length of the weed fragments was ≤10cm, and the weeds were evenly laid on the surface of the rice field. The directional induction type composite microbial agent prepared in Preparation Example 1 was diluted 100 times with deionized water, and the diluted microbial agent was uniformly sprayed on the surface of the weed layer using a power sprayer, and the spraying amount was 75L / ha; S2, the dual-response slow-release nitrogen fertilizer prepared in Preparation Example 2 was used in this embodiment; S3, the dual-response slow-release nitrogen fertilizer was uniformly applied to the surface of the treated weed layer, and the application amount was 400kg / ha (equivalent to pure nitrogen 176.8kg / ha). Subsequently, a shallow operation was performed using a rotary tiller to mix the fertilizer and the weed layer into the surface soil, and the operation depth was controlled at 10cm to form an integrated synergistic reaction matrix; S4, after the completion of the construction of the synergistic reaction matrix, rice (variety: Nangjing 9108) is transplanted, and the transplanting density is 200,000 clusters per hectare. On the day of transplanting, the first saturated irrigation is carried out on the field, so that a 3-5 cm water layer is established on the field surface and maintained for 24 hours. The irrigation mode of dry-wet alternation is adopted, and the soil humidity sensor is used for monitoring, so that the water content of the synergistic reaction matrix is maintained within the range of 70±5% of the field water holding capacity during the tillering stage to the jointing stage of rice; S5, during the entire growth period of rice, no nitrogen fertilizer is applied in any form.

[0034] Example 2: S1, the weeds in the field are crushed on site using a weed crusher, so that the length of the weed fragments is ≤10 cm, and the weeds are evenly laid on the surface of the rice field. The directional induction type composite microbial agent prepared in Preparation Example 1 is diluted 100 times with deionized water, and the diluted agent is uniformly sprayed on the surface of the weed layer using a power sprayer, and the spraying amount is 75 L per hectare; S2, only the freeze-dried bacillus amyloliquefaciens powder used in Preparation Example 2 is replaced with freeze-dried lactobacillus agilis powder in this embodiment to prepare a double-response type slow-release nitrogen fertilizer; S3, the double-response type slow-release nitrogen fertilizer is uniformly applied to the surface of the treated weed layer, and the application amount is 400 kg per hectare (equivalent to pure nitrogen 176.8 kg per hectare). Subsequently, a shallow operation is carried out using a rotary cultivator to mix the fertilizer and the weed layer into the surface soil, and the operation depth is controlled to be 10 cm to form an integrated synergistic reaction matrix; S4, after the completion of the construction of the synergistic reaction matrix, rice (variety: Nangjing 9108) is transplanted, and the transplanting density is 200,000 clusters per hectare. On the day of transplanting, the first saturated irrigation is carried out on the field, so that a 3-5 cm water layer is established on the field surface and maintained for 24 hours. The irrigation mode of dry-wet alternation is adopted, and the soil humidity sensor is used for monitoring, so that the water content of the synergistic reaction matrix is maintained within the range of 70±5% of the field water holding capacity during the tillering stage to the jointing stage of rice; S5, during the entire growth period of rice, no nitrogen fertilizer is applied in any form.

[0035] Example 3: S1, the weeds in the field are crushed on site using a weed crusher, so that the length of the weed fragments is ≤10 cm, and the weeds are evenly laid on the surface of the rice field. The directional induction type composite microbial agent prepared in Preparation Example 1 is diluted 100 times with deionized water, and the diluted agent is uniformly sprayed on the surface of the weed layer using a power sprayer, and the spraying amount is 75 L per hectare; S2, the double-response type slow-release nitrogen fertilizer prepared in Preparation Example 2 is used in this embodiment; S3, uniformly spreading the dual-response slow-release nitrogen fertilizer on the surface of the treated weed layer, with an application amount of 400 kg / ha (equivalent to pure nitrogen 176.8 kg / ha). Subsequently, shallow operation is performed using a rotary cultivator to mix the fertilizer and the weed layer into the surface soil, with an operation depth controlled at 5 cm, so as to form an integrated synergistic reaction matrix; S4, after the completion of the construction of the synergistic reaction matrix, rice (variety: Nangjing 9108) is transplanted, with a transplanting density of 200,000 clumps / ha. On the day of transplanting, the first saturated irrigation is performed on the field, so as to establish a 3-5 cm water layer on the field surface and maintain for 24 hours. The dry-wet alternating irrigation mode is adopted, and the water content of the synergistic reaction matrix is maintained at 70±5% of the field water holding capacity during the tillering stage to the jointing stage of the rice. S5, during the entire growth period of the rice, no nitrogen fertilizer is applied in any form.

[0036] Comparative Examples 1-4: Comparative Example 1: Compared with Example 1, the difference lies in that no microbial inoculant is sprayed, and the rest is the same.

[0037] Comparative Example 2: Compared with Example 1, the difference lies in that an equal amount of ordinary urea is applied instead of the dual-response slow-release nitrogen fertilizer.

[0038] Comparative Example 3: Compared with Example 1, the difference lies in that an equal amount of commercially available resin-coated slow-release urea is applied instead of the dual-response slow-release nitrogen fertilizer.

[0039] Comparative Example 4: Compared with Example 1, the difference lies in that after the dual-response slow-release nitrogen fertilizer is spread on the surface of the weed layer, the fertilizer is not mixed with the weed layer into the surface soil.

[0040] Experiment 1-2: Experiment 1: Purpose of the experiment: by comparing the changes of soil available nitrogen content over time in the example and each comparative example, the signal-regulated release and continuous stable supply of nitrogen are verified.

[0041] Experimental steps: Sample collection: on the 15th, 30th, 45th, 60th, 75th and 90th day after the rice is transplanted, soil samples are collected from the treatment fields of Examples 1-3 and Comparative Examples 1-4, respectively. Five-point sampling method is used for each treatment field to collect 0-20 cm plough layer soil. The soil samples collected from the five points are mixed uniformly in a clean container, and about 500 g is reserved as the sample to be tested by the four-part method.

[0042] Sample preparation: The soil sample to be tested was placed in a cool and ventilated place for air drying. After air drying, stones, plant roots and other visible residues in the sample were removed, the soil sample was ground and passed through a 2 mm aperture sieve, and then was packed into a sample bag for standby.

[0043] Content determination: The alkali hydrolysis nitrogen content of the soil sample was determined by alkali hydrolysis diffusion method. A predetermined amount of soil sample prepared in step 2 was placed in the outer chamber of the diffusion dish, and an alkali hydrolysis solution was added to the outer chamber at the same time. Boric acid absorbing solution was added to the inner chamber of the diffusion dish. The diffusion dish was sealed and diffusion was carried out under constant temperature conditions. After the diffusion was completed, the absorbing solution in the inner chamber was taken and titrated with an acid standard solution, and the alkali hydrolysis nitrogen content in the soil sample was calculated according to the titration consumption.

[0044] Data processing: Each treatment was set with three replicates, and the test results were recorded as the average of three replicate determinations.

[0045] The experimental results are shown in Table 1.

[0046] Table 1: Dynamic change of soil alkali hydrolysis nitrogen content (mg / kg) under each treatment Please refer to the attached Figure 2 As shown in Table 1, the soil available nitrogen content of the treatments of Examples 1-3 was maintained in the range of 104.6-149.3 mg / kg during 30-75 days after rice transplanting, and reached a peak around the 45th day. This indicates that the synergistic reaction matrix constructed by mechanically mixing weeds, directional induction type composite microbial agent and double response type slow-release nitrogen fertilizer can realize the sustained release of nitrogen. The signal molecules produced by the signal secretion bacterial community in the process of weed decomposition, through the mediation of water, activate the slow-release shell microorganisms in the coating layer of the slow-release nitrogen fertilizer, and the metabolic activity of the microorganisms causes the change of the coating layer structure, thereby controlling the release rate of the internal nitrogen. The release rate is coupled with the nitrogen demand rule of rice during the tillering to jointing stage.

[0047] In contrast, Comparative Example 1 did not apply the directional induction type composite microbial agent, the decomposition rate of weeds was low, and sufficient signal molecules could not be produced, resulting in the available nitrogen content being below 75 mg / kg throughout the entire growth period. Comparative Example 2 applied ordinary urea, and the available nitrogen content reached 186.2 mg / kg at 15 days after transplanting, and then decreased rapidly, indicating that nitrogen was released in large quantities during the period when the demand of the crop was low, and there was a risk of loss due to leaching or volatilization. Comparative Example 3 used a commercially available slow-release nitrogen fertilizer, and although its nutrient release curve was relatively flat compared to ordinary urea, the peak value and nutrient supply did not reach the level of Examples 1-3, indicating that there was no pre-set response relationship between the release mode and the decomposition signal of weeds.

[0048] The data of Comparative Example 4 further confirmed the necessity of constructing an integrated synergistic reaction matrix. In this comparative example, although all functional components were present, the weed decomposition zone and slow-release nitrogen fertilizer were physically separated due to the absence of shallow operation mixing, limiting the effective migration of signal molecules through water to the surface of fertilizer particles. This resulted in a decrease in the activation efficiency of microorganisms in the slow-release shell, and the amount of nitrogen released was significantly lower than that of Examples 1-3 throughout the entire measurement period, with a peak value of only 91.5 mg / kg. This result indicates that the formation of a matrix structure in which the components are in physical close contact through mechanical operation is a technical condition for effective signal transmission and on-demand release of nitrogen.

[0049] Experiment 2: Purpose of the experiment: By measuring the key agronomic traits, yield per unit area, and nitrogen utilization efficiency of rice, the effect of the examples and comparative examples on improving the yield and nitrogen utilization efficiency of rice was verified.

[0050] Experimental steps: Agronomic trait and yield determination: At the mature harvest period of rice, three 1 m2quadrats were randomly selected in each treatment plot. First, the average height of all plants in the quadrat was measured. Second, the average number of effective tillers per clump was calculated by counting the number of effective tillers (i.e., tillers with panicles) in each quadrat. After completing the trait determination, all rice plants in the quadrat were harvested, threshed, and the obtained grains were dried to constant weight at 75°C. The dry weight was measured, and the yield per unit area (kg / ha) was calculated based on the area of the quadrat.

[0051] Plant sample preparation: During the yield determination of step 1, 20 representative rice plants were randomly selected from each quadrat, and their stems, leaves, and panicles were separated and collected. The collected samples were killed at 105°C for 30 minutes to terminate their physiological activities, and then dried to constant weight in a 75°C oven. The dried samples were pulverized using a pulverizer and passed through a 0.5 mm mesh screen to obtain the plant powder sample for testing.

[0052] Total nitrogen content determination and utilization rate calculation: The Kjeldahl method was used to determine the total nitrogen content of the plant powder sample. Based on the dry weight of the plant and the total nitrogen content, the total nitrogen uptake of the plant was calculated.

[0053] Data processing: The final results of each treatment were recorded as the average of three repeated measurements.

[0054] The experimental results are shown in Table 2.

[0055] Table 2: Agronomic traits, yield, and nitrogen utilization efficiency of rice under different treatments Please refer to the attachedFigure 3 As shown in Table 2, the unit area yield of Examples 1-3 is all above 9000 kg / ha, and the nitrogen utilization rate is all above 44%. This result directly corresponds to the nitrogen release rule observed in Test Example 1. In the synergistic reaction matrix, nitrogen is released according to the strength of the weed decomposition signal, so that the nitrogen supply can be maintained at a high level during the key growth periods of rice tillering and jointing, thereby ensuring the formation of effective tiller number and final yield of the plant. The one-time matrix construction and fertilization operation completely replaces the multiple topdressing in traditional production, and achieves the preset technical effect.

[0056] The results of the comparative examples verify the necessity of various technical features in the technical solution from different aspects. Comparative Example 1 lacks microbial inoculants, and the release of nitrogen is blocked, and the crop shows sustained nitrogen stress, resulting in the lowest yield and nitrogen utilization rate. In Comparative Example 2, the application of ordinary urea leads to excessive nitrogen supply in the early stage, and the plant height is overgrown, and the nitrogen supply is insufficient in the later stage, and the effective tiller number and yield are at a low level. Although the yield and nitrogen utilization rate of Comparative Example 3 are higher than those of Comparative Example 2, they are still significantly lower than those of Examples 1-3, which shows that its inherent release mode, which is not directly related to the biological activity in the field, has a deficiency in the accuracy of nutrient supply.

[0057] In Comparative Example 4, the slow-release nitrogen fertilizer is not mechanically mixed with the weed layer, resulting in a significant decrease in all output indicators compared with Examples 1-3. This confirms the importance of constructing a synergistic reaction matrix in physical contact. Physical separation hinders the effective diffusion and transmission of signal molecules produced by weed decomposition to fertilizer particles, so that the microorganisms in the coating layer cannot be fully activated, thereby limiting the release efficiency of nitrogen. Therefore, mixing the components through shallow operation is a necessary step to achieve effective signal conduction and achieve the expected yield and efficiency results.

[0058] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for increasing rice yield by returning weeds to the field without tillage during winter and applying nitrogen fertilizer, characterized in that: The following steps are involved: S1. Crush the fallow weeds in the field and spread them on the surface of the rice field, and spray them with a targeted inducible composite microbial agent containing a signal-secreting bacterial community that can produce specific signal molecules in the process of decomposing the fallow weeds; S2. Coating the urea particles with a coating solution composed of chitosan, sodium alginate, polyvinyl alcohol, calcium carbonate, and slow-release microorganisms capable of responding to the specific signal molecule to form a coating layer on the surface of the urea particles to obtain a dual-responsive slow-release nitrogen fertilizer; S3. Applying the dual-responsive slow-release nitrogen fertilizer to the surface of the crushed weed layer, and applying the dual-responsive slow-release nitrogen fertilizer and the weed layer to form an integrated synergistic reaction matrix in the surface soil through shallow operation; S4. Regulating the moisture content of the synergistic reaction matrix, using moisture as a conductive medium to migrate specific signal molecules from the weed layer to the coating layer of the dual-responsive slow-release nitrogen fertilizer, thereby activating the microorganisms in the slow-release shell and initiating the release of the dual-responsive slow-release nitrogen fertilizer; S5. Sowing or transplanting rice into the synergistic reaction matrix, and cultivating the rice by continuously utilizing the nutrients provided by the synergistic reaction matrix throughout the entire growth period of the rice.

2. The rice yield increasing method of claim 1 by returning fallow weeds to the field without tillage and applying nitrogen fertilizer, characterized in that: The directed inducible composite microbial agent further comprises a fast-decomposing bacterial group, wherein the fast-decomposing bacterial group comprises Trichoderma reesei and Streptomyces thermophilus, and the signal-secreting bacterial group comprises a Rhizobium strain and a Pseudomonas strain.

3. The rice yield increasing method of claim 1 by returning fallow weeds to the field without tillage and applying nitrogen fertilizer, characterized in that: The microorganisms in the slow-release shell are soil Bacillus or soil Lactobacillus, which proliferate and metabolize after being activated by specific signal molecules.

4. The method for increasing rice yield by returning winter fallow weeds to the field without tillage and applying nitrogen fertilizer according to claim 1, characterized in that: In step S2, the step of coating the urea granules further includes: The coating solution is prepared by uniformly mixing chitosan, sodium alginate, polyvinyl alcohol, calcium carbonate and microorganisms in the slow-release shell in an aqueous solvent; The urea particles are placed in a coating device, and the prepared coating liquid is atomized and sprayed onto the surface of the urea particles in a rolling or fluidized state; The sprayed urea particles are dried at low temperature to solidify the coating liquid on the surface of the urea particles to form a coating layer.

5. The method for increasing rice yield by returning winter fallow weeds to the field without tillage and applying nitrogen fertilizer according to claim 4, characterized in that: The thickness of the coating layer is 5%-15% of the diameter of the urea particles.

6. The method for increasing rice yield by returning winter fallow weeds to the field without tillage and applying nitrogen fertilizer according to claim 1, characterized in that: In step S3, the step of forming an integrated synergistic reaction matrix of the dual-responsive slow-release nitrogen fertilizer and the weed layer in the surface soil by shallow operation further includes: Evenly spreading the dual-response slow-release nitrogen fertilizer on the surface of the weed layer at a preset application rate; Use a rotary tiller or disc harrow to perform shallow operations, turn the spread dual-response slow-release nitrogen fertilizer and the weed layer into and mix them at a depth of 5-15 cm in the surface soil to form a synergistic reaction base.

7. The method for increasing rice yield by returning winter fallow weeds to the field without tillage and applying nitrogen fertilizer according to claim 1, characterized in that: The organic acid, amino acid or polysaccharide produced during the decomposition process of the weed layer is directly used as a carbon source or nitrogen source for the growth metabolism of microorganisms in the slow-release shell in the synergistic reaction matrix.

8. The method for increasing rice yield by returning fallow weeds to the field without tillage during winter and applying nitrogen fertilizer according to claim 1, characterized in that: In step S4, the step of regulating the moisture content of the synergistic reaction matrix further comprises: After rice is sown or transplanted, the synergistic reaction matrix is ​​irrigated for the first time to ensure that water is sufficient as a conductive medium to trigger the initial migration of specific signal molecules; After the first saturated irrigation is completed, the water content of the synergistic reaction matrix is ​​maintained within the range of 60%-80% of the field water holding capacity to ensure the continuous migration of specific signal molecules and the physiological activity of the microorganisms in the slow-release shell.

9. The method for increasing rice yield by returning winter fallow weeds to the field without tillage and applying nitrogen fertilizer according to claim 1, characterized in that: The metabolic products of the microorganisms in the slow-release shell contain enzymes for degrading cellulose or lignin. After being released, the enzymes further promote the decomposition of the weed layer in the synergistic reaction matrix.

10. The rice yield increasing method of claim 1 by returning fallow weeds to the field without tillage during winter and applying nitrogen fertilizer, characterized in that: In step S2, the coating solution comprises, by weight, 2-5 parts of chitosan, 2-5 parts of sodium alginate, 1-3 parts of polyvinyl alcohol, 0.5-2 parts of calcium carbonate, and 1-4 parts of sustained-release microorganisms in the shell.

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