Corn drought-resistant planting method based on biochar marsh biological crust

Abstract

The invention relates to the technical field of agricultural water-saving cultivation, and discloses a drought-resistant corn planting method based on biochar marsh biological crust. The core of the method is that a composite substrate layer formed by mixing biochar particles and a marshland natural biological crust raw material is laid on the surface of a planting plot, and a continuous and stable artificial biological crust structure is promoted to be rapidly formed on the surface of the substrate through water spraying wetting and standing maintenance; and then corn seeds are sown in the soil below the crust in a no-tillage sowing mode. In the growth period, soil moisture evaporation is mainly inhibited by means of the crust structure, and a small amount of supplementary drip irrigation is carried out only in extreme drought. The crust structure has both physical barrier and biological water retention functions, can effectively maintain soil moisture content, and realizes drought-resistant and water-saving planting of corn.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural water-saving cultivation technology, and more particularly, to a corn drought-resistant planting method based on a biochar marsh biological crust. BACKGROUND

[0002] In recent years, the field of agricultural water-saving cultivation technology has been committed to developing sustainable farmland water management strategies. One of the significant trends in this field is to integrate environmental ecological principles to guide and accelerate natural processes through artificial intervention to construct farmland surface structures with ecosystem service functions. Among them, using new carbon materials such as biochar and the synergistic effect of soil microorganisms to improve water use efficiency has become an important research direction, aiming to achieve the coordinated improvement of water saving, carbon sequestration and soil health.

[0003] Existing farmland soil conservation technologies have their limitations. Although traditional mulching can effectively suppress evaporation, it can easily lead to white pollution and soil structure damage. Straw mulching has problems of nitrogen competition with crops during the early decomposition period and affecting the recovery of ground temperature. Single application of biochar can improve soil structure, but its light weight characteristics are prone to wind erosion and loss, and a hydrophobic layer is easily formed on the surface layer in dry conditions, hindering water infiltration. In addition, the existing technology for simulating natural biological crusts mostly relies on the inoculation of single microbial inoculants, and the film-forming process is slow, the structure is not stable enough, and it is difficult to meet the requirements of timeliness and mechanical strength for large-scale agricultural production in the field.

[0004] The present application aims to solve the above-mentioned deficiencies in the prior art, and the core is to provide a method for forming an artificial cover layer that can quickly and stably form an efficient water-retaining and wind-erosion-resistant artificial cover layer on the surface of farmland, which is compatible with agricultural operations, so as to ensure the water demand of drought-resistant crops such as corn during the critical growth period under the condition of minimizing irrigation. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a corn drought-resistant planting method based on a biochar marsh biological crust to solve the problems raised in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a corn drought-resistant planting method based on a biochar marsh biological crust, the method comprising the following steps: S1, uniformly laying a composite substrate layer composed of biochar particles and natural biological crust raw materials collected from a marsh on the surface of a to-be-planted plot before corn planting; S2, after the laying of the composite substrate layer is completed, water is sprayed for wetting treatment until the surface of the composite substrate layer presents a wet mud state without clear water accumulation, and then standing for curing to promote the natural formation of a continuous biological crust structure on the surface of the composite substrate layer; S3. After the biocrust structure has been stably formed, corn seeds are directly sown in the soil below the biocrust structure using a no-till sowing method. The sowing depth should be such that the seeds are in contact with the moist soil without damaging the integrity of the above-ground crust structure. S4. During the corn growing season, except for supplemental drip irrigation under extreme drought conditions, soil moisture is maintained by relying on the water retention and evaporation inhibition function of the biological crust structure.

[0007] Preferably, the composite matrix layer has a thickness of 10-30 mm, wherein the dry weight mixing ratio of the biochar particles and the natural biochar crust raw material is 2:1 to 5:1; the biochar particles are obtained by pyrolysis of agricultural waste at 300-600°C under oxygen-limited conditions, and have a particle size distribution of 0.5-5 mm and a specific surface area greater than 200 m² / g.

[0008] Preferably, the natural biocrust material is collected from the surface sediments of a natural swamp ecosystem, which contains live algae, cyanobacteria, bryophytes and their spores and vegetative propagules, as well as symbiotic microbial communities and organic debris; the natural biocrust material needs to be crushed and screened before mixing so that its maximum particle size does not exceed 5 mm.

[0009] Preferably, the water spraying and wetting treatment adopts a low-pressure atomized spraying method, and the water supply is controlled to make the water content of the composite matrix layer reach 60%-80% of its maximum water holding capacity; the static curing process is carried out under natural light conditions for a duration of not less than 7 days, during which the surface of the composite matrix layer is kept continuously moist but without water accumulation.

[0010] Preferably, the no-till sowing method is operated using a disc-type sowing machine with a bark-breaking and furrow-opening function. The disc blade of the sowing machine is designed to cut only the biological crust structure and break up the shallow soil. After sowing, the soil is gently backfilled to cover the seeds using a soil covering and compaction device to ensure that the large-area crust structure is not disturbed.

[0011] Preferably, the supplementary drip irrigation during the corn growth period is triggered by 15 consecutive days without effective rainfall and the soil moisture content in the 0-20cm layer being less than 10%; each drip irrigation water supply does not exceed 10mm, and the irrigation water is directly delivered to the crop root zone through the drip irrigation tape laid under the biological crust structure.

[0012] Preferably, after the corn harvest, the remaining biocrust structure is left on the ground without being disturbed, serving as the basis for the next planting season. Before replanting, only severely damaged areas need to be locally repaired, and the repair material has the same composition as the initially laid composite substrate layer.

[0013] Preferably, the method is applicable to semi-arid areas with an annual precipitation of 250-500 mm, and the soil texture of the plot to be planted is sandy loam to loam.

[0014] Preferably, the biochar particles are activated after pyrolysis to enhance their surface functional groups and adsorption properties; the activation treatment adopts steam activation method, with an activation temperature of 500-800°C and an activation time of 30-60 minutes.

[0015] The technical effects and advantages of this invention are as follows: Compared to existing technologies, this invention combines biochar particles of a specific size with natural biocrust material derived from swamps at a precise dry weight ratio, and then lays them out to form a composite matrix layer. This combination fully leverages the synergistic effect of the porous adsorption properties of biochar and the active microbial community and natural organic network structure in the natural biocrust material. After moistening and curing, the biochar, acting as a physical framework and water carrier, provides an excellent microenvironment for the colonization and reproduction of microorganisms. The microorganisms and their secretions further cement the biochar particles and soil particles, jointly forming a continuous and stable composite biocrust structure. This effectively overcomes the shortcomings of single biochar, such as easy loss and the formation of a hydrophobic layer, achieving more efficient and longer-lasting synergistic control of soil moisture evaporation, and significantly improving soil moisture retention and structural stability under drought conditions.

[0016] Compared to existing technologies, this invention precisely controls the thickness of the composite substrate layer and the particle size distribution of raw materials. During the curing stage, low-pressure atomized spraying is used to control the water supply, maintaining the substrate moisture content within a range suitable for rapid microbial reproduction. This is supplemented by at least seven days of natural light for static curing. This series of process parameter controls creates optimal physical conditions and nutritional foundations for the rapid colonization, expansion, and physiological activities of functional microbial communities (such as cyanobacteria and algae) in the composite substrate. This overcomes the technical bottleneck of slow and unstable formation of natural crusts or single-agent inoculation, enabling the induction of stable artificial biological crust structures with high mechanical strength and wind erosion resistance in a short period, ensuring the timeliness and feasibility of this technology in field agricultural production.

[0017] Compared to existing technologies, this invention utilizes a specially designed disc-type seeder with a ditching and furrowing function for no-till seeding. The disc's cutting edge is specially designed to precisely cut through the existing biocrust structure and shallow soil, creating a seed furrow. After sowing, a matching soil-covering and compacting device gently backfills and compacts the furrow. This process ensures that corn seeds are accurately sown into the moist seedbed soil while minimizing mechanical damage to the integrity of the surface crust during sowing. This resolves the inherent contradiction between protecting the biocrust and the agricultural operation of sowing, achieving a balance between moisture retention and evaporation control, and ensuring high seed germination rates, laying the foundation for the large-scale application of this technology. Attached Figure Description

[0018] Fig. 1 This is an overall flowchart of the method of the present invention.

[0019] Fig. 2 This is a flowchart illustrating the composite matrix layer laying and skin formation process of the present invention.

[0020] Fig. 3 This is a flowchart of the no-till seeding and water management process of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0022] As attached Figs. 1 to 3 The method for drought-resistant maize cultivation based on biochar swamp biocrusts includes the following steps: Implementation Step 1: Preliminary Preparation and Site Setup First, the planting area needs basic preparation. Select a plot with sandy loam to loam soil suitable for corn cultivation. Perform shallow tillage or harrowing to break up large clods, level the surface, and remove large weed debris or stones that may affect the substrate layer. Deep tillage is not necessary at this stage; the goal is to maintain the original soil structure and minimize water disturbance. The leveled surface should form a relatively loose but even seedbed base.

[0023] Two key materials are required: biochar granules and natural biocrust raw materials.

[0024] Preparation of biochar granules: Agricultural waste (such as rice husks, straw, sawdust, etc.) is used as raw material. Under limited oxygen conditions, pyrolysis and carbonization are carried out at temperatures ranging from 300-600℃. After pyrolysis, the resulting biochar is crushed and sieved to ensure that its particle size is concentrated between 0.5 mm and 5 mm. Biochar within this particle size range can form a stable porous framework without being easily dispersed by wind due to its fineness. The prepared biochar should have a specific surface area greater than 200 m² / g to ensure its excellent adsorption performance.

[0025] Collection and processing of natural biocrust raw materials: From healthy areas of natural swamp ecosystems, collect sediment from the top 0-5 cm layer. This sediment is rich in key biological components for biocrust formation, including living algae, cyanobacteria, spores and vegetative propagules of bryophytes, as well as complex symbiotic microbial communities and organic debris. After collection, the raw materials must be air-dried to a level easily broken down, avoiding direct sunlight. They are then crushed using a professional crusher or manually and screened to ensure the maximum particle size does not exceed 5 mm. During processing, care must be taken to avoid high temperatures or the use of chemical agents to maintain the activity of the biological components.

[0026] Prepare the composite matrix by calculating the total amount required based on the area of ​​the site to be treated. Mix the biochar granules and natural biocrust raw materials thoroughly according to a specific dry weight ratio of 2:1 to 5:1. The mixing process should be carried out on a clean, level surface using a mixer or manual turning to ensure even distribution and the formation of a homogeneous composite matrix.

[0027] Implementation Step 2: Precise Laying of Composite Matrix Layer Before the planned corn planting season, choose a windless or lightly windy day for spreading. Using a specialized spreader or manually with a standard sieve, evenly spread the prepared composite substrate from step 1 onto the prepared plot surface. The spreading thickness should be controlled between 10mm and 30mm. Too thin a layer will not form a continuous and effective cover, while too thick a layer may affect gas exchange and increase costs. To ensure uniformity, work can be carried out in sections and in fixed quantities. After spreading, use a light rake or dragline to gently smooth the surface, but avoid excessive handling that could cause severe mixing between the substrate and the underlying soil.

[0028] Step 3: Spray water to moisten and allow to stand still to induce crust formation. After the composite substrate layer is laid, it must be immediately moistened with water by spraying. This process must be carried out by low-pressure atomized spraying to avoid high-pressure water flow impacting and damaging the surface of the substrate layer or causing the substrate particles to splash and redistribute.

[0029] The goal of water spraying is to thoroughly wet the entire composite substrate layer until its surface appears as a moist slurry without any standing water. The water supply needs to be precisely controlled, ideally reaching 60% to 80% of the composite substrate layer's maximum water-holding capacity. This moisture level is most conducive to the recovery and rapid reproduction of microorganisms such as cyanobacteria and algae in the substrate.

[0030] After being moistened with water, the critical static curing period begins. This process must be carried out under natural light conditions, as light is an essential energy source for photosynthetic microorganisms to carry out life activities and secrete cementing substances such as extracellular polysaccharides.

[0031] During the curing period, the moisture content of the substrate surface must be closely monitored. Intermittent, light misting spraying should be used to maintain a consistently moist but not waterlogged surface. The entire static curing process should last no less than 7 days. During this time, the microorganisms in the substrate (especially cyanobacteria and algae) will rapidly recover, colonize, and multiply, secreting large amounts of extracellular polymers. These adhesive substances bind biochar particles, organic debris, and soil particles together, ultimately forming a continuous, dense, and mechanically strong artificial biocrust structure on the substrate surface. After 7 days, the stability of the crust can be determined by visual observation and slight touch. It typically exhibits a darker color (microbial pigment formation), a continuous membrane-like structure on the surface, and a certain resistance to minor external impacts.

[0032] Implementation Step 4: Precision Sowing Based on No-Till Principle The operation is carried out using a specially designed no-till seeder. The disc seeder with bark-breaking and furrowing function can precisely cut through the biological bark structure during the movement and smoothly cut through the lower shallow soil layer to form a narrow seed furrow without causing large-area tearing or lifting of the bark.

[0033] When sowing, corn seeds are precisely placed at the bottom of the cut furrow using a seeder. The sowing depth is determined by ensuring that the seeds are in direct contact with the underlying moist soil. This is usually based on local agricultural practices, but the principle is that the seeds must be located below the crust layer and in moist soil.

[0034] After sowing, the soil covering and compaction device equipped with the machine will immediately activate, gently backfilling a small amount of soil from both sides of the cut crust into the seed furrow to cover the seeds, and performing moderate compaction to ensure close contact between the seeds and the soil to facilitate water absorption and germination. At the same time, it will try to restore the cut crust edges as much as possible, reduce the opening, minimize damage to the crust's integrity, and ensure the crust's water retention function continues.

[0035] Implementation Step 5: Water Management and System Maintenance During the Growth Period After corn seedlings emerge, field management strategies differ significantly from traditional methods. The core of these strategies is to fully utilize the water-retention function of the biological crust and implement precise supplementary irrigation.

[0036] Throughout the entire growth cycle of corn, soil moisture is maintained primarily through the water-retaining and evaporation-suppressing functions of the artificial biological crust structure. The crust, through its physical barrier function and the water-retention mechanism regulated by internal microorganisms, effectively reduces ineffective evaporation of soil moisture. Supplemental drip irrigation is only initiated under extreme drought conditions. The triggering conditions for drip irrigation need to be strictly quantified: typically set at 15 consecutive days without effective rainfall (e.g., daily rainfall less than 5 mm), and soil moisture sensors detecting a volumetric water content of less than 10% in the 0-20 cm soil layer.

[0037] Supplemental irrigation uses drip irrigation, where irrigation water is delivered directly and slowly to the root zone soil of the crop through drip tape pre-laid beneath the biocrust structure. This reduces surface water evaporation loss and avoids water erosion of the biocrust surface. The amount of water added during each drip irrigation should be strictly controlled, usually not exceeding 10 mm (equivalent to 100 cubic meters per hectare). The purpose is to alleviate water stress in the root zone, rather than to provide full irrigation, and to encourage crop roots to make full use of the soil water stored in the biocrust.

[0038] Implementation Step 6: Protection and Cross-Season Utilization of Post-Harvest Crust Structure After the corn harvest, the remaining stalks can be disposed of in the usual way, but the artificial biological crust structure on the ground surface must be preserved. This crust will continue to play a role in water retention, dust suppression, and improving the surface micro-ecology, and will serve as the basis for the next planting season.

[0039] Before the start of the next planting cycle, only one inspection of the surface crust is needed. For severely damaged areas caused by the previous harvest or natural factors, spot or patch repairs should be carried out. The repair material is completely identical in composition to the initially laid composite substrate layer. Simply sprinkle a small amount of composite substrate on the damaged area, lightly spray water to moisten it, and after a short curing period (usually 3-5 days, but faster due to the existing microbial base), it will integrate with the original crust, restoring continuous ground cover. This maintenance method greatly reduces the cost of long-term application and environmental disturbance.

[0040] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for drought-resistant maize cultivation based on biochar swamp biocrust, characterized in that, The method includes the following steps: S1. Before corn sowing, a composite matrix layer made of biochar particles and natural biological crust material collected from swamps is evenly spread on the surface of the plot to be planted. S2. After the composite matrix layer is laid, it is sprayed with water to wet it until its surface appears as a wet mud but without any water accumulation. Then it is left to stand and cure so that a continuous biological crust structure can be naturally formed on the surface of the composite matrix layer. S3. After the biocrust structure has been stably formed, corn seeds are directly sown in the soil below the biocrust structure using a no-till sowing method. The sowing depth should be such that the seeds are in contact with the moist soil without damaging the integrity of the above-ground crust structure. S4. During the corn growing season, except for supplemental drip irrigation under extreme drought conditions, soil moisture is maintained by relying on the water retention and evaporation inhibition function of the biological crust structure.

2. The method for drought-resistant maize planting based on biochar swamp biocrust as described in claim 1, characterized in that, The composite matrix layer has a thickness of 10-30 mm, wherein the dry weight mixing ratio of the biochar particles and the natural biochar crust raw material is 2:1 to 5:1; the biochar particles are obtained by pyrolysis of agricultural waste at 300-600°C under oxygen-limited conditions, and have a particle size distribution of 0.5-5 mm and a specific surface area greater than 200 m² / g.

3. The method for drought-resistant maize planting based on biochar swamp biocrust as described in claim 2, characterized in that, The natural biocrust material is collected from the surface sediments of natural swamp ecosystems, which contains live algae, cyanobacteria, bryophytes and their spores and vegetative propagules, as well as symbiotic microbial communities and organic debris. The natural biocrust material needs to be crushed and screened before mixing so that its maximum particle size does not exceed 5 mm.

4. The method for drought-resistant maize planting based on biochar swamp biocrust as described in claim 1, characterized in that, The water spraying and wetting treatment adopts a low-pressure atomized spraying method, and the water supply is controlled to make the water content of the composite matrix layer reach 60%-80% of its maximum water holding capacity; the static curing process is carried out under natural light conditions for a duration of not less than 7 days, during which the surface of the composite matrix layer is kept continuously moist but without water accumulation.

5. A method for drought-resistant maize cultivation based on biochar swamp biocrust as described in claim 1, characterized in that, The no-till sowing method is operated using a disc-type sowing machine with a bark-breaking and furrow-opening function. The disc blade of the sowing machine is designed to cut only the biological crust structure and break up the shallow soil. After sowing, the soil is gently backfilled to cover the seeds using a soil covering and compaction device to ensure that the large-area crust structure is not disturbed.

6. The method for drought-resistant maize planting based on biochar swamp biocrust as described in claim 1, characterized in that, The supplemental drip irrigation during the corn growing season is triggered when there is no effective rainfall for 15 consecutive days and the soil moisture content in the 0-20cm layer is less than 10%; each drip irrigation water supply does not exceed 10mm, and the irrigation water is delivered directly to the crop root zone through the drip irrigation tape laid under the biological crust structure.

7. A method for drought-resistant maize cultivation based on biochar swamp biocrust as described in claim 1, characterized in that, After the corn harvest, the remaining biocrust structure is left on the surface without being disturbed, serving as the basis for the next planting season. Before replanting, only severely damaged areas need to be locally repaired, and the repair material is consistent with the composition of the initially laid composite substrate layer.

8. A method for drought-resistant maize cultivation based on biochar swamp biocrust according to any one of claims 1 to 7, characterized in that, The method is applicable to semi-arid areas with an annual precipitation of 250-500 mm, and the soil texture of the plot to be planted is sandy loam to loam.

9. A method for drought-resistant maize cultivation based on biochar swamp biocrust as described in claim 1, characterized in that, The biochar particles are activated after pyrolysis to enhance their surface functional groups and adsorption properties; the activation process is carried out by steam activation at a temperature of 500-800°C for 30-60 minutes.

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