Method for improving organic matter increment of sandy farmland soil

Abstract

This invention relates to the field of soil improvement technology and discloses a method for increasing the organic matter content of sandy farmland soil. The method includes the following steps: comprehensive soil testing; preparation of improvement materials based on the test results; deep plowing and returning the soil to the field; planting multifunctional intercrops; and, during the flowering to early pod-forming stage of the intercrops, crushing and compacting the intercrops into the soil layer for in-situ green manure return; application of a polymeric organic-inorganic composite conditioner; application of integrated water, fertilizer, and microbial regulation based on micro-sprinkler irrigation; and implementation of high-stubble no-till mulching with annual monitoring. The method described in this invention can significantly increase soil organic matter and porosity, and significantly improve the soil ecological environment.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and more specifically, to a method for increasing the organic matter content in sandy farmland soil. Background Technology

[0002] Sandy farmland is widely distributed in the arid and semi-arid regions of northern my country and is an important arable land resource for ensuring regional food security. However, due to the special texture of the soil itself and long-term human cultivation and management, its organic matter content is generally low, which has become a core bottleneck restricting the improvement of grain production capacity, the stability of arable land quality, and the sustainable development of agriculture. Therefore, conducting research and application of technologies to improve soil organic matter in sandy farmland has a clear practical need and scientific necessity.

[0003] Sandy soil particles have large interparticles (primarily aeration pores with insufficient capillary pores), acting like a "sieve." During rainfall or irrigation, water rapidly infiltrates, easily carrying water-soluble organic matter (such as small-molecule organic acids and amino acids) and loosely adsorbed organic colloids downwards, making it difficult for organic matter to remain in the topsoil layer (0-20cm). Simultaneously, sand particles have a small specific surface area (the surface area per unit mass of particles is much lower than that of clay particles), resulting in weak physical adsorption capacity for organic matter, further exacerbating the risk of organic matter leaching.

[0004] Soil microorganisms are the core "executors" of organic matter decomposition and transformation. However, sandy soils have poor water retention capacity (field holding capacity is usually <20%), and drought is the norm, resulting in a harsh living environment for microorganisms (such as bacteria, fungi, and actinomycetes), leading to low population numbers and low activity. On the one hand, microorganisms decompose organic materials (such as straw and manure) that enter the soil slowly, making it difficult to quickly transform them into humus that can be absorbed by crops. On the other hand, the small amount of organic matter that accumulates is easily oxidized and decomposed in environments with frequent alternations of dryness and wetness, creating an imbalance of "slow input and fast consumption."

[0005] Organic matter acts as a "cementing agent" in the formation of soil aggregates (0.25-10mm). Sandy soils, lacking organic matter, have loose, uncohesive particles and lack stable aggregate structures. This "loose sand" state weakens the soil's resistance to erosion, allowing wind erosion (especially in northern springs) and water erosion to directly carry away the fine, organic-rich particles from the surface. Simultaneously, the loose structure leads to excessive soil aeration, accelerating the mineralization and decomposition of organic matter (i.e., organic matter is broken down by microorganisms into CO2 and released into the atmosphere), creating a vicious cycle of "poor structure → organic matter loss → even worse structure."

[0006] Therefore, providing a method for improving and increasing the organic matter content in sandy farmland soil has significant practical implications. Summary of the Invention

[0007] In view of this, the present invention proposes a method for improving and increasing the organic matter content of sandy farmland soil, aiming to solve at least one of the problems in the background art.

[0008] This invention proposes a method for improving and increasing the organic matter content in sandy farmland soil, comprising the following steps:

[0009] The soil is comprehensively tested, and improvement materials are formulated based on the results of the comprehensive test. The soil is then deeply tilled and returned to the field.

[0010] Plant multi-functional intercrops, and when the multi-functional intercrops are in full bloom to early pod stage, crush and plow them into the soil layer to return them to the field as in-situ green manure.

[0011] Apply polymeric organic-inorganic composite conditioner;

[0012] Application of integrated water, fertilizer, and microbial regulation based on micro-sprinkler irrigation;

[0013] Implement no-till mulching with high straw retention and year-round monitoring.

[0014] Preferably, the comprehensive testing indicators include organic matter content, sand particle ratio, and pH value; the improved material includes the following components in parts by weight: 30-50 parts of wood fiber material, 20-40 parts of high-enriched organic matter material, 10-20 parts of clay minerals, 5-10 parts of calcium carbonate, and 1-2 parts of compound microbial agent.

[0015] Preferably, the lignocellulosic material is straw, sawdust, or mushroom residue; the high-enriched citric acid organic material is well-rotted cow or sheep manure or humic acid fertilizer; the clay mineral is bentonite or attapulgite; and the compound microbial agent includes Clostridium fibrinolyticum, Azotobacter chrysogenum, and Bacillus megaterium.

[0016] Preferably, the depth of the crushing and compaction into the soil layer is 0~20cm.

[0017] Preferably, the application of the polymeric organic-inorganic composite conditioner specifically involves applying the polymeric organic-inorganic composite conditioner in strips or holes when sowing the main crop in the next season. The conditioner is applied close to the seeds or seedlings but does not directly contact them.

[0018] Preferably, the polymeric organic-inorganic composite conditioner is prepared by the following method: humic acid, seaweed extract and polyglutamic acid are dissolved in water at a mass ratio of 5:2:1 to form a viscous liquid; the viscous liquid is mixed with weathered coal powder, phosphate rock powder and silicon-calcium-potassium-magnesium fertilizer at a mass ratio of 3:1:1:1, and the mixture is then made into particles with a particle size of 2-4 mm.

[0019] Preferably, the application of water, fertilizer and bacteria integrated regulation based on micro-sprinkler irrigation specifically involves: during the crop growing season, using a micro-sprinkler irrigation system to apply water, fertilizer and bacteria integrated topdressing three times.

[0020] The three-stage integrated application of water, fertilizer, and bacteria is as follows: the first application is a liquid fertilizer rich in humic acid, macronutrients, and gelatinous Bacillus during the jointing stage; the second application is a liquid fertilizer rich in trehalose, micronutrients, and Bacillus megaterium during the booting stage; and the third application is a liquid fertilizer rich in amino acids, potassium dihydrogen phosphate, and photosynthetic bacteria during the grain-filling stage.

[0021] Preferably, the implementation of high stubble no-till mulching is as follows: when the main crop is harvested, high stubble is left, with a stubble height of 30-40cm, and then the remaining straw is crushed and covered on the soil surface.

[0022] Preferably, the annual monitoring specifically involves: establishing a soil health record and testing soil organic matter content, aggregate stability, microbial community structure, and crop yield every two years.

[0023] This invention also provides the application of the method for improving and increasing the organic matter content of sandy farmland soil described in the above-mentioned technical solution in soil improvement.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) This invention uses a dual approach of “optimized organic material ratio + targeted microbial regulation”. On the one hand, it scientifically combines organic materials such as straw and green manure with water-retaining modifiers (such as humic acid and biochar) to enhance the adsorption strength of organic colloids on the surface of sand particles and reduce the risk of water-soluble organic matter being lost through water infiltration. On the other hand, it accelerates the conversion of organic materials into stable humus by inoculating drought-resistant and highly efficient functional microbial communities, significantly reducing the content of easily leached small molecule organic matter.

[0026] (2) This invention realizes the "continuous accumulation + tiered improvement" of organic matter. It combines the nutrient requirements of crops during their growth period and implements the organic matter input strategy of "base fertilizer carbon increase + topdressing nitrogen supplement + fallow fertilization" in stages. It also combines no-till and reduced tillage technology to reduce soil disturbance and lower the rate of organic matter mineralization and decomposition, forming a virtuous cycle of "input-conversion-retention".

[0027] (3) Improve water retention capacity: After the improvement of organic materials, the proportion of soil capillary pores increases, the field water holding capacity increases, the soil moisture content is maintained for a longer period of time without irrigation, and the drought resistance period of crops is significantly shortened; the increase of organic matter leads to the increase of soil cation exchange capacity, the adsorption capacity of nutrients such as nitrogen, phosphorus and potassium is increased, the fertilizer utilization rate is improved, and the amount of fertilizer used is reduced.

[0028] (4) Reshaping soil aggregate structure and enhancing erosion resistance: This invention promotes the formation of stable aggregate structure of 0.25-10mm through the cementing effect of humus and sand particles. Compared with traditional fields, the proportion of aggregate structure is increased, soil bulk density is reduced, total porosity is increased, and wind erosion resistance is significantly enhanced.

[0029] (5) Activating soil microbial ecology and strengthening nutrient cycling: The introduction of functional microbial communities and the improvement of the soil microenvironment (enhanced water and fertilizer retention capacity) create a synergistic effect, increasing the total amount of soil microorganisms (bacteria, fungi, actinomycetes) by 1-2 orders of magnitude. Among them, the activity of organic matter decomposing bacteria (such as Trichoderma and Bacillus) and nutrient conversion bacteria (such as nitrogen-fixing bacteria and phosphorus-solubilizing bacteria) is enhanced. The enhanced microbial activity not only accelerates the decomposition and conversion of organic materials, but also converts insoluble phosphorus and potassium in the soil into readily available nutrients, increasing the content of readily available phosphorus and potassium in the soil and reducing dependence on chemical fertilizers. Detailed Implementation

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0031] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0033] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0034] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0035] This invention provides a method for improving and increasing the organic matter content in sandy farmland soil, comprising the following steps:

[0036] The soil is comprehensively tested, and improvement materials are formulated based on the results of the comprehensive test. The soil is then deeply tilled and returned to the field.

[0037] Plant multi-functional intercrops, and when the multi-functional intercrops are in full bloom to early pod stage, crush and plow them into the soil layer to return them to the field as in-situ green manure.

[0038] Apply polymeric organic-inorganic composite conditioner;

[0039] Application of integrated water, fertilizer, and microbial regulation based on micro-sprinkler irrigation;

[0040] Implement no-till mulching with high straw retention and year-round monitoring.

[0041] The soil is comprehensively tested, and improvement materials are formulated based on the results of the comprehensive test. The soil is then deeply tilled and returned to the field.

[0042] After crop harvest, soil samples are taken and analyzed to determine soil organic matter content, sand content and pH value. Based on the diagnostic results, basal soil amendment materials are formulated and applied in a differentiated manner. Then, deep plowing is carried out to a depth of 25-35cm to evenly incorporate the amendment materials into the tillage layer.

[0043] In this invention, the comprehensive testing indicators include organic matter content, sand particle ratio, and pH value; the improved material preferably includes the following components in parts by weight: 30-50 parts of lignocellulosic material, 20-40 parts of high-enriched organic matter, 10-20 parts of clay minerals, 5-10 parts of calcium carbonate, and 1-2 parts of compound microbial agent; more preferably, it includes the following components in parts by weight: 30-40 parts of lignocellulosic material, 20-30 parts of high-enriched organic matter, 10-15 parts of clay minerals, 5-7 parts of calcium carbonate, and 1-1.5 parts of compound microbial agent.

[0044] The wood-based fiber material described in this invention provides a basic carbon source: acting as a "reservoir" for organic matter, it provides the carbon elements needed for decomposition by soil microorganisms, supporting subsequent humus formation; its fibrous structure forms a "skeleton" in the soil, increasing soil porosity (especially capillary porosity), alleviating the problem of "excessively large particle gaps and excessive aeration" in sandy soils, and also slowing down the decomposition of organic matter: the slower decomposition rate of fibrous materials can prevent rapid mineralization and loss of organic matter, achieving "slow release and continuous accumulation" of organic matter. This solves the imbalance problem of "rapid input and even faster consumption" of organic matter in sandy soils, and at the same time, through physical structural filling, it reduces the leaching of organic matter caused by rapid water infiltration.

[0045] The high-fulvic acid organic matter material described in this invention is well-rotted cow or sheep manure or humic acid fertilizer. It specifically addresses the shortcomings of sandy soils, such as "small specific surface area of ​​sand particles and weak adsorption capacity for organic matter," while rapidly replenishing high-quality organic matter and shortening the improvement cycle. Specifically, its effects include: directly replenishing active organic matter: rich in humic substances (especially fulvic acid), it directly increases soil organic matter content without long-term decomposition, rapidly improving the soil's "carbon pool" level; enhancing adsorption capacity: fulvic acid has strong colloidal properties, allowing it to adhere to the surface of sand particles, increasing the adsorption capacity of sand particles for water-soluble organic matter such as small-molecule organic acids and amino acids, reducing leaching loss; and improving the microbial environment: providing readily available nutrients for microorganisms, promoting their activity, and accelerating the conversion efficiency of other organic materials.

[0046] The clay minerals described in this invention are bentonite or attapulgite, addressing the core pain points of sandy soils, namely "unreasonable pore structure and weak water and fertilizer retention capacity," while providing a necessary binding carrier for the formation of soil aggregates. Specifically, its functions include: enhancing water and fertilizer retention capacity: possessing strong water absorption, swelling, and ion exchange properties, it can adsorb and retain water and nutrients such as nitrogen, phosphorus, and potassium in the soil, alleviating the problem of poor water and fertilizer retention in sandy soils; promoting aggregate formation: acting as a "binder," it binds loose sand particles with organic matter colloids, helping to form stable aggregate structures of 0.25-10mm, improving the "loose sand" state of the soil; and fixing organic matter: through physical adsorption and ion binding, it reduces the infiltration of water-soluble organic matter with water, enhancing the retention rate of organic matter in the topsoil layer (0-20cm).

[0047] This invention also includes calcium carbonate, which addresses the potential acidification problem in sandy soils caused by long-term cultivation, providing a suitable chemical basis for organic matter transformation and enhanced microbial activity. Specifically: It regulates soil pH: Sandy soils often exhibit acidity (common in arid and semi-arid regions of northern China). Calcium carbonate (alkaline) neutralizes this acidity, adjusting the pH to a range suitable for crop growth (6.5-7.5) and microbial activity; it enhances nutrient stability: Under suitable pH conditions, nutrients such as phosphorus and potassium are less likely to be fixed in the soil (e.g., phosphorus easily binds with iron and aluminum and becomes ineffective under acidic conditions), improving nutrient utilization; and it improves the soil chemical environment: providing a stable living environment for microorganisms (such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria), preventing extreme pH levels from inhibiting their activity.

[0048] The composite microbial agent of this invention includes Clostridium fibrolyticum, Azotobacter chrysogenum, and Bacillus megaterium.

[0049] It can effectively solve the problems of "low microbial activity and slow decomposition of organic materials" in sandy soils. Through the "targeted operation" of functional microbial communities, it achieves efficient conversion of organic materials and recycling of nutrients. Specifically, its effects include: 1. Targeted decomposition of organic materials: Clostridium difficile efficiently decomposes lignocellulosic materials (such as straw), converting recalcitrant fibers into small-molecule organic matter that is easily absorbed by crops; 2. Enhanced nutrient cycling: Azotobacter spp. converts atmospheric nitrogen into ammoniacal nitrogen that is available to the soil, supplementing nitrogen and reducing reliance on chemical fertilizers.

[0050] Bacillus megaterium decomposes insoluble phosphorus and potassium in the soil (such as phosphorus in phosphate rock powder) into readily available nutrients, thereby improving soil fertility; it also promotes humus formation: the metabolic products of the microbial community can accelerate the conversion of materials such as lignocellulose and eugenol into stable humus, thereby improving the "quality" (rather than the simple quantity) of organic matter.

[0051] In this invention, the lignocellulosic material is preferably straw, sawdust, or mushroom residue; the high-enriched citric acid organic material is preferably well-rotted cow or sheep manure or humic acid fertilizer; the clay mineral is preferably bentonite or attapulgite; and the composite microbial agent preferably includes Clostridium fibrinolyticum, Azotobacter chrysogenum, and Bacillus megaterium.

[0052] In this invention, the proportions of Clostridium difficile, Azotobacter chrysophagus, and Bacillus megaterium are not specifically limited and can be adjusted according to the actual test results of the soil. In the embodiments of this invention, a mass ratio of 1:1:1 is used.

[0053] Plant multi-functional intercrops, and when the multi-functional intercrops are in full bloom to early pod stage, crush and plow them into the soil layer to return them to the field as in-situ green manure.

[0054] After deep plowing and land preparation, sow multifunctional intercropping crops at the appropriate time, such as green manure crops intercropped with legumes and grasses. The preferred combination is a mixture of arrowhead pea and ryegrass, with a seeding ratio of 1:2. During the flowering to early pod stage of the green manure crop (when biomass is at its maximum), use a heavy-duty disc harrow, rotary tiller, or other agricultural tools to directly crush and compact it into the 0-20cm soil layer, completing the in-situ green manure return to the field.

[0055] During the peak flowering to early pod-forming stage of crops, the plants (stems, leaves, and flowers) are at their nutrient accumulation peak, with low lignification, moderate cellulose content, and rich in easily degradable organic components such as proteins and sugars. After being crushed and compacted, they can be quickly decomposed by soil microorganisms, preventing nutrient loss due to long-term accumulation. The compaction depth is controlled at 0-20cm, precisely targeting the topsoil layer where the main crop roots are distributed. Organic matter can be directly retained in the "key layer" most in need of improvement in sandy soils, specifically addressing the core problem of insufficient organic matter in the topsoil layer of sandy soils. The crushed green manure plants form a "fiber network" in the soil, filling the excessively large pores between sand grains. Simultaneously, the humic substances produced during their decomposition (such as humic acid and fulvic acid) act as a "cementing agent," binding loose sand grains into stable aggregates of 0.25-10mm. The formation of aggregates can reduce the bulk density of sandy soils (reducing the risk of compaction), while increasing the proportion of capillary pores, improving field water holding capacity, and alleviating the problem of sandy soils "leaking water like a sieve," providing a stable water environment for subsequent microbial activity and crop growth. The carbon-nitrogen ratio (C / N) in green manure plants is suitable (the C / N ratio is about 20-30:1 from full bloom to early pod stage, close to the optimal ratio for microbial decomposition), and bacteria, fungi, actinomycetes, and other microbial communities can be quickly activated without the need for additional nitrogen fertilizer. In particular, it promotes the reproduction of "organic matter decomposing bacteria (such as Trichoderma and Bacillus)" and "nutrient conversion bacteria (such as nitrogen-fixing bacteria and phosphorus-solubilizing bacteria)," increasing the total number of microorganisms by 1-2 orders of magnitude.

[0056] The organic acids released during the decomposition of green manure can slightly regulate the soil pH. Combined with the water and air retention effects of the granular structure, this creates a "moist, breathable, and pH-suitable" living environment for microorganisms, further enhancing their ability to decompose organic materials and transform insoluble nutrients (such as phosphorus and potassium), reducing dependence on chemical fertilizers. The planting and returning of multifunctional intercrops (preferably legumes such as milkvetch and alfalfa, or gramineous crops such as ryegrass) to the field can achieve "planting grain while nourishing the soil" without affecting the yield of the main crop (grain crop): intercrops are usually planted at staggered times with the main crop (e.g., planted after the main crop harvest, or coexist with the main crop but do not compete for light and nutrients). The time for plowing and covering during the full bloom to early pod stage allows time to be freed up for the sowing of the next season's main crop, avoiding conflicts with grain production. Returning green manure to the field not only replenishes organic matter in the same year, but the humus remaining after its decomposition can also remain in the soil for a long time, continuously increasing the soil cation exchange capacity (CEC) and enhancing the soil's adsorption capacity for nutrients such as nitrogen, phosphorus, and potassium. Combined with the "high stubble retention and no-till mulching" mentioned in the document, a long-term mechanism of "short-term fertilization + long-term soil nourishment" is formed, breaking the dilemma of "the more sandy farmland is planted, the thinner it becomes".

[0057] In this invention, the depth of crushing and compacting into the soil layer is preferably 0~20cm.

[0058] Apply polymeric organic-inorganic composite conditioner;

[0059] In this invention, the preferred method for applying the polymeric organic-inorganic composite conditioner is to apply it in strips or holes when sowing the main crop in the next season. The conditioner is applied close to the seeds or seedlings but not in direct contact.

[0060] In this invention, the polymeric organic-inorganic composite conditioner is preferably obtained by the following preparation method: humic acid, seaweed extract and polyglutamic acid are dissolved in water at a mass ratio of 5:2:1 to form a viscous liquid; the viscous liquid is mixed with weathered coal powder, phosphate rock powder and silicon-calcium-potassium-magnesium fertilizer at a mass ratio of 3:1:1:1, and the mixture is then made into particles with a particle size of 2-4 mm.

[0061] Specifically, when the humic acid, seaweed extract, and polyglutamic acid are dissolved in water, the amount of water used is 0.4 to 1 times the total amount of humic acid, seaweed extract, and polyglutamic acid. Furthermore, the granulation technique used to prepare particles with a diameter of 2-4 mm after mixing employs techniques well-known to those skilled in the art, and no specific limitations are imposed on the granulation parameters.

[0062] This invention achieves the technical effects of rapid fertilization and long-term soil nourishment by adding a polymeric organic-inorganic composite conditioner. Specifically, the phosphate rock powder (providing phosphorus) and silicon-calcium-potassium-magnesium fertilizer (supplementing potassium, calcium, magnesium, silicon and other trace elements) in the conditioner serve as inorganic nutrient sources. When the main crop is sown in the next season, it can be applied in strips or holes to quickly release the mineral nutrients urgently needed by the crop during germination and seedling stages, alleviating the problem of "easy leaching of nutrients and easy fertilizer deficiency in crops" in sandy soil. The humic acid, seaweed extract, and weathered coal powder in the conditioner are all high-quality organic raw materials. Humic acid can directly replenish the active organic matter in the soil, and its colloidal properties can enhance the adsorption capacity of sand particles for small-molecule organic nutrients, reducing the leaching and loss of organic matter. Seaweed extract is rich in active substances such as polysaccharides and amino acids, which not only provide carbon sources for soil microorganisms, but also promote the secretion of organic acids by crop roots, enhancing the efficiency of nutrient absorption. Weathered coal powder has a highly porous structure and can act as an "organic matter carrier," slowing down the decomposition rate of organic components such as humic acid, achieving "slow release and continuous accumulation" of organic matter, and avoiding the imbalance of "rapid input and rapid consumption" of organic matter in sandy soils.

[0063] This invention uses a granulation process to produce conditioner in granular form with a particle size of 2-4 mm. Sandy soils have large interparticle gaps and rapid water infiltration, making powdered conditioners easily lost with irrigation or rainwater. The granular structure, however, can create "localized nutrient enrichment zones" in the soil. Its density reduces the direct contact area between nutrients and water, and combined with the adsorption effects of humic acid and polyglutamic acid, it significantly increases the retention time of nutrients such as nitrogen, phosphorus, and potassium in the topsoil layer (0-20 cm). The granular conditioner slowly disintegrates in the soil, and the released nutrients synergistically work with subsequent "integrated water, fertilizer, and microbial regulation based on micro-sprinkler irrigation": precise water replenishment from micro-sprinkler irrigation promotes a match between the particle disintegration rate and the nutrient release rhythm, avoiding the contradiction in sandy soils where "nutrients cannot be absorbed when water is scarce, and nutrients are lost when watering," thus improving fertilizer utilization.

[0064] Furthermore, this invention limits the application of the conditioner to being close to the seeds or seedlings, but not in direct contact, thus avoiding burning the seeds or seedlings.

[0065] Application of integrated water, fertilizer, and microbial regulation based on micro-sprinkler irrigation;

[0066] In this invention, the preferred method for applying integrated water, fertilizer and bacteria control based on micro-sprinkler irrigation is to use a micro-sprinkler irrigation system to apply integrated water, fertilizer and bacteria in three separate applications during the crop's growing season.

[0067] The three-stage integrated application of water, fertilizer, and bacteria is as follows: the first application is a liquid fertilizer rich in humic acid, macronutrients, and gelatinous Bacillus during the jointing stage; the second application is a liquid fertilizer rich in trehalose, micronutrients, and Bacillus megaterium during the booting stage; and the third application is a liquid fertilizer rich in amino acids, potassium dihydrogen phosphate, and photosynthetic bacteria during the grain-filling stage.

[0068] This invention does not impose specific limitations on the content of different substances in the liquid fertilizer; the content of different components can be adjusted as needed. Furthermore, the application amount of the liquid fertilizer is not specifically limited and can be adjusted according to actual needs.

[0069] This invention supplies water to the soil surface evenly and slowly through a micro-sprinkler irrigation system, avoiding rapid water infiltration and deep leaching. This ensures that water is mainly retained in the 0-20cm topsoil layer where crop roots are distributed, providing a stable water environment for fertilizers and microbial agents to function effectively.

[0070] This invention provides a three-stage targeted supply of water, fertilizer, and bacteria combination to achieve on-demand supply. Specifically: During the jointing stage (critical period of vegetative growth): a liquid fertilizer rich in humic acid (active organic matter), macronutrients (nitrogen, phosphorus, potassium), and gelatinous Bacillus is applied. Humic acid rapidly replenishes organic matter, macronutrients support plant stem and leaf growth, and gelatinous Bacillus decomposes insoluble nutrients in the soil (such as phosphorus), providing sufficient energy for the crop's jointing stage. During the booting stage (initiation period of reproductive growth): a liquid fertilizer rich in trehalose (stress-resistance regulator), micronutrients (calcium, magnesium, zinc, etc.), and Bacillus megaterium is applied. Trehalose enhances the crop's drought resistance (suitable for the drought characteristics of sandy soils) and lodging resistance, micronutrients promote flower organ development, and Bacillus megaterium further activates soil nutrients, ensuring booting quality. During the grain-filling stage (core period of yield formation): a liquid fertilizer rich in amino acids (direct nutrient source), potassium dihydrogen phosphate (promotes grain filling), and photosynthetic bacteria is applied. Amino acids can be directly absorbed by crops, potassium dihydrogen phosphate accelerates the transport of nutrients to grains, and photosynthetic bacteria enhance soil microbial activity, promote the later-stage organic matter conversion, and help grains become plump.

[0071] This invention introduces functional microbial communities such as gelatinous Bacillus, Bacillus megaterium, and photosynthetic bacteria in stages, directly increasing the number of organic matter decomposing bacteria (decomposing organic materials such as straw and green manure) and nutrient conversion bacteria (nitrogen fixation, phosphorus solubilization, and potassium solubilization) in the soil. These microbial agents synergize with Clostridium cellulose-decomposing and Azotobacter chrysogenum, increasing the total number of soil microorganisms by 1-2 orders of magnitude. Furthermore, micro-irrigation maintains moderate soil moisture (avoiding drought), while the fulvic acid and amino acids in the liquid fertilizer provide carbon and nitrogen sources for the microorganisms. The combination of these three factors addresses the core issues of "water and food shortage" for microorganisms, significantly enhancing their activity, accelerating the conversion of organic materials into stable humus, and simultaneously converting insoluble phosphorus and potassium in the soil into readily available nutrients, reducing dependence on chemical fertilizers and forming a positive cycle of "microorganisms-nutrients-crops."

[0072] Implement no-till mulching with high straw retention and year-round monitoring.

[0073] In this invention, the preferred method for implementing high stubble no-till mulching is as follows: when the main crop is harvested, high stubble is left with a height of 30-40cm, and then the remaining straw is crushed and covered on the soil surface.

[0074] Residual crop stalks (stubble) will slowly release organic matter through natural degradation. Simultaneously, the shredded straw covering the soil surface will gradually decompose into humus under the action of microorganisms, continuously enriching the topsoil (0-20cm) and preventing a "carbon deficit" in sandy soils caused by "rapid organic matter decomposition and untimely replenishment." The straw covering the surface forms a "physical barrier," reducing direct contact between the soil and air, and mitigating the rapid mineralization of organic matter caused by excessive soil aeration (preventing the large-scale loss of organic matter as CO2 from microbial decomposition). This achieves "slow decomposition and continuous accumulation" of organic matter, forming a short-term + long-term organic matter replenishment system with the "rapid fertilization" of "green manure returning to the field."

[0075] In this invention, the annual monitoring is preferably carried out by establishing a soil health record and testing the soil organic matter content, aggregate stability, microbial community structure and crop yield every two years.

[0076] This invention establishes soil health records and regularly monitors indicators to provide data support for soil improvement, avoiding blind improvement. If monitoring reveals "slow increase in organic matter content," the proportion of high-enriched anorectic organic matter in the improvement materials can be adjusted, or the frequency of green manure return to the field can be increased. If "aggregate stability does not meet the standard," the application of polymeric conditioners can be strengthened or the straw cover thickness can be optimized. Through data feedback, "adjustment as needed and precise improvement" can be achieved. By continuously monitoring crop yield changes, it can directly verify whether "improvement in organic matter quality and quantity" is converted into actual production benefits (such as increased grain production). At the same time, through indicators such as microbial community structure and aggregate stability, the long-term impact of improvement measures on soil ecology can be verified.

[0077] This invention also provides the application of the method for improving and increasing the organic matter content of sandy farmland soil described in the above-mentioned technical solution in soil improvement.

[0078] Example 1

[0079] I. Implementation Steps

[0080] 1. Comprehensive soil testing and deep tillage and return of soil amendment materials to the field (after wheat harvest)

[0081] Testing Procedure: The experimental field is located in Dezhou City, Dezhou District. Soil samples from the 0-20cm topsoil layer were collected using a five-point sampling method and sent to a third-party testing institution to determine organic matter content, sand content, and pH value to obtain basic data. Basic soil indicators were: organic matter content 14.53 g / kg, sand content 65%, pH value 8.81, and field water holding capacity 19.8%. The previous crop was wheat, with a yield of 450 kg / mu. The main crop was winter wheat (variety: Jimai 22), with a planting cycle from October to July of the following year.

[0082] Improved material formulation (by weight):

[0083] 40 parts of wood fiber material (wheat straw crushed, particle size 2-3cm), 30 parts of high-humic acid organic matter material (composted cow and sheep manure, humic acid content ≥30%), 15 parts of clay minerals (bentonite, montmorillonite content ≥85%), 7 parts of calcium carbonate, and compound microbial inoculant (Clostridium cellulose: Azotobacter chrysogenum: Bacillus megaterium = 1:1:1, viable count ≥10). 8 Mix 1.2 parts of cfu / g thoroughly and let stand for 3 days (maintaining a moisture content of 20%).

[0084] Deep plowing and returning to the field: Apply the prepared amendment material at a rate of 1500 kg / mu to the surface of the land, and plow to a depth of 30 cm. After plowing, use a disc harrow to level the soil to ensure that the amendment material is evenly mixed with the topsoil.

[0085] 2. Planting multifunctional intercrops and returning green manure to the field in situ (mid-October to early April of the following year)

[0086] Intercropping: Select arrowhead pea (leguminous family) and ryegrass (grass family) and sow them together at a ratio of 1:2 (total sowing amount 3kg / mu). Use row sowing (row spacing 20cm) and sowing depth 3cm. Sow at the same time as wheat seeds (with a 10cm planting strip between them to avoid competition).

[0087] Crushing and Turning: In early April of the following year (when arrowhead peas are in full bloom and ryegrass is in the heading stage, with a fresh weight of about 2000 kg / mu), the intercrops are crushed into 5-10 cm pieces and simultaneously turned into the 0-20 cm topsoil. After turning, irrigate once (30 m³ of water per mu) to promote decomposition.

[0088] 3. Apply polymeric organic-inorganic compound conditioner (in mid-April of the following year, after the wheat has turned green).

[0089] Conditioner preparation:

[0090] The first step is to dissolve 50 kg of humic acid (humic acid content ≥70%), 20 kg of seaweed extract (alginic acid content ≥20%), and 10 kg of polyglutamic acid (molecular weight ≥1 million Da) in 200 L of water (water temperature 25℃) and stir for 30 minutes to form a viscous liquid.

[0091] The second step involves mixing the viscous liquid with 100 kg of weathered coal powder (fixed carbon content ≥40%), 100 kg of phosphate rock powder (available phosphorus ≥12%), and 100 kg of silicon-calcium-potassium-magnesium fertilizer (SiO2 ≥30%, CaO ≥20%, K2O ≥8%, MgO ≥5%). The mixture is then granulated into particles with a diameter of 2-4 mm using a rotary drum granulator and dried (moisture content ≤10%) for later use.

[0092] Application method: Apply in strips. Dig a 5cm deep trench between wheat rows (5cm away from the plant), apply the conditioner at a rate of 50kg / mu into the trench, cover with soil and compact (ensure that the distance between the conditioner and the wheat root system is ≥3cm to avoid burning the roots).

[0093] 4. Integrated water, fertilizer and microbial regulation based on micro-sprinkler irrigation (May-July of the following year, during the wheat growing season)

[0094] Micro-sprinkler irrigation system configuration: It adopts ZY-2 type rotary micro-sprinkler head (working pressure 0.2MPa, spray radius 3m, flow rate 50L / h), arranged at a spacing of 3m×3m, connected to PVC water supply pipe (diameter 50mm), and matched with fertilizer tank (capacity 200L) to realize water and fertilizer integration.

[0095] Phased supplementary treatment:

[0096] During the jointing stage (late May): Mix fulvic acid liquid fertilizer (fulvic acid ≥10%, N-P2O5-K2O=20-10-15) with a gelatinous Bacillus inoculum (live count ≥10). 8 Mix (cfu / mL) at a ratio of 100:1, dilute 100 times, and apply as a top dressing via micro-sprinkler irrigation. The dosage is 20L (liquid fertilizer) + 200mL (bacterial agent) per mu, with an irrigation volume of 40m³ / mu.

[0097] During the booting stage (mid-June): Mix trehalose liquid fertilizer (trehalose ≥ 5%, Ca + Mg + Zn ≥ 8%) with Bacillus megaterium inoculum (live count ≥ 10). 8 Mix (cfu / mL) at a ratio of 100:1, dilute 100 times and apply as a top dressing. The dosage is 15L (liquid fertilizer) + 150mL (microbial agent) per mu, with an irrigation volume of 35m³ / mu.

[0098] Grain filling period (early July): Mix amino acid liquid fertilizer (amino acids ≥15%, potassium dihydrogen phosphate ≥20%) with photosynthetic bacteria inoculant (live bacteria count ≥10). 7 Mix (cfu / mL) at a ratio of 100:1, dilute 100 times and apply as a top dressing. The dosage is 15L (liquid fertilizer) + 150mL (bacterial agent) per mu, with an irrigation volume of 30m³ / mu.

[0099] 5. Straw high-retention no-till mulching and year-round monitoring (late July of the following year, after wheat harvest)

[0100] High stubble mulching: Wheat is harvested using a combine harvester, leaving a stubble height of 35cm. The remaining straw (approximately 800kg / mu dry weight) is shredded into 10-15cm pieces using a straw crusher and evenly mulched on the ground with a mulch thickness of 3-5cm.

[0101] Annual monitoring: Establish soil health records and collect soil samples from the 0-20cm topsoil layer for testing.

[0102] Organic matter content: 16.71 g / kg;

[0103] Aggregate stability: 32% of the particles are 0.25-10mm;

[0104] Microbial community structure: Bacterial count 1.2 × 10⁻⁶ 9 cfu / g (an increase of 1.5 orders of magnitude from the initial value);

[0105] Wheat yield: 580 kg / mu (an increase of 28.9%).

[0106] II. Implementation Results

[0107] Compared with the unimproved control field:

[0108] Improved soil water retention capacity: Field water holding capacity increased from 19.8% to 24.3%, and the soil moisture content was maintained for 5-7 days longer under no irrigation conditions;

[0109] Improved nutrient utilization: fertilizer use decreased by 20%, soil available phosphorus content increased from 8.2 mg / kg to 12.5 mg / kg, and available potassium increased from 95 mg / kg to 130 mg / kg;

[0110] Enhanced erosion resistance: Wind erosion of surface soil decreased by 40% in spring, with no significant loss of particles.

[0111] Example 2

[0112] I. Implementation Steps

[0113] 1. Comprehensive soil testing and the application of soil amendment materials during deep tillage and return to the field.

[0114] Testing procedures: The experimental field was located in Shanxian County, Heze City. Similar to Example 1, the five-point sampling method was used to determine the basic soil indicators. The basic soil indicators were: organic matter content 9.46 g / kg, sand content 76%, pH value 8.04, and field water holding capacity 18.4%. The main crop was winter wheat (variety: Hemai 29), and the planting cycle was from October to July of the following year.

[0115] Improved material formulation (by weight):

[0116] 50 parts of wood fiber material (wheat straw + mushroom residue = 1:1, particle size 2-3cm), 40 parts of high-enriched citric acid organic matter material (humic acid fertilizer, humic acid content ≥40%), 20 parts of clay minerals (attapulgite, specific surface area ≥200m² / g), 10 parts of calcium carbonate (purity ≥95%), and compound microbial inoculant (Clostridium fibronectin: Azotobacter chrysogenum: Bacillus megaterium = 1:1:1, viable count ≥10 8 Mix two portions of cfu / g thoroughly and let stand for 5 days (maintaining a moisture content of 25%).

[0117] Deep tillage and returning to the field: Apply the improved material at a rate of 2000 kg / mu, and use a tractor-mounted deep tillage machine to till to a depth of 35 cm. After tillage, compact the soil with a roller to reduce large pores.

[0118] 2. Planting multifunctional intercrops and returning green manure to the field in situ (mid-October to early April of the following year)

[0119] Intercropping: Select milkvetch (leguminous family) for monoculture, with a seeding rate of 4 kg / mu, and use broadcast sowing method. Sow at the same time as wheat seeds (wheat row spacing 60 cm, milkvetch planted between rows), with a sowing depth of 2 cm.

[0120] Crushing and compaction: In early June (when milkvetch is in full bloom and fresh weight is about 2500 kg / mu), use a rotary tiller to crush and compact the milk to a depth of 0-20 cm. After compaction, irrigate once (35 m³ of water per mu) and apply 5 kg / mu of urea (adjusting the C / N ratio to 25:1).

[0121] 3. Apply polymeric organic-inorganic compound conditioner (in mid-April of the following year, after the wheat has turned green).

[0122] Conditioner preparation: Same as in Example 1, but with the following adjusted amounts: 60 kg of humic acid, 24 kg of seaweed extract, and 12 kg of polyglutamic acid, corresponding to 120 kg of weathered coal powder, 120 kg of phosphate rock powder, and 120 kg of silicon-calcium-potassium-magnesium fertilizer, to be made into 2-4 mm granules.

[0123] Application method: Apply by hole application. Make a 5cm deep hole 5cm to the side of the wheat sowing hole, apply the conditioner at a rate of 60kg / mu, cover with soil and then sow wheat (the distance between the seed and the conditioner is ≥3cm).

[0124] 4. Integrated water, fertilizer and microbial regulation based on micro-sprinkler irrigation (May-July of the following year, during the wheat growing season)

[0125] Micro-sprinkler irrigation system configuration: Same as in Example 1, except the spacing between micro-sprinklers is adjusted to 2.5m × 2.5m (suitable for high-density wheat planting).

[0126] Phased supplementary treatment:

[0127] During the jointing stage (late May): Mix fulvic acid liquid fertilizer (fulvic acid ≥10%, N-P2O5-K2O=18-8-18) with gelatinous Bacillus inoculant at a ratio of 100:1, dilute 100 times and apply as a top dressing. The dosage is 25L (liquid fertilizer) + 250mL (inoculant) per mu, with an irrigation volume of 45m³ / mu.

[0128] During the booting stage (mid-June): Mix trehalose liquid fertilizer (trehalose ≥5%, Ca+Mg+Zn ≥10%) with Bacillus megaterium inoculum at a ratio of 100:1, dilute 100 times and apply as a top dressing. The dosage is 20L (liquid fertilizer) + 200mL (inoculum) per mu, with an irrigation volume of 40m³ / mu.

[0129] Grain filling period (early July): Mix amino acid liquid fertilizer (amino acids ≥15%, potassium dihydrogen phosphate ≥25%) with photosynthetic bacteria inoculant at a ratio of 100:1, dilute 100 times and apply as top dressing. The dosage is 20L (liquid fertilizer) + 200mL (bacterial agent) per mu, and the irrigation amount is 35m³ / mu.

[0130] 5. Straw high-retention no-till mulching and year-round monitoring (late July of the following year, after wheat harvest)

[0131] High stubble mulching: When wheat is harvested, leave a stubble height of 40cm. The remaining straw (about 1000kg / mu dry weight) is crushed into 10-15cm pieces and covered on the ground with a mulch thickness of 5-6cm.

[0132] Annual monitoring: Soil health record test results:

[0133] Organic matter content: 12.3 g / kg;

[0134] Aggregate stability: 28% of the particles are 0.25-10mm.

[0135] Microbial community structure: Bacterial count 8.5 × 10⁻⁶ 8 cfu / g (an increase of 1.8 orders of magnitude from the initial value);

[0136] Wheat yield: 620 kg / mu (an increase of 63.2%).

[0137] II. Implementation Results

[0138] Compared with the unimproved control field:

[0139] Improved soil structure: Soil bulk density decreased from 1.65 g / cm³ to 1.42 g / cm³, and total porosity increased from 38% to 45%.

[0140] Improved fertilizer retention capacity: Soil cation exchange capacity increased from 8.5 cmol / kg to 12.3 cmol / kg, and nitrogen leaching decreased by 35%;

[0141] Enhanced resilience: When wheat experiences a 20-day drought during its growth period, untreated fields experience a 40% yield reduction, while the fields described in this example only experience an 8% yield reduction, demonstrating a significant improvement in drought resistance.

[0142] In summary, the method used in this invention is a significant improvement over the unmodified control field.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for upgrading the organic matter content of sandy farmland soil, characterized by, It comprises the following steps: comprehensive detection of the soil, preparation of improvement materials according to the results of the comprehensive detection, deep ploughing of the soil and returning to the field; planting multifunctional intercropping, and during the flowering to early pod stage of the multifunctional intercropping, crushing and turning under the soil layer for in-situ green manure; application of polymeric organic-inorganic composite conditioner; water, fertilizer and microorganism integrated control based on micro-sprinkling irrigation; high stubble retention no-tillage mulching and year-round monitoring; the indicators of the comprehensive detection include organic matter content, sand ratio and pH value; the improvement materials include the following components in mass fraction: 30-50 parts of wood fiber material, 20-40 parts of high humic acid organic material, 10-20 parts of clay mineral, 5-10 parts of calcium carbonate and 1-2 parts of composite microbial agent; the wood fiber material is straw, sawdust or mushroom residue, the high humic acid organic material is matured cow and sheep manure or humic acid fertilizer, the clay mineral is bentonite or attapulgite, and the composite microbial agent includes Clostridium cellulolyticum, Azotobacter chroococcum and Bacillus megaterium; the polymeric organic-inorganic composite conditioner is prepared by the following method: dissolving humic acid, seaweed extract and polyglutamic acid in water at a mass ratio of 5:2:1 to form a viscous liquid; mixing the viscous liquid with weathered coal powder, phosphate rock powder and silicon calcium potassium magnesium fertilizer at a mass ratio of 3:1:1:1, and then making particles with a particle size of 2-4 mm after mixing; the water, fertilizer and microorganism integrated control based on micro-sprinkling irrigation is specifically: during the growth season of crops, using a micro-sprinkling irrigation system, water, fertilizer and microorganism integrated topdressing is carried out three times; the three times of water, fertilizer and microorganism integrated topdressing are specifically: the first time is to apply liquid fertilizer rich in fulvic acid, macroelements and jelly-like Bacillus sp. at the jointing stage, the second time is to apply liquid fertilizer rich in trehalose, microelements and Bacillus megaterium at the booting stage, and the third time is to apply liquid fertilizer rich in amino acids, potassium dihydrogen phosphate and photosynthetic bacteria at the filling stage.

2. The sandy farmland soil organic matter upgrading delta method according to claim 1, characterized by, The depth of crushing and turning under the soil layer is 0-20 cm.

3. The method for upgrading the organic matter increment of sandy farmland soil according to claim 1, characterized in that, The application of polymeric organic-inorganic composite conditioner is specifically: at the time of sowing the main crops in the next season, polymeric organic-inorganic composite conditioner is applied in strips or holes, and the conditioner is close to the seeds or seedlings but does not directly contact them.

4. The sandy farmland soil organic matter upgrading delta method according to claim 1, characterized by, The implementation of high stubble retention no-tillage mulching is: at the time of harvesting the main crops, high stubble retention is implemented, with a stubble height of 30-40 cm, and then the remaining straw is crushed and mulched on the soil surface.

5. The sandy farmland soil organic matter upgrading delta method according to claim 1, characterized by, The year-round monitoring is specifically: establishing a soil health file, and detecting the soil organic matter content, aggregate stability, microbial community structure and crop yield every two years.

6. Application of the method for increasing the amount of organic matter in sandy farmland soil in claim 1-5 in soil improvement.