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In organic fertilizer production, high-moisture materials (35%-45% moisture content) have always been a major challenge in granulation. Traditional extrusion or disc granulation requires moisture content below 30%, otherwise the granules are loose, easily stick to the walls, and drying energy consumption increases dramatically. In recent years, new organic fertilizer granulators based on centrifugal wet granulation (such as stirring tooth granulators and wet drum granulators) have successfully solved this problem. This article analyzes this from three aspects: the principle of centrifugal force, the advantages of wet granulation, and particle density.

Centrifugal Force Principle: Instant Formation Under High-Speed ​​Throwing

The core structure of the new wet granulator is a high-speed rotating rotor (speed can reach 300-600 rpm), on which wear-resistant stirring teeth or blades are installed. When organic materials with a moisture content of 35%-45% fall into the machine cavity through the feed inlet, the enormous centrifugal force generated by the rotor throws the material against the cylinder wall. Simultaneously, the material is subjected to high-speed shearing, tumbling, and compression in the annular gap between the stirring teeth and the cylinder wall.

Unlike traditional disc granulation, which relies on material rolling and agglomeration, centrifugal granulation is a forced forming process. The material completes the transformation from powder to granules within 0.5-2 seconds: moisture is evenly squeezed onto the granule surface under centrifugal force to form a liquid film, while solid particles interlock under high pressure. This principle allows materials with a moisture content 5-10 percentage points higher than conventional methods to successfully granulate.

Advantages of Wet Forming: No Drying Pre-treatment Required

The biggest breakthrough of the new granulator is that it allows raw materials to enter the granulation process directly in a high-moisture state after fermentation, eliminating the need for a secondary drying step before granulation.

High Raw Material Tolerance: It can process semi-wet organic materials with a moisture content of 35%-50%, including well-rotted chicken manure, cow manure, kitchen waste, and biogas residue. Traditional equipment suffers from severe clogging at this moisture level, while the self-cleaning effect generated by centrifugal force prevents material from adhering to the drum wall.

Eliminates the pre-drying step: Conventional processes require drying the material to below 25% before granulation, resulting in high energy consumption and dust generation. After the new wet granulation process, the particle moisture content remains between 30% and 40%, requiring only one drying cycle to reach the finished product standard, reducing overall energy consumption by approximately 30%.

Addition of liquid inoculants: During the wet molding process, microbial inoculants or binder solutions can be sprayed simultaneously at the feed inlet, achieving integrated “granulation + inoculation” and avoiding microbial loss caused by subsequent spraying.

III. Particle density: Porous but not loose. The biggest concern with high-moisture granulation is insufficient particle strength. The new granulator solves this problem through a three-stage densification mechanism: Centrifugal compaction: Under high-speed rotation, the material is subjected to centrifugal force dozens of times its own weight, resulting in denser granules; Axial extrusion: The spiral arrangement of the agitator teeth propels the material from the feed end to the discharge end, subjecting it to continuous axial pressure; Surface polishing: The granules are polished by friction near the discharge port, forming a smooth outer shell to prevent moisture absorption and pulverization.

Actual test data shows that when the new wet granulator processes well-rotted chicken manure with a moisture content of 40%, the resulting 2-5mm organic fertilizer granules have a compressive strength of 8-12N. Although slightly lower than the 15N or more of dry extrusion, this fully meets the requirements for transporting and spreading commercial organic fertilizer. More importantly, the granules maintain appropriate porosity, which facilitates rapid decomposition and fertilization after application to the soil.

Applicable Scenarios and Maintenance Recommendations The new wet granulation machine is particularly suitable for the following scenarios: Direct granulation after fermentation, without the need for drying or pre-drying areas; Production of bio-organic fertilizer, requiring the addition of liquid functional bacteria during granulation; Processing high-fiber, high-viscosity raw materials (such as cow dung, medicinal herb residue, and distiller’s grains).

Maintenance considerations: Monthly inspection of the agitator teeth and liner wear, maintaining a gap of 5-8mm; Cleaning the spray nozzles every shift; Adding high-temperature grease to the bearings every 500 hours. Under proper use, the equipment lifespan can reach 5-8 years.

The breakthrough of the new type organic fertilizer granulator (centrifugal wet granulation) is not an isolated innovation — it perfectly complements the upstream processing chain. Reliable organic fertilizer production starts with advanced fermentation composting turning technology, where equipment such as the large wheel compost turning machine and windrow composting machine ensures thorough aeration, temperature control, and pathogen elimination for high‑moisture raw materials like poultry manure. For dedicated manure handling, a robust chicken manure fertilizer machine series (including dewatering and mixing units) prepares the semi‑wet material, followed by precise fertilizer formula processing to balance carbon‑to‑nitrogen ratios and add functional microbes or binders. This pretreated, still‑moist (35%–45%) feedstock then enters the high‑speed centrifugal granulator, which eliminates pre‑drying, reduces energy consumption by ~30%, and produces porous yet sturdy granules (8–12N compressive strength). By integrating these technologies — from windrow or large‑wheel turning to formula adjustment and finally wet granulation — organic fertilizer plants can achieve a streamlined, low‑carbon process: less drying, less dust, and better microbial survival. The result is a new generation of commercial organic fertilizer that combines the handling convenience of dry granules with the biological activity of minimally processed wet materials, offering both agronomic performance and operational economy.

What is Bio-organic Fertilizer?

Bio-organic fertilizer refers to a new type of fertilizer that combines specific functional microorganisms (such as nitrogen-fixing bacteria, phosphate-solubilizing bacteria, potassium-solubilizing bacteria, and antagonistic bacteria) with well-rotted organic fertilizer carriers, processed in a factory setting. Its essential difference from ordinary organic fertilizer lies in that it not only provides organic matter and trace elements, but also continuously improves the soil microecology, inhibits soil-borne diseases, and activates fixed mineral nutrients through the metabolic activities of active microorganisms.

my country’s agricultural industry standard (NY/T 884-2012) clearly stipulates that bio-organic fertilizer must have an organic matter content ≥40%, an effective live bacteria count ≥0.2 billion/gram, and a miscellaneous bacteria rate ≤30%. This means that simply having good organic fertilizer raw materials is not enough; the problem of how to successfully “marry” the “bacteria” and “fertilizer” on the production line must be solved.

Four Mainstream Methods for Adding Functional Microbial Agents to Production Lines

Because functional microorganisms are extremely sensitive to high temperature, high pressure, and strong shear, the timing and process of addition directly determine the final survival rate of live bacteria in the product. The following four methods have been proven effective in actual production:

Post-fermentation inoculation (mixing microorganisms in the later stage of fermentation)

During the cooling stage of organic fertilizer fermentation (when the pile temperature drops below 40℃), liquid or powdered microbial agents are evenly sprayed or mixed into the material, and then piled for 2-3 days for “post-fermentation.” At this stage, the high temperature is no longer present, and the microorganisms can gradually colonize the organic carrier.

Applicable equipment: Tracked compost turner with a spray system, or twin-shaft mixer.

Advantages: The microorganisms and carrier are fully integrated, and the survival rate can reach over 85%.

Low-temperature mixing before granulation

For manufacturers that need to produce granular bio-organic fertilizer, the granulation process is the biggest risk point. A normal temperature or low-temperature physical granulation process (disc granulation or roller extrusion granulation) must be used, and the microbial agent and powder must be evenly mixed before the granulator.

Key control points: Mixer chamber temperature ≤45℃; premix the microbial agent with bran, rice husk powder, or other “protective carriers” at a ratio of 1:5-10 to absorb frictional heat.

Precautions: Do not use steam or high-temperature drying. Allow the granules to air dry naturally or dry in a fluidized bed at low temperature (≤50℃) after granulation.

Post-coating process (most reliable): After granule cooling and sieving, and before packaging, a post-coating process is implemented. Liquid microbial agent is evenly sprayed onto the granule surface using a high-pressure atomizing nozzle, followed by mixing with a low-speed roller to coat the granules with the microbial solution.

Equipment configuration: Spraying roller (8-12 rpm), microbial storage tank (with stirring and temperature control to prevent sedimentation), metering pump.

Advantages: Completely avoids heat damage during granulation and drying; survival rate can reach over 95%. Disadvantages: The microbial cells adhere to the surface; moisture protection is necessary after packaging.

Direct Mixing of Powdered Products

For powdered bio-organic fertilizer, the process is the simplest: Mix the fermented, decomposed, pulverized, and sieved organic powder with the microbial agent in a double-shaft paddle mixer or ribbon mixer at room temperature for 15-20 minutes. The powder moisture content should be ≤20%, and the coefficient of variation for mixing uniformity should be <10%.

III. Summary and Recommendations for Process Routes

Regardless of the method used, three “ironclad rules” must be followed:

Avoid high temperatures: The temperature of all materials in contact with the microbial agent must be below 50℃.

Avoid strong light and ultraviolet radiation: Packaging bags should be made of light-blocking material.

Avoid chemical inhibition: The microbial agent must not be added simultaneously with high-concentration chemical fertilizers or fungicides.

For newly constructed production lines, a combination scheme of “decomposed organic fertilizer + powdered mixing or post-spraying granulation” is recommended: First, produce high-quality organic fertilizer base material, then flexibly add different functional microbial strains (such as rhizobia for legumes, antagonistic bacteria for continuous cropping obstacles) according to order requirements to achieve flexible production of small batches and multiple varieties.

Engineering Living Fertilizers Through Integrated Production Systems

The commercial viability of bio-organic fertilizer hinges on the seamless fusion of microbial viability preservation with robust manufacturing infrastructure, making advanced bio-organic fertilizer production technology indispensable for modern agricultural input enterprises. At the fermentation stage, deploying precision fermentation composting turning technology—such as a windrow composting machine with integrated temperature monitoring and controlled aeration—ensures complete organic matter decomposition while creating an optimal microbial carrier matrix with stable porosity and balanced carbon-nitrogen ratios. The entire fertilizer manufacturing process must be architected as a low-temperature, low-shear ecosystem where live bacteria inoculation timing, protective carrier blending, and gentle granulation or coating are orchestrated to maintain survival rates above 85%-95%. For enterprises scaling production, establishing a dedicated bio organic fertilizer production line with modular post-fermentation inoculation zones, low-temperature mixing stations, and surface-coating capabilities enables flexible switching between functional strains—such as nitrogen-fixing rhizobia for legumes or antagonistic bacteria for continuous cropping systems—without cross-contamination risks. Ultimately, the factories that will lead the bio-fertilizer market are those that treat every gram of product not as inert chemistry, but as a living ecosystem engineered to thrive in the soil rhizosphere.

In traditional fertilizer granulation processes, the drying and cooling system is the most energy-intensive, space-consuming, and environmentally demanding part of the entire production line. The emergence of the new twin-roll extrusion granulator, with its “no room temperature drying required” technical feature, is redefining the efficiency limits of small- and medium-scale fertilizer production lines.

The Innovative Logic of the Process Flow: Unlike rotary drum granulation, which relies on liquid-phase bonding, extrusion granulation uses a physical dry granulation principle. The material is forced under extremely high pressure between two counter-rotating rollers, compressed into hard flakes, and then enters the crushing and grading stage to form granules. Since no additional moisture is added during the entire process (utilizing only the material’s own moisture content), the product does not need to go through a lengthy drying process after granulation and can be directly screened and packaged.

Moisture Requirements and Precise Control: This process requires extremely low moisture content in the raw materials, typically strictly controlled within the golden range of 5% to 10%. If the material is too dry, the granules are difficult to form and easily pulverize; if it is too wet, it will cause the rollers to stick. This stringent requirement for moisture content forces factories to implement more precise raw material storage management, thereby improving the overall stability of the process.

Energy Efficiency and Cost Savings: From an economic perspective, the no-drying process can save factories approximately 30%-45% on electricity costs and completely eliminates the purchase of coal, natural gas, or biomass fuels. This not only means a significant reduction in the cost per ton of fertilizer production, but also provides a natural advantage in environmental inspections by eliminating the need for hot air furnaces and exhaust gas dust removal systems. Furthermore, this technology effectively protects the activity of microbial agents or heat-sensitive nutrients, making it an ideal equipment solution for producing high-end functional fertilizers.

A Paradigm Shift in Sustainable Fertilizer Manufacturing

In organic fertilizer production, the turner is the core equipment that determines the success or failure of fermentation. Currently, the two mainstream types of self-propelled turners on the market—the large wheel turner and the windrow composting turner—while aiming at the same goal, differ significantly in their working principles and applicable scenarios. Understanding their differences can help organic fertilizer plants choose the right type.

Oxygenation Principle: Throwing vs. Turning

The large wheel turner relies on a giant wheel with a diameter of 1.5-2 meters, the wheel surface equipped with multiple wear-resistant blades. During operation, the wheel rotates at high speed (200-300 revolutions per minute), and the blades cut into the material and instantly throw it into the air 2-4 meters high, causing the material to scatter in a fan shape. This process forces the material into intense contact with the air, resulting in extremely high oxygen dissolution efficiency, while simultaneously breaking up clumps.

The windrow composting turner, on the other hand, uses a low-speed roller or chain plate structure. The drum has spirally arranged lifting plates welded on it. As it rotates (30-60 revolutions per minute), it scoops up the material from the bottom of the shovel, flips it over, and re-piles it. The material displacement path is similar to a “tumbling” process; although it is still loose, the throwing height is low, and the oxygenation method is mainly “interlayer displacement” rather than strong aeration.

Increased Fermentation Speed: Rapid Dehydration vs. Uniform Heating

Due to the different oxygenation intensities, the two methods significantly differ in their effect on accelerating the fermentation cycle. The large wheel type can repeatedly throw the material into the air, reducing the material’s moisture content by 3%-5% with each turn. Aerobic bacteria then metabolize rapidly in the oxygen-rich environment, typically shortening the traditional 45-day fermentation cycle to 20-25 days. This is especially noticeable when processing loose materials such as straw and furfural residue, where the wheel’s dual effect of crushing and aeration is significant.

The advantage of the shovel-type compost turner lies in its gentle and uniform action. It avoids over-crushing materials, preserving the porous structure within the strips, and ensuring a stable temperature rise (generally reaching 65℃ in 3-5 days), with an overall fermentation cycle of approximately 30-35 days. While its absolute speed is slower than the rotary wheel type, it is suitable for applications requiring the preservation of material fiber structure (such as seedling substrate production), preventing excessive pulverization.

III. Applicable Sites: Open Farms vs. Compact Plants

Large wheel compost turners have higher site requirements: they require strips at least 4-6 meters wide, a large turning radius, and a hardened or flattened surface. They are suitable for large open-air organic fertilizer plants and centralized processing areas in livestock farms, with a single machine capable of turning 300-500 cubic meters per day, offering extremely high efficiency.

Strip compost turners are more flexible and lightweight: their narrow body (1.5-2.5 meters wide) allows operation on strips up to 2.5 meters wide, with a small turning radius, even adapting to simple sites with a slight slope. They are particularly suitable for small organic fertilizer workshops, greenhouse production, or agricultural supply stations with limited land resources, and their investment cost is approximately 30% lower.

Strategic Equipment Selection in Modern Composting Operations

The evolution of fermentation composting turning technology has fundamentally reshaped how organic fertilizer plants approach raw material decomposition and quality control. For large-scale operations prioritizing throughput and rapid moisture reduction, investing in a robust large wheel compost turning machine delivers measurable advantages in cycle compression and material homogenization, particularly when processing bulky agricultural residues. Conversely, facilities requiring gentle handling of fibrous substrates or operating within constrained footprints will find that a compact windrow composting machine provides the operational flexibility and lower capital expenditure necessary for sustainable production. When specifically addressing the composting process for animal manure, selecting an appropriate animal manure compost turner becomes critical, as the high moisture and nitrogen content of livestock waste demands precise aeration management to prevent anaerobic pockets and odor emissions. Ultimately, the choice of turning equipment directly influences downstream efficiency across the entire fertilizer production process, from fermentation maturity to final product stability. As the industry advances, integrating intelligent monitoring systems with proven fertilizer granulation technology will enable manufacturers to transform composted organic matter into premium, market-ready granular fertilizers, thereby maximizing both agronomic value and commercial profitability in an increasingly competitive landscape.

Soil Degradation: A Silent Agricultural Crisis

Globally, 33% of soil is moderately to highly degraded. Long-term excessive use of chemical fertilizers has led to a drop in arable land organic matter content to below 1.5% (healthy levels should be above 3%), resulting in soil compaction, acidification, and secondary salinization. The black soil layer in Northeast China is losing 0.3 to 1 cm annually; the soil carbon pool in the Ganges Plain of India has decreased by nearly 40% in the past 30 years. Crops are increasingly reliant on chemical fertilizers, while fertilizer utilization rates have fallen below 40%. Soil restoration has become the most pressing issue for global agriculture—and bio-organic fertilizer is the most direct solution to this crisis.

Policy Dividends: From Encouragement to Mandatory Measures

From 2025 to 2026, many countries have elevated soil health to a strategic level. The EU’s Soil Monitoring Act requires member states to increase soil organic matter by 0.5% by 2030; during China’s 14th Five-Year Plan period, over 300 pilot counties were established for organic fertilizer substitution of chemical fertilizers, with subsidies of 50 to 150 yuan per mu; India has included bio-organic fertilizers in its national fertilizer subsidy catalog, with a subsidy rate of 25% on the ex-factory price. More importantly, the carbon trading market has begun to accept soil carbon sequestration projects—the application of bio-organic fertilizers can certify 2 to 5 tons of carbon sequestration per hectare, creating additional revenue streams for producers and farmers. Policies have shifted from “encouraging use” to “restricting chemical inputs and rewarding biological inputs,” a window of opportunity expected to last at least ten years.

High Profit Margins: Three Proven Profit Models

Raw Material Cost Advantage. The core raw materials for bio-organic fertilizers—livestock manure, straw, kitchen waste, and sludge—are at a negative cost in most areas (the processor pays). For example, the cost of transporting chicken manure from farms is $10 to $30 per ton, while the selling price after processing into organic fertilizer can reach $100 to $180 per ton. The “negative cost + high selling price” price scissors effect at the raw material end creates a profit margin that traditional fertilizers cannot replicate.

Deep processing adds value. Powdered organic fertilizer sells for $60 to $100 per ton, while granulated bio-organic fertilizer, after granulation, the addition of functional bacteria, and the formulation of trace elements, can sell for $150 to $300, representing a value increase of 50% to 200%. Functional products (such as agents for resisting soil-borne diseases and those specifically for phosphorus and potassium solubilizing) command even higher premiums, with selling prices exceeding $500 per ton. The payback period for deep processing equipment is typically 1.5 to 3 years.

Carbon sequestration and brand premium. Organically certified bio-organic fertilizers can command a 30% to 50% brand premium in the EU, North America, and high-end tea, fruit, and vegetable markets. Simultaneously, producers can develop soil carbon sequestration into carbon credits, selling them at $5 to $15 per ton of CO2 equivalent. A 50,000-ton-per-year organic fertilizer plant, covering and improving 20,000 hectares of soil, can generate annual carbon sequestration revenue of $200,000 to $500,000. Bio-organic fertilizer is not a quick-money business; it requires fermentation cycles, microbial cultivation, and farmer education. However, once a raw material collection network, stable fermentation process, and regional brand are established, its competitive advantage will deepen. In the next decade, soil remediation is a definite need, and bio-organic fertilizer is the key to unlocking this underground goldmine.

The core value of bio-fertilizers lies in their live bacteria. However, from the factory to the field, microorganisms undergo multiple trials, including granulation, extrusion, packaging, storage, and long-distance transportation. Survival rates often plummet from 99% at the factory to below 30% during shelf life. How to maintain this “live” fighting power? The answer lies in three key aspects: low-temperature granulation, packaging permeability, and shelf-life management.

Low-Temperature Granulation: Avoiding “Heat Death” of Functional Bacteria

Traditional compound fertilizer granulation uses high-temperature steam or melting processes, where material temperatures can reach 80-120℃, enough to instantly kill most microorganisms. Bio-fertilizers must use low-temperature physical granulation technology.

Process Selection: Disc granulation or roller extrusion granulation are the mainstream solutions. The former uses spray humidification and room-temperature rolling to form spheres, with the material temperature ≤40℃ throughout the process; the latter uses high pressure to directly press semi-wet powder into flakes and then crush and granulate, generating almost no temperature rise.

Temperature Threshold: The lethal temperature for most functional bacteria (Bacillus subtilis, Bacillus mucilaginosa, etc.) is above 60℃. During production, the temperature of the mixer and granulator chambers should be monitored in real time to ensure it does not exceed 50℃. In summer, a cooling system can be installed in the workshop to control the ambient temperature below 25℃.

Carrier Protection: Pre-mixing 5%-10% of an organic carrier (such as humic acid, diatomaceous earth, or defatted rice bran) into the powder can absorb frictional heat and provide a microporous shelter for the bacteria. Actual tests show that adding a carrier can increase the granulation survival rate from 65% to over 85%.

Packaging Permeability: Solving the Problems of “Suffocation” and “Dehydration”

Microorganisms are living organisms that need to breathe oxygen and maintain adequate moisture. Ordinary plastic woven bags lined with polyethylene film have almost zero permeability; live bacteria in a sealed environment will die in large numbers due to lack of oxygen and poisoning from their own metabolites.

Proper Packaging Materials: Use one-way breathable membrane bags or microporous coated woven bags. These materials have a pore size of 0.1-0.5 micrometers, allowing oxygen to slowly enter and carbon dioxide and excess moisture to escape, while blocking external bacteria and liquid water from entering.

Two-Layer Packaging Strategy: The inner layer is a breathable PE film (microporous), and the outer layer is a regular woven bag. Some high-end bio-fertilizers also use paper-plastic composite bags, which naturally offer better breathability but have slightly weaker moisture resistance, making them suitable for dry areas.

Light-Proof Storage: Ultraviolet light kills live bacteria. The packaging bag should have black masterbatch or an outer layer printed with light-blocking ink to prevent direct sunlight exposure.

III. Shelf Life Management: Combating “Starvation” and Decay

Even in suitable packaging, microorganisms will naturally decline over time. Shelf life management is the last line of defense for factories to protect product reputation.

Setting a Reasonable Shelf Life: Powdered bio-fertilizers are usually labeled with a 12-month shelf life, while granular fertilizers, because the bacteria are encapsulated in a matrix, can have a shelf life extended to 18-24 months. However, it is practically recommended to control the shelf life within 6 months, and each batch should be sampled and tested at room temperature before leaving the factory.

Nutritional Dormancy Technology: Adding trehalose, glycerin, or skim milk powder (1%-2%) to the formula can form a glassy protective layer on the surface of the microorganisms, causing them to enter a dormant state, with metabolism almost stopping. The survival rate of dormant bacteria can reach over 90% within six months.

Terminal Reminder Mechanism: Print the “Production Date” and “Use within 30 days after opening” notice in a prominent position on the packaging. It is also recommended that distributors adopt “First-In, First-Out” inventory management to avoid product accumulation during the summer (high temperature and humidity accelerate decay).

Preserving microbial viability throughout the fertilizer production process demands a paradigm shift from conventional thermal manufacturing to biologically sensitive process engineering. The upstream foundation of any robust bio-organic fertilizer production technology begins with optimized organic matter preparation, where advanced fermentation composting turning technology—whether delivered by a high-capacity large wheel compost turning machine or a versatile animal manure compost turner—ensures thorough pathogen elimination and stable substrate formation without compromising the physicochemical properties essential for subsequent bacterial inoculation. Once mature compost is achieved, the transition to low-temperature granulation, breathable packaging, and rigorous shelf-life management forms an integrated preservation chain that safeguards live inoculants from thermal death, oxygen deprivation, and metabolic decay. By treating microorganisms as living production partners rather than passive additives, manufacturers can consistently deliver bio-fertilizers with viable counts that meet label claims and perform reliably in the field—bridging the critical gap between laboratory potency and agricultural efficacy.

What is NPK Fertilizer Solubility?

NPK fertilizer solubility refers to the rate and extent to which nitrogen, phosphorus, and potassium compound fertilizer granules disintegrate in water and release soluble nutrients. Solubility directly determines whether nutrients can be quickly absorbed by crop roots and is a core admission indicator for drip irrigation systems and fertigation facilities. Insufficiently soluble granules will accumulate and clog sprinklers or drippers, causing equipment malfunctions and nutrient waste.

Raw Material Purity: The First Threshold for Solubility

Water-insoluble matter in raw materials is the primary culprit for decreased solubility. Industrial-grade monoammonium phosphate should have less than 0.5% water-insoluble matter, while agricultural-grade may have as high as 2% to 3%. Using phosphorus sources produced by the thermal phosphoric acid process instead of wet-process phosphoric acid products can reduce water-insoluble matter from 1.5% to below 0.3%. For potassium sources, fully water-soluble potassium sulfate or potassium nitrate should be preferred, avoiding the use of low-end potassium chloride containing magnesium chloride impurities. Before raw materials are stored, an additional solubility test is added—the sample is dissolved in 40°C warm water at a 1:10 ratio and stirred for 2 minutes, then visually observed for any turbidity or sediment. For every 1% reduction in water-insoluble matter, the dissolution time of the finished product can be shortened by 15% to 20%.

Granulation Process: From Physical Structure to Disintegration Rate

Traditional steam drum granulation produces dense spherical particles with low internal porosity and long water molecule penetration paths, requiring 8 to 15 minutes for complete dissolution. Using a roller extrusion granulation process results in particles with a porous, irregular structure, increasing the specific surface area by 40% to 60%, and reducing the dissolution time to 3 to 5 minutes. If drum granulation must be used, 3% to 5% urea can be introduced into the formulation as a granulation aid—urea dissolves rapidly in water, forming microporous channels inside the particles and accelerating nutrient release. Another approach is to reduce granulation density: decreasing the filling rate of the drum granulator from 25% to 18% and adjusting the steam pressure from 0.3 MPa to 0.2 MPa increases particle porosity by approximately 12 percentage points, correspondingly accelerating the disintegration rate.

Ultra-fine grinding: Breaking through the dissolution rate bottleneck

For the high-end water-soluble fertilizer market, granule solubility requires achieving a “fully water-soluble” standard—complete dissolution within 2 minutes without residue. This necessitates adding an air-jet milling process before granulation, finely grinding the mixture to 150-200 mesh (particle size 0.075-0.1 mm). After ultra-fine powder granulation, the internal crystal size is small, the water molecule diffusion path is short, and the dissolution rate increases exponentially. Air-jet milling uses high-pressure air (0.6-0.8 MPa) to cause particles to collide and break apart, with a material temperature rise of less than 10 degrees Celsius during the process, avoiding degradation of heat-sensitive components. A matching vortex classifier automatically returns coarse powder to the grinding chamber, ensuring consistent output fineness. Although this process increases energy consumption by approximately 80 to 120 kWh per ton, the product premium can be 2 to 3 times that of ordinary granular fertilizer, making the economic benefits still valid.

Formula Fine-tuning: Chemical Synergy Accelerates Dissolution

Introducing chelated trace elements (EDTA iron, zinc, manganese) into the basic nitrogen, phosphorus, and potassium formula not only improves nutrient availability, but the chelating agent molecules can also complex with calcium and magnesium ions, preventing the formation of insoluble precipitates of phosphates in hard water. For areas with high calcium and magnesium water quality, adding 0.5% to 1% citric acid or ammonium polyphosphate as a co-solvent can increase the clarity of the dissolved solution from 85% to over 98%. The pH value of the formula is controlled within the range of 5.5 to 6.5; a slightly acidic environment is conducive to maintaining the dissolved state of phosphate ions, preventing their conversion to citrate-soluble calcium phosphate under alkaline conditions.

What is the best large-scale chicken manure composting equipment?

Large-scale chicken manure composting equipment refers to a highly efficient, mechanized aerobic fermentation system configured for poultry farms processing over 10 tons of fresh chicken manure per day (equivalent to a farm with 50,000 to 100,000 laying hens). Its core objective is to transform fresh chicken manure with a moisture content of 75% to 80% and a nitrogen content of 2% to 4% into odorless, insect-egg-free, and organic matter-rich mature material with a content of over 45% within 15 to 20 days, providing qualified raw materials for subsequent deep processing of organic fertilizer.

Trough-Type Turning Fermentation System: The Cost-Effectiveness Benchmark for Large-Scale Processing

Trough-type turning machines are the mainstream choice for large-scale chicken manure composting projects. The fermentation trough is constructed of concrete or brick, with a width of 3 to 6 meters, a height of 1.2 to 1.5 meters, and a length of 30 to 80 meters, with PVC perforated ventilation pipes laid at the bottom. The track-mounted turning machine runs back and forth along the trough, using a high-speed rotating blade roller to break up, displace, and convey the material backward, turning it every 1 to 2 days. The forced ventilation system automatically adjusts based on pile temperature feedback—initially, the airflow is 0.2 to 0.3 cubic meters per minute per cubic meter of material, increasing to 0.5 to 0.8 cubic meters per minute during the high-temperature period. This configuration allows the pile to reach 55 to 65 degrees Celsius within 48 hours, maintaining this high temperature for 10 to 12 days, sufficient to kill avian influenza virus, coccidia oocysts, and E. coli. A trough system with a daily output of 20 tons of material requires an investment of approximately US$30,000 to US$60,000, with energy consumption of 0.8 to 1.2 kWh per ton processed. One worker can manage 3 to 5 fermentation tanks. Compared to the rotary turner system, the trough system has a slightly higher civil engineering investment, but it is easier to control air pollution and offers greater operational stability during the rainy season.

Solid-liquid separation pretreatment: a crucial step in dehumidification and impurity removal. Directly adding fresh chicken manure to the tank will result in excessively high moisture content, pore blockage, and anaerobic foul odor. A screw extrusion solid-liquid separator is a standard pre-processor—using a variable-diameter screw to expel free water under pressure of 20 to 30 MPa, reducing the moisture content of solid materials from 80% to 55% to 65%, and decreasing volume by 40% to 50%. The separated liquid contains high concentrations of ammonia nitrogen and can be fed into an anaerobic digester to produce biogas or treated in an oxidation pond for irrigation. For chicken manure containing feathers and bedding impurities, a drum screen (6 to 10 mm mesh) needs to be installed before the separator, achieving a removal rate of over 80%. The solid-liquid separation unit costs approximately US$5,000 to US$12,000, but it can shorten the subsequent fermentation cycle by 5 to 7 days and reduce ammonia emissions by over 60%, resulting in a significant return on investment.

Drum Fermentation Reactor: A Fast-Turn Upgrade Solution

When environmental rating requirements are stringent or land is scarce, the drum fermentation reactor becomes an upgraded alternative to the trough system. This equipment is a closed horizontal rotating cylinder. Material enters from one end and is propelled forward by the slow rotation of the cylinder and the push of internal baffles, compressing the fermentation cycle to 7 to 10 days. The closed structure combined with a biological filter deodorization system reduces ammonia emissions by over 85%. Ventilation can reach 1.0 to 1.5 cubic meters per minute per cubic meter of material, with oxygen supply efficiency 2 to 3 times that of a trough system. However, the equipment investment is 2 to 3 times that of a trough system, with a single unit’s maximum processing capacity of approximately 20 tons per day; large-scale projects require multiple units operating in parallel.

Regardless of the main unit chosen, three auxiliary systems are indispensable. For the deodorization system, the investment in a biological filter or chemical scrubbing tower requires an additional 15% to 25%, especially necessary for facilities near sensitive areas. Regarding the screening and crushing equipment, after fermentation, the material is screened through an 8 to 12 mm screen to remove large pieces, and then crushed to a fineness of less than 3 mm by a semi-wet material crusher before entering the granulation or packaging process. For environmental monitoring, it is recommended to embed temperature probes and oxygen sensors in the fermentation tank, with data connected to a PLC control system to achieve automatic linkage between the turning frequency and ventilation volume.

What is Humic Acid Fertilizer?

Humic acid fertilizer is a type of functional fertilizer made from peat, lignite, or weathered coal rich in humic acid. Through processes such as alkali extraction, acid precipitation, and compounding, humic acid is converted into a form that can be absorbed by plants and combined with nitrogen, phosphorus, potassium, and trace elements. Humic acid has a triple effect of improving soil structure, chelating nutrients, and stimulating root growth, making it a core functional component in the production of high-quality organic-inorganic compound fertilizers. The humic acid content (dry basis) of the raw materials must be no less than 40%, with weathered coal reaching 50% to 70%.

Raw Material Pretreatment: Preparation Before Activation

Solid humic acid raw materials (weathered coal, lignite) need to be crushed and sieved before extraction. A Raymond mill or hammer mill is used to crush the raw materials to 80 to 120 mesh (particle size 0.125 to 0.18 mm). The fineness of the powder directly affects the extraction efficiency—for every 20-mesh increase in specific surface area, the alkali extraction rate increases by approximately 5% to 8%. The pulverized material is collected by a cyclone separator, and the initial humic acid content is tested. Calcium, magnesium, and iron ions in the raw material reduce the solubility of humic acid; therefore, it is recommended to pre-treat with 1% to 2% dilute hydrochloric acid (adding 200 to 300 liters per ton of raw material) before extraction, which can improve the subsequent extraction rate by 10% to 15%.

Alkali Extraction: Dissolution and Separation of Humic Acid

Humic acid forms soluble humate salts under alkaline conditions. The extraction reaction is carried out in a stainless steel reaction vessel equipped with a steam jacket and a stirrer. The process parameters are: solid-liquid ratio 1:8 to 1:12, potassium hydroxide or sodium hydroxide concentration 1% to 2%, reaction temperature 80 to 95 degrees Celsius, and reaction time 60 to 90 minutes. Under alkaline conditions, humic acid is converted into potassium (or sodium) humate and enters the liquid phase, while the residue (coal gangue, quartz, etc.) remains solid. After the reaction, a plate and frame filter press is used for solid-liquid separation. The filtrate is a brownish-red humic acid solution, and the solid residue is discarded or used as packing material. The humic acid extraction rate of the primary extraction is approximately 70% to 85%, and the secondary extraction (re-extraction of the residue) can increase it to 85% to 95%.

III. Acid Precipitation Purification (Optional): High-Purity Product Process

For the production of high-purity humic acid (for water-soluble fertilizers or foliar fertilizers), the alkaline extract can be acid-precipitated. Under stirring conditions, dilute hydrochloric acid or dilute sulfuric acid is slowly added to the extract to adjust the pH to 2.0 to 2.5. The solubility of humic acid drops sharply under acidic conditions, causing it to flocculate and precipitate from the liquid phase. After standing for 1 to 2 hours, the precipitate is collected using a centrifuge or plate and frame filter press and washed with water until neutral (wash water conductivity less than 500 microsiemens per centimeter). Wet humic acid is dried at low temperature (below 70 degrees Celsius) and then pulverized to obtain high-purity humic acid powder (content above 90%). The acid precipitation mother liquor needs to be neutralized before discharge or reuse.

Compounding and Granulation: Formation of the End Product

Humic acid is compounded in different ways depending on the target product form. For humic acid compound fertilizer, humic acid extract (or high-purity humic acid powder) is uniformly mixed with nitrogen, phosphorus, and potassium base fertilizers in a mixer. The mixing ratio is determined according to the product design—the humic acid content is usually 5% to 15%. After mixing, the material has a moisture content of approximately 25% to 35%, and is granulated using a roller extrusion granulator or a disc granulator. For humic acid water-soluble fertilizer, the extract is directly compounded with urea, potassium dihydrogen phosphate, and trace elements in a reaction tank. After heating and dissolving, it is homogenized, filtered, and filled. For humic acid organic fertilizer, the extract is sprayed onto fermented and decomposed organic fertilizer raw materials, mixed, and then dried at low temperature.

Key Equipment Configuration and Investment Reference: A 10,000-ton-per-year humic acid compound fertilizer production line (including an extraction unit) includes the following equipment: Raymond mill (1-2 units), alkali extraction reaction tanks (5-10 cubic meters, 316L stainless steel, 2-3 units), plate and frame filter press (60-100 square meters), concentrator evaporator (triple-effect or membrane concentrator), mixer, granulator, and drying and cooling unit. The total investment is approximately US$200,000 to US$400,000. The extraction and concentration unit accounts for 50% to 60% of the total investment.

In terms of annual operating costs, raw materials (weathered coal) account for approximately 30%, alkali reagents approximately 15%, energy (steam, electricity) approximately 25%, and labor and maintenance approximately 20%. The production cost per ton of humic acid compound fertilizer (10% humic acid content) is approximately US$80 to US$120, the market price is US$150 to US$250, and the gross profit per ton is approximately US$50 to US$130. The investment payback period is typically 3 to 5 years. In regions rich in humic acid resources (such as Shanxi, Inner Mongolia, Xinjiang, North Dakota in the United States, and Siberia in Russia), raw material costs can be further reduced by 20% to 30%.

What is a Mobile windrow composting machine?

A mobile windrow composting machine is a self-propelled aerobic fermentation device that can move freely in open-air or indoor windrow composting machine yards. Unlike trough compost turners that rely on fixed tracks, mobile compost turners straddle the windlass or move along its side, using high-speed rotating cutter rollers or drums to break up, mix, and throw the material backward. Its core advantages are that it requires no civil engineering, has strong site adaptability, and low investment threshold, making it particularly suitable for small to medium-sized organic fertilizer production projects with ample land but limited budgets.

Structural Differences Between Self-Propelled and Towed Types

Self-propelled compost turners integrate a power system, a walking system, and a turning system, allowing for operation by a single operator. Their turning width is typically 2 to 3 meters, and the turning depth is 1.2 to 1.8 meters. They can process 200 to 500 cubic meters of material per hour, suitable for daily processing scales of 20 to 100 tons. Powered by a 60-120 kW diesel engine, the tracked or wide-tire walking mechanism exerts low ground pressure, making it less prone to getting stuck even on soft stacks with a moisture content of 65%. Self-propelled equipment costs between $20,000 and $50,000, making it the preferred option for farms and cooperatives.

Towed compost turners lack their own power source and require a tractor to pull them and provide the power take-off shaft for turning. They have a narrower turning width (1.5 to 2.5 meters), but a simpler structure, lower maintenance costs, and a price only 40-60% of the self-propelled type (approximately $8,000 to $20,000). The disadvantages of the towed option are a large combined turning radius (8-10 meters) and the need for a tractor during turning operations, making it suitable for small farms that only need occasional turning.

Cutter Roller Design and Turning Uniformity Turning uniformity is a core indicator of equipment performance and directly depends on the cutter roller structure. The roller-type compost turner features spirally arranged blades or toothed plates welded to its surface. During rotation, it throws material upwards from the bottom, reaching a height of 1.0 to 1.5 meters, dispersing the material in the air and ensuring full contact with oxygen. The toothed roller type uses individual turning teeth arranged in a V-shape or trapezoidal pattern, providing stronger penetration of high-fiber materials (such as straw compost) and reducing the risk of entanglement. Both designs require wear-resistant alloy blades—when processing livestock manure, the blade lifespan is typically 800 to 1200 hours; after wear, they need to be replaced on one or both sides to extend their service life.

A simple method to judge the uniformity of turning is to measure the temperature distribution of the compost pile before and after turning. Before turning, the temperature difference between the center and edge of the cross-section of the stack can be 15 to 20 degrees Celsius; after one thorough turning, the temperature difference should be reduced to within 5 degrees Celsius.

III. Power Matching and Operating Efficiency The power requirements of the compost turner are positively correlated with its processing capacity. Approximately 25 to 35 kilowatts of power are required per meter of turning width. A machine with a turning width of 2.5 meters is recommended to have a power output of 60 to 80 kilowatts. The travel speed is typically set at 5 to 15 meters per minute—too fast a speed will result in insufficient turning depth and uneven material mixing; too slow a speed will reduce daily processing capacity. At a turning depth of 1.5 meters and a travel speed of 10 meters per minute, a 2.5-meter wide machine can process approximately 225 cubic meters per hour, equivalent to processing a standard windrow measuring 50 meters long, 2.5 meters wide, and 1.5 meters high in one day.

Matching Windrow Dimensions with the Turner: The mobile windrow turner must be precisely matched to the windrow dimensions. The ideal cross-section of the windrow is trapezoidal or triangular: base width 2.5 to 3.5 meters, top width 0.8 to 1.2 meters, and height 1.2 to 1.8 meters. When the stack height exceeds the maximum working depth of the compost turner, the material at the bottom cannot be effectively turned, creating an anaerobic dead zone. When the stack width exceeds the design span of the compost turner, unturned material will remain on both sides. It is recommended to determine the cross-section of the stack before selecting a compost turner, and then choose a model with a turning width and turning depth that are 10% to 15% larger than the cross-section parameters.

In summary, the fermentation composting turning technology embodied by the mobile windrow composting machine represents a practical and scalable solution for modern organic waste management. By integrating a robust power system, precision cutter roller design, and matched windrow dimensions, these machines significantly enhance the composting process for animal manure, ensuring uniform oxygen distribution and accelerated decomposition. For poultry operations, the chicken manure fertilizer machine variant effectively addresses high-moisture, high-fiber feedstock challenges, transforming waste into nutrient-rich organic fertilizer. The animal manure compost turner not only reduces labor intensity but also optimizes the fertilizer production process by maintaining ideal temperature and moisture profiles throughout the aerobic cycle. Whether selecting a self-propelled or towed configuration, operators should prioritize blade wear resistance, power-to-width matching, and site adaptability. Ultimately, the self propelled compost production machine stands out as the preferred choice for farms and cooperatives seeking cost-effective, high-efficiency organic fertilizer manufacturing with minimal civil engineering investment.

What is Poultry Manure Fertilization Treatment?

Poultry manure fertilization treatment refers to a systematic solution that uses specialized pretreatment, fermentation, and granulation machinery to convert manure generated during the raising of poultry such as chickens, ducks, and geese into commercial organic fertilizer. Unlike natural composting, mechanized treatment can shorten the processing cycle from 60-90 days to 15-20 days, while significantly reducing ammonia emissions, killing pathogens, and producing organic fertilizer that meets national standards. Poultry manure (especially laying hen manure) is characterized by high moisture content (70%-80%), high nitrogen content (2%-4%), fine fibers, and easy putrefaction, placing special requirements on equipment selection.

Solid-Liquid Separation and Impurity Removal Module

Poultry manure often contains feathers, feed residue, eggshell fragments, and grit during collection. A drum screen (6-10 mm mesh) effectively separates feathers and coarse residue, achieving a removal rate of over 80%. The undersize material enters a screw extrusion solid-liquid separator, where the moisture content is reduced from 75-80% to 55-65% under high pressure. The separated solid material is reduced in volume by 40-50%, facilitating subsequent fermentation; the liquid portion (high ammonia nitrogen concentration) can be used to produce biogas in an anaerobic digester or treated in a multi-stage oxidation pond to meet standards before irrigating farmland.

Auxiliary Material Proportioning and Mixing Module: Poultry manure has a low carbon-to-nitrogen ratio (approximately 10:1 for chicken manure and 12:1 for duck/goose manure), requiring the addition of high-carbon auxiliary materials to adjust to a suitable range (25:1 to 30:1). An automatic batching system precisely controls the amount of auxiliary materials added. Recommended ratio: 80-120 kg of chopped straw or 40-60 kg of rice husks per ton of wet chicken manure. A twin-shaft paddle mixer thoroughly mixes poultry manure with auxiliary materials for 3 to 5 minutes, requiring a uniformity coefficient of variation of less than 10%. After mixing, the moisture content of the material should be reduced to 55% to 65%, and the carbon-to-nitrogen ratio should be increased to above 25:1.

III. Tank-type Aerobic Fermentation Module: The mixed materials enter the tank-type fermentation system. The fermentation tank is 3 to 5 meters wide and 1.2 to 1.5 meters high, with PVC perforated pipes at the bottom for forced ventilation (airflow rate of 0.3 to 0.6 cubic meters per minute per cubic meter of material). A track-mounted turner turns the pile every 1 to 2 days, raising the pile temperature to 55 to 65 degrees Celsius within 48 hours and maintaining this temperature for 10 to 12 days to kill avian influenza virus, coccidia oocysts, and E. coli. The fermentation cycle for chicken manure is 18 to 25 days, while for duck and goose manure, due to its slightly coarser fibers, it requires an extended period of 22 to 28 days. After fermentation, the material is dark brown, odorless, and loose in texture.

Aging, Crushing, Granulation, and Packaging Module The fermented material requires aging for 7 to 10 days to stabilize pH and moisture content. After aging, the material is crushed in a semi-wet material crusher (90% fineness passing through a 3mm sieve), and then impurities are removed by a drum screener (2 to 4mm sieve openings). For granulation production, a roller extrusion granulator is recommended—the granules produced from fermented poultry manure can achieve a strength of 12 to 20 Newtons, allowing for packaging without drying, thus eliminating the energy-intensive drying process. The finished product is automatically packaged into 25kg or 50kg bags.

From Poultry Waste to Standardized Organic Input

What is Specialized Fertilizer Equipment for Ecological Agriculture?

Specialized fertilizer equipment for ecological agriculture refers to fertilizer production equipment that focuses on the resource utilization of organic waste while considering soil health and environmental carrying capacity. Unlike conventional fertilizer equipment, ecologically oriented equipment emphasizes low-temperature processes, low-energy operation, and the positive regulatory function of products on the soil microecology. Its output includes organic fertilizer, bio-organic fertilizer, and organic-inorganic compound fertilizer, among other inputs that meet green planting standards.

Trench Turning Machine: The Core of Low-Energy Aerobic Fermentation

In the ecological agricultural system, aerobic fermentation is the bridge connecting livestock waste and planting needs. The trough turning machine, with its low energy consumption and high controllability, has become the standard configuration for this stage. Compared to the disc turning machine, the energy consumption per ton processed by the trough solution is only 0.8 to 1.2 kWh, approximately 60% to 70% of the former. A forced ventilation system is installed at the bottom of the fermentation tank, automatically adjusting the airflow according to the pile temperature—0.3 to 0.5 cubic meters per minute per cubic meter of material in the initial stage, increasing to 0.8 to 1.2 cubic meters per minute during the high-temperature period. This precise oxygen supply strategy can control ammonia volatilization loss to within 5%, significantly higher than the 15% to 25% nitrogen loss rate of natural composting. The fermentation cycle is 15 to 25 days, and the organic matter content after decomposition can reach over 45%.

Roller Extrusion Granulator: Additive-Free Dry Forming Ecological agriculture has strict restrictions on fertilizer additives. The roller extrusion granulator uses a purely physical forming principle, requiring no chemical binders or additional moisture, perfectly aligning with the ecological principle of “low input, low output.” Raw materials are compacted into granules under a linear pressure of 150 to 250 MPa, with a granule strength of 15 to 25 Newtons and a pulverization rate of less than 3%. More importantly, the extrusion process does not generate high temperatures—the particle temperature rises only 15 to 20 degrees Celsius above the ambient temperature, avoiding the inactivation of heat-sensitive microbial agents (such as Bacillus subtilis and phosphate-solubilizing bacteria). For bio-organic fertilizer products that need to simultaneously provide organic matter and functional bacteria, the survival rate of live bacteria after extrusion granulation can reach over 85%, while the survival rate of steam drum granulation is usually below 50%.

III. Low-Temperature Belt Dryer: Gentle Drying to Retain Nutrients Ecological fertilizers place new demands on the drying process: it must reduce moisture content to facilitate storage and transportation, while avoiding the destruction of organic matter and microbial activity due to high temperatures. The low-temperature belt dryer adopts a layered circulating hot air design. The material moves slowly on multiple layers of stainless steel mesh belts, with the hot air temperature controlled between 60 and 80 degrees Celsius, and the discharge temperature not exceeding 45 degrees Celsius. Compared to traditional rotary dryers (inlet temperature 300-400 degrees Celsius), the low-temperature belt dryer reduces organic matter loss from 12%-18% to 3%-5%, and increases microbial survival rate from less than 40% to over 70%. Although its energy consumption is 15%-20% higher than high-temperature drying, the resulting highly active organic fertilizer commands a 30%-50% premium, making it economically viable. A biomass hot air furnace or a solar-assisted system can be used as the heat source to further reduce the carbon footprint.

Comparison of Benefits between Ecological and Traditional Equipment: Based on a 10,000-ton-per-year organic fertilizer production line, the initial investment for an ecological equipment combination (trough turning + roller extrusion + low-temperature belt drying) is approximately US$120,000 to US$180,000, about 15%-25% higher than the traditional equipment combination (disc turning + drum granulation + rotary drying). However, in terms of operating costs, the eco-solution can save approximately $15,000 to $25,000 annually in chemical binder procurement costs (based on a 3% addition rate and $200 per ton), and approximately $8,000 to $12,000 in nitrogen loss costs. More importantly, the fertilizer produced by the eco-solution is eligible for organic certification, and the premium at the end-market price can contribute an additional $30,000 to $60,000 in annual profit. The payback period is typically 2.5 to 4 years, roughly the same as conventional solutions, but the long-term returns in soil health and brand value far exceed those of traditional pathways.

Engineering Soil Health Through Low-Impact Processing

Specialized fertilizer equipment for ecological agriculture represents a paradigm shift from conventional high-temperature, additive-intensive manufacturing to processes that preserve biological activity and minimize environmental footprint. At the fermentation stage, advanced fermentation composting turning technology—whether deployed through a precision trough-type compost turner with forced ventilation and ammonia control, or a flexible windrow composting machine for open-field operations—ensures that livestock waste decomposes aerobically with nitrogen losses below 5%. For nitrogen-dense poultry streams, a dedicated chicken manure fertilizer machine workflow optimizes thermophilic phases, while a versatile animal manure compost turner adapts to mixed dairy and swine substrates across varying scales. Once stabilized, the compost enters a low-impact fertilizer production process featuring roller extrusion granulation and low-temperature belt drying, which together retain >85% microbial viability and reduce organic matter loss to under 5%. Although the initial capital outlay for ecological equipment exceeds traditional alternatives by 15%–25%, the elimination of chemical binders, reduced nitrogen volatilization, and organic certification premiums generate annual savings and revenue uplift that compress payback periods to 2.5–4 years. Ultimately, this equipment architecture does not merely produce fertilizer—it cultivates soil microbiome resilience, closes agricultural waste loops, and delivers measurable long-term value that transcends short-term yield metrics.

What is Rapid Fermentation?

Rapid fermentation refers to a technical system that compresses the natural fermentation cycle of livestock and poultry manure from 60-90 days to 15-25 days by adjusting parameters such as the carbon-to-nitrogen ratio, moisture content, oxygen supply, and microbial population. Its core objectives are to achieve harmlessness (killing insect eggs and pathogens), stabilization (reducing ammonia and odor emissions), and humification (forming stable organic matter), providing qualified raw materials for subsequent organic fertilizer production.

Carbon-to-Nitrogen Ratio Adjustment: Optimizing the Microbial Diet High nitrogen content and insufficient carbon in manure, resulting in an imbalanced carbon-to-nitrogen ratio, is the primary reason for slow aerobic fermentation. The ideal initial carbon-to-nitrogen ratio is 25:1 to 30:1. Fresh chicken manure has a carbon-to-nitrogen ratio of approximately 10:1, requiring adjustment by adding 80-120 kg of chopped straw (carbon-to-nitrogen ratio approximately 60:1) or 150-200 kg of rice husks (carbon-to-nitrogen ratio approximately 70:1) per ton. The carbon-to-nitrogen ratio of cow manure is approximately 20:1, so the amount added should be halved. The calculation method is: Target addition amount = Manure mass × (Target carbon-to-nitrogen ratio – Manure carbon-to-nitrogen ratio) / (Additive carbon-to-nitrogen ratio – Target carbon-to-nitrogen ratio). After adjustment, the fermentation start-up time of the material can be shortened from 5-7 days to 24-36 hours.

Moisture Control: The Activity Medium for Aerobic Bacteria. Microbial activity is inhibited when the moisture content is below 40%, and above 70%, the pores are filled with water, leading to oxygen deficiency. The optimal range is 55% to 65%. Fresh chicken manure has a high moisture content of 75% to 80%, requiring adjustment in three ways: adding straw additives with a moisture content of 10% to 15% (100-150 kg per ton of manure); spreading it out in the sun for 3-5 hours to reduce the moisture content to around 65%; or using a solid-liquid separator to reduce the moisture content to 60% to 65%. Judgment criteria: The material should clump together when squeezed in the hand, with moisture between the fingers but not dripping, and naturally disperse upon landing. For every 5 percentage points above the optimal range, the fermentation cycle is extended by approximately 3 to 5 days.

III. Forced Ventilation: From Passive to Active Oxygenation

Traditional windrow composting relies on natural convection and turning for oxygen supply, with an oxygen diffusion depth of only 30 to 50 centimeters, easily leading to an anaerobic zone in the center of the pile. Forced ventilation delivers oxygen to the core of the pile. The bottom of the trough-type fermentation system is equipped with perforated PVC pipes (5 to 10 mm diameter, 15 to 20 cm spacing), and the blowers operate intermittently—ventilating for 30 minutes and then pausing for 60 minutes, with an airflow of 0.2 to 0.5 cubic meters per minute per cubic meter of material. Forced ventilation can bring the high-temperature period forward by 3 to 5 days, reducing the pile temperature uniformity from ±8 degrees Celsius to within ±3 degrees Celsius.

Fermentation tanks (drum or vertical) offer the most efficient oxygen supply, as the material continuously tumbles within the sealed container and comes into contact with the forced airflow. Ventilation can be increased to 1.0 to 1.5 cubic meters per minute per cubic meter of material, compressing the fermentation cycle to 7 to 12 days. However, the equipment investment is 2 to 3 times that of a trough system.

Exogenous Microbial Inoculation: Targeted Enhancement of Functional Microbiota Natural fermentation relies on the existing microorganisms in the feces, requiring 3 to 7 days to establish a population. Inoculating with exogenous fermentation agents can shorten this adaptation period to within 24 hours. Commercial fermentation agents typically contain: thermophilic bacteria (accelerate organic matter degradation), actinomycetes (decompose cellulose), yeast (produce enzymes), and lactic acid bacteria (inhibit putrefactive bacteria). The inoculation amount is 0.5 to 1 kg per ton of material (with a viable bacterial content of no less than 1 billion per gram). The effect is reflected in three indicators: the onset time is shortened from 72 hours to 24 hours, the maximum temperature is increased from 55 to 60 degrees Celsius to 65 to 70 degrees Celsius, and the duration of the high-temperature period is extended by 2 to 3 days—which is precisely the optimal window for killing insect eggs and pathogens.

Turning Frequency: A Lean Accelerator in Traditional Methods

Increasing the turning frequency is the most direct way to accelerate fermentation without increasing equipment investment. In windrow composting, the conventional turning frequency is once every 5 to 7 days. A rapid fermentation program adjusts this to: turning once a day from days 1 to 3 (to promote temperature rise), turning once every 2 days from days 4 to 10 (to maintain high temperature), and turning once every 3 to 4 days from days 11 to 20 (to cool and mature the compost). A self-propelled compost turner can process 200 to 500 tons of material per hour, with a turning depth of 1.2 to 1.8 meters. Each ton of material consumes approximately 0.5 to 0.8 kWh of electricity during turning, but can shorten the overall fermentation cycle by 30% to 40%.

Quality Verification Indicators for Rapid Fermentation

After fermentation, the material must meet the following four standards before entering the organic fertilizer production stage: Temperature drops to ambient temperature plus or minus 5 degrees Celsius and does not rise again; color is dark brown or blackish-brown, without the original manure color; odor is earthy or slightly ammonia-like, without putrid or fecal odor; seed germination index is not less than 70% (using the fermented material extract to cultivate cucumber or radish seeds, comparing germination rate and root length after 48 hours). It is recommended to take 3 to 5 samples from each batch to test the above indicators. If any indicator fails to meet the standard, extend the fermentation period by 5 to 7 days and retest.

We provide a complete set of rapid fermentation equipment and auxiliary material solutions, including a trough-type compost turner, forced ventilation system, and exogenous fermentation agents. We can also customize the carbon-nitrogen ratio, turning frequency, and ventilation parameters free of charge according to your manure type and site conditions, helping you reduce the fermentation cycle from 60 days to 15 to 25 days and stably reach the decomposed standard.

Accelerating the Biological Conversion Pipeline

Standard Procedures for Raw Material Pre-treatment: Although large wheel compost turning machines possess powerful turning capabilities, raw material pre-treatment is still indispensable. Fresh manure such as chicken and pig manure requires solid-liquid separation to reduce the moisture content from over 80% to below 70%. Corn stalks, wheat straw, and other straws need to be crushed to 10-20 cm in length using a shredder; excessive length will affect the uniformity of turning, while insufficient length will reduce the permeability of the pile. Industrial waste such as distiller’s grains and medicinal residues require manual removal of impurities such as metal and plastic. During the batching process, the carbon-to-nitrogen ratio needs to be adjusted to between 25 and 30:1; a too-high carbon-to-nitrogen ratio slows down fermentation temperature rise, while a too-low ratio results in significant ammonia loss.

Operating Parameters for Pile Construction and Turning: The cross-section of the windrows is trapezoidal or triangular, with a base width of 5-8 meters, a top width of 1.5-2.5 meters, and a height of 1.5-2 meters. The pile length can be flexibly determined according to the site conditions, typically 50-100 meters. The spacing between piles is 3 to 5 meters to ensure sufficient space for equipment passage while avoiding interference between adjacent piles. The initial turning is performed when the pile temperature reaches 50 to 60 degrees Celsius, typically on the 1st to 3rd day after pile construction. During the high-temperature period, turning is done every 2 days, for a total of 3 to 4 times. During the cooling period, turning is done every 3 to 4 days, for a total of 2 to 3 times. After each turning, the material is completely rotated from top to bottom of the pile to ensure uniform fermentation.

Production Line Integration and Continuous Production

In organic fertilizer production lines with an annual output of over 100,000 tons, the rotary turner can achieve continuous production through multi-pile rotation: one pile receives new material for initial fermentation, one pile is in the high-temperature period, and one pile is in the cooling and maturation period. The equipment operates sequentially between piles according to a fixed cycle, with a daily processing capacity of 800 to 1500 tons. The matured material is then transported by a loader to subsequent crushing, screening, and granulation processes, forming a complete pretreatment-large-scale fermentation-deep processing production chain.

Orchestrating Continuous Fermentation at Industrial Scale

The integration of a large wheel compost turning machine into a high-capacity organic fertilizer operation transforms discrete batch fermentation into a continuous, pipeline-style biological conversion system. Through disciplined fermentation composting turning technology—including precise raw material pretreatment, controlled windrow geometry, and phased turning protocols—this compost turner machine achieves daily throughputs of 800 to 1,500 tons while maintaining thermophilic stability across the entire composting process for animal manure. Whether processing nitrogen-dense poultry litter through a dedicated chicken manure fertilizer machine workflow or managing mixed livestock waste via a versatile animal manure compost turner, the multi-pile rotation strategy ensures that initial fermentation, high-temperature decomposition, and cooling maturation proceed in parallel without interruption. Once stabilized, the matured compost feeds seamlessly into downstream crushing, screening, and granulation stages, completing the fertilizer production process from waste reception to marketable product. Within the broader fertilizer manufacturing process, this fermentation stage also serves as a critical input for fertilizer chemical formula processing, where organic matter is blended with inorganic nutrients to create compound formulations. By synchronizing turning frequency with pile temperature profiles and linking fermentation output directly to material handling logistics, operators convert what was once a seasonal, weather-dependent activity into a year-round, industrially calibrated fertilizer production process that underpins both standalone organic fertilizer sales and integrated compound fertilizer manufacturing.

What is Large-Scale Farm Composting Equipment?

Large-scale farm composting equipment refers to mechanized aerobic fermentation systems configured for livestock or agricultural settings processing over 10 tons of organic waste per day (equivalent to the excrement of 500 dairy cows or 3000 pigs). Its core function is to rapidly decompose livestock manure, straw, and vegetable waste under controlled conditions, transforming them into stable organic fertilizer.

TroughCompost Turner: The Benchmark for Cost-Effectiveness in Large Farms

The trough compost turner is currently the most widely used composting solution in large farms worldwide. Its system consists of: a concrete or brick fermentation trough (typically 3 to 6 meters wide, 1.2 to 1.8 meters high, and the length can be extended to 30 to 80 meters depending on the daily processing capacity), a track-mounted compost turner, and a forced ventilation duct at the bottom. The turner travels back and forth along the track, using rollers to break up, displace, and convey the material backward. According to process data, the fermentation cycle of a trough system is approximately 15 to 25 days, with energy consumption of only 0.8 to 1.2 kWh per ton of raw material processed. Equipment investment is at a moderate level among the three mainstream options—a configuration with a daily output of 20 tons requires approximately $30,000 to $60,000. Its biggest advantage lies in its mature technology and simple operation; one worker can manage multiple fermentation tanks.

Rotary Drum Fermentation Reactor: The Fastest Solution with the Smallest Footprint When farms face land scarcity or strict environmental odor controls, the rotary drum fermentation reactor becomes an alternative. This equipment is a closed, horizontal rotating cylinder. Material enters from one end and is propelled forward by the slow rotation of the cylinder and the action of internal baffles, compressing the fermentation cycle to 7 to 10 days. The closed structure, combined with a biological filter deodorization system, can reduce ammonia emissions by more than 85%. However, the cost is a higher unit investment—for the same processing capacity, the equipment cost of a rotary drum reactor is approximately 2 to 3 times that of a trough system, and the maximum processing capacity of a single unit is typically around 20 tons per day; very large farms may require multiple units in parallel. Suitable for large-scale farms with high land prices, proximity to residential areas, or strict environmental rating requirements.

III. Windrow compost Turner: The Most Flexible and Lowest Threshold Option Windrow composting is the simplest form: materials are piled into long, strip-shaped heaps (trapezoidal cross-section, 3-5 meters wide at the base and 1.2-1.5 meters high), and periodically turned by a towed or self-propelled turner. Compared to trough systems, windrow composting requires no civil engineering investment, only a hardened ground surface, reducing equipment purchase costs by 40-60%. However, the trade-off is a longer fermentation cycle of 40-60 days, more than double the required floor space, and a slower turner speed—processing the same 100-meter-long heap takes approximately three times longer with a trough turner. Furthermore, controlling moisture content is difficult during open-air operation in the rainy season, making windrow composting more suitable for arid climates or farms with ample land.

The Importance of Auxiliary Equipment

Regardless of the main unit chosen, the following three auxiliary systems directly determine compost quality: Forced ventilation system – perforated ducts buried at the bottom of the fermentation tank, with a recommended ventilation rate of 30 to 60 cubic meters per square meter per hour, precisely controlling the oxygen concentration in the compost pile between 8% and 15%; Deodorization system – for facilities near sensitive areas, investment in biological filters or chemical scrubbing towers requires an additional 15% to 25%; and screening and crushing equipment – ​​after fermentation, the coarse compost needs to be screened (usually using 8 to 12 mm screens) and crushed before it can be sold as commercial organic fertilizer or further granulated.

Optimal Matching Recommendations for Different Scales

Based on the typical capacity requirements of large-scale farms, the recommended solutions are as follows: For daily processing of 10 to 30 tons of organic waste, a trough-type compost turner offers the best overall cost-effectiveness, with controllable total investment in civil engineering and equipment, and the lowest operating and maintenance costs. For daily processing of 30 to 60 tons, a configuration of dual parallel troughs or a single wide trough with a large compost turner can be used, with unit processing costs decreasing as the scale increases. For daily processing capacities exceeding 60 tons or requiring an AAA environmental rating, a combination of rotary drum fermentation reactors and trough systems should be considered. The rotary drum handles the rapid degradation during the primary fermentation stage, while the trough system handles the stabilization during the post-fermentation stage. The overall investment payback period is typically controlled within two to three years.

Selecting the optimal composting system for large-scale livestock operations demands a rigorous trade-off analysis among fermentation speed, capital intensity, land availability, and environmental compliance. At the foundation of every successful deployment lies advanced fermentation composting turning technology calibrated to the specific waste stream—whether processing nitrogen-rich poultry litter through a dedicated chicken manure fertilizer machine workflow, or managing bulky fiber-laden dairy waste via a cow manure fertilizer machine configuration. For operations processing 10–30 tons daily with moderate budgets and ample space, a trough-type compost turner anchored in concrete fermentation lanes delivers the benchmark cost-effectiveness, compressing the composting process for animal manure to 15–25 days with energy consumption below 1.2 kWh per ton. When land scarcity or stringent odor regulations dominate decision-making, the large wheel compost turning machine or closed rotary drum reactor—though commanding 2–3× the unit capital—achieves 7–10 day cycles and >85% ammonia reduction, justifying the premium in high-density agricultural zones. Conversely, for arid-region farms with surplus land and minimal environmental pressure, a flexible windrow composting machine or towed animal manure compost turner eliminates civil engineering entirely, reducing upfront investment by 40–60% while extending the cycle to 40–60 days. Regardless of the primary compost turner machine selected, integrating forced ventilation, deodorization, and post-fermentation screening transforms raw waste stabilization into a commercially viable organic fertilizer production platform—delivering pathogen-free, humus-rich outputs that close the nutrient loop between livestock operations and crop production.

What is a large wheel compost turning machine?

A large wheel compost turning machine is a fermentation treatment device used in large-scale organic fertilizer production. It uses a rotating wheel with a diameter of several meters as its core working component, for turning and mixing materials. Its core working principle is: the continuous rotation of the wheel drives the turning teeth on its edge to throw, break up, and re-pile the material in a windrow-like shape, allowing the material to fully contact the air, regulating the temperature and humidity of the pile, and accelerating the aerobic decomposition and maturation process of microorganisms.

Processing Capacity and Applicable large wheel compost turning machineshave a large coverage area in a single operation, processing 100 to 200 tons of material per hour, which is 3 to 5 times the processing capacity of tracked compost turners. This characteristic makes it particularly suitable for large-scale organic fertilizer production bases with an annual output of over 10,000 tons. According to process data, a single unit can complete the turning operation of 500 to 1000 tons of material per day, significantly reducing the labor and time costs of large-scale fermentation. Compared to trough-type compost turners, the disc-type system eliminates the need for concrete fermentation tanks, increasing site utilization by approximately 30%.

Applicable Raw Material Types The large wheel compost turning machine’s powerful turning capacity efficiently processes a variety of organic raw materials. For livestock manure, it can process chicken, pig, and cow manure from large-scale farms, using high-temperature fermentation to kill pathogens and insect eggs, with a daily processing capacity of several hundred tons. For crop straw, it can process corn stalks, wheat straw, and rice straw, breaking up bundles of straw and mixing them evenly with manure to promote cellulose degradation. It can also process industrial organic waste such as distiller’s grains, sugar residue, and medicinal residue, as well as municipal sludge and garden waste that have passed quality testing.

III. Core Components and Maintenance Points The disc body is welded from high-strength steel, typically with a diameter of 5 to 10 meters. Turning teeth are evenly distributed along the edge, and the rotation speed is controlled at 10 to 20 revolutions per minute. The turning teeth are made of wear-resistant alloy steel and should be replaced promptly when wear exceeds one-third of their original length. The walking mechanism is equipped with large-diameter wide tires or tracks, resulting in low ground pressure and adaptability to soft ground. The power system includes a wheel drive motor (30 to 75 kW) and a walking drive motor (15 to 30 kW), available in both diesel and electric power options. Routine maintenance includes daily checks for looseness and wear of the turning teeth, weekly checks for transmission component lubrication, and monthly checks for wheel welds and structural deformation.

Scaling Aerobic Fermentation with Industrial Precision

The large wheel compost turning machine represents a decisive evolution in fermentation composting turning technology, bridging the gap between artisanal composting and industrial-scale organic waste valorization. By processing 100–200 tons per hour across open windrows, this equipment eliminates the civil infrastructure burden of trough systems while delivering the aeration intensity required for high-throughput composting process for animal manure—whether managing nitrogen-rich streams from poultry operations via a dedicated chicken manure fertilizer machine workflow, or processing bulky fiber-laden substrates through a cow manure fertilizer machine configuration. The wheel’s rotating teeth achieve thorough pulverization and homogenization, accelerating thermophilic phases and pathogen inactivation across diverse feedstocks including straw, distiller’s grains, and municipal sludge. For operations not yet requiring disc-scale throughput, a versatile windrow composting machine offers comparable aeration logic with lower capital commitment. Once fermentation reaches maturation, advanced fertilizer granulation technology transforms stabilized compost into uniform, marketable pellets—completing the circular journey from waste stream to agronomic input. By matching turning equipment capacity to raw material volume and site constraints, producers build a scalable bioconversion platform that converts environmental liability into sustained soil fertility value.

The Role of the large wheel compost turning machine in the Fermentation Process

The large wheel compost turning machine is the core equipment in the fermentation process of an organic fertilizer production line. Its function is to aerobically ferment pre-treated raw materials in windrows, completing the harmless and stabilization process. Compared to traditional trough fermentation, the large wheel compost turning machine solution requires no civil engineering and has a wider single-turn width, making it more suitable for large-scale production bases with relatively abundant land resources.

Four Key Stages of Fermentation Operation

The first stage is raw material pretreatment. Livestock and poultry manure undergoes solid-liquid separation to reduce the moisture content to below 70%. Straw is shredded to a length of 10 to 20 centimeters. Industrial waste needs to have impurities such as metal and plastic removed. The materials are mixed at a carbon-to-nitrogen ratio of 25 to 30 to 1, and the initial moisture content is adjusted to 55% to 60% by adding straw or manure. The second stage is windrow construction. The pre-treated materials are piled into windrows 5 to 8 meters wide and 1.5 to 2 meters high, with a 3 to 5-meter passageway between the windrows for equipment movement. The third stage is turning and fermentation. Start the large wheel compost turning machine, adjust the wheel height to be level with the top of the windrow, and slowly move the equipment along the length of the windrow. Initial fermentation lasts 1-3 days, with the first turning performed when the pile temperature reaches 50-60 degrees Celsius; the high-temperature period lasts 4-10 days, with turning every two days when the pile temperature reaches 60-70 degrees Celsius; the cooling period lasts 11-25 days, with turning every three- to four days when the pile temperature drops to 40-50 degrees Celsius. The entire fermentation cycle is 20-30 days. The fourth stage is maturity assessment. Maturity is complete when the pile temperature is close to ambient temperature, the material is dark brown, odorless, and has a faint earthy smell.

Quantitative Expression of Process Advantages: The large wheel compost turning machine can turn to a depth of 1.5-2 meters, ensuring thorough mixing of materials between layers and a temperature difference of no more than 2 degrees Celsius within the pile. Compared to manual turning or small equipment, it can reduce labor costs by 50-70%, and the energy consumption per unit of material is 20-30% lower than traditional equipment. We provide large wheel compost turning machines and complete fermentation process packages, from raw material pretreatment and proportioning to composting cycle control. We can also customize composting parameters and composting frequency schemes free of charge according to your raw material’s carbon-nitrogen ratio and moisture content, helping you achieve a stable and efficient fermentation cycle of 20 to 30 days with standardized operations.

Scaling Aerobic Fermentation with Precision Turning