2025/11/21
The "problem chain" in organic fertilizer production process is concentrated in four stages: fermentation, equipment, raw materials, and post-processing:
Fermentation Stage:
* Slow heating: Moisture content < 45% or C/N ratio > 35, low bacterial activity; moisture content > 65% and lack of oxygen, also resulting in slow heating.
High temperature > 65℃: Oversized pile, insufficient turning, shrinking the aerobic zone, killing beneficial bacteria.
Foul odor: C/N ratio < 20, ammonia volatilization, or pH > 8.5, large amounts of hydrogen sulfide produced; if anaerobic, the rotten egg smell is stronger.
Flies and caking: Fresh manure not covered on the surface of the raw materials in time, low turning frequency, forming a surface breeding zone; large pieces of straw not crushed cause airflow short circuits, resulting in "cold core" caking.
Equipment Stage:
70% of fermentation compost turning machine failures originate from hydraulic oil—insufficient oil level, oil temperature > 70℃, or the presence of metal shavings, leading to weak operation and crawling.
Organic fertilizer granualtors often encounter problems such as "sticking to the mold, clogging, and uneven granulation," mostly due to excessively high moisture content in the raw materials, decreased mold smoothness, or improper speed-pressure matching.
Post-processing and storage/transportation: Insufficient cooling after drying, with granules exceeding 40℃ before bagging, leads to external moisture migration, resulting in surface condensation and crusting after 5-7 days.
Poor packaging sealing causes moisture absorption during storage and transportation, reducing granule crush resistance by more than 30%, and causing clogging at the fertilizer inlet during application.
Transportation costs are higher than for chemical fertilizers (railways do not enjoy preferential freight rates), and ammonia volatilization losses in the stockpile during the off-season can reach 8-12% of total nitrogen.
Solutions: First, "stabilize fermentation"—moisture content 50±5%, C/N ratio 25-30, oxygen >10% after turning; second, "control equipment"—online filtration of hydraulic oil, moisture content ≤35% before granulation; finally, "strong cooling + moisture-proof packaging + shaded storage," which can reduce the rework rate to below 3%.
