The quality inspection of organic fertilizer granulation is a key link to ensure that the product meets standards, guarantees application effectiveness and safety. It needs to be carried out around four dimensions: physical properties, chemical indicators, biological safety, and application applicability, covering comprehensive verification from particle appearance to internal composition. The following are specific testing items, methods, and judgment criteria (referring to the GB/T 19524.1-2021 standard for organic fertilizers):

Physical property testing: determining particle stability and ease of use

The physical properties directly affect the storage, transportation, and field application of organic fertilizers (such as whether they are easy to break and whether they are evenly spread), with three core testing indicators:

1. Particle appearance and uniformity

Purpose of testing: To determine whether the particles have formed, whether there are impurities, and whether the particle size meets production requirements.

Testing method:

Judgment criteria:

2. Particle compressive strength

Purpose of testing: To determine whether particles are easily broken during storage and transportation (low compressive strength can lead to excessive dust and affect application).

Testing method:

Judgment criteria:

3. Moisture content

Purpose of testing: Excessive moisture content can easily lead to particle moisture absorption, agglomeration, and mold growth; If it is too low, the particles will be fragile and affect the stability of organic matter.

Testing method: Using the "oven drying method" (method specified in GB/T 19524.1-2021):

Judgment criteria: The moisture content of organic fertilizer particles should be ≤ 30% (in actual production, it is usually controlled at 8% -15% for easy storage, at which point the particles do not absorb moisture or clump).