Organic Matter有机质
Soil organic matter is the carbon-containing material in soil derived from plant and animal residues and their decomposition products. It is one of the core indicators of soil fertility. In fertilizer products, organic matter content is an indicator separate from total nutrient content.
Key points
- Organic matter and total nutrients in a product are two independent indicators and must not be counted into one another; GB 18382-2021 requires separate declaration.
- Under NY 884-2012, bio-organic fertilizer must contain at least 40% organic matter (dry basis); the organic fertilizer standard NY/T 525-2021 requires at least 30% organic matter (oven-dry basis) and at least 4.0% total nutrients.
- Organic matter improves soil structure, water and nutrient retention and cation exchange capacity. It is a slow variable, and its short-term yield effect is less obvious than that of chemical fertilizer.
- More is not automatically better: undecomposed material with a high C/N ratio competes with the crop for nitrogen and can cause nitrogen deficiency at the seedling stage.
Related terms
Organic Fertilizer
An organic fertilizer is a carbon-containing material derived mainly fro…
Bio-organic Fertilizer
A bio-organic fertilizer combines specific functional micro-organisms wi…
Organic-Inorganic Compound Fertilizer
An organic-inorganic compound fertilizer is made by adding organic mater…
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Category and source
- Category：Soil
- Definition basis：NY/T 525-2021 Organic fertilizers
Updated：Oct 19, 2026