Part 1 introduces soil fertility improvement materials approved in organic agriculture under PGS Standards. A = allowed; R = restricted, must be approved by PGS prior to use.
Part 1: Soil fertility improvement inputs
Conditions for using fertilizers and soil conditioning materials
| Inputs | A/R | Details and conditions |
|---|---|---|
| Animal manure | R | All animal manure must be hot composted or thoroughly dried before use. Do not use manure from commercial farms; manure from smallholder livestock or naturally grazed animals may be used if properly processed in accordance with regulations. |
| Wood ash | R | Only use ash from wood as a source of potassium. It should be used regularly in small amounts, stored covered, and mixed with finished compost to avoid raising soil pH. |
| Compost | A | Materials should be collected on the farm; do not use municipal waste. Straw, rice husks, green plant matter, animal manure, and coffee husks may be added from external sources. The compost pile must reach above 60°C for 8–15 days and be turned when it begins to cool. |
| Microbial fertilizer | R | Only use products approved by PGS; microbial fertilizers derived from peat are prohibited. |
| Mineral fertilizer | R | Only use certified or approved sources and use solely as a supplement; rock phosphate must be ground very finely before application. |
| Sedimentary rock | A | Used as a soil supplement when needed. |
| Limestone | A | Used as a soil supplement when needed. |
| Rice husks | A | Used as mulch or composting material to retain nutrients. |
| Straw, stubble | A | Used for composting or soil mulching. Bedding straw from livestock must be hot composted before field application. |
| EM (vi sinh có ích) | A | Liquid EM is allowed for use. |
| Micronutrients | R | Prioritize natural mineral sources. Synthetic nutrients may only be used when plants and soil exhibit clear deficiencies; do not use nitrates and chlorides. |
| Legume plant material | A | Leaves and branches of legumes such as sesbania, coral tree (vông), wild peanut, senna (muồng), and pigeon pea can be used for base mulching or composting. |
| Mushroom substrate | R | Only use when the substrate has not been treated with fungicides to kill spores. |
| Molasses | A | Used when composting green materials as a food source for microorganisms. |
| Vermicompost, worm castings, and worm liquid | A | Prioritize raising worms with plant waste. Vermicompost can be applied directly, or dilute one liter of worm liquid with 10–20 liters of water for irrigation. |
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