Burned rice husk is fully carbonised rice hull — a black, lightweight biochar material produced by controlled high-temperature combustion of paddy husks. Its porous carbon matrix improves drainage, increases aeration, and provides long-lasting physical structure in any substrate blend. Unlike organic amendments, carbonised rice hull does not decompose and contributes stable, permanent porosity to the mix.

pH approximately 7.0–8.5 (slightly alkaline). Sterile. Weed-free. Long-lasting structural amendment. Use at 10–20% by volume in mixed substrates. Pair with worm castings or fertiliser for nutrition — carbonised husk is not a nutrient source.