Carbonized Rice Hull (Crh) I Starter Soil Amendment For Plants, Houseplants, Cactus, SucculentsCarbonized Rice Hull (CRH), is made from the partial burning of rice hull. It is an excellent soil fertilizer and soil conditioner which contains Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), and other micro nutrients necessary for plant growth. Carbonized rice hull serves as a soil amendment. Soil amendments are materials added to soil to improve its physical qualities such as water retention, permeability, water infiltration,