The present invention relates to methods for recycling used mushroom casing soil. Specifically, the present invention relates to methods for recycling used mushroom casing soil comprising mushroom waste residue, which method comprises the steps: a) providing a used mushroom casing soil comprising mushroom waste residue; b) reducing the mean particle size of the mushroom waste residue to a mean particle size smaller than 6 mm, thereby providing reduced mushroom casing soil.