(a) The producer must manage mushroom production in accordance with the provisions of §§ 205.200, 205.201, 205.202 as applicable, 205.203(e), and 205.206(a)(2) and (3) and (b) through (f). The producer may manage crop nutrients for mushroom production in accordance with the provisions of § 205.203(d).

(b) The producer must manage mushroom substrate and mushroom spawn media, including spent mushroom substrate and mushroom spawn media, in a manner that does not contribute to contamination of crops, mushroom spawn, mushroom substrate, soil, or water by pathogenic organisms, heavy metals, or residues of prohibited substances.

(c) Mushroom substrate may be composed of the following materials in accordance with the conditions specified in this paragraph:

(1) Composted plant and animal materials. Compost used in mushroom substrate must be described in the organic system plan. It must be produced through a process that maintains a temperature of at least 131 °F for at least three days;

(2) Uncomposted plant materials. Uncomposted plant materials must be organically produced: Except, that, nonorganically produced uncomposted plant materials may be used when a functionally equivalent organically produced material is not commercially available. Prohibited substances must not be applied to nonorganically produced uncomposted plant materials after harvest. Operations that use nonorganically produced uncomposted plant materials in mushroom substrate (except for wood materials allowed under paragraph (c)(3) of this section) must describe in the organic system plan:

(i) The procedures used to search for organic materials and the records kept to document searches;

(ii) The criteria used to evaluate if functionally equivalent organic materials are commercially available; and

(iii) The recordkeeping system used to document purchases of nonorganic materials, including a summary of the type(s) and total amount of each nonorganic material used in mushroom substrate.

(3) Wood chips, sawdust, logs, or other materials derived from wood that have not been treated with a prohibited substance after harvest;

(4) Nonsynthetic substances, except those on the National List of nonsynthetic substances prohibited for use in organic crop production (§ 205.602); and

(5) Synthetic substances on the National List of synthetic substances allowed for use in organic crop production (§ 205.601).

(d) Mushroom spawn must be organic: Except, that, nonorganic mushroom spawn may be used to produce an organic crop when an equivalent organic mushroom spawn is not commercially available.

(1) Organic mushroom spawn requirements.

(i) Agricultural materials used as mushroom spawn media must be organic: Except, that, nonorganic wood materials in compliance with paragraph (c)(3) of this section are allowed.

(ii) Mushroom spawn media may contain materials allowed in mushroom substrate at paragraphs (c)(1), (4), and (5) of this section.

(iii) Organic mushroom spawn must be under continuous organic management after the mycelium is applied to the mushroom spawn media.

(2) Organic mushroom operations that produce their own mushroom spawn for their own organic mushroom production must use organic agricultural materials for mushroom spawn media, unless a functionally equivalent organic agricultural material is not commercially available: Except that, wood materials in compliance with paragraph (c)(3) of this section are allowed.