Farm inputs and materials

#Using approved materials

Understanding if a material — fertilizer, pest control, etc. — can be used in organic takes a few extra steps. Even when consulting the resources, always check that you are using the material for its reviewed purpose and following all the restrictions.

What materials do I need to use during my transition to organic?

For the transition leading up to organic certification, you can only use materials that are allowed in organic production. This includes fertilizers, pest and disease controls, seeds, seed treatments, livestock treatments, cleaning agents, and any other materials used on the farm. The USDA National List of Allowed and Prohibited Substances outlines what’s permitted (and what’s not) in organic.

How do I know if a material is ok to use on my farm?

In general, synthetic materials are not allowed for use in organic, unless they’re on the National List.

The Organic Materials Review Institute (OMRI) offers the best searchable list for approved-for-use materials. We’ve outlined the process for finding, adding and documenting materials to use on your farm. But we always recommend checking with us prior to using any questionable material during your transition process.

#Using fertilizers

Organic farmers are required to manage soil fertility and crop nutrients in a way that maintains or improves soil organic matter content.

Approved methods include, but are not limited to, crop rotations, cover crops, and the incorporation of plant and animal materials into soil. All fertilizers and soil amendments must be included in your Organic System Plan and approved by OTCO.

How do I know if I can use a fertilizer?

When asking, “Can I use this fertilizer or material?,” focus on the product’s composition. You must follow the same guidelines for materials, observing all approved product restrictions and prohibitions per the National List.

Do not risk jeopardizing your certification — a label may not disclose all of the product’s ingredients. For all non-OMRI or non-WSDA approved materials, request approval from your client service team. Never use an unapproved fertilizer until after OTCO review and receipt of approval.

What chemical fertilizers are prohibited?

All chemical fertilizers — particularly macronutrient nitrogen, phosphate (e.g., triple or super) or potash — as identified on the product composition label are prohibited for use.

Are ammonia and nitrate-based fertilizers prohibited?

All ammonia fertilizers and most nitrate fertilizers are not allowed.

Are soluble natural fertilizers allowed?

All highly soluble natural fertilizers are permitted for use with restrictions.

Is lime permitted for use?

Not all sources of lime are allowed. Mined limestone (calcium carbonate) and dolomite (magnesium carbonate) are permitted for use, while quicklime (calcium oxide), burnt dolomite (magnesium oxide), slaked lime (calcium hydroxide), and milk of magnesia (magnesium hydroxide) are prohibited.

What about fish-based or aquatic products?

Stabilized liquid fish products, aquatic plant extracts and humic acid derivatives are permitted for use with restrictions.

Are there any prohibitions for compost?

Compost made from sewage sludge (human waste/bio-solids) or fortified with synthetic fertilizers is prohibited. Additionally, you must follow compost restrictions and guidelines.

#Using micronutrients

If organic farm methods for nutrient management such as cover crops and application of compost can’t resolve soil deficiencies, micronutrients may be allowed for use.

When are synthetic micronutrients allowed for use?

Synthetic micronutrients are allowed only in cases of clearly document soil deficiency of a specific nutrient. We accept soil or plant tissue tests as documentation prior to approval for use. In addition, you must document the nutrient requirements for the crop.

As with all agricultural inputs, never risk your certification. For all non-OMRI or non-WSDA approved materials, request approval from your client service team. Never use an unapproved micronutrient until after OTCO review and receipt of approval.

#Using manure

In farm crop production, you can use raw animal manure to enrich soil fertility — i.e., fresh manure not added to a compost process — under specific conditions and restrictions.

What restrictions apply for using manure with crops not destined for human consumption?

There are no restrictions for using manure with crops not for humans.

What restrictions apply for using manure with crops for human consumption?

Manure must be applied at least 120 days before the harvest date if the crop is for human consumption and the edible part touches soil surfaces or particles.

What restrictions apply for using manure with crops for human consumption that do not touch soil surfaces?

Manure must be applied at least 90 days before the harvest date if the crop is for human consumption but the edible part does not touch soil surfaces or particles.

Is livestock grazing near crops for harvest allowed?

Livestock grazing is allowed on certified organic land and follows the same rules for raw manure. Animals must be removed either 90 or 120 days prior to harvest depending on if the edible part of the crop comes into contact with soil or not.

Are there special requirements, besides crop contact (or not) with soil when using off-farm sourced manure?

For off-farm manure, you will need a statement from the supplier for all ingredients — including any additives, bedding, inoculants, anti-caking/flow agents, etc. — to show it doesn’t contain prohibited materials per the National List.

#Using compost

In general, compost is only required to meet specific requirements if it has animal materials and is applied to crops destined for human consumption. A pre-harvest interval is not required for manure/compost applied to crops not for human consumption, as this requirement was put in place to prevent human microbial contamination.

What are the restrictions for using plant-based compost without manure or animal materials?

Compost made from plant byproducts — such as prunings, leaves, or hay — can be used on any crops without additional restrictions as long as feedstocks are non-synthetic. No pre-harvest interval is required. Please make sure to add the compost to your materials list if acquiring from off-site.

What are the restrictions for making and using compost with manure or other animal materials?

Compost containing animal materials such as manure or carcasses can either:

  1. Be treated as raw manure, meaning it must be applied at least 90/120 days before harvest as described above, or
  2. Be composted according to the NOP requirements as defined below

If you would like to apply compost containing animal materials to your crops closer to the harvest date than 90/120 days, it must be composted according to the following NOP requirements:

  • Compost temperature must be kept for at least 3 days above 131 degrees Farenheight
  • Clear, auditable records must be available of your composting process including feedstocks (ingredients) as well as, and logs measuring temperature and time

In either scenario please make sure you add the compost/manure to your approved materials list.

Are there any restrictions for using off-farm sourced compost with animal materials?

The product must come with a statement of feedstocks (ingredients), times, and temperatures and pile turnings to show it meets all the above requirements.

If you do not have documentation of times and temperatures, you may apply the compost as you would manure (at least 90/120 days before the harvest date if the crop is for human consumption).

For all non-OMRI or non-WSDA approved materials, request approval from your client service team. Never use an unapproved compost until after you’ve received approval from OTCO for the material review.

#Using mulches and biodegradable biobased mulch film

In farm crop production, you can use mulches — bark, leaves, hay, newspaper — under specific conditions and restrictions.

All mulches and crop inputs must be included in your Organic System Plan and approved by OTCO prior to being used for any purpose on certified land.

What types of mulch are allowed for use in organic crop production?

Nonsynthetic mulches (i.e. bark, leaves, hay) are allowed for any application in organic crop production and may be used as a fertilizer, pesticide, general crop tool or production aid.

Synthetic mulches are prohibited, except for three types approved for use in organic agriculture:

  • Newspaper or other recycled paper, without glossy or colored inks
  • Plastic mulch and covers (petroleum-based, PVC-free)
  • Biodegradable biobased mulch (BBM) produced without organisms or feedstock derived from excluded methods (non-GMO)

Allowed synthetic mulches must comply with all organic regulations that limit how the mulch is produced and used in organic application.

Can I use newspaper and recycled paper as mulch?

Newspaper and other recycled paper (including cardboard) free of glossy and colored inks may be used as mulch in organic crop production, an herbicide or weed barrier, or as compost feedstock.

Can I use plastic as a mulch?

Plastic mulch that does not contain polyvinyl chloride (PVC-free) may be used in organic crop production as an herbicide or a weed barrier only and must be removed at the end of the season.

Plastic mulches used in perennial crop applications may be left for more than one season as long as it’s removed before the plastic decomposes, breaks into pieces, or becomes impossible to effectively remove from the soil. Plastic mulches that biodegrade or break down are not allowed since removal at the end of the season is required.

Can I use a biodegradable biobased mulch film (BBM) as a mulch?

There are very few BBM approved for use in organic production. Before using any BBM, you must request approval from your organic certifier to review for compliance and verify whether it meets the following regulatory requirements:

  • Compostability standards ASTM D6400, ASTM D6868, EN 13432, EN 14995, or ISO 17088
  • At least 90% biodegradation absolute or relative to microcrystalline cellulose in less than two years in soil, according to one of the following test methods: ISO 17556 or ASTM D5988
  • Must be biobased with content determined using ASTM D6866, 7 CFR 205.3
  • Non-GMO


Although multiple submissions for BBM approval have been received, Oregon Tilth has yet to approve any BBM for organic crop production due to the inability to meet regulations.

Can the BBM regulatory requirements change in the future?

The National Organic Standards Board (NOSB) considered revising the definition and requirements for BBM at the Fall 2020 NOSB Meeting.

Both industry representatives and certification bodies commented that current BBM regulations result in very few approvals. Regrettably, other less environmentally friendly plastics with harsher impacts on the planet are approved and used.

Oregon Tilth encourages stakeholders and interested parties impacted by current BBM regulations and policies to submit comments and opinions to the NOSB and to the NOP. Help regulators understand the detrimental impacts of current legislation and the organic industry’s desire to modify regulations to provide a more environmentally friendly, usable alternative.

Get Forms & Documents

Download the documents and forms you need.

Access Blank Forms

Still need help?

Our team is here to assist you.

Contact Support