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What Are the Organic Rules for Manure and Compost?
Last reviewed July 22, 2026 · 5 min read · eCFR-verified
At a glance
Organic soil fertility is governed by 7 CFR § 205.2031, the "soil fertility and crop nutrient management practice standard." The headline rules farmers ask about most: raw animal manure must be either composted, applied to a non-food crop, or incorporated into the soil at least 120 days before harvest for crops whose edible portion touches the soil (90 days for crops whose edible portion does not) — and compost must hit specific temperature and carbon-to-nitrogen targets to count as compost rather than raw manure.
The reasoning behind the whole section is in its first two paragraphs: you build fertility with biology, not bags. The producer "must select and implement tillage and cultivation practices that maintain or improve the physical, chemical, and biological condition of soil and minimize soil erosion" (§205.203(a)), and "must manage crop nutrients and soil fertility through rotations, cover crops, and the application of plant and animal materials" (§205.203(b)). Manure and compost are tools inside that system — not a license to fertilize by the truckload.
The raw manure rule: 90 or 120 days
Under §205.203(c)(1)1, raw animal manure must be composted unless one of three exceptions applies:
- (i) it is applied to land used for a crop not intended for human consumption;
- (ii) it is incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or
- (iii) it is incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have such contact.
The 120-day category covers what you'd expect: leafy greens, root crops, low-growing berries — anything where the food you eat can touch soil or splash. The 90-day category covers crops held up off the ground, like sweet corn, trellised tomatoes, or tree fruit. When in doubt, treat the crop as soil-contact and use 120 days. The interval runs from incorporation to harvest, so it is a calendar-planning problem: a June harvest of soil-contact vegetables means raw manure has to be in the ground by mid-February.
These intervals exist for food safety — they give soil biology time to break down pathogens. Note that the USDA rule is stricter and more specific than "just spread it in fall"; missing the window is one of the more common noncompliances an inspector will look for, which is why we cover it in the pre-inspection records checklist.
When manure becomes compost — the temperature and C:N test
Composting is the way to sidestep the 90/120-day intervals, but only if it's real compost by the regulatory definition. §205.203(c)(2)1 requires composted plant and animal materials to be produced through a process that:
- (i) established an initial C:N ratio of between 25:1 and 40:1; and
- (ii) maintained a temperature of between 131 °F and 170 °F for 3 days using an in-vessel or static aerated pile system; or
- (iii) maintained a temperature of between 131 °F and 170 °F for 15 days using a windrow composting system, during which the materials were turned a minimum of five times.
If your pile hits those marks, the finished product is compost and the 90/120-day intervals don't apply. If it doesn't — a cold pile, a pile you never turned, a pile with the wrong carbon balance — it is still legally raw manure, and the intervals do apply no matter what it looks like. This is the single most misunderstood point in the section: "aged" manure is not composted manure. Only the temperature-and-turning process converts it.
Record the C:N inputs, the temperature log, and the turning dates. Without that documentation you cannot prove the material qualified as compost, and an inspector will default to treating it as raw.
What else § 205.203 governs
The rest of the section rounds out the fertility program:
- Uncomposted plant materials — cover crop residue, mulch, and green manures — are allowed under §205.203(c)(3) and are the backbone of most organic fertility.
- Soil amendments must not contain prohibited substances; you manage them "without contributing to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances."
- Sewage sludge (biosolids) is prohibited, full stop, as is burning crop residue except to suppress the spread of disease or to stimulate seed germination.
- Any synthetic you want to use for fertility has to appear on the National List at §205.6012 — see Is this input allowed? for how to check a specific product.
How to document this on your farm
Every manure and compost application is a record your certifier expects to see: what material, from where, applied to which field, on what date, and — for the 90/120-day rule — the planned harvest date that proves you cleared the interval. For compost, add the temperature and turning log that proves the material qualified.
This is exactly the kind of record OrganicAssistant captures automatically: message your farm's chat when you spread ("incorporated composted chicken manure on the north block today") and it logs the input, the field, and the date, then flags the harvest-interval math before it becomes an inspection problem. You can draft your Organic System Plan's fertility section automatically from those records rather than reconstructing a year of applications from memory.
The bottom line
USDA organic doesn't ban manure — it times it. Compost your manure to the temperature-and-C:N standard and you can apply it freely; use it raw and you're on the 90- or 120-day clock. Get the interval wrong on a food crop and you risk a noncompliance; document every application and you sail through inspection.
This explainer summarizes federal regulation in plain language; it is not legal advice or a compliance determination. Your certifier makes the final call on your operation. Reviewed against the eCFR text of 7 CFR § 205.203 current as of 2026-07-22.
Frequently asked questions
When can I apply raw manure to my organic crops?
Raw animal manure must be composted, applied to a crop not intended for human consumption, or incorporated into the soil ahead of harvest. For crops whose edible portion touches the soil, incorporate it at least 120 days before harvest; for crops whose edible portion does not touch soil, the interval is 90 days. The interval runs from incorporation to harvest, so it is a calendar-planning problem.
What makes manure count as compost instead of raw manure?
To qualify as compost, the process must establish an initial C:N ratio of between 25:1 and 40:1 and reach a temperature of between 131 and 170 degrees F. That temperature must hold for 3 days in an in-vessel or static aerated pile, or for 15 days in a windrow system where the materials are turned at least five times. If it hits those marks, the 90/120-day intervals no longer apply.
Can I use sewage sludge or burn crop residue on an organic farm?
No. Sewage sludge, also called biosolids, is prohibited outright under the soil fertility standard. Burning crop residue is also not allowed, except to suppress the spread of disease or to stimulate seed germination.
Does aged manure count as composted manure for organic certification?
No. Aging alone does not convert manure; only the temperature-and-turning composting process does. If a pile does not meet the temperature and C:N standards, it is still legally raw manure, and the intervals do apply no matter what it looks like. Without a documented C:N, temperature log, and turning dates, an inspector will default to treating it as raw. Note that your certifier makes the final call on your operation.
References
Last reviewed July 22, 2026. Your accredited certifier makes all compliance decisions for your operation.
Keep these records without the paperwork
Organic Assistant turns the messages, receipts, and files you already have into organized, inspection-ready records — and drafts your Organic System Plan from them.