What is Practice 336?
Conservation Practice Standard 336, Soil Carbon Amendment, is the USDA Natural Resources Conservation Service (NRCS) standard for applying carbon-based amendments derived from plant materials or treated animal byproducts — including biochar, compost and biochar-compost blends. It was adopted nationally in 2022, replacing interim standard 808.
The four purposes
A 336 practice is planned to accomplish one or more of: improving or maintaining soil organic matter; sequestering carbon and enhancing soil carbon stocks; improving soil aggregate stability; and improving habitat for soil organisms. Degraded, sandy or acidic soils often see the greatest gains.
Who and what land qualifies
Agricultural producers and private forest landowners on cropland, pasture, range, forest, associated agricultural land and farmsteads where a carbon amendment will improve soil conditions.
How to get a 336 contract
- Contact your local USDA Service Center and ask about Soil Carbon Amendment (336) through EQIP.
- Develop a conservation plan with NRCS or a Technical Service Provider that identifies your soil resource concerns.
- Apply before your state’s ranking date. Applications are taken continuously, but each state sets its own cutoffs.
- Apply qualifying biochar on the enrolled acres and keep application records and lab analysis.
What the biochar must meet
Biochar under 336 is produced by heating biomass above 350 °C with limited oxygen. Material must be made by approved methods and documented with a lab analysis — including carbon content and the hydrogen-to-carbon (H:C) molar ratio that indicates stable, persistent carbon. Every Ashwood agricultural product ships with its lab sheet.
Companion practices
336 is commonly planned alongside Nutrient Management (590), Conservation Crop Rotation (328), Cover Crop (340) and Residue & Tillage Management, No-Till (329). Stacking practices can strengthen an application’s ranking.
Payment rates
Payment rates are set by each state’s NRCS payment schedule and are reevaluated periodically. Through our Carbon Assistance Program, enrolled farmers typically earn $100–$300 per acre with no upfront material cost.
Not using NRCS?
You don’t have to. The same biochar is available direct from $250/ton delivered (subject to freight). Get a price quote.
Sources: NRCS — Soil Carbon Amendments · CPS 336 Practice Overview · eFOTG state standards