Sebastian County Conservation District
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Composting for Soil Restoration

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Compost is decomposed organic matter — the end product of a biological process that transforms raw plant and animal materials into a stable, nutrient-rich amendment that improves virtually every measurable soil property. For Sebastian County landowners working to rebuild degraded soils, compost is one of the most powerful tools available, and most of the raw materials are already on your property.

The Carbon-to-Nitrogen Ratio

Successful composting depends on balancing carbon-rich materials (browns) with nitrogen-rich materials (greens) in roughly a 25:1 to 30:1 ratio by weight. Browns include dry leaves, straw, wood chips, and cardboard. Greens include fresh grass clippings, kitchen scraps, manure, and green plant material. Too much carbon and the pile decomposes slowly; too much nitrogen and it becomes anaerobic and smelly. A simple rule of thumb: three parts browns to one part greens by volume works well for most farm situations.

Hot Composting

Hot composting — maintaining pile temperatures between 130°F and 160°F — produces finished compost in 30–60 days and kills weed seeds and pathogens. The pile needs to be at least three feet in each dimension to hold heat, and it needs to be turned every three to five days to maintain oxygen levels and even decomposition. A compost thermometer is a worthwhile investment. When the pile no longer reheats after turning, it is ready to cure for two to four weeks before use.

Windrow Composting

For larger volumes — livestock manure, crop residues, or municipal organic waste — windrow composting is the standard approach. Windrows are elongated piles typically four to six feet tall and eight to twelve feet wide, turned with a tractor or dedicated windrow turner. On a working farm, a simple three-bin system using concrete blocks or wooden pallets allows continuous production: one bin filling, one actively composting, one curing.

Application Rates

For general soil improvement, apply one to three inches of finished compost and incorporate it into the top six inches of soil. For severely degraded soils, higher rates of three to five inches may be warranted in the first year. Compost can also be applied as a surface mulch without incorporation — particularly effective in no-till systems where it feeds soil biology from the top down. Avoid applying more than five inches in a single season, as excess nitrogen can leach into groundwater.

Key Takeaways

  • Aim for a 25:1 to 30:1 carbon-to-nitrogen ratio — roughly 3 parts browns to 1 part greens
  • Hot composting at 130–160°F kills weed seeds and pathogens in 30–60 days
  • A three-bin system enables continuous production on working farms
  • Apply 1–3 inches for general improvement; up to 5 inches for severely degraded soils