Many farmers are discovering that composting, combined with cover cropping and regenerative agriculture practices, can dramatically boost soil health, reduce input costs, and improve long-term productivity. One of the most effective — and often overlooked — materials for composting is rice hulls, a carbon-rich byproduct available across the Delta region at no cost.
Arkansas farmer Adam Chappell has developed a practical system that transforms these free hulls into nutrient-dense compost that strengthens his soils and significantly cuts fertilizer expenses.
Why Rice Hulls Are a Valuable Compost Resource
Abundant, Free, and Carbon-Rich
According to Chappell, rice mills throughout the Delta are eager to dispose of rice hulls. This creates a major opportunity for farmers:
- Rice hulls cost nothing
- They offer a high-carbon base for composting
- They are easy to store and handle
“This is free fertilizer and it’s good fertilizer,” Chappell said.
Each year, he brings in fresh hulls from a nearby mill and lets them rest in organized piles for about 12 months, allowing the material to break down and prepare for composting.
How the Composting System Works
Blending Compost Ingredients
Chappell enriches the rice hull base using a combination of:
- Molasses
- Nitrogen sources like 32% urea ammonium sulfate
- Optional add-ins such as cotton trash or chicken litter
These materials help create an ideal carbon-to-nitrogen ratio that supports microbial growth — the engine of healthy compost.
Monitoring and Turning the Piles
The composting process runs through the winter. Chappell:
- Screens hulls to remove unwanted debris
- Injects molasses and nitrogen sources
- Monitors temperature and CO₂ levels
- Mechanically turns the piles using a tractor
Turning is more frequent early in the process and slows to once a month by spring.
If temperatures drop too low, more nitrogen is added. Chappell notes that older hulls compost better, because fresher hulls generate higher heat and require more turning.
Spreading the Compost on the Fields
Applying 3–4 Tons Per Acre
Once ready, the compost is applied using a standard spreader. The process is not exact, but experience guides the distribution. Last year:
- Chappell applied 3–4 tons per acre
- Across 1,000–1,200 acres
- With enough hulls stored to repeat this for two more years
“We just pick a different field each year,” he explained.
Composting + Cover Crops = Reduced Fertilizer Costs
Major Reductions in Synthetic Inputs
By combining five years of composting with more than 15 years of cover cropping, Chappell has stacked multiple soil-building practices and achieved remarkable reductions in fertilizer use.
Since 2016, he has applied no synthetic phosphorus or potassium. Nitrogen applications have also dropped significantly:
- Standard regional rate: 220–230 units/acre
- Chappell’s 2025 rate: 165 units/acre
This combination has cut costs dramatically while maintaining strong yields.
Testing Compost Quality With the Haney Soil Test
What the Haney Test Revealed
Chappell and farm partner Taylor Herren tested a compost sample using the Haney soil test, which measures both nutrient availability and microbial activity. Results showed exceptional nutrient density:
- 1,068 lbs nitrogen
- 885 lbs phosphorus
- 1,931 lbs potassium
- 6,000 lbs carbon
- 26.1% organic matter
- Respiration rate: 232 ppm CO₂
- Carbon-to-nitrogen ratio: 9:1
These numbers reinforce the value of compost as a powerful soil amendment that enhances both fertility and biological activity.
NRCS Support and Cost Savings
Funding Opportunities for Farmers
Chappell’s composting approach qualifies under NRCS Practice 336 — Soil Carbon Amendment, which supports:
- Adding organic, carbon-rich materials to farmland
- Improving soil structure, organic matter, and carbon storage
- Providing farmers with financial cost-share options
Since rice hulls are free, Chappell’s only significant investment is labor. “It just takes work,” he said. “The mills want to get rid of the hulls, and the NRCS cost share makes the system even better.”