Compost
Why hemp hurd and horse manure make good compost
1. Fiber acres. The grower bales the stalk.
2. Inbound truck. Bales arrive at the mill.
3. Mill floor. The line splits hurd and bast.
4. Outbound truck. Bagged hurd goes to the barn.
5. The stall. A horse stands on hurd.
6. Return truck. Spent bedding comes back.
7. Compost pad. It sits beside the plant.
8. Finished compost goes back on the acres.
A cubic yard is a box three feet on each side.
| Pine | Hemp hurd | |
|---|---|---|
| Material | $697 | $176 |
| Labor | $1,643 | $1,232 |
| Waste hauled | 10 cubic yards | 6 cubic yards |
| Compost time | 2–3 years | 6–9 months |
| Net versus pine | — | $1,081 |
Pine material $697 · hemp material $176 · material saved $521. Pine labor $1,643 · hemp labor $1,232 · labor saved $411. Material + labor saved $932. Haul saved $74 — the 4 cubic yards the hemp column does not haul. This is the remainder already inside the locked $1,081. It is not a published hauler invoice. Compost credit inside the $1,081: 6 cubic yards × $25 = $150. The ledger books half of that, $75, as the barn’s credit. The other half stays with whoever runs the pad. $521 material + $411 labor + $74 haul + $75 compost credit = $1,081.
The $1,081 is the barn versus pine. Material, less stall labor, less haul, and a compost credit.
In Phase 1 the mill does not run the pad. The barn or the subcontracted hauler takes that pile. The stall can still beat pine. The mill is paid when it sells the bag.
Barn compost credit — already inside the $1,081.
Yard compost sale — CleanLoop, not inside the $1,081.
The pad sits next to the plant
The compost pad is on the mill yard, not a third-party dump. That is what makes the loop close.
- The same gate that takes in stalk bales takes in spent bedding.
- The pad is sized for the stalls named on that pin. Figures are estimates if a barn bought the bag. A conservative 12×12 throws about 6 cubic yards of waste a year after the 40% reduction versus pine.
- Windrows sit on the yard. A managed pile at 130–160°F knocks down fly larvae, parasite eggs, and weed seeds.
- Six to nine months later the pile is finished compost, about 1–1.5% nitrogen class, applied in tons per acre.
- The truck that already ran bedding out can haul finished compost back to the grower who sold the stalk. That is the 100% loop: acres feed the mill, the mill beds the stall, the stall feeds the pad, the pad feeds the acres.
- Nothing in that loop requires a landfill or a wood-waste hauler.
One sentence on what 100% loop does not mean: it does not mean every pound is composted on day one, and it does not mean the barn is paid for manure. It means the mill never needs an outside dump for the stall waste it created.
Phase 1 does not run the pad. The barn or the subcontracted hauler takes the pile. The mill opens without owning the trucks. The loop can be added when the pile is real. CleanLoop
A stalled horse produces 12 to 13 tons of manure and soiled bedding a year. With pine shavings that pile sits for years and can lock nitrogen in the soil. With hemp hurd the same pile becomes compost.
Horse manure supplies the nitrogen. Hemp hurd — the woody core of the stalk — supplies the carbon, holds the liquid, and breaks down in a season.
Carbon and nitrogen
The pile wants about 25 to 35 parts carbon for each part nitrogen. Horse manure is already close. Hurd keeps it there. Pine shavings run 200 to 500 parts carbon and slow the pile down.
The liquid stays in the stall
Hurd holds two to four times its weight in liquid. Urine nitrogen stays in the stall instead of running to the aisle.
Ammonia stays in the compost
Hurd binds more ammonia than wood chips, so more of that nitrogen is still in the compost.
Six to nine months
Hemp composts in six to nine months. Pine takes two to three years.
A smaller pile
The pile is smaller — about 40 percent fewer cubic yards than pine.
A cleaner pile
In a 2025 University of Kentucky test, hemp hurd mixed with manure had lower E. coli than pine shavings or cut straw.
Heat
A managed pile at 130 to 160 degrees knocks down fly larvae, parasite eggs, and weed seeds.
Soil
Finished compost is a soil builder: organic matter, slow-release nutrients, better water-hold in sand and better drainage in clay.
The same acres that grew the fiber can take the finished compost back.
How the pile is run
Keep the pile as damp as a wrung-out sponge. Turn it so the center gets air. Heat of 130 to 160 degrees is the working range. Test a finished windrow before any nutrient number goes on a bag. Phosphorus often sets how many acres can take the compost.