Compost notes
Why hemp hurd and horse manure make good compost
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.