Note: Any claim without a supporting scientific evidence is incomplete. As simplified as possible, science can still be boring. What, Why, How - if these questions fascinate you, then you will enjoy this article.
Nature has designed coco bedding in such a way that dust and allergens get trapped in the fibrous structure and remains locked. Animal Studies conducted on coconut fibers show a 80% reduction in cough and dust related issues in comparison to wood chips. Air quality in the stalls is a major worry for most of the horse owners.
Horse Manure contains about 50% organic carbon and about 5% nitrogen. The Carbon [C] to Nitrogen [N] ratio (C/N) is the deciding factor that determines the decomposition rate of a manure pile.
Any material, which has more carbon than nitrogen is generally referred as "browns". The reverse is called as "greens". In a compost pile, a fine balance has to exist between the browns ad the greens. This helps the natural bacteria to easily work on the pile and breakdown the material into a fine quality compost.
When C is high, the beneficial microbes will not be available in sufficient numbers to breakdown the compost pile. When N is high, excess nitrogen will be released in the composting process, which forms methane and other foul smelling gases.
Microbes need large quantities of sugar (which they get from Carbon) and proteins (which they get from the Nitrogen). But too much of sugar will make the microbes go berserk. Too much of nitrogen will cause excessive amounts of amino-acids in their system causing other problems. There has to be a right balance.
Here's a small list of C/N ratio of the FRESH bedding material in a horse stall:
Here's a small list of C/N ratio of the SOILED bedding material after removal from a horse stall:
The "meal" wasn't agreeable to the microbes in the wood chips-manure pile. The C/N ratio was 400:1, too high to begin with. And after all the work by the microbes, it still is very high 325:1. Therefore, the pile will take a good while before it is completely broken down [statistics vary between 9 months to 2+ years depending on various factors].
When left by itself, discarded coconut husks/fibers take a very long time to break down. [note: high in carbon] C/N is 66:1.
When left by itself, farm manure, rots slowly. It also has a foul smell because of excess ammonia and methane gases [note: high in nitrogen] C/N is 14:1
But when both get mixed up, it's a dynamite! The excessive nitrogen in the manure is absorbed by the coconut fibers. The C/N ratio in coconut fibers is now lowered. The C/N ratio in the manure is now raised.
The mix now has a C/N [22:1] which is close to the ideal ratio [30:1]. The protozoa, microbes and other beneficial organisms are invited to an "all you can eat" buffet! They feast on this manure-coir mix and break down the pile. In about 90 days or so, we get a sweet smelling composted product. The N, P & K in this mix is readily absorbed by the soil.
In the case of saw-dust or wood chips, because of the drastic imbalance in the C/N ratios when the composting starts, it takes a long time to break down. Hence the bedding thrown out from stalls that uses saw-dust or wood chips will create more problems. It requires additional adjustments to make this pile decompose in a safe manner.
But in the case of coco bedding-manure pile, it decomposes naturally and much quicker too!
I am a science graduate and a salesman - rolled into one. I have a penchant for writing, but edit my copy so much that usually lands me in the same spot I originally began with! My hobby is to roam around Montana on a horse back [just a dream! I don't have a horse and never been to Montana!]