Horse Bedding: Sand
Recommendation: An inexpensive, but low quality bedding. See Horse Bedding for a comparison to other options.
Sand can be used for horse bedding over either a solid floor (e.g. concrete) or over a permeable floor (e.g. gravel or beaten earth). In both cases, the benefits are cost (sand is relatively cheap), low waste (a small amount of bedding to be removed) and low labour (feces and soiled sand easily and quickly removed).
Unfortunately, the disadvantages are substantial:
Over the short term, sand on a permeable floor (e.g. beaten earth or gravel) works better as the urine can drain off. However, over the longer term, the urine tends to build up under the bedding (e.g. in the earth) and ammonia becomes an issue. To avoid this, one needs high quality drainage (e.g. deep gravel, over non-clay soil).
One should never feed horses or put edible items in a stall with sand bedding. This is because some food tends to fall on the floor and when the horse eats it, they ingest sand at the same time. Such ingested sand can lead to colic, a condition which is sufficiently common that it has a special term 'sand colic'. Horses which have low levels of fiber in their diet (e.g. fed musli or grain rather they grass and hay) are more prone to sand colic and other digestive issues if they ingest sand.
One should also use a type of sand (e.g. river sand) which is low in dust, to avoid respiratory issues.