Roland Piquepaille writes: "You all know that agricultural crop production relies on fertilizers, such as composted waste materials. But I bet you wouldn't have thought to add human hair to animal manure to produce better and greener fertilizers. Yet, a study done by Mississippi State University researchers has shown that human hair, 'combined with additional compost, is an additional nutrient source for crops.' Apparently, barbershops and hair salons are selling human hair for a couple of years now — a fact I didn't know. Anyway, even if human hair can be used to grow some plants, 'further research is necessary to determine whether human hair waste is a viable option as fertilizer for edible crops.' Read more for additional details and references."