Calcium silicate hydrate nanoparticles are combined with ammonia control materials (e.g. alum, aluminum chloride, ferric chloride, ferric sulfate, and/or sodium bisulfate) to create a phosphorus-binding composition. In the preferred embodiment, the composition is applied to poultry litter, poultry bedding or other non-aqueous substrates that are at least partially comprised of animal manure. The composition binds with phosphorus to at least reduce the amount of phosphorus in runoff water or in leachate from fields fertilized with treated manure. The combining of the calcium silicate hydrate nanoparticles with the ammonia control products has a surprising and unexpected result. The calcium silicate hydrate-ammonia control material mix reduces soluble phosphorus more than either component of the mix alone.