ABSTRACT NITROGEN in manure can be lost by ammonia volatilization, nitrate leaching, and denitrification. Such loss can reduce the value of manure as a source of crop nutrients. This paper reviews past practices in attempting to conserve nitrogen by adding chemicals to manure. Results of two recent experiments are reported. In one, three chemicalsgypsum, super-phosphate, and phosphoric acidwere added to manure to produce a stable ammonium compound. Results indicated that superphosphate and phosphoric acid are effective in conserving ammonia but are not cost effective. In the second study a nitrification inhibitor was found to be effective in conserving manurial nitrogenespecially for manure applied in the fall.