Reducing nitrogen losses during simulated composting of poultry manure using adsorbents or chemical amendments

Ammonia emissions during composting of poultry manure can be significant, r epresenting increased environmental pollution and decreased fertilizer valu e of manure. The objectives of this study were to measure NH3 volatilizatio n losses during composting of poultry layer manure, and to evaluate the pot ential of different amendments to reduce NH3 losses using a laboratory comp osting simulator. The poultry manure was treated with various amendments wh ich included two natural zeolites, clay, coir (mesocarp of coconut fruit), CaCl2, CaSO4, MgCl2, MgSO4, and Al-2(SO4)(3). The manure was composted for 49 to 56 d. Ammonia volatilized from the manure was trapped in a 0.3 M H2SO 4 solution. The composts were weighed and analyzed for moisture content, to tal N and NH4+. The NH3 volatilization loss for the unamended manures range d from 47 to 62% of the total manure N. A layer of 38% zeolite placed on th e surface of the manure reduced NH3 losses by 44%, whereas 33% coir plated on the surface of the manure reduced NH3 losses by 49%. The 20% alum treatm ent reduced NH3 losses by 28%. Composting poultry manure with zeolites, coi r, and alum produced composts with high NH4+ concentrations ranging from 17 to 53% of total N. The addition of 20% CaCl2 to poultry manure decreased N H3 volatilization but did not result in increased NH4+ or NO3- concentratio ns. The 38% zeolite Z1 and 33% coir-treated composts had total N concentrat ions of 17 and 31 g kg(-1), respectively. The zeolite and coir amendments w ere proposed to be the most suitable for reducing NH3 losses during compost ing of poultry manure.