AMMONIA VOLATILIZATION AND CARBON-DIOXIDE EMISSION FROM POULTRY LITTER - EFFECTS OF FRACTIONATION AND STORAGE TIME

In many poultry producing areas, the amounts of poultry litter generat ed exceeds the amounts needed for application to soil, as fertilizer, at environmentally safe rates. To reduce the amounts of litter produce d, Ndegwa et al. (1991) proposed fractionating the litter to generate a fine fraction that could be used as fertilizer, and a coarser fracti on that could be recycled into poultry houses as bedding material. Bec ause the fine fraction may need to be stored for several months before land application, knowledge of the changes that occur during storage would be important from the point of view of litter utilization. The o bjective of this study was to monitor water and inorganic nitrogen (N) contents, as well as potential ammonia (NH3) volatilization and carbo n dioxide (CO2) emission in samples of whole litter and fine fraction stored in an unheated building for 16 weeks. Potential NH3 volatilizat ion and CO2 emission were measured at unamended water contents and at a water content of 0.5 kg kg-1. Water and inorganic N contents of the whole litter and fine fractions showed some fluctuations during the fi rst 4 weeks, but remained relatively stable from weeks 4 to 16. At una mended water contents, potential NH3 volatilization and CO2 emission w ere relatively low and similar for the whole litter and the fine fract ion. Also, potential NH3 volatilization remained stable whereas CO2 em ission decreased with time. Increasing the water content to 0.5 kg kg- 1 significantly increased potential NH3 volatilization and CO2 emissio n in the whole litters and fine fractions, with larger increases usual ly observed in the fine fractions. At 0.5 kg kg-1, both potential NH3 volatilization and CO2 emission decreased with time. These results sug gest that the fine fraction and the whole litter should be stored at r elatively low water contents to prevent N losses through NH3 volatiliz ation and possibly denitrification.