Application of poultry litter (PL) to soil may lead to nitrogen (N) losses through ammonia (NH(3)) volatilization and to potential contamination of surface runoff with PL-derived phosphorus (P). Amending litter with acidified biochar may minimize these problems by decreasing litter pH and by retaining litter-derived P, respectively. This study evaluated the effect of acidified biochars from pine chips (PC) and peanut hulls (PH) on NH(3) losses and inorganic N and P released from surface-applied or incorporated PL. Poultry litter with or without acidified biochars was surface-applied or incorporated into the soil and incubated for 21 d. Volatilized NH(3) was determined by trapping it in acid. Inorganic N and P were determined by leaching the soil with 0.01 M of CaCl(2) during the study and by extracting it with 1 M KCl after incubation. Acidified biochars reduced NH(3) losses by 58 to 63% with surface-applied PL, and by 56 to 60% with incorporated PL. Except for PH biochar, which caused a small increase in leached NH(4) (+)-N with incorporated PL, acidified biochars had no effect on leached or KCl-extractable inorganic N and P from surface-applied or incorporated PL. These results suggest that acidified biochars may decrease NH(3) losses from PL but may not reduce the potential for P loss in surface runoff from soils receiving PL.
Keywords: acidified biochar; ammonia volatilization; inorganic nitrogen; inorganic phosphorus; poultry litter.