This study aimed to 1) evaluate the effect of acidified biochar on the release of NH3, CO2 and inorganic N and P from surface-applied (SPL) or incorporated poultry litter (IPL), and 2) investigate the sorption and desorption of NH4+ and ortho-P on acidified biochar. SPL or IPL with or without acidified biochar was incubated for 21 d. Acidified biochars reduced NH3 losses by 24 to 67% and CO2 evolved by 9 to 22% from SPL. Also, it decreased NH3 volatilized by 55 to 60% but increased CO2-C emission by 0.5 to 45% from IPL. Acidified biochars generally did not affect leachable inorganic P and N or extractable inorganic P and NH4+ from SPL and IPL. It did not affect extractable NO3- from SPL (except PC600) and from IPL (except for PC600 and PH600). The biochars could sorb NH4-N but not ortho-P. Acidified biochars could reduce NH3 losses but could not address the problem on P loading in runoff from poultry litter in pasture soils.