IMMOBILIZATION OF (NH4)-N-15 BY CATTLE SLURRY DECOMPOSING IN SOIL

Almost half the N-15-labelled N added to a cattle slurry-soil were con verted to an organic form in 9 days: 5% was fixed by clay minerals and ca 20% lost from the system. The ATP content of the slurry-soil mixtu re more than doubled in 9 days, suggesting that about 24% of the N-14 converted to organic N at the end of 9 days was present in the form of labelled microbial biomass.