Importance of pools varies with nutrients Nitrogen (N) Almost entirely in organic form in soil(500- 5000kg/ha); exchange NH4 0-400kg/ha Soil solution: anion and cation(NO30.1 5mM) and NHa, 0.01-0. 5mM); very soluble low buffering capacity Large inorganic pool in atmosphere(N2);very inert(unreactiveImportance of pools varies with nutrients Nitrogen (N) – Almost entirely in organic form in soil(500- 5000kg/ha); exchange NH4 + 0-400kg/ha – Soil solution: anion and cation (NO3 - ,0.1- 5mM) and NH4 + , 0.01-0.5mM); very soluble; low buffering capacity – Large inorganic pool in atmosphere (N2); very inert (unreactive)