Nutrient balance models- a management tool? △nutrient stock(N) input from the atmosphere(deposition) +biological fixation fertilization losses with seepage - denitrification losses with harvest Nutrient balance models – a management tool? Δ nutrient stock (N) = input from the atmosphere (deposi4on) +biological fixa4on + fer4liza4on - losses with seepage - denitrifica4on - losses with harvest