Where is nitrogen going in long-term cropping systems?
Fertilizer nitrogen use efficiency (NUE) is normally low, and has led to the idea that a large proportion of N applied as fertilizer is lost from the soil. However, N balances calculated for a long-term rotation study at Swift Current indicate that losses of fertilizer N from the soil are small, and comparison of cumulative N balances with actual soil organic matter measurements show that an overwhelming proportion of this N is cycled through the organic matter, through microbially mediated processes, enhancing the fertility of the soil.
fertilizer, nitrogen use efficiency, nitrogen balances, cropping systems
Soils and Crops Workshop