Relationship between soil δ15N, C/N and N losses across land uses in New Zealand

▶ We hypothesized fractionating N losses are driven by land use in New Zealand. ▶ Soil δ15N was highest in cropping and dairy and lowest in indigenous systems. ▶ There was a relatively strong correlation (ρ = −0.73) between δ15N and C/N. ▶ N balances showed that fractionating N losses increased with increasing land-use intensity. ▶ δ15N may be a useful tool in assessing potential N losses in different agronomic soils.