Table 2.

Different N loss pathways expressed as a percentage (mean ± SD) of N application rate in farmers' N practices (Field Study 3, Lysimeter Study)

ComponentTaihu region
North China Plain
RiceWheat-southWheat-northMaize
N rate (kg of N per hectare)300250325263
Recovery rate (%)*29.6 ± 4.918.4 ± 6.331.0 ± 3.625.5 ± 5.2
Retention rate (%)*21.7 ± 5.128.5 ± 4.645.7 ± 5.433.9 ± 2.3
Loss pathwayNH3 volatilization (%)11.6 ± 4.72.1 ± 1.419.4 ± 5.224.7 ± 5.6
Leaching out of 1 m soil depth (%)0.3 ± 0.53.4 ± 2.12.7 ± 2.612.1 ± 8.5
Denitrification (%)36.443.50.1 ± 0.043.3 ± 1.6
  • *Measured from corresponding 15N field experiments.

  • Calculated by difference method.