Denitrification Studies with 13N-Labeled Nitrate.

Nitrate labeled with (13)N ((13)NO(3)(-)) was produced in a cyclotron by the (16)O(p, alpha)(13)N reaction with protons having energies of 14.5 million electron volts. The (13)NO(3)(-) was used as a tracer for direct quantitative measurements of denitrification rates in soils from flooded rice fields. The (13)N technique provides a new tracer method for the measurement of denitrification rates in natural systems over short time intervals, without changing the concentration of NO(3)(-)in the system.