First detailed report on 13C6-metamitron turnover mass balance in soil. 13C6-metamitron was ultimately degraded to CO2 and biogenic residues. Metamitron was biodegraded via two routes: desamino-metamitron and “Rhodococcus”. Desamino-metamitron route was assigned to growth metabolism. “Rhodococcus” route was related to starvation metabolism.