Accelerated Degradation and Mineralization of Atrazine in Surface and Subsurface Soil Materials

In surface soils, atrazine is considered to be a moderately persistent herbicide, with half-lives ranging generally from one to two months. In subsoils, however, its degradation is generally slower. This paper reports the degradation of atrazine in soil and subsoil samples taken from six Belgian maize fields. Rapid degradation can take place in some samples taken from surface and in some from subsurface soils. Subsoil samples were found to degrade atrazine either very strongly or not at all. Experiments with [ring-U-14C] atrazine showed that the micro-organisms responsible for the rapid degradation cleave the triazine ring and extensively mineralize the molecule.