Effects of imazamox on soil carbon and nitrogen mineralization under Mediterranean climate

Imazamox is an herbicide intensively used in the peanut fields of Turkey. Carbon and nitrogen mineralizations were determined at 20 °C to evaluate the effects of the herbicide in soils humidified to 60% and 80% of field capacity (FC) over 45 days. Three doses of this herbicide [recommended dose (RD, 10 mg kg^–1), 2× RD, and 4× RD] were added to soils without any previous imazamox application (NI) and to peanut soils with previous applications of imazamox (I). Carbon mineralization, determined by CO2 respiration, at RD of I soil at 80% humidity was higher than that of the other herbicide doses at both 80% and 60% humidities. NO3-N contents (mg kg^–1) of I and NI soil controls were significantly higher than with all herbicide doses at 80% and 60% of FC. Nitrate production decreased with increasing doses of herbicide and was significantly lower in I soil than NI soil at both humidity levels. It may be concluded that the presence of imazamox in both soils was negatively affected by nitrate bacteria.