Abstract: A pot experiment using rhizospheric bags were carried out to investigate regularity of the degradation of sulfadiazine in acclimated and unacclimated corn rhizospheric soils and non-rhizospheric soils. Results show that the degradation tallies with the first order kinetic reaction model, with degradation rate constant varying in the range of 0.015 -0.043 d^-1 and the half life in the range of 16.8-46.5d. The degradation rate of sulfadiazine added at a rate of 2 , 5 and 10 mg•kg^-1, separately, reached 65.5% and 43.9%, 60.4% and 40.2%, and 58.5% and 34.2%, respectively, in unacclimated rhizospheric and non-rhizospheric soils after 40 days of incubation.The degradation date of sulfadiazine in acclimated rhizospheric and non-rhizospheric soils were 77.7% and 58.4%,71.3% and 53.4%,and 66.1% and 51.9%,respectively.Obviously,the degradation rate was much higher in rhizospheric soils than in non-rhizospheric soils and in acclimated soils than in unacclimated soils.The synergy of the root system with appropriate acclimation may significantly improve degradation rate of sulfadiazine in soils.

Key words: sulfadiazine, rhizospheric soils, acclimation, degradation