Part I. Colorimetric methods for the determination of 2-chloro-4, 6-bis (ethylamino)-1, 3, 5-triazine (simazine) and related compounds. Part II. Degradation of C14-labeled simazine [2-chloro-4, 6-bis (ethylamino)-l, 3, 5-triazine] by plants and soil microorganisms.