DELTAMETHRIN DYNAMICS IN SOILS FROM DAERAH ISTIMEWA YOGYAKARTA PROVINCE

Deltamethrin is a synthetic pyrethroid and one of the most widely used insecticide for crop protection. Laboratory trials were conducted to investigate the dynamics of the insecticide in soils obtained from three different areas in Daerah Istimewa Yogyakarta (DIY): Pakem, Wonolelo and Glagah, including the sorption, the retention, the mobility, and the dissipation. Batch experiments were carried out in the sorption study whereas soil column were used to study the retention and mobility of deltamethrin in soils. DT50 determinations were carried out by placing 500 mg soils which were deltamethrin has been applied on media covered with alumunium foil. The soils were sun exposed for 30 days. Soil samples for deltamethrin analysis were collected after 0, 1, 2, 3, 5, 7, 10, 20 and 30 days of application. Sorption isotherm of deltamethrin follows the Freundlich adsorption model (r 2 =0.999).The stronger deltamethrin sorption were observed for soils with higher content of organic matter. In soil column studies (30 cm soil depth), cumulative leaching was generally low, and deltamethrin were detected at 5-10 cm depth in soils within 2.5 and 10 days. Microbial activitiy appeared to dominate the dissipation process. The results may be used as part of efforts to reduce deltamethrin residues in the environment and to evaluate the safety and effectiveness of insecticide deltamethrin in agricultural activities.