Residue Kinetics of Insecticide Pymetrozine in Rice Field Soil

Abstract

Soils are the most diverse and complex ecosystem in the world. In addition to providing humanity with 98.8% of its food, soils provide a broad range of other services, from carbon storage and greenhouse gas regulation, to flood mitigation and providing support for our sprawling cities. Therefore, protection of soil health from various pollutants including pesticides is important for its future sustenance. The pesticide Pymetrozine widely used in rice fields for the control of aphids and whiteflies is also registered in India for crop protection in Paddy. This study aimed to examine how long the pesticide Pymetrozine persists and how it breaks down in different types of soil in West Bengal. This research was conducted through laboratory experiments using LC-MS/MS at Bidhan Chandra Krishi Viswavidyalaya, Nadia. Applied two doses of Pymetrozine and analyzed soil samples over 30 days. Pymetrozine levels decreased by 95-97% after 15 days and fell below detectable levels after 30 days. Dissipation followed first-order kinetics, with a faster rate in new alluvial soil compared to red lateritic soil. This difference could be due to variations in soil properties, like organic carbon content and water retention.