Use of chain_2d to model the effect of fumigant application mitigation strategies on volatilization from soil

AGRO 89

Ian J. van Wesenbeeck, ijvanwesenbeeck@dow.com, Regulatory Labs, Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268 and Steven A. Cryer, sacryer@dowagro.com, Global Ag Math Modeling and Analysis, Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268.
Emissions of soil applied fumigants to the atmosphere are being scrutinized by regulatory bodies for their contribution to atmospheric VOC's. A soil physics computer model, CHAIN_2D, is used to simulate the emissions of soil fumigants under typical agronomic conditions and practices. A sensitivity analysis for CHAIN_2D is performed, and the model is validated against several diverse field datasets where emission flux was determined using the aerodynamic method. The effects of soil incorporation, plastic mulch, and soil water content on emission reduction are provided for several common soil fumigants. Simulation results indicate careful management of soil water content prior to fumigation, increased depth of injection, and the use of plastic mulch can reduce fumigant emissions. The validated model can be used to generate transient emissions losses from soil and provides the necessary source input for air dispersion models to predict off-site movement and bystander exposure.