Author
|
Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 12/24/2008 Publication Date: 9/6/2010 Citation: Wang, D. 2010. Chapter 5: Pesticide models for simulating environmental transport of soil fumigants. pp. 211-225. In K. Bundgaard and L. Isaksen (eds.) Agricultural Research and Technology. Nova Science Publishers, Inc., Hauppauge, NY. Interpretive Summary: Process-based pesticide simulation models and computer programs have long been used to help determine the relative importance of different chemical, environmental, and management factors that affect the efficacy and environmental impact of pesticides. Soil fumigants are a special group of pesticides, and because of the high vapor pressure they are also volatile organic compounds (VOCs). Since the decision of phasing out methyl bromide in the early 1990s, considerable research has been carried out on documenting the environmental fate and transport of methyl bromide and its potential alternatives. The scope of this article is to review modeling activities related to soil fumigants after the early 1990s with a special focus on simulating fumigant emission fluxes. A general overview of fundamental physical and chemical principles for modeling the environmental fate and transport of soil fumigants is provided. The review covers primarily process-based numerical models and to lesser extent the survey-type empirical or statistical analysis tools or air dispersion models. Strengths and weaknesses of the different models and their limitations are discussed. Future needs in modeling soil fumigants are also discussed. Technical Abstract: Soil fumigants are a special group of pesticides that possess relatively high vapor pressure. Thus a large fraction is in the vapor phase after application in the substrate soil environment. Because of the high vapor pressure, they are also volatile organic compounds with strong potential for air pollution if large emission losses occur. Considerable soil fumigation research has been carried out in the past 15 years because of the phaseout of methyl bromide in the early 1990s. The main research focus has been on documenting the environmental fate and transport of methyl bromide and its potential alternatives using lab and field experiments and computer models. Simulation models are valuable tools for estimating the environmental fate and transport of pesticides and relative importance of pesticide properties, such as vapor pressure, that would affect dominant transport mechanisms in the environment. This article provides a general overview of fundamental physical and chemical principles for modeling the environmental fate and transport of soil fumigants. Discussions are also provided for feasibility assessment of existing pesticide models for simulating soil fumigants and future research needs in modeling soil fumigation. |
