What to Consider when Emission Reduction is Required from Soil Fumigation

Emission is one of the key factors affecting fumigant use in California due to regulations. Many commodities depend on pre-plant soil fumigation to achieve profitable yield and healthy crops. The phase-out of methyl bromide as a broad-spectrum soil fumigant in pest control has placed formidable challenges in searching alternatives. Most alternatives registered today are highly regulated because of their toxic properties and their nature as volatile organic compounds (VOCs). Minimizing emissions becomes essential to maintain the practical use of fumigants. This paper reviews and summarizes findings towards field practices to minimize emissions from soil fumigation. The effectiveness on emission reduction, impact on pest control and cost are important factors to consider in determining emission reduction technique. High-value cash crops (e.g. strawberry) can afford using highly effective, but costly low permeable plastic mulches whereas crops with lower profit margins (e.g. stone fruit orchards) may need to consider lower cost methods such as water treatments and/or target-area fumigation. More stringent regulations on fumigants are likely to develop in the future. Continuous research is necessary to develop good fumigation practices in various agronomic systems to sustain agricultural production while minimizing potentially detrimental impact.