1a.Objectives (from AD-416)
To develop efficient and cost-effective field management practices to minimize emissions of methyl bromide alternative fumigants from pre-plant soil fumigation while achieving effective pest control.
1b.Approach (from AD-416)
Field management methods that have potential to reduce fumigant emissions and improve efficacy will be tested. Methods including fumigant application (new shank design, and drip. vs. shank application), low permeable tarps, irrigation, and soil amendment with organics as well as combination of these methods will be determined for their effectiveness and feasibility. Field trials will be conducted in air-quality non-attainment areas in California including Ventura County and the San Joaquin Valley. Data on emission rates, total emission losses, distribution of fumigants in soil profile and efficacy on soil pest control will be collected. Monitored data will be summarized to identify good and effective practices that can be adopted in growers’ fields. Documents SCA with UC Davis.
Under this agreement, collaborative research has been conducted to develop agricultural practices to minimize fumigant emissions and improve efficacy from soil fumigation. Field trials were conducted and tested emission reduction methods including application (subsurface drip, spot-drip, strip-shank, modified shank, vs. broadcast shank applications), plastic tarping, and surface soil treatment. Emission reduction from soil fumigation must be exercised because > 60% of fumigant applied can be lost easily through emissions without any control. Post-water treatments with sprinklers can reduce peak emission flux more effectively than it can reduce cumulative emission loss. Surface soil amendment with composted manure and without water treatments does not always result in reduced emissions. Virtually impermeable films (VIF) can reduce emission flux and cumulative emission loss significantly while improving pest control when the tarp is installed successfully in the field. This research continues to provide solutions for the effective use of soil fumigants and minimizing their negative environmental impacts. This project is monitored by regular site visits by ARS, and regular conference calls between ARS and the University investigators on this project.