Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: September 11, 2008
Publication Date: November 14, 2008
Citation: Wang, D.,N. tharayil, R. Qin, S. Gao, B.D. Hanson. 2008. Reducing 1, 3-D and Chloropicrin Emissions with Subsurface Drip and VIF. International Conference on Methyl Bromide Alternatives and Emissions Reductions. 33:1-3. Interpretive Summary: Soil fumigation through drip-application is widely adopted by strawberry growers in California. Field studies also showed emission reduction of 1,3-dichloropropene (1,3-D) when applied by drip irrigation compared to shank injection, and additional emission reductions were achieved when covering the field plots with a virtually impermeable film (VIF). As part of an ongoing methyl bromide alternatives project, this study compared the effect of subsurface drip and/or VIF on reducing 1,3-D emissions in vineyard replant fumigation. Many grape orchards are irrigated using surface drip-irrigation systems, so application of fumigants using subsurface drip is likely a viable choice. After the fumigation, these drip lines can be used for irrigation of the grape orchard. However, results from the study appear to show that fumigation with subsurface drip is not effective in reducing emissions. Covering the soil surface with a VIF produced consistently low emissions.
Technical Abstract: Grape growers in central California fumigate their fields with shank injection of 1,3-D and CP to control soil-borne pests during vineyard replant. Potential 1,3-D emission losses have not been studied under this cropping system. The objective of this study was to quantify the emission rates and evaluate delivering fumigants through a subsurface drip irrigation system and covering the soil with a VIF. Fumigant emissions were measured with flux chambers on 12 replicated field plots treated with subsurface drip with or without VIF cover and in comparison with shank injection with or without VIF. Results indicate that applying fumigants with subsurface drip at 50 cm depth without VIF cover generated similar cumulative 1,3-D emissions to shank application at 45 cm depth. The VIF tarp significantly reduced fumigant emissions in both the shank and the subsurface drip application treatments.