Submitted to: Almond Industry Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 10, 2008
Publication Date: December 10, 2008
Citation: Gao, S., B. Hanson, D. Wang, and J. Gerik. 2008. Using irrigation and organic amendments to reduce fumigant emissions. In 2008 Proceedings, 36th Almond Industry Conference. Dec. 10-11, Modesto, CA. pp. 244-247. Interpretive Summary: Reducing fumigant emissions is important to minimize potential risks of soil fumigation. Effective, economically feasible and environmentally safe methods are mostly needed. This research tested several potential surface seal and soil treatment methods to reduce emissions of 1,3-Dichloropropene and chloropicrin emissions from shank-injection of Telone C35 under field conditions in the San Joaquin Valley of California. Application of potassium thiosulfate was most effective to reduce emissions but caused some unknown reactions in the soil. Pre-irrigation that can be easily managed reduced more emissions than post-fumigation water seals. However, application of composted manure to soil surface followed by standard plastic tarp did not reduce emissions and further tests are necessary to define soil/environmental conditions for using organic amendment to achieve low emissions from soil fumigation.
Technical Abstract: Telone or 1,3-dichloropropene and chloropicrin are primary alternative soil fumigants to methyl bromide and their emission reductions are required to improve air-quality standards in California. Research has identified various methods including plastic tarp, irrigation, and soil amendment with organic materials or chemicals to reduce fumigant emissions. Effective and economically feasible field methods, however, are not clearly defined. The objective of this study was to determine the effectiveness of several surface seals and treatment methods including pre-irrigation, post-fumigation water seals with or without potassium thiosulfate (KTS) amendment, and tarp over soil amendment with either KTS or composted manure on fumigant emissions. Results showed that pre-irrigation that can be easily applied reduced emissions more than post-water seals. The KTS treatments were the most effective to reduce fumigant emissions but caused some unknown reactions in surface soils. The application of composted manure followed by HDPE tarp did not reduce emissions in this trial indicating the need for further research to use organic amendment to achieve low emissions.