Submitted to: Almond Industry Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 31, 2009
Publication Date: December 9, 2009
Citation: Gao, S., B. Hanson, and D. Wang. 2009. Using Irrigation and Organic Amendment to Reduce Fumigant Emissions. In 2009 Proc. California Almonds Conference. Almond Board of California, Modesto, CA. Dec. 9-10, 2009. p. 258-261. Interpretive Summary: Prunus and many other perennial crops require pre-plant soil fumigation in order to establish profitable crops for years to come. Use of soil fumigants has been largely affected by environmental regulations due to detrimental emissions. A field trial was conducted to compare the effectiveness of several feasible field methods to reduce emissions from soil fumigation including incorporation of organic materials, post-fumigation water treatments, standard plastic or polyethylene tarp, and use of a low permeable tarp as VIF (virtually impermeable film). The most promising emission reduction technique was tarping with a VIF. Post-fumigation water seals and standard plastic film reduced emissions ranging from 20-50% that are likely depending on soil and environmental conditions as well as how the treatment is applied. The VIF significantly reduced emissions and illustrated the high potential to improve efficacy by retaining high fumigant concentration under the tarp and also improving fumigant distribution in soil. This can lead to the use of lower rates than currently used. The information is valuable for commodities that depend on pre-plant soil fumigation and regulatory agencies or policy makers on soil fumigant use.
Technical Abstract: Essential emission reductions from soil fumigation can increase the probability of continued use of soil fumigants to commodities such as prunus and many other perennial crops. Our research was to identify effective, economically feasible and environmentally sound field methods. To determine the effectiveness of several feasible surface sealing and tarping treatments on emission reductions, a field trial was conducted in a sandy loam soil in the San Joaquin Valley Agricultural Sciences Center (SJVASC), California in fall 2008. Emissions of 1,3-dichloropropene (1,3-D) was measured from several surface treatments over shank injection of Telone® II. In addition, gaseous fumigant concentrations at various depths over time were also monitored. Surface treatments included a bare-soil control, a high application rate of composted dairy manure, post-fumigation intermittent water seals, and tarping with standard polyethylene (PE) film and a low permeable film as VIF (virtually impermeable film). The manure application did not reduce fumigant emissions. Water seals and the standard PE tarp reduced emissions about 20% and 50%, respectively that depends on soil and environmental conditions or how the treatment is applied. The VIF reduced emissions most effectively (>95% reduction compared to a bare soil) and glue joints did not present problems in the field to reduce the tarp effect. The VIF illustrated the potential to improve uniform distribution of gaseous fumigants in the soil profile and to retain higher concentrations under the tarp than other surface treatments that can lead to iproved efficacy and/or the potential of using lower rates, which required further detailed investigations. The information is valuable for commodities depending on pre-plant soil fumigation and regulatory agencies or policy makers on soil fumigant use.