|Qin, Ruijun - UC DAVIS|
|Tharayil, Nishanth - CLEMSON UNIVERSITY, SC|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 6, 2009
Publication Date: May 21, 2009
Citation: Suduan Gao, Ruijun Qin, Bradley D. Hanson, Nishanth Tharayil, Thomas J. Trout, Dong Wang and James Gerik Effects of Manure and Water Applications on 1,3-Dichloropropene and Chloropicrin Emissions in a Field Trial. J. Agric. Food Chem., 2009, 57 (12), pp 5428–5434. Interpretive Summary: Achieving low emissions from soil fumigation will allow continued availability of fumigants to growers by minimizing environmental pollution and meeting air quality standards. Methods that are effective, economically feasible and environmentally sound are mostly desired. The objective of this study was to determine the effectiveness of soil amendment with composted manure with or without water applications on emission reductions. A field trial was conducted in a sandy loam soil in the San Joaquin Valley of California in fall 2007. Emissions of 1,3-dichloropropene and chloropicrin were monitored from shank injection of Telone C35. Field treatments included a bare-soil control, composted manure at 12.4 and 24.7 Mg ha-1, post-fumigation intermittent water seals, incorporation of manure at 12.4 Mg ha-1 combined with the water seals or a high density polyethylene (HDPE) tarp. Results showed that neither the manure application rates alone reduced emissions compared to no manure treatment. However, water treatments with or without manure application significantly reduced emissions and the effect was greater on peak emission (80% reduction) than 10-day cumulative emission loss (~50%). The HDPE tarp over manure amended soil resulted in the lowest CP emissions, but slightly higher 1,3-D emissions than the water treatments. This research indicated that using manure applications alone may not be able to reduce fumigant emissions under field conditions. The information is valuable for growers or different commodities and regulatory agencies to identify practices to minimize emissions from soil fumigation.
Technical Abstract: Minimizing fumigant emissions following field applications is required for meeting air quality standards. Application of organic materials (OM) to surface soil has been effective in reducing fumigant emissions during laboratory tests; but the potential to reduce emissions in the field under various management practices, including incorporation methods and application rates, has not been evaluated. The objective of this study was to determine the effectiveness of incorporated composted manure with or without water applications on fumigant emissions under field conditions. Treatments included a bare-soil control, composted manure at 12.4 and 24.7 Mg ha-1, post-fumigation intermittent water seals (11 mm water irrigated immediately following fumigation, and 4 mm at 12, 24, and 48 h), incorporation of manure at 12.4 Mg ha-1 combined with the water seals or a high density polyethylene (HDPE) tarp. Telone C35 was shank-applied at 553 kg ha-1. Emissions of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) were monitored for 10 days. The results indicate that, compared to the control, neither the tested manure application rates reduced emissions. In contrast, the water treatments with or without OM incorporation significantly reduced emissions and this reduction was greater on peak emission (80% reduction) than cumulative emission loss (~50% reduction). Compared to water treatments, the manure + HDPE treatment resulted in the lowest CP emissions but slightly higher 1,3-D emissions. The significant peak emission reduction from water treatment is important in reducing acute exposure risk to workers and bystanders. This research demonstrated that incorporation of composted manure alone did not reduce fumigant emissions.