Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 2009
Publication Date: February 3, 2009
Citation: Gao, S., R. Qin, B. Hanson, D. Wang, and J. Gerik. 2009. Comparison of using irrigation and organic amendment to reduce emissions from soil fumigation. p. 184. In Proceedings, 2009 California Plant and Soil Conference, Fresno, CA, February 3 & 4, 2009. Technical Abstract: Many perennial and annual crops require pre-plant soil fumigation to control soil pests for establishing healthy crops and profitable yields. Fumigant use, however, is highly regulated for minimizing emissions to improve air quality in California. To develop practical agricultural practices, we conducted three field trials to evaluate the effectiveness of irrigation and organic amendment on fumigant emissions from broadcast shank application of Telone C35. One field trial indicated that amendment with composted manure at 5 ton/ac under HDPE tarp did not reduce emissions compared to the control (bare soil without manure application). A second field trial tested treatments including control, composted manure rates of 5 and 10 ton/acre, post-fumigation water seals, and combination of manure (5 ton/ac) and the intermittent water seals. Water treatments with or without manure incorporation reduced emissions significantly; but the manure application at both rates did not reduce emissions compared to the control. Emission reduction by water seals was more pronounced on flux peak for both 1,3 dichloropropene and chloropicrin than cumulative emission loss over a 10-day monitoring period. The significant peak emission reduction from water treatment is important to reduce potentially acute exposure risk to workers and bystanders. These data showed that manure amendments alone up to 10 tons per acre are unlikely to reduce fumigant emissions under field conditions. Much higher manure rates may be needed to reduce emissions. A recent field trial tested composted manure application rate at 25 ton/ac and results will be available in the near future. Higher manure application rates, however, would increase the cost, which may not be feasible for some low-profit margin commodities.