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United States Department of Agriculture

Agricultural Research Service

Title: Effect of Soil Factors on Methyl Bromide Volatilization after Soil Application

Authors
item Gan, Jianying - U C RIVERSIDE
item YATES, SCOTT
item Wang, Dong
item Spencer, William - 5310-20-05 (COLLABORATOR)

Submitted to: Journal of Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 30, 1996
Publication Date: N/A

Interpretive Summary: There is great need to accurately estimate methyl bromide (MeBr) volatilization rate into the atmosphere from soil fumigation, and to develop application and soil management techniques that minimize this volatilization. In this study, we investigate how various factors affect MeBr in the soil and its volatilization rate from the soil surface. Methyl lbromide losses were significantly decreased in an organic-matter-rich soil due to enhanced degradation, and in moist and dense soils due to reduced movement in the gas phase. These results imply that MeBr losses will vary for different application methods. To minimize MeBr loss from soil, MeBr should be applied deep in moist soil under tarped conditions, with soil surface packed before or immediately after the application. Applying MeBr at a shallow depth into elatively dry and loose soil under untarped conditions will result in maximum volatilization and therefore should always be avoided.

Technical Abstract: Two current tasks regarding the use of methyl bromide (MeBr) as a soil fumigant are to accurately estimate its volatilization rate in the atmosphere from soil fumigation, and to develop application and soil management techniques that minimize this volatilization. In this study, we established experimentally that a series of soil factors, e.g., soil type, soil water content and bulk density, affect MeBr behavior in the soil- water-air phases and its volatilization rate from the soil surface. Methyl bromide volatilization was significantly decreased in an organic-matter- rich soil due to enhanced degradation, and in moist and dense soils due to reduced diffusion in the gas phase. These results imply that ther does not exist a typical MeBr emission ratio for different applications. To minimize MeBr volatilization from soil, MeBr should be injected at great depths in moist soil under tarped conditions, with the soil surface packed before or immediately after the application. Apply MeBr at a shallow depth into relatively dry and loose soil under untarped conditions will result in maximum volatilization and therefore should always be avoided.

Last Modified: 9/10/2014
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