My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in JEQ

  1. Vol. 25 No. 1, p. 184-192
     
    Received: Dec 16, 1994
    Published: Jan, 1996


    * Corresponding author(s):
 View
 Download
 Alerts
 Permissions

doi:10.2134/jeq1996.00472425002500010024x

Methyl Bromide Emissions from a Covered Field: I. Experimental Conditions and Degradation in Soil

  1. S. R. Yates *,
  2. J. Gan,
  3. F. F. Ernst,
  4. A. Mutziger and
  5. M. V. Yates
  1. USDA-ARS, Soil Physics and Pesticide Res. Unit, U.S. Salinity Lab., 450 Big Springs Road, Riverside, CA 92507;
    Dep. of Soil and Environ. Sci., Univ. of California, Riverside, CA 92521.

Abstract

Abstract

An experiment is described to investigate the environmental fate and transport of methyl bromide in agricultural systems. The experiment was designed to determine the dynamics of methyl bromide movement through soil, degradation, and total emissions to the atmosphere. This is of particular interest because it will allow an assessment of the environmental impacts (i.e., stratospheric ozone depletion) resulting from the agricultural use of methyl bromide. Methyl bromide was applied at a rate of 843 kg in a 3.5-ha (i.e., 240 kg/ha) field at a depth of 0.25 m and covered with a sheet of 1-mil polyethylene plastic. The maximum methyl bromide concentration in the atmosphere occurred at night between 0200 and 0600 h. During the first 3 d of the experiment, the maximum daily concentrations at 0.2 m above the soil surface were 30, 5, and 1 mg/(m3 of air), respectively. The trend of reduced emissions with time continued until the plastic was removed, when a momentary increase in the methyl bromide emissions occurred. The maximum soil gas concentration 24 h after injection was 30 g/m3 located at a 0.25-m depth. When the plastic was removed from the field (at 5.6 d), the maximum soil gas concentration was approximately 2 g/m3 at a 0.5-m depth. A mass-difference method for estimating the total methyl bromide emissions from the soil, based on degradation of methyl bromide to Br, indicates that approximately 39% or 325 kg (± 164 kg) of the applied methyl bromide was converted to Br and, therefore, 61% or 518 kg (±164 kg) was lost via volatilization.

This study was supported by USDA Coop. State Res. Service Agreement no. 92-34050-8152.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .

Facebook   Twitter