Thiosulfate and manure amendment with water application and tarp on 1,3-dichloropropene emission reductions

Reducing fumigant emissions is required for minimizing bystander risk and environmental impact. Effective and economic field management methods including commonly used surface sealing technique and soil amendments are needed for achieving emission reductions. This research determined the effectiveness of ammonium thiosulfate (ATS) and composted manure amendments to surface soil in combination with water application or high density polyethylene (HDPE) tarp on reducing emissions of 1,3-D from soil columns. Surface treatments included an untreated control, water seal (single water application at time of fumigant injection), ATS amendments at 1:1 and 2:1 molar ratio of ATS:fumigant, composted steer manure at 3.5 kg m(-2), and HDPE tarp over 1:1 ATS or the manure amendment. Cumulative 1,3-D emission loss over two weeks was greatest for the control (52% of applied). The HDPE tarp over ATS and manure treatments had the lowest 1,3-D emissions at 24 and 16%, respectively. Treatments with ATS or manure alone reduced 1,3-D emissions (29-39%) more effectively than water seal (43%) and further benefit was gained with the addition of HDPE tarp. Amendment of surface soil with organic materials shows greater potential in minimizing fumigant emissions than with chemicals with the need for a better understanding of the organic-fumigant reaction mechanism.