Qin Ruijun, Gao Suduan, Hanson Bradley D, McDonald Jason A, Trout Thomas J, Ajwa Husein
Department of Plant Sciences, University of California, Davis, 1636 East Alisal Street, Salinas, California 93905, USA.
J Agric Food Chem. 2007 Oct 3;55(20):8193-9. doi: 10.1021/jf071946w. Epub 2007 Sep 12.
Low permeability tarps can effectively minimize fumigant emissions while improving fumigation efficacy by retaining fumigants under the tarp. However, when planting holes are cut through the tarps, high-concentration fumigants may be released and result in environmental and worker safety hazards. In a 11-day column study, we explored the effect of drip irrigation application of ammonium thiosulfate (ATS) on 1,3-dichloropropene (1,3-D) and chloropicrin (CP) degradation in soil. Decrease of 1,3-D and CP concentrations in soil-gas phase followed a three-parameter logistic equation for all treatments. It was slowest in the control with a half-life ( t 1/2) of 86.0 h for 1,3-D and of 16.3 h for CP and most rapid when ATS was applied at 4:1 ATS/fumigant molar ratio with a half-life of 9.5 h for 1,3-D and of 5.5 h for CP. Our results indicate that applying ATS via the drip-irrigation systems to soil can accelerate fumigant degradation in soil and thus reduce emissions. This technical solution may be applicable in raised-bed strawberry production where drip-application of fumigants under tarps has become common.
低渗透性苫布可以通过将熏蒸剂保留在苫布下，有效减少熏蒸剂排放，同时提高熏蒸效果。然而，当在苫布上切割种植孔时，高浓度的熏蒸剂可能会释放出来，从而造成环境和工人安全危害。在一项为期11天的柱体研究中，我们探究了通过滴灌施用硫代硫酸铵（ATS）对土壤中1,3-二氯丙烯（1,3-D）和氯化苦（CP）降解的影响。所有处理中，土壤气相中1,3-D和CP浓度的降低均符合三参数逻辑方程。在对照处理中降解最慢，1,3-D的半衰期（t1/2）为86.0小时，CP为16.3小时；当以4:1的ATS/熏蒸剂摩尔比施用ATS时降解最快，1,3-D的半衰期为9.5小时，CP为5.5小时。我们的结果表明，通过滴灌系统将ATS施用于土壤可以加速土壤中熏蒸剂的降解，从而减少排放。这种技术解决方案可能适用于高畦草莓生产，在这种生产方式中，在苫布下滴施熏蒸剂已变得很普遍。
