Potential of Using Low Permeability Tarp to Reduce Emissions and Application Rates in Soil Fumigation.

Potential of using low permeability tarp to reduce emissions and application rates in soil fumigation

Suduan Gao, Ruijun Qin, Alfonso Cabrera, Brad Hanson, and Dong Wang 

Soil fumigation is an important tool in controlling soil-borne pests such as nematodes and weeds. The detrimental impact of fumigant emissions on the environment, however, has resulted in stringent regulations on fumigant use and challenges to the future availability of fumigants for agricultural use. The objective of this study was to test the impact of tarping with a newly commercialized low permeability film (VaporSafe^TM, also known as totally impermeable film or TIF) on pest control efficacy, fumigant concentration in the soil, and fumigant emissions. A field trial was conducted in a sandy loam soil near Parlier, California to test full (the currently used maximum rate) and half rates of Telone C35 with TIF tarp compared to a conventional HDPE tarp. In addition to improved weed control, the 50% reduced rate under TIF had an efficacy of 98% or more, on citrus (Tylenchulus semipenetrans), and pin (Paratylenchus spp.) nematodes at different soil depths. Emission data showed that TIF can reduce emission >90% compared to bare soil and standard polyethylene tarp.  However, surges of emissions upon tarp-cutting after two-weeks were measured that potentially endanger workers and by-standers. Either increasing the waiting period before the tarp is cut or using lower rates are possible solutions to reducing potentially exposure risks.  The field data indicate that using TIF tarp in soil fumigation can effectively reduce emissions to ultra-low level and has a great potential to reduce chemical input to the soil/environment.