Biodegradable mulches have been promoted as an environmentally-friendly alternative to plastic mulches. However, according to Washington State University graduate student Henry Sintim, more research is needed to determine how much these mulches actually do degrade and what impacts they might have to the soil.

It is assumed that microorganisms in the soil break down the biodegradable plastic mulch mainly to water, carbon dioxide, and biomass. But to what extent?

Sintim’s Western SARE-funded graduate student project tests four biodegradable plastic mulches. The good news is that in the early stages of the project the biodegradable plastic mulches maintain soil microclimate similar to the polyethylene mulch and provide similar benefits. While the project is still on-going, composting the mulches resulted in more degradation than tilled in soil so this could be a viable disposal method.

NIFA supports this research through the Western SARE grant program and the Specialty Crop Research Initiative. Learn more about biodegradable mulch at the University of Tennessee.

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