Minnesota DOT Explores Hemp for Erosion Control

By Jean Lotus, PanXchange

A pilot program to develop hemp-based erosion control materials for the Minnesota Department of Transportation is in its second year to develop alternatives to plastic erosion tools. 

The $200,000 program develops ways of processing hemp fibers into biodegradable prototypes of erosion control blankets, hydraulic mulch, sediment control logs and silt fences. 

MnDOT wants to replace temporary plastic products used for construction projects. Plastic products generate 30 tons of plastic to be landfilled per year or remain on the landscape, degrading into microplastics, the agency said. 

“One of MnDOT’s sustainability goals is to reduce the use of plastic by requiring biodegradable erosion and sediment controls,” Riley Gordon, project manager, said in a statement. Hemp is an ideal crop because it provides “significantly greater water quality, soil erosion and C02 sequestration benefits than other crops,” Gordon added.

The private-public partnership includes the Agricultural Utilization Research Institute (AURI) and the Minnesota Department of Agriculture along with regional hemp processors and growers in Minnesota and North Dakota. Researchers hope the manufacture of the new bio-products will create supply chains for hemp farmers and processors aimed at a large institutional buyer. Already bio-based erosion products exist for agricultural waste products using straw, coconut fiber, aspen fiber, jute and wattle from rice and wheat. 

MnDot installs enough erosion and sediment control products to protect 1,100 acres from erosion and prevent 125,000 tons of sediment from entering surface waters each year. 

With seed money to develop the bio-derived products, MnDOT plans to phase in specifications to allow their use. Supporters expect local governments and private construction projects will also adopt the specs, and MnDOT has received interest from other state DOTs, who face similar plastic problems, the agency said.