By Elizabeth Dunbar

MPR.org/90.1 FM

Many farmers have long endorsed the practice of planting buffer zones to separate farm fields from waterways. But now that Gov. Mark Dayton and legislators from both parties are pushing a bill to require buffers, some farm groups are objecting.

Buffers can be grasses, trees or shrubs. They drink up some of the pollutants — like nitrates from fertilizer — that wash off farm fields and end up in waterways. They also help keep stream banks and riverbanks in place.

It’s not a new concept, and Steve Woods of the Freshwater Society has proof.

Inside a ‘90s-era document sporting vintage computer graphics on its cover are some of the same recommendations state lawmakers are considering today.

“At that time they were talking about 50-foot setbacks,” Woods said. “This is well-established physical science.”

Dayton first proposed requiring 50-foot buffers on all streams and rivers in the state back in January.