Grass waterways are an important part of a farm's overall soil conservation plan, but producers and landowners have to work at maintaining them or they cannot fulfill their function, said DeAnn Presley, K-State Research and Extension soil management specialist.
Grass waterways are permanent strips of grass seeded in areas of cropland where water either concentrates or flows off a field from terraces or diversions. They have several functions, each of which adds value to a farm, Presley said.
"The overall purpose of the waterway is to carry runoff water from a field. The grass prevents the water from forming a gully and traps some sediment," she said. "In addition, the vegetation absorbs some of the chemicals and nutrients in the runoff water, and provides habitat for small animals and birds."
For maintenance of grass waterways, Presley recommends:
Lift equipment out of the ground and shut off spray equipment when crossing the waterway. Encourage commercial applicators to do the same.
If bare spots appear, reseed with sod-forming grasses.
Do not use the waterway as a roadway. Tracks can turn into gullies in single, intense rain events.
Do not overgraze or allow livestock trails to form. These can quickly turn into gullies.
If gullies form, fill, reshape, and reseed. Contact your local USDA Natural Resources Conservation Service field office for recommendations on grass species to plant.
Fertilize cool-season grasses regularly at a rate of 30 to 40 pounds of nitrogen per acre between November and mid-March. Many producers fertilize grass waterways when they topdress wheat.
Mow periodically, but don't mow between April 20 and July 15 when birds are nesting. It's important to mow grass because it encourages the formation of a dense sod. Also, shorter, thick grass is more effective at trapping sediment than tall grass, which will lay over in an intense rain event.
Be careful not to till into the edges of the waterway.
Avoid end rows planted parallel along the waterway. They may allow gullies to form on the waterway edge.
For more information, see K-State publication MF-1064, "Maintaining Grass Waterways," available at your local county Research and Extension office or at: http://www.ksre.ksu.edu/library/crpsl2/mf1064.pdf/.