Source
Weed 'Em and Reap Part 2: Reduced tillage strategies for vegetable cropping systems [DVD]. A. Stone. 2006. Oregon State University Dept. of Horticulture. Corvallis, Oregon. Available at: http://www.weedemandreap.org (verified 17 Dec 2008).
Featuring
Nancy Creamer, Center for Environmental Farming Systems. Goldsboro, NC.
Audio Text
The undercutter was designed to kill cover crops and leave them on the surface as a mulch. By leaving cover crop residue intact versus mowing them into smaller pieces, growers can get longer weed suppression from the cover crop mulches. The first tool in the undercutter is this coulter that cuts through the cover crop. A lot of times we use hairy vetch which is quite viney, so we need to really have a clean cut so the rest of the implement can work. The second part of the undercutter is the cutting blade. And this we actually used a motor grader blade upside down and it cuts the whole width of the raised bed about 2” below the soil surface. Finally the last tool on the undercutter is this roller, which is just some notched steel and it just rolls the cover crop down nice and flat as it moves through the field.
There are several existing implements in agriculture that can be modified to do the same job as this, for example, a beet lifter might be used. While this system can work well in lighter soils and with good soil moisture, some further engineering would help it be more applicable with a broader range of soil types and soil moisture conditions. Weed suppression can last about 6 weeks, but it really depends on the thickness of mulch that’s left on the soil surface. Another thing that this system can really benefit from is a cultivator that could work underneath the killed residue if weeds do get out of control later in the season.