I attended a CRAFT field day yesterday comparing mulches. Scotch Hill Farm in Brodhead, WI received a SARE Grant to study three different types of mulch: oat straw, wheat straw and switchgrass.
The farmers have planted a 4.5 acre field in switchgrass, with the seed being the correct genetically native species for that county/area (donated by Applied Ecological). During the first year, the farmers should mow 2 to 3 times and then burn in the fall or spring. The Scotch Hill farmers have only mowed once, but when we visited their switchgrass field - all was not lost, there was quite a bit of switchgrass.
One of the many benefits of using switchgrass is that it doesn't require yearly planting. Once you get a switchgrass field established; it can last more than 10 years, supplying you with switchgrass straw for mulching and livestock bedding. Once establisheed, it forms a native planting root mat which keeps other plantings (i.e. invasives) from growing. Also, you can cut/bale it in November instead of July or August when oat and/or wheat need to be cut and baled. This is a huge advantage for market growers who obviously are pretty busy during July and August.
Their switchgrass field had been in corn. It was chopped as low as possible and disc'd. Immediately before planting it was disc'd again and then the switchgrass was planted with a seed-drill. These farmers worked closely with the DNR and in fact, were able to borrow the DNR's seed-drill. Frost seeding also works well for switchgrass.
The field day participants also viewed some of the planting fields that were mulched with the 3 different types. They had a crop failure of their heirloom brussels sprouts. The ones with wheat and oat straw were quite stricken - those with switchgrass mulch were not as bad. The switchgrass mulch was still readily apparent and the weed barrier was much better than the oat or straw. Switchgrass breaks down slower allowing for better weed suppression. Oat and straw and also harbor mold and rust which when used as mulch can transfer the infection to the crop. (Barb, you were right!)
Scotch Hill Farm strives to grow all of their inputs needed for their livestock. They have 10 acres in hay and 5 in switchgrass. They raise 10 ewes for meat and wool and 12 goats for goat's milk; along with 75-100 chickens.