Looking at this forum post:
www.ytmag.com/cgi-bin/viewit.cgi?bd=oliver&th=77717
it looks to me as if coverboard may be synonymous with trashboard.
This site:
www.overums-bruk.se/overums/bxcxdx/bxcxdxindex.htm
translates "coverboard" to "diflecteur" in French, so maybe the Spanish will be "deflector" or "desviador" but I can't find any exact reference to this Spanish use.
I must say I am not entirely clear what it is. There is supposed to be a picture on:
http://www.howard-australia.com/prod...erum103.pdf%22
but I can't decide what it is supposed to be.
There's also one at:
www.farmstar.co.uk/genkv.htm
which makes me think it may be something like the "Vorscläger od. Dungeinleger" at:
http://de.wikipedia.org/wiki/Bild:Vdpflug.jpg
which I think pushes crop remains and animal manure into the path of the plough although the Överum pdf suggests to me that trashboard/coverboard may be a type of skimming plough (i.e. a trashboard/coverboard is a particular type of mouldboard) just to remove crop debris.
At:
www.freepatentsonline.com/5191945.html
is a patent which starts:
"A plow debris deflector for attachment to plows is disclosed. The plow debris deflector improves trash flow, buries stalks, stems, leaves and other debris without discing and requires low maintenance while providing excellent soil rotation and burying cover crops, trash, litter and other debris eight to ten inches beneath the surface of the soil. The plow debris deflector may include a first vertical portion having a mounting mechanism for mounting the plow debris deflector to a moldboard plow."
which to my mind strengthens the "Einleger Streichblech"/"deflector" idea.
