>Mark, light weight prairie ecologist, says...
>A major factor in the prairie system is the mix of C-3 (3 carbon
>photosynthesis, or cool season) and C-4 (4 carbon, warm season) grasses and
>forbs. The C-4's are typically bunch grasses and take more time and care to
>establish than the C-3's. The growth curve of the C-4's almost perfectly
>compliments the dip the c-3's take in mid summer. The real tricky part in a
>grazing system is growing these plants together. In general the
>recomendations I get are to grow C-4's alone or with a single legume
>species. In native prairies in the upper midwest we do get some cool season
>native grasses that do well with the C-4's, especially Elymas sp. and Stipa
>sp. These species mix well with the C-4's and are your best bet for full
>season growth. I'm looking into using C-4 grasses, Cup plant (Silphium
>perfoiliatum) and native legumes, esp. lead plant (amorpha canensis) as a
>basic summer pasture with a little elymas as an early green up c-3 (Elymas
>canadensis is also an excellent nurse crop for prairie development). I
>probably won't graze this until mid summer and stop in early fall when my
>C-3 pastures come back in. At this point I'm not trying to get a full
>season mix, just not sure how to do it. Any ideas on this?
>Mark
Mark, that's a really nice answer, which I am going to put into my files on
that subject as a gem. However, you leave out the broadleaf plants
altogether. Also some bunch grasses hear and there seem to have high sugar
contents (by the sophisticated analytical method of sucking the stems) and
probably contribut to overall digestion of coarse material.
As you know, I'm interested in sustainability and though not a finished
ecosystem, the grass, Indian, buffalo prairies were sustainable.
I'm not sure where the fixation on grasses comes from in grazing. I see my
animals eating leafy vegetation, including tree leaves. Russion research
(which I read about second or third hand in the Maine Tree Crops newsletter)
indicates that poplar leaf and twig meal has feeding value equal to (or
slightly better than) alfalfa. In my situation, where water competition is
not an issue, spot stands of poplar can serve as shelter (larger trees) and
feed, smaller trees, and I doubt that the grass will even notice that they
are there.
It was the forb and broadleaf annual ebb and flow on the prairie, where I
watched it in Kansas, that fascinated me. It didn't require a lot of inputs
to keep it productive and if we can make as much money with a more beautiful
pasture that emulates the prairie by spending a lot less to produce a little
less, I'm for it.
Dan