it's been over a year since i through out some sucra seed and other mixes in my pasture.
i'd have to say i wished i did the whole thing. probably the only thing that does better (don't know about dry matter measurement) with less water is some fescue in another mix. the faster, longer growing grasses help shade the soil FAR better than the annual grasses. i have reasonable amounts of clover. the orchard grass areas seem to not do as well on my soils without more water. i think i'll fence of the sucra area and gather some more seed. the fescue seems real agressive and the cattle don't seem to like it as much. seems a little harder. sometimes i mow it and gather it and they really like it compared to forage hay.
the thing i like about the sucra seed grass is that it chokes out weeds real well, especially some of the last i'm trying to get rid of, foxtail. all you have to do is mow it when the foxtail heads are green till the sprigs run their course and no more foxtail heads. the sucra areas seem to stay the wettest longest of any area. went back and looked at their site and they mention drought tolerance. what that means, i don't know.
basically, over time, i've gotten rid of broad leaves like mustard, radish, weedy bur clover, russian thistle, fiddleneck, curly dock, coyote bush (a native), and a few other locals. probably one of the worst we have is ripgut brome. i've been throwing native california fescue where the ripgut is and it seems to choke it out pretty fast. my favorite native, blue rye, just isn't tough enough or palatable enough for grazing. the purple needle grass is, but it can get areas that dry out and decay, but it does real well with foot traffic and organic matter accumulation. not real clear on longer term effects of that, though it does stay green for an amazing amount of time.
all in all, i think i would do narrow strips of native, with wider strips of the "improved" grasses with less orchard grass.
there's a better populated testimonial section.
http://www.sucraseed.com/success/index.php
i wished i lived in an area like most on this site and could do a lot more of this.
here's a section for you chambero
http://www.sucraseed.com/success/SweetSpot.php