I have the same mix. Buffalograss will come up later. They look identical unless you let them go to seed (or you see the buffalograss growing runners/stolons ). The problem that I regret to this day is that I tilled the ground which brought up the dormant weed seeds. I should've watered the bare ground for 2/3 weeks and let the weeds sprout and then kill them with round up (no tilling). I hate to say this but you'll be dealing with those weeds forever now. Buffalo /grama won't choke them out like bermuda could once established.

Please don't put 2-4d. It's nasty stuff and will kill your buffalo/grama as they are first year seedlings.

Thanks adp abq, I was afraid of that - I knew I should have done that too, but was kind of preasured to hurry because I am putting up a swing-set there for my 3 yr old... well, ok, thanks for the advise. Did you get your seed from Plants of the SW? (I love that place)

Corn Glutten Meal is an organic byproduct of dog food etc. A friend who is a Master Gardener in Denver swears by it. The catch is, that it is most effective when applied early spring. Deep watering only as often as the grass requires will help. Frequent watering helps the weeds germinate. You will want to keep the grass fertilized and mowed frequently to make the grass thrive and provide less shade for weed sprouts. Good luck. I'm trying to deal with a monster crab grass invasion in my new planting of Blue Gamma. The Blue Gamma is a real champ in the heat. If either of us comes up with any good leads maybe we could swap info. One of the NM Universities might have good resources through their "Extension Services". Colorado State University Extension Services (see their web site) has a lot of good info on best practices to deter weeds, but weak on natural methods. I'm not into the chemicals because my dogs are grazers.
Good luck!