buckmine - thanks

If you were knifing in the urea - it would probably be ok - but most people knife in Anhydrous not urea. If you were over-the-top-spraying liquid Urea - I'd agree with Ron and say - "probably not" - because the Glyphosate needs a chance to work on an "actively growing" plant (weed). and a liquid Urea application at the same time - might cause the weed to "go dormant" in response to the quick fix of Urea - reducing the Roundup effectiveness.

However - with that line of thought - a spraying of Round up 1 week after Urea incorporation would be a good thing. Once the plants (weeds) have a chance to get accoustomed to the N, they grow quickly - the Roundup at that stage would cause a very quick reaction.