And make sure you follow the mixing directions, too much crop oil can burn and set back the broadleafs(clover) you are trying to keep. Clover is pretty resilient, but too much crop oil has been known to set it back in some cases. I think it would be fine to use the n-i surfactant since you already have it, but you will definitely ensure a better kill on your grasses with crop oil. If you have foxtail, the n-i surfactant will likely do the trick, something like quackgrass or johnsongrass on the other hand, will likely require crop oil to get any type of decent kill, and it will only top kill the johnsongrass, it will likely live on through the underground rhizomes. Not sure on how solid the kill would be on quackgrass?