It depends on the kind of weeds. Choose different herbicides according to different grass species. There is also the purpose of weeding, whether to kill only unearthed weeds or to seal the soil. 1. Soil treatment: trifluralin and diuron. There are atrazine, simazine, acetochlor ... 2. Stem and leaf treatment (directional spraying): glyphosate, paraquat, ... can be selected according to the specific situation, and the effect should be good. I guess you should use it to seal sulfonylureas, which lasts for a long time and should be your choice.