This will probably be considered a stupid question or idea by a newbie but I'll ask it anyway. Since it is so difficult for these chemicals to get down to the submerged nuts and tubers for a real kill and because Nutsedge tends to grow in small clusters why not inject this chemical six inches down into the ground around the tubers and nuts and in the area of the cluster? I'm thinking of a hypodermic needle like pointed steel tube connected to a high pressure container with a trigger mechanism. Wet the ground to soften it, push in the tube to a depth of 5-6"s and pull the trigger. Has this been tried before?