We used #9 wire (heavy) for corn stalks "here" also. You're probably right, it worked better for alfalfa & the likes, but it worked somewhat for stalks. We kept the whole roll of wire right up on the plow frame of each plow & replaced broken wires as necessary. It took a good pair of pliers to cut #9 wire. We attached the wires above the coulter itself, but still on the coulter shank. It was somewhat replaced in later years by a commercial product called a "Buster Bar", which I believe was made by Midwest Harrow. It was a large diameter, heavy gauge tube harrow tube that ran from front to rear being carried just past the moldboards on a flex hinge mechanism. We & others in our area also used home made type coverings. You'd bolt a 2x12 to chains & let it dangle over the moldboards & it would help bury trash by forcing the trash down & putting fresh dirt on top of it. Problem became the lack of longevity of the board. It would split & crack after being terribly beat up. Commercial "cover boards" had their own problems. They didn't scour often as well as the plow bottoms & would lead to blockage, but they did become fairly popular for some plows.