I get your point if you regard them as a asset but if you want rid just spray, far cheaper than mowing and baling and they are gone in year one. Speaking as a farmer on a Cumbrian hill farm with the second highest rainfall in England ( after the lake district) we see a lot of rushes in the area …..some can control them some cannot but lack of control is not always poor farm practice but often to do with environmental schemes, or even the desire for shelter for the outside lambing guys.I would totally disagree. Some of us down here cut fields with rushes every year and bale it up dry for bedding, trouble is , the rushes get less every year. Also after cutting, put a bit of muck or slurry on the ground and the stock will eat the succulent young growth.