Bill others have already sent confirmation that crawler tractors were used in ag service. In my experience in Iowa, not so much. In Iowa crawler tractors were mostly construction equipment. Farmers in the mid-west preferred rubber tired tractors. In the past decade or so large farms have been using tracked tractors, but they have rubber tracks not metal tracks. I may be making assumptions but I believe several factors influenced the choice of farmers.
1) The tracks were hard on road and bridge surfaces. Rubber tires were far less destructive, and easier to fix/repair.
2) Crawler tractors are slow, a factor when moving from field to barn or when taking farm products to town for sale or shipment.
3) Crawler tractors had more power than was needed on smaller farms. Midwest grain farms were small until past the time era of this list.
4) Crawler tractors were expensive, esp diesel powered units. If you didn’t need it why spend money for it. Mid-west farmers are frugal
Well you get the idea. I think you had to be a very large farmer to justify the use of a crawler tractor in typical mid-west farm operations. The John Deere B or McCormick Deering Farmal (later IH) was the tractor of choice up through the mid 50s.