Thanks everyone for the thoughts above. Stevenf - your pricing seems very similar to what I have been quoted given your larger tire size. I have decided now to go ahead and fill. I appreciate you sharing your experience with the filled tires. Dateacha - I do think some spraying is in my future as well. The CRP program is in the process of developing new regulations and I think in future years, instead of mowing, we are looking at strip disking about 1/3 of the grassland per year, or applying chemicals and mowing about the same amount. Then in succeeding years, you do a different 1/3 until in 3 years everything has been covered. My fear is that it will be 3 years on any given slice of ground between whatever treatment is chosen, and I may still wind up with the spears in the field. I guess I can't complain too much as long as they are paying the bills. Thanks to all. Great forum, great info.