My tractor insurance was an additional $40 per year (with my excavator being another $40 a year on top of that) as listed on my homeowner's policy. They were listed for a specified value. It was extremely wisely spent money when my shop burned last summer. It sure hurts to be picking up the burned remains of your favourite tractor and dropping it in the scrap bin. Knowing what you're getting for it, no quesitons asked helps a little. By agreeing to specified value, it means that when lost, that's what is paid out - no depreciation. I lost an uninsured airplane and 6x6 ATV which really stung, but overall the insurance company was excellent with me, and actually paid me more than I asked for, so brand new JD 1025R replacement tractor. I understand that tractors of more than 30HP are insured differently.
Either insure it, or be prepared to put on your big boy pants and walk away without a word if you lose it - I didn't expect to have a fire!