In general, you must report crop insurance proceeds in the year you receive them. Federal crop disaster payments are treated as crop insurance proceeds. However, if you use the cash method of accounting and 2014 was the year of damage, you can elect to include certain proceeds in income for 2015. To do this, check the box on line 5c and attach a statement to your return. See chapter 3 of Pub. 225.
Form 4835 Instructions