Dan is absolutely right. At an area feed mill I did see some 50# bags of 0-0-46 potassium, and 0-42-0 phosphorus (or similar), so it is available. You can mix/put down, what ever fertilizer blends you have locally available to get as close to the recommended applications of P & K as you can. Trick would be to do it with as little Nitrogen as possible, at this time.