My yard is approx. 3 acres and I have never fertilized the grass.I also have a pasture thats approx. 5 acres. Its pretty obvious that I need to fertilize but need to know what to use that won't cost a fortune.Is there a product that would be"affordable"to use on this size lot?? Or do I need to remortgage my house??What do farmers use? Any help would be appreciated,Thanks,Gary