When mounting a snow plow to your vehicle, you are adding additional weight to the front end of your vehicle. As such, it sometimes becomes necessary to counterbalance that weight by adding ballast. "Ballast" by definition is a heavy material carried temporarily to provide stability. Ballast needs and requirements will vary depending on what you put on and in your truck. You will want to refer to your snowplow manufacturer recommendations to know if and how much ballast is recommended.