I don't need to tell you tire ballast is important. Tractors and combines have more power than their weight can use and, by adding weight to the tires and/or frame, one can improve the machine's traction and prevent wheel slippage which can damage tires.
There are a couple different ways farmers can add weight to their tractor or combine.
For many years liquid ballast was the main answer. Calcium chloride is a heavy liquid and does not freeze, so was put in the tire tube to add weight.
In recent years, however, manufacturers have moved toward another type of tire ...