Just make sure the fuel is fresh and put in a container that is clean and free of water. Most of the issues that people use additives for are an attempt to remedy one of more of those issues, or an attempt to fix a starting or running problem on the tractor that isn't related to the fuel itself (such as worn rings, worn seals/gaskets, a worn or out of time injection pump, worn/defective injectors, worn battery, worn starter, corroded or loose battery cables, worn/defective glow plugs, etc.)
Modern diesel fuel is different from previous diesel fuel. Since 2010 all diesel fuel, including off-road (red) diesel is ultra-low sulfur diesel with less than 15 ppm sulfur. Red diesel is simply on-road (clear) diesel with a red dye to mark that you didn't pay road fuel tax on it. From 1993 to 2010, there were different allowable sulfur levels in on-road vs. off-road diesel, but not since then. Sulfur in on-road used to be as high as 5000 ppm in 1992, in 1993 that was lowered to <500 ppm, and in 2007 it was lowered to the current standard of <15 ppm. Off-road was limited to <3000 ppm in 1993, <500 ppm in 2006, and <15 ppm in 2010. Diesel fuel must meet certain ASTM lubricity standards to be sold as diesel fuel and ULSD is no exception. ULSD does require additives to meet this that regular diesel did not, but those additives are added prior to the fuel being sold, the user of the fuel doesn't need to add anything to the fuel for it to meet specs.