If you're importing goods for the farm, your best bet is to have a broker do the entry under your farm's business number, or your son would need signing authority and would have to complete his own entry for the farm.
Your personal goods, no issues at all, but the tractor parts and farm parts are considered commercial goods so best to be prepared and have an entry completed or be prepared to complete a commercial entry.
A lot of farm goods used for tractors/combines/etc are tax free and a broker's entry will account for the exemption codes as well.
https://www.cbsa-asfc.gc.ca/import/guide-eng.html