To extend the life of your drill and to reduce damage how you store your drill after use is very important. There are 3 main actions to carry out:
Ensure the drill is thoroughly cleaned out, and all the seed (and fertiliser if it is a grain and fert drill) is removed, leaving seed in the hopper can not only damage the drill but also encourages rodent activity which can cause a lot of expensive damage to the metering system and the electrics.
The drill should be cleaned and oiled/greased this will help keep any water out of the bearings and moving parts which will prevent them from being seized next time you come to use it.
Keep the control box in a warm, dry place. The control box is one of the most important parts of the drill but is also one of the most delicate. Ensuring that it doesn’t get damp and is kept at a constant temperature means it’ll be working again next year.