How to make a 500+day server run smooth again?

So , i just realized that after a long time playing on the same world , with 500+ days or so, the amount of trash that stays on the ground makes the server lag. Not too much for me, but a lot for some of my friends, either way its an issue for everybody.

The first thing that comes in my mind is using console commands to get rid of the items on the ground, but i am not sure what commands to use, if they are effective, and if it may accidentally  delete important things from the world. Also, any other advice on keeping a server running smooth for a long time will be very appreciated.

TLDR : I Would like to know console commands to keep 500 day+ worlds running smooth , thanks!