Well I'm about to post about the recycled soil I've made today because of the same reason. I have used a oild soil mixed with a lot of stuffs but I have the chance to have some dry grow nutrients from Greenhouse feeding and some from Mr B's Green trees , I've mixed 3 table spoon of each , I've put some coco fibers and coco coir into the soil from a young coconut tree that was drying in the soil , I've taken some wood from a dead trunk that is almost like peat as the trunk is dead since a while , I 've put some potassium sulfate that I've saved from a Sweat potatoes grow and tommorow I will burn some palm trees "leaves" to get some arsh to mix it with the soil.
If you are just re using the soil without improvng it like I've done then use the full dosage of nutrients and consider your soil like a light mix , if you can inoculate some beneficials it will be better