because synthetic kills the organics that's already in the soil. I would let the micro organism do the work for me rather than fighting against nature that has already been done for years naturally. How do you think trees and other plants that grow in the wild? Natural organic nutes are already in the ground for them from decaying plant matter or worms in the soil birds shit etc.I would just dig the hole and fill up the space with your choice of organic soil and just let it grow and add a little food here and there at the end of its cycle. Less work IMO.