The best soil would be a loose soil that can clump together but easily breaks apart with very little pressure. The soil should smell nice. But clumpy soil can cause major problems depending on how thick it really is. These clumps will end up becoming dry inside and roots that grow into them may die because of this if the clumps are large enough. But if there just some small clumps you should be fine for the most part a plant here or there while young may die by contacting clumps like this especially when using a fertilizer like miracle grow if it's not dissolved and roots come in contact with the hard crystal granules your roots will most likely begin to have problems and fry the plants.

After your harvest try adding some green sand or perlite to help your soil from clumping in future years which will save you the work of declumping in the first place.