Yes, you can use it without fertilizer, but it is recommended to use a low rate of N when you first switch over to the product. It helps with the transition from synthetic to organic.
We are applying 7 oz holganix with .25 lbs N (from soluble urea) I will probably switch that to 1/8 lb N for the next round. And continue with that thru the summer and test a few without any N to see if there is an appreciable difference.
"What do you mean we canít get rid of those weeds in time? Then go over there and put some fancy signs with Latin names in front of them."