I attended a blueberry training earlier this week in Gainseville, FL. We stopped at Island Grove nursery and toured their farm. In the below picture are 2 year old Meadowlark blueberries.
In order to get fertilizer through the plastic mulch they cut slits in the plastic and use special equipment to blow fertilizer through each opening.
The fertilizer is blown in each opening using the equipment seen in the below pictures
I’d say the results speak for themselves!