A pickup bed can only hold 1/2 cord of firewood if stacked neatly in the pickup bed.
So it would take 2 pickup bed loads of firewood to equal 1 cord of firewood.
A full cord of firewood has a volume of 128 cubic feet, and is measured as a pile 8 feet long, 4 feet high and 4 feet wide.
So you could fit a full cord of firewood on a large trailer but not in the back of a pickup bed.