Abstract: A fertilizer injection apparatus having hollow, ground-piercing knives connected by tubes to a hopper with a fertilizer delivery system. A tool bar is connected to the hopper by rigid links pivoted to the tool bar at one end about the single axle of the hopper at the other end. A bell crank lever mechanism interconnected between the tool bar, each link and the hopper, maintains the hopper level with the ground regardless of whether the knives are above ground or how far they are inserted. The tool bar and hopper combination are pivotally towed by a tractor and a liquid fertilizer tank system which delivers its contents through hoses to an anterior point on each knife is towed behind the hopper.