Is phosphate and phosphorus the same in fertilizer?

Phosphate is a chemical group with the formula R3PO4 where R represents a generally reduced chemical group such as a methyl group or a Hydrogen atom for covalent Phosphate compounds and PO4(-3) for the Phosphate anion with 4 Oxygen atoms covalently bonded to a central Phosphorus atom with 3 negatively charged electrons shared between the four Oxygen atoms. Phosphide is an anion where Phosphorus has three electrons bound to it. It is an extremely strong base in contrast to Phosphate which is a significantly weaker base. Phosphide is also a very strong reducing agent.