Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electric charge. The SI unit of electrical resistivity is the ohm metre (Ωm). It is commonly represented by the Greek letter ρ (rho).

Electrical conductivity or specific conductance is the reciprocal quantity, and measures a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ (sigma), but κ (esp. in electrical engineering) or γ are also occasionally used. Its SI unit is siemens per metre (S·m⁻¹) and CGSE unit is reciprocal second(s⁻¹):

what EC fertilizer do we have?
Calcium ammonium nitrate
Calcium nitrate
Potassium nitrate
Mono potassium phosphite
Mono potassium phosphate