THE AIRPORT CONSISTS OF THREE SOD STRIPS NONE OF WHICH CONTAINS RWY LIGHTS. THE CFI AND STUDENT DEPARTED THE ARPT FOR A LOCAL NIGHT FLIGHT. THE CFI STATED THAT UPON RETURNING TO THE ARPT HE CALLED THE ARPT OFFICE ON THE UNICOM FREQ AND REQUESTED THE NIGHT DISPATCHER TO DRIVE OUT AND ILLUMINATE THE APPROACH END OF THE RWY SO THAT HE COULD LAND. THE CFI CIRCLED THE ARPT AND SAW THE VEHICLE NEAR THE RWY WITH THE HEADLIGHTS POINTED IN THE DIRECTION OF LANDING. THE CFI CONTINUED TO STATE THAT THERE WERE NO GROUND FEATURES VISIBLE BECAUSE IT WAS DARK. THE ACFT TOUCHED DOWN NEAR THE ILLIMINATED AREA ON A NORTHERLY HEADING AND HE ASSUMED HE WAS ON RWY 36. SHORTLY AFTER TOUCHDOWN THE ACFT WENT INTO A SOYBEAN FIELD AND COLLIDED WITH A DITCH. AFTER THE ACCIDENT IT WAS DISCOVERED THAT THE DISPATCHER'S VEHICLE WAS NOT ILLUMINATING THE APPROACH END OF RWY 36 BUT INSTEAD WAS ILLUMINATING AN AREA NEAR THE INTERSECTION OF RWYS 21 AND 32.