The experiments were carried out at the farm of El-Gimmaza Research Station, El-Gharbia Governorate , on clayey soil . The field study was conducted to determined the energy requirements for operating the rotary plow as primary and secondary tillage machin under Egyption conditions . The results indicated that , the energy requirement for operating the chisel plow the equivalent of 67% from the energy requirement rotary plow  at the same operating speed and soil conditions .The rotary plow produce a suitable seedbed without a secondary tillage operation . Therefore , the use of rotary plow to prepare a suitable seedbed as secondary tillage need the energy equivalent to 82 % of the energy needed using the chisel plow for seedbed preparation.