The effect of six tillage systems consisting of 3 primary (moldboard, disk and chisel plows) and 2 secondary (disk harrow and field cultivator (twice)) tillage tools on corn production were studied in a factorial of two factors based on a completely randomized block design of six treatments and four replications. The experiments were conducted on Agricultural Faculty of Urmia University farms in 2002. The studied parameters were: tractor fuel energy consumption; soil penetration energy requirement, and yielded corn energy content. The results showed that the lowest and highest fuel energy consumption belonged to chisel plow + disk harrow (962.9 Mj/ha) and disk plow (twice) field cultivator (1871.5 Mj/ha) respectively. The fuel energy consumption IN chisel plow and disk harrow treatments were found to be 30.1% and 23.3% lower than those for disk plow and field cultivator (twice) respectively. There were no significant differences observed among treatments for either corn grain or forage yields .For all treatments the calculated energy output for corn grain was between 36516.8 and 67638.3 Mj/ha, and for corn forage between 154580.1 and 212657.8 Mj/ha. For corn energy ratio (yields’ energy/ consumed fuel energy) the highest were obtained from chisel + disk harrow treatment for corn grain plus forage, the lowest from moldboard plow + 2 times field cultivator treatment for corn grain, and disk plow + 2 times field cultivator for corn forage. The highest soil needed penetration energies for 5 to 40 cm depths belonged to the plots of disk plow + disk harrow, and the lowest to moldboard and chisel plow with disk harrow treatments. The results finally indicated that chisel plow + disk harrow (treatment A) with lowest fuel energy consumption, highest yielded energy and lowest needed soil penetration energy, was the most suitable tillage system.
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