The experiment was conducted in fields of Agricultural College - University of Baghdad in 2009 insilt - clayey soil in order to study the effect of sowing speeds on some economical, technical performance indicators and energy requirements for machinery unit under variable levels of sowing depths. The tractor "New Holland" and the grain drill“Stegested"were used machineryunit. Threesowingspeed(6.28, 7.61, and 11.43) km / hrepresented the main plots and three sowing depths (3, 6, and 9) cm represented the sub-plots. Some technical performance indicators for machinery unit were studiedwhich include: percentage of slippage, effective field capacity, field efficiency and fuel consumption per unit area,as well as calculating the total operation costs and energy requirements for the machinery unit. The Experiment was carried out by using split - plot with complete randomized block design in three replicates. The results showed that the third speed of sowing 11.43 km / h was superior among other sowing speeds in recording higher rate of effective field capacity of 1.08ha / h and lower rate of fuel consumption per unit area of 8.11 L / ha and lower rate of total operation costs for machinery unitof 13594 ID / ha(10.875 US$ / ha) with lower rate of energy requirements for machinery unit of 29.40kW. h / ha while the percentage of slip was within the permissible limits of 10.98%.The first depth of sowing of 3 cm was superior amongother sowing depths in recording lower rate of slippage percentage of 4.64% and higher rate of effective field capacity (0.87ha /h) and higher rate of field efficiency (71.72 %) with lower rate of fuel consumption per unit area of 8.38L / ha and lower rate of total operation costs for machinery unit of 16721 ID / ha (13.376 US$ / ha) with lower rate of energy requirements for machinery unit of 30.34kW. h / ha.
As for the interaction between sowingspeedand sowing depth, it was significant for all parameters whereas the third speed of sowing of 11.43 km / h with the first depth of sowing (3 cm) was superior in recording higher rate of effective field capacity (1.16ha / h) and lower rate of fuel consumption per unit area (6.32L / ha) and lower rate of total operation costs for machineryunit of 12022 ID / ha (9.617 US$ / ha) with lower rate of energy requirements for machinery unit (23.05 kW. h / ha) while the percentage of slip was within the permissible limits of 6.59%.