The experiment lay out; Where, O= oats pure stand; O+V= oats-vetch mixture; V= vetch pure stand; R1= first replication; R2= second replication; R3= third replication; R4= fourth replication; T1= zero tillage; T2= minimum tillage (one tillage with moldboard plough and four ploughings with cultivator) and T3= conventional tillage (one tillage with moldboard plough and six ploughings with cultivator).