Rotary coulter position effects upon rigid shank’s chisel plows performance.

Field tests were carried out with the aim to evaluate the rotary coulter influence on chisel share efficiency. Two test series were conducted. In the first series, three interacting rigid shanks were used and the coulters mounted: a) immediately ahead and b) in the inter-line space of the shanks. In the second trial only one rigid shank (without interaction) was used and the rotary coulter placed in the same position. Both treatments were compared with the shanks working without coulters. A pull-type implement and a FWD, 68.6 kW tractor were used, and recorded the drawbar pull with the aid of a dinamograph. The loosened area was registered through a profile meter and calculated the specific resistance from this data. The loosened area was affected by the spatial arrangement of the rotary coulters. Significantly reductions on drawbar pull were registered with rotary coulters working in the interline space of the shanks respect the treatment without coulters. The drawbar pull reduction of interacting and no interacting tines were 7.5 % y 19.2 % respectively. The rotary coulters and his spatial arrangement show influence on the tillage efficiency.

Key words: Chisel plow, rotary coulter, traction, performance, specific resistance.