Disk harrow operational performance in three engine rotation speeds
Even with the current techniques of conservation tillage, mobilization is still a widely used practice, either in initial preparation as in reform of agricultural areas. In this context the harrows are widely used, mainly because of the good working capacity and high efficiency in tillage soil. Thus, this study aimed to evaluate the operating performance of a disc harrow in clay soil using different spins. The experiment was conducted at the Experimental Farm Lageado, belonging to the Faculty of Agricultural Sciences - UNESP Botucatu - SP. For accomplishment of the tillage was used a disk harrow, mark Tatu Marchesan model GAICR off-set, with a cutting width of 2.57 m and consists of 20 cut disks of 0,71 m (28 inches) spaced at 0.27 m. To exert traction the disk harrow was used of tires tractor John Deere brand, model JD6600 with power 91.48 kW (121 hp) engine. The used treatments were three engine revolutions, 157 rad s-1 (1500 rpm), 189 rad s-1 (1800 rpm) and 220 rad s-1 (2100 rpm), and evaluated the working speeds achieved, effective field capacity, operational fuel consumption, working depth of the disc harrow, skating wheels of the tractor and drawbar force. The results indicated that most job rotation provided lower fuel consumption and greater field capacity. However, the increase in speed of work provided a reduction of working depth of the discs of the harrow.