FIELD TESTING OF A PTO POWERED DISK TILLER

Field testing of a PTO powered disk tiller was conducted in Bangkok cl ay soil. Tests were conducted at different forward speeds of 1, 2, 3, 4 and 5 km/h and 33, 28 and 23-degrees gang angles. Average PTO speed was 540 rpm and average soil moisture content was 26% during all the t ests. The draft requirement was measured by a three point linkage dyna mometer. The PTO torque was measured by a slip ring torque transducer. Specific draft, specific torque, power and energy consumption to till a unit volume of soil were calculated for different gang angle settin gs during passes 1 and 2. Quality of work was assessed in terms of soi l cone index. Better tillage performance was observed at 28-degrees ga ng angle than at 33-degrees. At 23-degrees gang angle the implement di d not penetrate well due to the gage wheel remaining on unplowed soil. It was observed that at 28-degrees gang angle setting, the implement consumed less power compared to the 33-degrees gang angle setting at a ll forward speeds and passes. It consumed as much as 27% more power at 33-degrees gang angle setting than at 28-degrees gang angle setting. The power consumption decreased with higher passes. The energy consump tion was higher at 33-degrees gang angle than at 28-degrees. It was al so higher at lower forward speed compared to higher forward speed at a ny given gang angle setting and pass. The work quality in terms of soi l cone index at 28-degrees gang angle was better than at 33-degrees ga ng angle. Disk tiller performance in unpowered mode was also evaluated . It consumed more draft power during unpowered mode compared to power ed mode.