Design, development and performance of a disc plough combined with rotary blades

This research focused on the development of a new combined tillage machine for adequate clod breaking/pulverizing in a single pass. A disc plough combined with rotary blades (Comboplow) for land preparation was designed, fabricated and tested at Universiti Putra Malaysia (UPM) Research Farm. The machine consists of a chassis, three point hitch, transmission system (universal joint with safety clutch, gear box, input shaft, output shaft, chain, sprockets, main shaft, and holder of blades), disc, rear wheel, rotary blades and adjusting mechanism. The Comboplow includes two units of tillage tool comprising of a disc plough and several rotary blades. The disc plough cuts partially or completely inverts a layer of soil to bury surface material. The soil in contact with the surface of disc would be cut and pulverized by the rotary blades. Multiple tillage operations are reduced to a single pass and thus reduce the number of field trips as compared to conventional tillage practices resulting in reductions of soil compaction, labour, fuel cost and operation time. The rotary blades can be adjusted to certain speed and depth with the help of changing the sprockets and nuts, respectively. The Comboplow, was tested in the Serdang sandy clay loam soil texture for energy consumption and some soil characterization parameters. The tests were performed based on 2×3 factorial treatment in RCBD experimental design with three replications. Block dimensions were 25m×27m. The treatments were three types of blade (straight, curved, and L-shaped) and three rotary speeds (130 rpm, 147 rpm and 165 rpm). The parameters measured were consumption of energy, bulk density, moisture content, Mean Weight Diameter dry basis (MWDdry), Mean Weight Diameter wet basis (MWDwet),Stability Index (SI), Instability Index (II), 2<Aggregate Size Distribution<8mm (ASDd8) and 0<Aggregate Size Distribution