Performance of combine mounted straw managing system during rice crop harvesting

The major problem during sowing under conservation tillage in combine harvested paddy fields is the frequent choking of conservation tillage machines due to long loose straw, lying in the windrows. Effective residue management requires both straw and chaff to be finely chopped and evenly spread over the entire cutting width of combine. The study was undertaken to evaluate the performance of straw managing system (SMS), developed as an attachment for the existing combine, affected by various independent parameters. Three levels of number of rows of stationary blades (one, two & three rows), three levels of rotor speed index (30, 35 & 40) and two levels of deflector angle (20° & 30” with horizontal) were selected for the study. Optimal combination of different independent parameters was selected on the basis of uniformity of straw thrown (C.V. basis). Uniformity of straw thrown improved significantly when number of rows of stationary blades was increased from one to three. Similar pattern was observed when rotor speed index was increased from 30 to 40. Deflector angle had nonsignificant effect on uniformity of straw thrown. Optimal combination, at which there was maximum uniformity of straw thrown i.e. C.V. 15.25% was observed at combination of three rows of stationary blades, rotor speed index of 40 and deflector angle of 20°. Sowing performance of spatially modified no-till drill while harvesting paddy crop at optimal settings of straw managing system was almost same as the performance of conventional no-till drill operated in clean field.