Design and field testing of whole-stalk sweet sorghum harvester

A pull-type, single-row whole-stalk harvester was designed, built, and tested. Power was delivered via a u-joint driveline to five pumps (five hydraulic circuits) on the harvester. Stalks were captured with gathering chains, cut at the base with a disk cutter, and conveyed rearward in a vertical position. As the top was released from the gathering chains, the butt was captured between two rotating disks and the stalk rotated 90° onto a cross conveyor, and thus conveyed to a bin (accumulator). The accumulator periodically dumped bundles to produce windrows of aligned-stalk bundles across the field. Bundles weighed approximately 180 kg (400 lb), and in a field yielding 36 Mg/ha (16 ton/acre), windrows were spaced 62.5 m (205 ft) apart. Stalk height ranged from 3 to 4 m (9 to 13 ft). The harvester operated best at 3.56 km/h (2.2 mph), the same speed used for a forage chopper in the same field. Estimated field capacity was 1.56 ha/day (3.9 acre/day), or 54 Mg/day (60 ton/day). Over a season with 30 operating days, 1620 Mg (1,780 ton) could be harvested. A bond graph model and simulation of the accumulator dump drive showed that bundles up to 300 kg (660 lb) could be dumped without the hydraulic motor over-running.