Harvest of change
Rotary combine harvesters have established a reputation as the ‘big beasts’ of the cereal harvest, achieving massive outputs while staying within a manageable size for road travel and movement within fields. One or two rotors carry out the threshing and separation steps, using centrifugal force to remove the grain from the straw.
Arguments for single vs twin rotors centre around simplicity and the ability to work in difficult conditions against crop quality and power consumption.
Concerns about straw – and to a lesser extent grain – quality due to the action of the rotors have been a limiting factor in the universal adoption of rotaries, especially in mixed farming areas. However, the latest designs overcome this, especially with the advent of driver-friendly automation of settings whereby the machine works with the operator to minimise losses and maintain throughput as crop and atmospheric conditions change. Hybrid systems use a drum or cylinder ahead of single twin rotors, carrying out most of the threshing and giving a gentler action on both straw and grain.
The efficient threshing and separation offered by both types of machine allow the use of wider, more productive headers, including belt and draper designs which present the crop more evenly to the feeder and the
