Separably driven rotor portions (30) for a combine harvester (10) and a method for threshing grain using separably driven rotor portions are provided. The combine harvester is moved through harvest material comprising grain material and material other than grain ('MOG'). The grain material is separated from the MOG using multiple processing areas. The auger portion (70) may be stopped or rotated at a slower speed with respect to rotation of the threshing portion (80) to simulate the gathering of a large amount of crop material even when small plots are involved thereby providing the benefits of large plot harvesting to small plot applications.
