The last rows in flow diagrams in Figures 7.2 and 7.3 show harvesting and collecting the entire crop that includes straw and grain in a single operation. The entire material is trans­ferred to a central location where the crop is fractionated into grain and biomass. The whole crop harvesting and fractionation concept has been researched for many years (Buchele 1976). A whole crop wheat harvester was developed in Sweden in the early 1980s (Lucas 1982) at a cost of more than $5 million. The self-propelled machine was able to harvest the entire crop, thresh and clean the grain, and bale the straw, all in one step. Recent efforts by Quick and Tuetken (2001) have been reported to develop a whole crop harvester and transporter for corn.

The McLeod Harvester (St. George 2000) developed in Canada fractionates the harvested crop into straw and graff (graff is a mixture of grain and chaff). The straw is left on the field. Grain separation from chaff and other impurities take place in a stationary system at the farmyard. The new machine is credited with higher capacity and efficiency than current grain combines. PAMI (1998) conducted an economic analysis to show that whole crop baling resulted in the highest net return among six different systems including McLeod harvester. For the whole crop baling, the crop (wheat) was cut and placed in a windrow for field drying. The entire crop was then baled and transported to the processing yard. The bales were unwrapped and fed through a stationary processor that performed all the functions of a normal combine. The straw was then rebaled.