The
combine harvester, or simply
combine, is a machine that harvests
grain crops. The name derives from its combining three separate operations comprising harvesting—
reaping,
threshing, and
winnowing—into a single process. Among the crops harvested with a combine are
wheat,
oats,
rye,
barley,
corn (
maize),
sorghum,
soybeans,
flax (
linseed),
sunflowers, and
canola. The waste
straw left behind on the field is the remaining dried stems and leaves of the crop with limited
nutrients which is either chopped and spread on the field or
baled for feed and bedding for livestock.