Total harvest loss is the sum of all losses from each operation plus any losses that may have occurred between operations. This is determined by measuring the loss after all field operations are completed and subtracting any pre-harvest loss. The most important measurement is that of an individual operation loss . This measurement assigns the loss to a particular operation and allows corrective action. To determine the harvest loss of a particular operation, measure the loss before and after that operation.
Combine loss can occur at the pickup or in threshing.
It is often helpful to separate these two losses to be able to correct any problem. Total combine loss can be found by measuring before and after a pass with the combine. Combine pickup loss can be measured by stopping the combine's forward travel and allowing the header to clean out. Lift the header, back up the combine, and measure the loss in an area between the rear of the header and where the tailings dropped from the shoe. Subtract losses that occurred before the combine pickup.