Workability Parameter, Definition

The workability parameter represents the probability of successfully harvesting a certain crop. The factor considers the number of work days available for fall harvest, and surface soil moisture in relation to its effect on farm machine tractability. Details of the workability parameter are given in Stewart (1981).

Briefly, the growing season length for each map unit was compared with the growing season requirements for each crop. From this a workday requirement, varying from 5 out of 10 to 10 out of 10 days available to harvest the crop was established. The probability of achieving this workday requirement was then calculated for the harvest period. The harvest period of all crops was assumed begin the date the crop matured and to end at the end of the growing season, or after 20 days, whichever occurred first. A workability parameter of 70% means that on average 70% of the crop is harvested successfully over the long term.