For example, assuming that sufficient information has been gathered over several years, the farmer may have historical records on the effect of all of the inputs to his system for a specific field, including the crop yield.
(the farmer; may have; historical records on the effect of all of the inputs to his system for a specific field, including the crop yield)
the farmer
may have
historical records on the effect of all of the inputs to his system for a specific field, including the crop yield