Tractors did not destroy the older agrarian world. Tractors replaced mules in a world that had already changed away from mule breeding and mule keeping. Most of the new technologies in farming arise as a response to the collapse of an older social order, not from a sinister weighting of one technology against another. Round bale hay making did not drive the young men from the farms. The young men were already gone when their fathers and grandfathers embraced the round balers as a solution to a critical labor problem.
Every technology is embedded within a context of a supporting sociology.
Social change most often results from changes in the social order, not from the appearance of an alternative technology itself. When the stack made itself and the last load tossed slid off the stack, we capped it off with a piece of tarp. Down the field a dozen or more stacks stood in irregular rows waiting the hay wagon. The square baler that followed the men in the fields arrived as our families were getting smaller and as more men worked at jobs off the farm. When we tossed hay, it took a half dozen or more men to work the field.