"...California agriculture was a leader in mechanization, in part because many farmers had large acreages, capital and were well educated. Thus, wheat farmers in 19th century California soon learned that they could use large plows to turn over only a few inches of topsoil and encouraged local inventors to develop plows that could cover far more acres in a day than in the rest of the US. Dry summers with little threat of rain allowed wheat to be harvested by combine sooner in California than in the Midwest...."
~1910-1915 (best guess)

