If you look back across the span of time, you see wood plows being used in 4000 BC, then irrigation five hundred years later.
The chief thing in his eyes was not the nitrogen in the soil, nor the oxygen in the air, nor manures, nor special plows, but that most important agent by which nitrogen, oxygen, manure, and plow were made effective-- the peasant laborer.
The return trip from Grand Junction had taken Dean twice the usual two hours, a slalom of ditched autos, snow plows, ice and stopped traffic.
How would you define plows? Add your definition here.