>>Wide spread chemical fertilizers came after the tractor. << Actually, completely wrong. It came into widespread use after newly opened farmlands were quickly depleted by monocropping and lack of crop rotation. For cotton farming it became absolutely essential and even then didn't prevent the lands from being completely depleted for future cotton crops. After the self-propelled tractor did become popular on small family farms, we actually see a drop in commercial fertilizer use, most likely because of reduced acres in farming as a result of federal programs in the 1930s. Which is not to say that fertilizer use doesn't then skyrocket in the 1950s and after -- it does, because of even more farming.
http://www.agclassroom.org/gan/timeline/farm_tech.htm 1843 Sir John Lawes founded the commercial fertilizer industry by developing a process for making superphosphate 1849 Mixed chemical fertilizers sold commercially 1890-99 Average annual consumption of commercial fertilizer; 1,845,900 tons 1900-09 Average annual consumption of commercial fertilizer 3,738,300 tons 1910-19 Commercial fertilizer use: 6,116,700 tons/year 1920-29 Commercial fertilizer use: 6,845,800 tons/year 1920-40 Farm production gradually grows from expanded use of mechanized power 1926 Cotton-stripper developed for High Plains; successful light tractors developed 1930-39 Commercial fertilizer use: 6,599,913 tons/year _______________________________________________ Marxism-Thaxis mailing list Marxism-Thaxis@lists.econ.utah.edu To change your options or unsubscribe go to: http://lists.econ.utah.edu/mailman/listinfo/marxism-thaxis
