Minnesota's early drainage ditches were plowed by oxen.

A reader of The Farmer recently contacted me and wondered if a 19th-century climate trend was partially responsible for the widespread adoption of agricultural drainage ditches in Minnesota between 1897 and 1915. Minnesota's 19th-century climate data show that there were highly unusual, wetter-than-normal Aprils in 1883, 1887, 1888, 1892, 1893, 1894, 1896 and 1897. [Extracted from the article]