When the average values of the crops secured under various rotations were calculated over a ten-year period, it appears that a three-year rotation of corn, oats and clover yielded much greater economic returns from the crops grown than a two-year alternation of corn and oats or the growing of corn continuously on a typical Wisconsin drift soil area. This was true on the untreated areas and on areas which were treated with manure and lime, manure, lime and rock phosphate, crop residues and lime, and crop residues, lime and rock phosphate. The difference was greater between the yields under the three-year rotation and the two-year alternation than between those on the three-year rotation and the continuous corn plot. This was true on the untreated or check soil and on the soils treated with manure and lime.
Under the five-year rotation of corn, oats, clover, wheat and alfalfa, where alfalfa remained on the land for five years, the value of the crops grown over the ten year period was slightly greater than under the three-year rotation on the check plots, definitely greater on the plots treated with manure and lime, but not quite as large on the plots treated with manure, lime and rock phosphate. Here the value of the crop was about $5 greater under the three-year rotation system. On the plots treated with crop residues and lime there was a slight difference in favor of the three-year rotation, but where rock phosphate was added with the crop residues and lime the crops under the five-year rotation were worth considerably more.
Stevenson, W. H.; Brown, P. E.; and Forman, L. W.
"Crop returns under various rotations in the Wisconsin drift soil area,"
Bulletin: Vol. 20
, Article 1.
Available at: https://lib.dr.iastate.edu/bulletin/vol20/iss241/1