Last year we continued our study and comparison of the disk, lister, subsurface tiller and plow for preparing seedbeds for corn. This was the fourth year that these implements have been compared, but since they perform differently on different soils, we do not believe we have the complete answer about them yet. In only 1944 and 1945 have they been studied at a sizable number of locations and on several soils.
Browning, G. M. and Norton, R. A.
"More Seedbed Studies,"
Farm Science Reporter: Vol. 7
, Article 4.
Available at: http://lib.dr.iastate.edu/farmsciencereporter/vol7/iss2/4