How can we use our limited supplies of fertilizer most effectively? Not only is this a question in the minds of many farmers now, but it is an important problem from the standpoint of the nation’s total production.
Pierre, W. H.
"Methods of Applying Fertilizer,"
Farm Science Reporter: Vol. 6
, Article 3.
Available at: http://lib.dr.iastate.edu/farmsciencereporter/vol6/iss1/3