One source of “ammunition” for the “war food front” which many an Iowa farmer should seriously consider using this year is commercial fertilizer. If used wisely, it can profitably increase crop production.
Englehorn, A. J. and Meldrum, H. R.
"Fertilizer Backs Bombs,"
Farm Science Reporter: Vol. 5
, Article 7.
Available at: https://lib.dr.iastate.edu/farmsciencereporter/vol5/iss1/7