Highly favorable growing season weather last year helped break crop yield records. But lower soil moisture reserves in most Iowa areas have reduced chances of duplicating 1963 records.
Shaw, R. H. and Duncan, E. R.
"Crop Yield Prospects for 1964,"
Iowa Farm Science: Vol. 18
, Article 8.
Available at: https://lib.dr.iastate.edu/farmscience/vol18/iss7/8