Our surplus stocks stem from our capacity to produce more than we use. But the results of a study at Iowa State show that roughly half of the increase in feed-grain production since 1950 has resulted form above-average weather.
Thompson, Louis M.
"How Serious Are Our Feed-Grain Stocks?,"
Iowa Farm Science: Vol. 17
, Article 4.
Available at: https://lib.dr.iastate.edu/farmscience/vol17/iss8/4