The economics of crop rotations is a research problem of central importance in Iowa agriculture. Although the major portion of Iowa cash farm income is derived from livestock, a greater share of the state's gross value of agricultural products is attributable to crops than to livestock and livestock products. Livestock and livestock products provide the greatest part of the total cash income since the major portion of the hay and feed grains is not sold in the market but is, processed through livestock on the farms where the crops are produced. Livestock production adds 40 to 60 cents (depending on feed/livestock price ratios) to each dollar's worth of crops fed to livestock in Iowa. The importance of crop production economics in Iowa agriculture is thus apparent: Economic balance in the production of crops is of foremost concern (1) to the individual farm operator and farm owner in Iowa because of the large contribution of crops to total income and (2) to the nation's consumers since the output from any resources employed in the state's agricultural production represents an important part for the country as a whole.
Heady, Earl O. and Jensen, Harald R.
"The economics of crop rotations and land use: A fundamental study in efficiency with emphasis on economic balance of forage and grain crops,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 30
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol30/iss383/1