Iowa crop yields by counties and townships, 1930-1939, 1940.

Trend of crop production indicated by the average yield per acre of crops is one of the factors of direct analysis and importance in agricultural programs, whether the program is for securing crop acreage balance, or soil fertility, or one of crop insurance and land valuation appraisal. County average yield per acre of barley, corn, oats, soybeans and winter wheat are included as well as Township average yield per acre of corn and oats