Measurement of soil productivity on four selected soils in terms of corn yield

The purposes of this study were: 1) Using field conditions, to estimate the maximum yield on four East Tennessee soils in 1957 which have a rather wide range of physical profile properties; 2) to compare soil productivity as measured by corn grain yields at different nitrogen and population levels on a particular soil as well as among soils; and 3) to determine the combination of population and nitrogen which would give maximum yield on each soil.