Modeling corn grain yield in relation to soil erosion using a water budget approach.

The effect of long-term soil loss on corn (Zea mays L.) grain yields in shallow soils of the Northeast is evaluated using a simple computer simulation model. Easily obtainable soil and meteorological data are used as input. The model relates the change in soil productivity to the reduction of available water holding capacity caused by long-term soil loss by erosion. The model is based on the established relationship between relative yields and the relative transpiration ratio. A simple water budget estimates actual transpiration on a daily basis and calculates stress as a function of relative transpiration ratio. Yields are predicted from total seasonal stress and accumulated heat units. The model has been run using 16 yr of meteorological data to simulate varying climatic conditions, and correlations between actual and predicted yields on deep to moderately deep soils are good. - from Authors