2008 Joint Annual Meeting (5-9 Oct. 2008): "Assessing Crop Yield and Water Quality Impact using Models".

Assessing Crop Yield and Water Quality Impact using Models

Parajuli, P.B., and N.O. Nelson

ABSTRACT

The variability on crop yield and water quality might be controlled by intrinsic soil properties and extrinsic factors such as climate, management, crop rotation, and topography. This study applied a modeling approach to determine whether the different crop rotations and tillage practices effect on crop yield and water quality. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy/Environmental eXtender (APEX), within SWAT and APEX (SWAPP) models were used to investigate crop yield, flow, sediment yield and total phosphorus transport results from field and watershed scales watersheds in south-central, KS. Both SWAT and APEX models reasonably responded crop yields with a correlation coefficient range from 0.32 to 0.79 in various crop rotations and tillage practices when compared with 10 years field measured crop yields data. The SWAT and APEX models results at field scale watersheds for water quality and SWAT model results at watershed scale for crop yield and water quality will also be presented in this paper.