Ritchie, J.T., A. Gerakis, D.P. Rasse, and A.J.M. Smucker
Presented at the All Scientist Meeting (1998-07-21 to 1998-07-22 )
SALUS (Systems Approach to Land Use Sustainability) is a model for long-term simulation of soil health. SALUS can simulate rotations of different crops and/or fallow with different management strategies such as tillage, residue application, irrigation, tile drainage, and nitrogen application. The model combines the crop and water balance accuracy of CERES with the soil biochemistry simulation of CENTURY. The generic crop module uses the same algorithm to simulate growth and development for various cereal crops, so that the user only has to change species and cultivar coefficients.Four years of data (1991–94) from the interaction lysimeters were processed and simulated. The data were sorted and converted from a raw state to spreadsheets and SALUS input files. The data processed to-date are: drainage volume, nitrate concentrations, soil water content, and root images. Nitrate leaching mass was estimated from water drainage and nitrate concentration. SALUS input files such as weather, soils, crop information, and management files were prepared from the data.Because the lysimeters drain when the bottom-most layer is near saturated, we simulated the drainage as tile drainage. We simulated the hypothetical tile at the bottom of the lysimeter and a restrictive layer below the tile layer. This approach significantly improves simulation of soil water content. Lately we developed a new generic runoff module for SALUS that estimates runoff from daily rain, as a function of saturated hydraulic conductivity and a time-varying parameter. The lysimeter data were very helpful in testing and refining the latest SALUS enhancements.Return to Contents
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