Rasse, D.P., A.J.M. Smucker, and J.T. Ritchie
Presented at the All Scientist Meeting (1998-07-21 to 1998-07-22 )
Distribution of corn root systems throughout Kalamazoo loam soils were recorded by minirhizotron technology at the Agroecosystem Interactions (AI) site from 1986 to 1997. Forty five degree-angle minirhizotrons were installed under corn in 1986, 87, 88, 90, 91, 92, 93, 96, and 97. Horizontal minirhizotrons were installed in four large monolith lysimeters at the AI site in 1990 and recorded for every subsequent growing season. This very large data set is currently being analyzed for growing season variability and tillage effects. Early results suggest that for most growing seasons no-tillage induced greater corn root populations (Fig. 1). Nevertheless, tillage effects differed among growing seasons. For some growing seasons, such as 1986, conventional tillage induced significantly greater root populations than no-tillage for some soil layers (Fig. 1).This project is aimed at determining the environmental factors that control root proliferation at given depths in response to tillage management. Corn water stress and soil water content per horizon is being modeled for the12 year-period at KBS with CERES-Maize (Fig. 2). In addition, modifications of soil water content by tillage managements are being simulated using the SALUS model, as explained in part III of this abstract. Possible interactions between simulated soil water content and root numbers for given sets of soil depth, growing season and tillage management will be analyzed.Return to Contents
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