Hello Everybody -- I've been working with an Ag-Economist on some Maize-Soybean rotations under DSSAT 3.0. We are getting more N leaching than we were told was "normal" for this region and looking at the NITROGEN.OUT file we find N fixation for different years of soybean of between 150-350 Kg N/ha (and in one case 518 Kg N/ha) with the average an average of around 225 Kg N/ha. I looked in a basic crop production book and it seems to indicate that 200 Kg N/ha is the maximum one would expect with Soybeans. So guess we are wondering: are the predictions we are getting too large? If so have other people noticed this problem? Is there a way to get CROPGRO to predict lower values? Thanks for your help. ============================================================================= Brian Baer [log in to unmask] --------------------------------------+--------------------------------------- Program Analyst | Acting Center Coordinator Dept. of Crop & Soil Science | The Listening Ear A574 Plant and Soil Science Building | Crisis Intervention Center Michigan State University | 423 Albert Street East Lansing, Michigan 48824-1325 | East Lansing, Michigan 48823 (517) 353-8537 | (517) 337-1717 =============================================================================