Maize-N, a modeling system developed at the University of Nebraska, provides predicted nitrogen leaching rates for agricultural soils based on climate, soil, and management practices. Management practices may influence the rate at which nitrogen leaches from the field, and these practices are options that Maize-N provides to the user. The two soils used for this Maize-N simulation experiment are located near Kanawha, in north central Iowa. The management practices chosen for simulation included tillage type (plow/disk, reduced till, and no-till), tillage timing (fall/spring), fertilizer application timing (fall/spring), and residue amount (all or none). Predicted nitrogen leaching rates were modeled for 2004, 2005 and 2008. In a given year, the Nicollet and Estherville soils experienced similar trends in leaching rates in response to the various management practices. The Estherville soil had a higher predicted nitrogen leaching rate than the Nicollet soil for each year studied. Of the management practices, tillage timing had the greatest impact on the predicted nitrogen leaching rate. Soil properties (e.g., texture and porosity) may influence nitrogen leaching more than management practices. Management practices may interact with soil properties to regulate nitrogen loss, yet soil properties appeared to play a dominant role in the comparisons of leaching in these two soils.

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