Best management practices (BMPs) for nitrogen (N) and their implementation are critical to achieving profitable crop production while minimizing nitrate losses to ground and surface waters. Nitrogen BMPs for corn (Zea mays) grown after soybean (Glycine max) in south-central Minnesota were developed from long-term, subsurface tile drainage research conducted at the University of Minnesota's Southern Research and Outreach Center at Waseca. A four-year study showed significantly greater nitrate losses in tile drainage accompanied by no increase in corn yield or profitability when applied N rates exceed the University's recommended rate. A 15-year study indicated that spring application of ammonia produced greatest yield and profit while minimizing nitrate loss to drainage compared with fall-applied ammonia without N-Serve, and thus is a preferred BMP. Fall application of ammonia with N-Serve also significantly reduced nitrate losses but is considered a BMP with RISK because yields and economic return were lower in years when May and/or June were very wet. Results from these studies clearly show application rates in excess of University recommendations and fall application of ammonia without N-Serve are not BMPs for south-central Minnesota.