Row-placed fertilizer for maize grown with an in-row crop residue management system in southern Wisconsin

Refinements of high residue cropping practices are needed to provide crop producers viable systems that are both economically and environmentally sound. Several tillage treatments in combination with row-placed fertilizer were evaluated in a 3 year study on maize (Zen mays L.) on a Luvic Phaeozem in southern Wisconsin, USA. Tillage treatments included fall chisel, fall and spring in-row residue management (I-RRM) using planter mounted finger coulters, and no-till. Row fertilizer treatments consisting of none, fall surface strip, fall subsurface band, and subsurface band at planting were superimposed over tillage treatments. Early season in-row soil temperatures in the fall I-RRM treatment were usually similar to those found in the chisel system and were typically 3-5 degrees warmer than those under no-till. The gravimetric water content of the no-till treatment was 20-40 g kg(-1) higher than those of the chisel and fall I-RRM, which were usually similar. In-row residue management resulted in residue levels of about 30-50% in the row and 80-90% in the inter-row. Residue in chisel and no-till were relatively uniform across the row, averaging 26 and 89%, respectively. Early season crop growth and silking progress were significantly delayed in no-till and were only slightly reduced in the I-RRM treatments when compared to chisel. Grain yield averaged over 3 years was not significantly affected by tillage treatment; however, fall I-RRM was 0.4 Mg ha(-1) higher than spring I-RRM in the first year. Row fertilizer at planting increased in early mass and silking progressed 50% in the second year. When averaged over 3 years, row fertilizer reduced grain water content 10 g kg(-1) and increased yield 0.5 Mg ha(-1) when compared to the control. A significant interactive effect showed a positive grain yield response to row fertilizer in all tillage treatments except chisel. This research demonstrates that I-RRM, in combination with row fertilizer, offers a high residue alternative to full-width tillage in regions with limited growing season. (C) 2000 Elsevier Science B.V. All rights reserved.