Corn Response to Nitrogen Source, Drainage, and Irrigation in a Claypan Soil.
Tuesday, November 5, 2013: 3:00 PM
Tampa Convention Center, Room 25, First Floor
Kelly A. Nelson, University of Missouri, Novelty, MO and Peter P. Motavalli, University of Missouri, Columbia, MO
This 2006 and 2007 study of corn (Zea mays L.) evaluated the effects of nitrogen (N) sources [non-treated control, anhydrous ammonia, urea, polymer-coated urea (PCU), and 32% urea ammonium nitrate (UAN) at 168 kg N ha-1] and water management systems [drained, non-irrigated (DNI) at 6.1, 9.2, and 12.2 m spacings; non-drained, non-irrigated (NDNI); non-drained, overhead irrigated (NDOHI); and drained plus subirrigated (DSI) at 6.1, 9.2, and 12.2 m spacings] on yield, plant population, grain protein, and grain N removal. DNI increased grain yield 0.92 to 1.88 Mg ha-1 (10% to 22%) compared to NDNI. DSI increased yields up to 4.41 Mg ha-1 (24% to 38%) depending on N source and spacing. Nitrogen sources in the NDOHI increased yields 42% to 45% compared to NDNI, and 10% to 20% compared to DSI 6. In irrigated and poorly drained claypan soil (NDOHI), PCU increased yield 0.88 Mg ha-1 compared to NCU. PCU had the highest yields among N sources with DSI 6, DSI 9, DSI 12, and DNI 12. In a well drained soil (DNI 6), NCU had the highest yield (8.94 Mg ha-1) among N sources, while anhydrous ammonia had the highest yields in the NDNI control (7.89 Mg ha-1) and DNI 9 (9.07 Mg ha-1). Grain N removal was greatest (201.9 to 202.2 kg ha-1) with anhydrous ammonia and PCU with NDOHI. Nitrogen source selection is an important component of high-yielding corn production systems depending on water management system.
