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Consequences Of "Shallow" Pre-Plant Anhydrous Ammonia Placement On Corn Production.

Tuesday, November 5, 2013: 10:00 AM
Marriott Tampa Waterside, Grand Ballroom G, Second Level

Péter Kovács1, George E. Van Scoyoc2 and Tony J. Vyn1, (1)Purdue University, West Lafayette, IN
(2)Agronomy, Purdue University, West Lafayette, IN
Few studies have investigated consequences of alternate methods of anhydrous ammonia (NH3) fertilizer placement in multiple tillage systems on corn (Zea mays L.) growth and plant N responses. Field studies were conducted between 2010 and 2012 near West Lafayette, IN to compare two "shallow" pre-plant NH3 placements (diagonal to the row vs. parallel but 15-cm offset from the row) in no-till and conventional tillage systems at different nitrogen (N) rates (145 and 202 kg N ha-1). Corn was planted with additional starter N (20 kg N ha-1) within 6 days of NH3 application. Diagonal NH3 application placement never resulted in significant corn seedling mortality. Conventional tillage increased mean grain yields by ~1 Mg ha-1. Tillage did not impact reproductive-stage leaf chlorophyll content (SPAD), or grain N content, when NH3 was parallel-applied, but the same plant responses were significantly lower in no-till after diagonal NH3 application. Parallel NH3 application increased grain N concentration in 2010 compared to diagonal NH3 placement. Lowering the N rate to 145 from 202 kg N ha-1 significantly lowered corn biomass production, grain N, and whole-plant N accumulation in 2010 and 2012 when NH3 was diagonally applied, but not when NH3 was parallel applied. The benefit of parallel, relative to diagonal, placement at the lower N rate, and in no-till, was also evident in higher leaf SPAD during grain filling. The potential for lowering N rates, without yield penalty, with "shallow" pre-plant NH3 application is more likely via parallel placement to corn rows than with diagonal application.
See more from this Division: SSSA Division: Soil Fertility & Plant Nutrition
See more from this Session: Soil Fertility and Plant Nutrition Division and Nutrient Management and Soil and Plant Analysis Division Graduate Student Oral Competition - Nitrogen Management (PhD degree)

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