ASA Southern Branch 2008 Annual Meeting
February 3-5, 2008
Dallas, TX
Sunday, February 3, 2008
Influence of Nitrogen Fertilizer Placement on Corn Yield in Single and Twin Row Production Systems.
Henry J. Mascagni Jr. and Robert Bell. Northeast Research Station, LSU AgCenter, P.O. Box 438, St. Joseph, LA 71366
Nitrogen (N) fertilizer placement is an important part of a total fertilizer management program that maximizes N fertilizer use efficiency (NFUE). Cultural practices that enhance NFUE increase profitability, particularly with the current high N fertilizer prices, and, at the same time, lessen environmental concerns relating to nitrate pollution. A field experiment was conducted in 2007 on Sharkey clay at the Northeast Research Station near St. Joseph , LA evaluating the placement of N fertilizer for both single and twin-row corn produced on 40-inch wide beds. Treatments consisted of two row configurations (RC), single and twin row, two N fertilizer knife placements (KP), single and dual band, and two N rates, 150 and 240 lb acre-1. Croplan Genetics 818 was planted on April 10 at approximately 30,000 seed acre-1. Nitrogen as 32%-N solution was injected approximately 2-inches deep at the two to three leaf growth stage using either single or dual knifes. Corn was hand harvested to determine the interaction of N placement and row position (RP) on the twin row. Averaged across treatments, yields were significantly higher for the single compared to twin-row production system (175.9 versus 164.9 bu acre-1). There were significant RC x KP and KP x RP interactions for yield and seed N. Single-knife placement increased yield 10% greater than dual-knife placement for single row, while dual-knife placement increased yield 8% greater than single-knife placement for the twin-row system. When N fertilizer was applied on twin rows in a single band, the row closest to the fertilizer band produced 42% higher yield than the companion row. Seed N was significantly higher for the single- versus dual-knife placement for the single row, but there were no differences between placements for the twin row. Similar to yield response, the row closest to the single fertilizer band had higher seed N than did the adjoining row for the twin row configuration. There were no differences in yield or seed N between paired rows when N fertilizer was applied with dual knives.