292-2 Nitrogen Economy and Partitioning in Sunflower from Split-Applied or Slow-Release UAN.

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: 5 Minute Rapid--Agronomic Production Systems

Tuesday, November 8, 2016: 2:25 PM
Phoenix Convention Center North, Room 126 B

Christopher J. Graham, South Dakota State University, Rapid City, SD and Jac Varco, Plant and Soil Science, Mississippi State University, Mississippi State, MS
Abstract:
In general, sunflower (helianthus annuus L.) will respond to modest amounts of applied nitrogen (N) fertilizer. To ensure crop N needs are met, it is important to have N in place as it is needed throughout the growing season. During years where high rainfall promotes excess N leaching or denitrification, a split-application of N may improve seed yield and oil content.  This presentation will discuss a two-year study with four site-years in central and western South Dakota examining the effects of at-planting and/or split-applying N to sunflower using 15N-labelled UAN. Results include yield and oil content along with a discussion on the partitioning of N to seed and biomass as related to the timing of N application.

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: 5 Minute Rapid--Agronomic Production Systems