|MULVANEY, MICHAEL - University Of Florida|
|WOOD, CHARLES - University Of Florida|
|JORDAN, DAVID - North Carolina State University|
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/12/2016
Publication Date: 12/1/2016
Citation: Mulvaney, M.J., Balkcom, K.S., Wood, C.W., Jordan, D.L. 2016. Potential nitrogen credits from peanut residue [abstract]. American Peanut Research and Education Society. p. 176.
Technical Abstract: Availability of residue nitrogen (N) to succeeding crops is dependent on N mineralization rates during decomposition. Following peanut (Arachis hypogaea L.) production, extension currently recommends 22-67 kg N ha-1 credit to subsequent crops, but these recommendations are not supported in the literature, nor do they specify if the credit is applied to a subsequent winter or spring crop. The objective of this study was to assess N release rates in the field from the residues of three peanut varieties (NC V-11, GA 02-C and ANorden) at two placements (surface and 10 cm deep) and two locations representing northern and southern extremes of commercial peanut production in the US (North Carolina and Alabama). Litterbags containing the equivalent of 3.5 Mg ha-1 were placed in a completely randomized design at both locations with four replications and retrieved periodically up to 335 days after application. Results were fit to single or double exponential decay models to determine N mineralization during subsequent crops. N mineralized from peanut residue during a subsequent wheat (Triticum aestivum L.) crop was estimated at 14-19 kg N ha-1 when peanut residues were buried after harvest, and 19-24 kg N ha-1 when left on the soil surface. N mineralized during a subsequent cotton (Gossypium hirsutum L.) crop was estimated at 2-9 kg N ha-1 (buried) and 6-10 kg N ha-1 (surface). Current extension publications recommend N credits following peanut at higher rates than the results of this study suggest and warrant re-examination.