Author
MULVANEY, MICHAEL - UNIVERSITY OF FLORIDA | |
Balkcom, Kipling | |
WOOD, CHARLES - UNIVERSITY OF FLORIDA | |
JORDAN, DAVID - NORTH CAROLINA STATE UNIVERSITY |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/3/2017 Publication Date: 3/9/2017 Publication URL: https://handle.nal.usda.gov/10113/5763056 Citation: Mulvaney, M.J., Balkcom, K.S., Wood, C.W., Jordan, D.L. 2017. Peanut residue carbon and nitrogen mineralization under simulated conventional and conservation tillage. Agronomy Journal. 109:696-705. Interpretive Summary: Residue management is an important aspect of crop production systems and plant residue nitrogen (N) availability to succeeding crops is dependent on N mineralization rates during decomposition. Researchers at the National Soil Dynamics Laboratory in Auburn, AL with university researchers at the Univ. of Florida and North Carolina State Univ. ,monitored field N release rates from residues of three peanut cultivars (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). Estimated N credits from peanut residue to 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. Estimated N credits to a subsequent cotton (Gossypium hirsutum L.) crop were reduced to 2-9 kg N ha-1 (buried) and 6-10 kg N ha-1 (surface). These results can be used to complement fertilizer recommendations for winter or summer crops following peanut by lowering existing N fertilizer applications across the Peanut Belt. Although small, these N fertilizer reductions will reduce N fertilizer costs and minimize potential environmental impacts associated with over-application of N fertilizer. Technical Abstract: Residue management is an important aspect of crop production systems. Availability of plant residue nitrogen (N) to succeeding crops is dependent on N mineralization rates during decomposition. Cooperative Extension currently recommends 22-67 kg N ha-1 credit to subsequent crops following peanut (Arachis hypogaea L.), 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 cultivars (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. Based on these empirical models, a N credit to 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. When N credits were applied to a subsequent cotton (Gossypium hirsutum L.) crop, they were reduced to 2-9 kg N ha-1 (buried) and 6-10 kg N ha-1 (surface). Current recommendations are generally higher than the results obtained in this study suggest and warrant re-examination. |