Nitrogen mineralization from peanut residue components under simulated conservation and conventional tillage on a major peanut-producing soil series

Authors: JANI, ARUN - University Of Florida; MULVANEY, MICHAEL - University Of Florida; Balkcom, Kipling; WOOD, C. WESLEY - University Of Florida; JORDAN, DAVID - North Carolina State University; WOOD, BRENDA - Pensacola State College

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/3/2019
Publication Date: 11/12/2019
Citation: Jani, A.D., Mulvaney, M.J., Balkcom, K.S., Wood, C., Jordan, D.L., Wood, B.H. 2019. Nitrogen mineralization from peanut residue components under simulated conservation and conventional tillage on a major peanut-producing soil series[abstract]. ASA-CSSA-SSSA Annual Meeting. CD ROM.

Interpretive Summary:

Technical Abstract: A large portion of peanut leaves abscise in windrows during pod drying, resulting in an uneven distribution of leaves and stems when residues are spread during harvest. Possible differences in nitrogen (N) mineralization rates from peanut leaves and stems may create spatial and temporal differences in inorganic N availability during subsequent crops. The aim of this study was to assess N mineralization on a major peanut-producing soil of the southeastern USA amended with different peanut residue components under simulated conventional and conservation tillage practices. A 252-day controlled incubation was conducted with peanut leaves, stems, and a 1:1 leaf:stem mixture that were incorporated or placed on the soil surface to simulate conventional or conservation tillage, respectively. Soils were periodically leached to determine N mineralization compared to a soil-only control. Peanut residue component, but not placement, affected N mineralization. Soil amended with leaves mineralized 10% more N compared to the soil only control or soil containing stems. Leaves provided 25 kg N ha-1 over 252 days at 0-15 cm soil depth, an amount that would likely be inadequate to generate a yield response by a subsequent crop. Our results indicate that the uneven distribution of peanut leaves and stems following harvest likely lead to only minor spatial and temporal diifferences in inorganic N availability during a subsequent crop. Future research efforts should focus on quantifying the different environmental and biological pathways by which peanut residue N may be lost or made temporarily unavailable. A better understanding of these pathways could lead to residue management practices that increase the availability of peanut residue-derived N during subsequent crops.