Submitted to: Peanut Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/22/2004
Publication Date: 6/30/2004
Citation: Balkcom, K.S., Wood, C.W., Adams, J.F., Wood, B.H. 2004. Composition and decomposition of peanut residues in Georgia. Peanut Science. 31:6-11. Interpretive Summary: Legumes typically decompose rapidly and can contribute nitrogen (N) to crops planted after residues decompose. Peanut is a legume, but limited information exists how much N peanut residue can provide a crop. The objective of this study was to determine how much N is released from peanut residue. Two types of peanut residue were collected. Aboveground peanut residue was collected before peanut harvest and residue spread on the ground after peanut harvest was also collected. Residue was analyzed to determine the carbon (C) and N content and then mixed with two different soils. Each mixture of soil and residue was kept in the laboratory at a constant temperature for 98 days. These data indicate that peanut residue will not supply significant amounts of N for a crop grown in these two soils.
Technical Abstract: Legumes typically mineralize rapidly and can contribute to nitrogen (N) requirements of succeeding crops, but limited information exists on the mineralizable N content of peanut (Arachis hypogaea L.) residue. The objective of this study was to determine net N mineralization from two types of peanut residue for two soil types. Aboveground peanut residue (cv. Georgia Green) was collected prior to digging (pre) and immediately after harvest (post) of peanuts. Leaf and stem residues were mixed and analyzed for carbon (C), N, lignin, and cellulose. Residue equivalent to 4.5 Mg/ha was applied to a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults) and a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudult) and aerobically incubated for 98 d in the dark at 25 C to determine C and N mineralization. Each soil was incubated simultaneously, with and without residue. Pre-harvest residue had lower C, lignin, and cellulose concentrations, but higher N concentrations than post harvest residue. Differences in residue quality corresponded to differences in cumulative C mineralized and C turnover for the Tifton soil, but did not result in differences for cumulative N mineralized or relative N mineralized within either soil type. These data indicate that peanut residue will not supply significant amounts of N to a subsequent crop for these two soil types.