Composition and Decomposition of Peanut Residues in Georgia

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 1 d prior to digging (PRE) and immediately after peanut threshing (POST). Leaf and stem residues were mixed and analyzed for carbon (C), N, lignin, and cellulose. Peanut 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 concen-trations, 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.

Suitability of peanut residue as a nitrogen source for a rye cover crop

“…During the first two years, the N concentration following peanut residue was lower as compared to removed peanut residue, but was higher the last year of the study (data not shown). The lower N concentration observed following retained peanut residue indicates that the peanut residue could have immobilized N, which is supported by the incubation study conducted by Balkcom et al (2004) Total C 1216 (18) 1247 (16) 1007 (41) Total N 48 (2) 32 (5) 38 (1) Total P 3.0 (0.2) 4.6 (0.6) 4.9 (0.04) concentration was higher following the retention of peanut residue. Since the N concentration and C/N ratio are related due to the relatively constant C concentration of plant tissues, the interaction for C/N ratio between year and peanut residue was similar to that of N concentration.…”

“…Researchers in the U.S. Corn Belt have found that alfalfa (Medicago sativa L.) and soybean [Glycine max ( L.) Merr. ], can decrease the fertilizer N requirements of a succeeding corn (Zea mays L.) crop (Bruulsema & Christie, 1987;Bundy et al, 1993;Morris et al, 1993). Although peanut is a legume that is widely grown in the southeastern USA, no previous research has examined the N contribution of peanut residues to a rye cover crop utilized in a conservation system.…”

“…Winter annual legumes, such as crimson clover (Trifolium incarnatum L.) and hairy vetch (Vicia villosa Roth. ), are utilized as N sources for summer crops (Touchton et al, 1984;Brown et al, 1985;Reeves, 1994). Sunn hemp, a summer legume, has also been shown to decrease corn N requirements in the southern USA (Balkcom & Reeves, 2005).…”

“…Legume N in symbiosis with Rhizobium bacteria contributes to succeeding non-legume crops upon decomposition of legume top and root material (Bruulsema & Christie, 1987;Touchton et al, 1984). Winter annual legumes, such as crimson clover (Trifolium incarnatum L.) and hairy vetch (Vicia villosa Roth.…”

Nitrogen Contribution of Peanut Residue to Cotton in a Conservation Tillage System

“…In South Carolina, Hunt et al (1998) reported a low potential of N contribution to the soil system, which was consistent with their observation of no cotton yield response following peanut. An incubation of two soils with and without two types of peanut residue also indicated no significant amounts of N were mineralized under laboratory conditions (Balkcom et al, 2004). In contrast, other incubation studies have indicated peanut residues mineralized N and increased mineralization of indigenous and fertilizerderived soil N (Smith and Sharpley, 1990;Constantinides and Fownes, 1994).…”