{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["026:00"], "contactPoint": {"@type": "vcard:Contact", "fn": "Earthdata Forum", "hasEmail": "mailto:earthdata-support@nasa.gov"}, "description": "It has been proposed that the C/N ratio, or quality, of litter or mulch mixtures affects N release. Although total N release from these mixtures and the effects on soil N are relatively well understood, a mechanistic understanding of the interactions between litter species with respect to their N release is still lacking. This study examines decomposition and N dynamics in mixtures of high-quality leguminous mulch, gliricidia [Gliricidia sepium (Jacq.) Kunth. ex Walp.] with a C/N ratio of 13, and low-quality cupuacu [Theobroma grandiflorum (Wild. ex Spring) Schumann] litter with a C/N ratio of 42, which occur in combination in agroforestry systems. Ratios of 100:0, 80:20, 50:50, 20:80, 0:100 of fresh 15N-enriched gliricidia leaves and senescent cupuacu leaves, totaling the same dry weight of 6.64 t ha-1, were applied to an Oxisol and sampled at 6, 14, 38, and 96 days after application. After more than 40% of the N in the gliricidia leaves had been released and the microbial biomass N reached its peak, a significant increase in available soil N occurred at day 14, which was more pronounced with greater amounts of gliricidia in the leaf mixture. However, relative to the N applied in the leaf mixture, there was no significant difference in available soil N with greater proportions of gliricidia. Total N release from the mixtures corresponded to the total N applied by gliricidia. Until day 38, cupua\u00c3\u0192\u00c2\u00a7u C mineralization was significantly faster in the presence of the highest proportion of gliricidia compared to lower proportions. This faster C mineralization of more than 0.5% per day, however, did not increase total C loss or N release from cupua\u00c3\u0192\u00c2\u00a7u leaves after 96 days. The use of 15N tracers identified an N transfer from gliricidia leaves and the soil to cupua\u00c3\u0192\u00c2\u00a7u leaves and consequently, a lower N release from gliricidia to the soil in the presence of cupua\u00c3\u0192\u00c2\u00a7u leaves. Though we expected that available N in the soil would also decrease with greater amounts of cupua\u00c3\u0192\u00c2\u00a7u litter in the mixture, our results indicated an additive effect of the two species on N release and soil mineral N, with gross interactions between them canceling net interactive effects. Therefore, N release of leaf mixtures behaved as predicted from a calculated sum of individual release patterns, in spite of a transfer of N from the high- to the low-quality leaves.", "distribution": [{"@type": "dcat:Distribution", "conformsTo": "http://www.isotc211.org/2005/gmi", "description": "The metadata's original source.", "downloadURL": "https://cmr.earthdata.nasa.gov/search/concepts/C2784834826-ORNL_CLOUD.iso19115", "format": "ISO", "mediaType": "text/xml", "title": "Original Metadata"}, {"@type": "dcat:Distribution", "downloadURL": "https://daac.ornl.gov/graphics/browse/project/square/lba_logo_square.png", "format": "PNG", "mediaType": "image/png"}, {"@type": "dcat:Distribution", "downloadURL": "https://data.ornldaac.earthdata.nasa.gov/protected/bundle/ND11_Nitrogen_Transfer_Leaf_Litter_915.zip", "format": "ZIP", "mediaType": "application/zip"}, {"@type": "dcat:Distribution", "downloadURL": "https://data.ornldaac.earthdata.nasa.gov/public/lba/nutrient_dynamics/ND11_Nitrogen_Transfer_Leaf_Litter/comp/ND11_Nitrogen_Transfer_Leaf_Litter.pdf", "format": "PDF", "mediaType": "application/pdf"}, {"@type": "dcat:Distribution", "downloadURL": "https://doi.org/10.3334/ORNLDAAC/915", "format": "HTML", "mediaType": "text/html"}, {"@type": "dcat:Distribution", "downloadURL": "https://search.earthdata.nasa.gov/search/granules?p=C2784834826-ORNL_CLOUD", "format": "BIN", "mediaType": "application/octet-stream"}], "identifier": "10.3334/ORNLDAAC/915", "keyword": ["earth-science-soils-land-surface-carbon", "earth-science-soils-land-surface-nitrogen", "earth-science-vegetation-biosphere-carbon", "earth-science-vegetation-biosphere-litter-characteristics", "earth-science-vegetation-biosphere-nitrogen"], "license": "https://www.usa.gov/government-works", "modified": "2026-06-22", "programCode": ["026:000"], "publisher": {"@type": "org:Organization", "name": "ORNL_DAAC"}, "spatial": "[\"CARTESIAN\", [{\"WestBoundingCoordinate\": -60.03, \"NorthBoundingCoordinate\": -2.518, \"EastBoundingCoordinate\": -60.03, \"SouthBoundingCoordinate\": -2.518}]]", "temporal": "2002-07-11/2002-10-15", "theme": ["Earth Science"], "title": "LBA-ECO ND-11 Litter Decomposition, Carbon, and Nitrogen Dynamics in Agroforestry"}