LBA-ECO ND-11 Litter Decomposition, Carbon, and Nitrogen Dynamics in Agroforestry
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, cupuaçu 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 cupuaçu leaves after 96 days. The use of 15N tracers identified an N transfer from gliricidia leaves and the soil to cupuaçu leaves and consequently, a lower N release from gliricidia to the soil in the presence of cupuaçu leaves. Though we expected that available N in the soil would also decrease with greater amounts of cupuaçu 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.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[
"026:00"
]
|
| contactPoint |
{
"fn": "Earthdata Forum",
"@type": "vcard:Contact",
"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, cupuaçu 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 cupuaçu leaves after 96 days. The use of 15N tracers identified an N transfer from gliricidia leaves and the soil to cupuaçu leaves and consequently, a lower N release from gliricidia to the soil in the presence of cupuaçu leaves. Though we expected that available N in the soil would also decrease with greater amounts of cupuaçu 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",
"title": "Data Information (PNG)",
"format": "PNG",
"mediaType": "image/png",
"downloadURL": "https://daac.ornl.gov/graphics/browse/project/square/lba_logo_square.png"
},
{
"@type": "dcat:Distribution",
"title": "Data Information (ZIP)",
"format": "ZIP",
"mediaType": "application/zip",
"downloadURL": "https://data.ornldaac.earthdata.nasa.gov/protected/bundle/ND11_Nitrogen_Transfer_Leaf_Litter_915.zip"
},
{
"@type": "dcat:Distribution",
"title": "Data Information (PDF)",
"format": "PDF",
"mediaType": "application/pdf",
"downloadURL": "https://data.ornldaac.earthdata.nasa.gov/public/lba/nutrient_dynamics/ND11_Nitrogen_Transfer_Leaf_Litter/comp/ND11_Nitrogen_Transfer_Leaf_Litter.pdf"
},
{
"@type": "dcat:Distribution",
"title": "Data Information (HTML)",
"format": "HTML",
"mediaType": "text/html",
"downloadURL": "https://doi.org/10.3334/ORNLDAAC/915"
},
{
"@type": "dcat:Distribution",
"title": "Data Information (Unknown Format)",
"format": "BIN",
"mediaType": "application/octet-stream",
"downloadURL": "https://search.earthdata.nasa.gov/search?q=ND11_Nitrogen_Transfer_Leaf_Litter_915&ac=true"
}
]
|
| 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"
]
|
| landingPage | https://search.earthdata.nasa.gov/search?q=ND11_Nitrogen_Transfer_Leaf_Litter_915&ac=true |
| modified | 2026-02-17 |
| programCode |
[
"026:000"
]
|
| publisher |
{
"name": "ORNL_DAAC",
"@type": "org:Organization"
}
|
| spatial |
"[[{"WestBoundingCoordinate":-60.03,"NorthBoundingCoordinate":-2.518,"EastBoundingCoordinate":-60.03,"SouthBoundingCoordinate":-2.518}],"CARTESIAN"]"
|
| temporal | 2002-07-11/2002-07-11 |
| theme |
[
"Earth Science"
]
|
| title | LBA-ECO ND-11 Litter Decomposition, Carbon, and Nitrogen Dynamics in Agroforestry |
