Plant rhizodeposition: A key factor for soil organic matter formation in stable fractions

Soil organic carbon formation remains poorly understood despite its importance for human livelihoods. Uncertainties remain for the relative contributions of aboveground, root, and rhizodeposition inputs to particulate (POC) and mineral-Associated (MAOC) organic carbon fractions. Combining a novel fr...

Descripción completa

Detalles Bibliográficos
Autores: Villarino, Sebastián Horacio, Pinto, Priscila, Jackson, Robert B., Piñeiro, Gervasio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/164549
Acceso en línea:http://hdl.handle.net/11336/164549
Access Level:acceso abierto
Palabra clave:SOIL CARBON
MINERAL‐ASSOCIATED ORGANIC MATTER
PARTICULATE ORGANIC MATTER
https://purl.org/becyt/ford/4.1
https://purl.org/becyt/ford/4
Descripción
Sumario:Soil organic carbon formation remains poorly understood despite its importance for human livelihoods. Uncertainties remain for the relative contributions of aboveground, root, and rhizodeposition inputs to particulate (POC) and mineral-Associated (MAOC) organic carbon fractions. Combining a novel framework with isotope tracer studies, we quantified POC and MAOC formation efficiencies (% of C-inputs incorporated into each fraction). We found that rhizodeposition inputs have the highest MAOC formation efficiency (46%) as compared to roots (9%) or aboveground inputs (7%). In addition, rhizodeposition unexpectedly reduced POC formation, likely because it increased decomposition rates of new POC. Conversely, root biomass inputs have the highest POC formation efficiency (19%). Therefore, rhizodeposition and roots appear to play opposite but complementary roles for building MAOC and POC fractions.