Soil microbial community structure and carbon dynamics in response to compost and livestock management in grassland soils
Organic amendments are widely promoted to restore soil fertility in degraded agroecosystems, yet their effects may depend strongly on land-use history. We evaluated the interactive influence of composted olive mill waste (alperujo) and three grazing management regimes—livestock exclusion, ovine, and...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:dnet:idus________::f6abafe2741a4180ec9011c2659c8539 |
| Acceso en línea: | https://hdl.handle.net/11441/186214 https://doi.org/10.1016/j.agee.2026.110261 |
| Access Level: | acceso abierto |
| Palabra clave: | Carbon mineralization Priming effect Livestock diversity Grazing exclusion Nutrient cycling |
| Sumario: | Organic amendments are widely promoted to restore soil fertility in degraded agroecosystems, yet their effects may depend strongly on land-use history. We evaluated the interactive influence of composted olive mill waste (alperujo) and three grazing management regimes—livestock exclusion, ovine, and equine grazing—on soil chemical properties, microbial communities, and carbon (C) mineralization in a Mediterranean dehesa. Across treatments, livestock exclusion consistently increased soil C and N contents compared with grazed areas, with total C (TC) 42 % higher than in equine-grazed plots and 52 % higher than in ovine-grazed plots, and total nitrogen (TN) 18 % higher than in equine plots (with similar TN levels in ovine plots across samplings). Compost addition further increased plant-available phosphorus (P) and potassium (K) by 243 % and 270 % in the more degraded equine-grazed soils. Compost did not significantly increase TC or TN but induced marked shifts in bacterial and fungal community composition, with responses modulated by grazing legacy and initial fertility. Taxonomic changes were most pronounced within oligotrophic and copiotrophic bacterial groups (e.g., Chloroflexi, Verrucomicrobiota) and certain fungal phyla (e.g., Rozellomycota, Ascomycota), although overall microbial diversity remained largely unchanged. Functionally, compost reduced both initial C mineralization rates and cumulative respiration, as well as the priming effect, especially in exclusion and ovine soils. This suppression likely reflects the compost’s high chemical stability, low labile C content, and its influence on microbial carbonuse strategies. Spatial heterogeneity of organic inputs remained a challenge in grazed systems, but compost partially mitigated nutrient depletion in under-enriched areas. Our findings highlight that the effects of organic amendments are context-dependent, shaped by grazing legacy and nutrient status. They underscore the importance of integrating organic amendments with tailored grazing management to optimize nutrient balance, microbial function, and long-term soil C sequestration in Mediterranean rangelands. However, as this study was conducted at a single site with one compost type over a short-term period, further research across sites, compost types, and longer time scales is needed to generalize these findings. |
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