Examinando por Materia "Pastizales altoandinos"

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Contribución de bacterias endófitas nativas en la acumulación de nutrientes en poaceas altoandinas
(Universidad Nacional Mayor de San Marcos, 2021-10-27) Santillana Villanueva, Nery; Tineo Bermudez, Alex; Mamani Mamani, Godofredo; Aylas Chavez, Michael; Gonzales Guzman, Wilfredo; Espinoza Montes, Francisco
El objetivo de la investigación fue determinar la contribución de las bacterias endófitas nativas en la acumulación de nutrientes en tres poaceas altoandinas a 4116 msnm. Se determinó el contenido de macro y micronutrientes en la biomasa aérea de Calamagrostis vicunarum, Festuca dolichophylla y Muhlenbergia ligularis inoculadas con 19 bacterias endófitas, las que se compararon con tres controles (abonamiento básico, fertilización química y sin ninguna aplicación). Los resultados en Calamagrostis vicunarum evidenciaron que cuatro aislados de Bacillus mycoides (13, 19, 12 y 16) contribuyeron entre 15.2 y 35.6% en la acumulación de S, Ca, Na, Mg, P, K y N (macronutrientes) y de Fe, B, Zn, Mn, Cu y Mo (micronutrientes). En Festuca dolichophylla, dos aislados de B. mycoides (16 y 14) y las bacterias Paenibacillus tundrae (10) y Staphylococcus warneri (7) contribuyeron entre 8.6 y 25.9% en la acumulación de S, Ca, Mg, P y K (macronutrientes) y B, Zn, Mn y Cu (micronutrientes). En Muhlenbergia ligularis, Bacillus simplex (2), B. mycoides (19 y 15), P. xylanexedens (17) y P. amylolyticus (9) contribuyeron entre 10.7 y 73.6% en la acumulación de Na, N, K, Mg, S, P y Ca (macronutrientes) y de Cu, Mo, B, Fe, Zn y Mn (micronutrientes). Estos resultados evidencian el potencial de las bacterias endófitas estudiadas para mejorar el contenido de nutrientes en las poaceas altoandinas, aunque muestran cierta especificidad de la especie en el efecto.
Trace metals in high-Andean forages: differential dietary exposure in cattle, sheep, and alpacas, and lack of non-carcinogenic risk
(Research Square, 2026-06) Arias Arredondo, Alberto Gilmer; Lopez Rodriguez, Melina; Cruz Luis, Juancarlos Alejandro; Contreras, Jose; Ramos Acuña, Hebert; Solórzano Acosta, Richard Andi
Trace metal accumulation in forage plants is a growing concern in mountain grazing systems, yet the relative importance of environmental and biological drivers remains poorly understood in the high Andes. This study evaluated trace metal concentrations in soils and cultivated forages along an altitudinal gradient (4,098–4,467 m a.s.l.) in the Junín region of central Peru and assessed potential dietary risks for livestock. Soil properties and concentrations of Zn, Cd, Cu, Mn, Pb, and Cr were determined in soils and four forage species (Avena sativa, Dactylis glomerata, Lolium multiflorum, and Lolium perenne) across eight plots. Dietary exposure was estimated using the Estimated Daily Intake (EDI), while non-carcinogenic risks for cattle, sheep, and alpacas were assessed through the Hazard Quotient (HQ) and Hazard Index (HI). Marked spatial variation in soil properties and trace metal concentrations was observed among plots, indicating that metal accumulation was primarily driven by local soil heterogeneity. Altitude was not associated with trace metal concentrations, and forage species showed no significant differences in metal accumulation (p > 0.05). Although sheep exhibited the highest EDI values, all HQ and HI values remained below 1. These findings demonstrate that fine-scale soil heterogeneity is a stronger determinant of trace metal accumulation than altitude or forage species identity in high-Andean forage systems. The study provides new evidence that current trace metal exposure levels do not represent a significant non-carcinogenic risk for cattle, sheep, or alpacas under the evaluated environmental conditions.
Trichoderma mobilizes phosphorus and cobalt while excluding sodium in the foliar ionome of high-Andean grasses enriched with biochar
(Willey, 2026-09-11) Arias Arredondo, Alberto; Lopez Rodriguez, Melina; Cruz Luis, Juancarlos Alejandro; Solórzano Acosta, Richard Andi
Acidic high-Andean soils constrain grassland productivity by limiting nutrient availability and altering plant ionomic balance. Biochar inoculated with plant growth-promoting microorganisms has emerged as a promising strategy to mitigate these constraints; however, the extent to which microbial identity modulates plant nutrient acquisition remains poorly understood. This study evaluated the effects of Trichoderma sp., Bacillus sp., and Pseudomonas sp. as inoculants of guinea pig manure–derived biochar on soil pH and the foliar ionome of Carex sp., Dactylis glomerata, Festuca dolichophylla, and Lolium perenne in a high-Andean Andisol (4150 m a.s.l.). A randomised complete block design (4 × 4 factorial, three replicates) was used. Biochar (20 t ha⁻¹) was applied at establishment, and microbial inoculants (5 L ha⁻¹) were applied at sowing and during crop development. Foliar elemental concentrations were determined by MP-AES and analysed using ANOVA and multivariate approaches. Biochar significantly increased soil pH (p < 0.001). Ionomic responses depended on microbial identity: Trichoderma sp. enhanced P and Co accumulation while reducing Na (p < 0.05), indicating coordinated nutrient regulation. Micronutrients (Fe, Mn, Cu) were primarily species-driven. These findings demonstrate that microbially functionalized biochar can selectively reconfigure plant ionomes, supporting microbiome-assisted strategies to improve nutrient efficiency and resilience in acidic agroecosystems.