Instituto de Investigaciones Agropecuarias

Antecedentes y Objetivos: Los bosques de oyamel en la Reserva de la Biósfera Mariposa Monarca (RBMM) están siendo seriamente amenazados por sequías más cálidas y por plagas (escarabajo descortezador) debido al cambio climático, lo cual ha producido un declive en el número de árboles que son el hábitat invernal de la mariposa monarca. Los objetivos de este trabajo fueron: (1) estimar la supervivencia y crecimiento de dos especies de arbustos plantados en un sitio altamente perturbado de la Zona Núcleo de la RBMM; (2) determinar el efecto del tamaño inicial de planta y su disposición en la supervivencia y crecimiento de los arbustos; (3) estimar el tiempo que les llevará alcanzar 1 m de altura, misma que se considera necesaria para que funcionen como nodrizas del oyamel. Métodos: Se establecieron 30 bloques completos al azar, en los cuales se sembraron plántulas de Ageratina glabrata y Baccharis conferta producidas en vivero. Se evaluó la supervivencia y crecimiento durante 2.5 años. Resultados clave: La supervivencia e incremento en altura promedio fue de 42% y 36.2 cm para A. glabrata y 49% y 31.3 cm para B. conferta, respectivamente. Con base en los datos de incremento de altura de los arbustos se estimó que el tiempo necesario para que ambas especies alcancen 1 m es aproximadamente cinco años. Conclusiones: Cuando no hay arbustos preexistentes en el sitio a reforestar con oyamel, es viable establecer un dosel de arbustos nodriza; sin embargo, se recomienda que los arbustos sean plantados cinco años previos a la reforestación con oyamel.

How land-use intensity (LUI) affects soil structure-dependent functions and organic matter (OM) quality in Patagonian wetland soils (Vegas) of southern Chile is an intriguing question. These wetland soils, which store large amounts OM and regulate water and nutrient fluxes, are increasingly exposed to intensification. While degradation of peatlands under drainage and conversion to agricultural activities is well documented, the long-term effects of contrasting LUI under intensification of livestock systems and peat extraction in southern Patagonia remain poorly understood. Research was conducted along a west–east climatic and aridity gradient in the Magallanes Region Chile. Four pairs of Vegas with contrasting LUI, low-and-high-intensity use of livestock and peat extraction sites were selected, spanning Histosols and Gleysols, including sedge meadows and Sphagnum peatlands. At each site, environmental conditions, vegetation inventory, and livestock management (stocking rate and density) were characterized. Soil structure-dependent functions were quantified from undisturbed cores collected at the surface horizon (5 cm) and the last horizon (~ 70 cm) before the appearance of glacial material or the water table. The water retention and shrinkage curves were measured, and from this, the bulk density (BD), air capacity (AC), plant available water (PAW), coefficient of linear extensibility (COLE), air permeability (Ka) were derived. The saturated hydraulic conductivity (ks), and anisotropy of air and water flows were quantified. The total and dissolved organic carbon and nitrogen (TC, TOC, IC, DOC, TN, TIN and TON), stable isotopes (¹³C, ¹⁵N), and ATR-FTIR spectroscopy. Most Vegas showed high OC (3,69-44%) with very high porosity (>80%), high shrinkage capacity, and strong deformation due to soil drying (COLE> 0.09), particularly in Histosols. and ks decrease with depth, especially in Sphagnum peatlands due to the OM decomposition and pore-size reduction. A soil structural shrinkage phase normally is presence, being often a residual and zero-shrinkage phases absent under low LIU. Anisotropy in fluid conduction was sporadic and more pronounced in the Gleysolic sites. OM quality varied strongly in the top and depth soils across sites. Sphagnum peatlands had the highest C:N ratios and high FTIR signatures of recalcitrant organic compounds, whereas sedge-dominated Vegas showed more similar spectral patterns. Depth profile declines in C:N and shifts in ¹³C and ¹⁵N abundances showing progressive OM decomposition and N enrichment. Unexpectedly, we found that high LUI did not deteriorate the structure-dependent functions. In several cases, more intensive but better managed systems displayed higher porosity, greater ks and Ka, and well-developed structural shrinkage phases. However, peat extraction in Sphagnum systems clearly damaged structural integrity. Results indicate that LUI effects are context dependent and that both low-intensity and over grazing for livestock production can be detrimental. A high LUI did not result in a marked deterioration of structure dependent soil functions, instead, it revealed a continuum of responses across the study sites. Recovery in structure-dependent soil functions were primarily associated with increased organic matter content, accompanied by a relative enhancement in organic matter quality. This implies that low land use intensity can be just as harmful without proper utilization and controlled use of natural resources.

Climate hazards impact pastoral communities due to their dependency on nature for their primary livelihoods. This study analyzes climate risk in ten pastoral livestock farming communities in Patagonia drylands of Argentina. A participatory impact chains (PICs) approach was used as a qualitative and participatory bottom-up methodology allowing for the identification and contextualization of climate hazards, exposure, intermediate impacts and vulnerability dimensions through knowledge co-production with local stakeholders. Results show that, although drought is the predominant climate hazard across the region, its impacts are heterogeneous and mediated by local socio-environmental conditions. The analysis underlines that vulnerability is not evenly distributed but is shaped by specific historical, political and environmental pathways. These findings challenge standardized top-down risk assessments, and highlight the need for adaptation strategies that are context-sensitive, territorially differentiated and that integrate local knowledge. The study also contributes to advancing qualitative participatory methodologies for climate risk assessment in pastoral systems in arid areas of Latin America, showing the regional heterogeneity and social inequalities.

El presente artículo plantea una reflexión para comprender las dinámicas diferenciales de la estigmatización ligadas al género y la clase. Para ello se toman dos casos del mercado sexual argentino: mujeres que hacen comercio sexual callejero y varones que comercializan contenido erótico en la plataforma OnlyFans. Estos casos representan una oportunidad para repensar teóricamente la conceptualización del estigma pues ambos casos la exposición y la visibilización son una condición de posibilidad para la participación en dicho mercado, sin embargo, existen marcadas diferencias en la gestión de la propia imagen, la posibilidad del manejo de la información, las narrativas sobre el yo, el impacto y las reacciones frente al estigma en un grupo y el otro. En este sentido, el artículo busca explorar las diferencias de género y clase en la regulación cultural de la sexualidad y la emergencia de plataformas digitales que reconfiguran las formas de legitimación en el mercado sexual.

Climate hazards impact pastoral communities due to their dependency on nature for their primary livelihoods. This study analyzes climate risk in ten pastoral livestock farming communities in Patagonia drylands of Argentina. A participatory impact chains (PICs) approach was used as a qualitative and participatory bottom-up methodology allowing for the identification and contextualization of climate hazards, exposure, intermediate impacts and vulnerability dimensions through knowledge co-production with local stakeholders. Results show that, although drought is the predominant climate hazard across the region, its impacts are heterogeneous and mediated by local socio-environmental conditions. The analysis underlines that vulnerability is not evenly distributed but is shaped by specific historical, political and environmental pathways. These findings challenge standardized top-down risk assessments, and highlight the need for adaptation strategies that are context-sensitive, territorially differentiated and that integrate local knowledge. The study also contributes to advancing qualitative participatory methodologies for climate risk assessment in pastoral systems in arid areas of Latin America, showing the regional heterogeneity and social inequalities.

ABSTRACT Legumes, through atmospheric N fixation, enhance soil health and fertility by increasing organic matter and nitrogen (N) availability. This study evaluated the productivity, N fixation and N transfer from annual legume mixtures (LM) to a companion ryegrass ( Lolium multiflorum ) in mixed swards, under Mediterranean conditions. The LM swards with different phenologies (designated M400, M500 and M600), comprised cultivars of Trifolium subterraneum , T. michelianum and Medicago polymorpha , grown either alone or in combination with ryegrass (LM + R ). Plots were established in May 2014 and were evaluated from 2014 to 2017. Dry matter production varied significantly among LM, LM + R and ryegrass monocultures across the different years. The LM + R swards produced 35%–47% more dry matter than LM swards and 33%–68% more than ryegrass alone. The mixture M400 + ryegrass achieved the highest production (6.64 t ha −1 average; 14.85 t ha −1 in 2015). N derived from the atmosphere ranged from 84% to 94% in LM swards. The mixture M500 fixed the highest amount of N across years. The nitrogen yield (kg N ha −1 ) was higher in LM + R swards compared to LM alone. M600 showed the highest N transfer to ryegrass. All LM + R swards had land equivalent ratio (LER) > 1, indicating better resource use than monocultures. The demonstrated benefits of mixed cropping systems—higher productivity, enhanced N fixation, effective N transfer and improved resource use efficiency—align with the goals of reducing synthetic fertiliser dependency and mitigating environmental impacts.

Se desarrollo una investigación durante la época seca desde el año 2020 al 2023, con el objetivo de cuantificar el efecto del déficit hídrico en las diferentes etapas fenológicas del cultivo del maíz. El estudio se desarrolló en la Estación Experimental El Ejido-Los Santos. La unidad experimental constó de seis surcos de 5.2 m de largo. Se evaluaron cuatro niveles de estrés en distintas etapas del cultivo y dos híbridos. Para establecer los distintos niveles de deficiencia hídrica, se suspendió el riego por goteo luego de llegar a la fecha indicada hasta finalizar la misma. Los tratamientos tuvieron un arreglo Factorial en Fajas 4 x 2 en un diseño de Bloques Completos al Azar con tres repeticiones. Se calculó la Tasa de crecimiento Relativo y absoluto para cada tratamiento. Las variables climáticas se obtuvieron de una estación meteorológica portátil tipo Davis. El análisis estadístico indicó que hubo diferencias estadísticas altamente significativas para el Factor Etapa de la deficiencia hídrica para casi todas las variables. Se observó que el estrés en el secado de grano (85 a 110 dds) no difirió estadísticamente de las parcelas sin déficit hídrico (riego durante todo el desarrollo del cultivo), estos presentaron rendimientos de grano de 5.32 y 5.24 tha-1, respectivamente. La fase de prefloración fue la menos afectada con una reducción de 26 %. Mientras que, la etapa floración y llenado del grano (50 a 84 dds) fue la más afectada con una reducción del 55 % del rendimiento.

Potassium (K) is an essential macronutrient that plays a central role in grapevine physiology and fruit quality. This study aimed to evaluate the effects of different K concentrations in the nutrient solution on berry composition, color development, and mineral concentration in leaves, petioles, and berries of fruit-bearing cuttings of Vitis vinifera L. cv. Tempranillo. Fruit-bearing cuttings were grown under controlled greenhouse conditions and irrigated with modified half-strength Hoagland solutions containing 0%, 25%, 50%, 75%, or 100% K and a control nutrient solution. Berry quality parameters, including total soluble solids, acidity, anthocyanins, and phenolic maturity, were significantly influenced by K availability. Moderate K treatments (50–75%) produced the most favorable outcomes in terms of sugar accumulation, anthocyanin concentration, and nutrient balance. The results suggest that optimized K fertilization is critical for improving grape quality while avoiding potential negative effects associated with deficiency or excess. These findings provide valuable insights for K management in viticulture.