Soil health indicators based on microbial biodiversity are increasingly used in agricultural sustainability assessments. However, little is known about how microbial communities vary within micro-environmental gradients across different land uses, which is crucial for designing field sampling and monitoring protocols. Our objective was to assess how soil microbial communities changed with soil depth and spatial distance across land-use types. We sampled soils in four spatial distances (within 0.1–70 m) and four depths (within 0–40 cm) in forests, grasslands, and horticultural lands, and combined 16S rRNA gene sequencing, DNA quantification and soil chemical characterization to explore micro-environmental variation in microbial biomass, α-β-diversity, and communities’ assembly processes. Depth and spatial distance had differential effects on microbial biodiversity within different land uses. Microbial biomass was most sensitive to depth, α-diversity to spatial distance, and β-diversity to both depth and spatial distance. Deterministic processes dominate microbial communities’ assembly along depth in all land uses, which is a promising result for developing soil quality indicators based on microbial biodiversity. Overall, our results suggest that collecting soil samples separated by at least 12 m is adequate to capture biodiversity changes across land uses. However, collecting randomly within the first 10 cm is recommended for native forests, while systematic sampling within the first 20 cm is advised for grasslands and horticultural lands. Our findings underscore the need for land use-specific sampling frameworks in soil life-based sustainability assessments for meaningful regional comparisons.

La co-innovación en el desarrollo de prácticas productivas que permitan disminuir el uso de insumos externos y ser amigables con el ambiente es una de las principales búsquedas en agroecología. Específicamente, disminuir el uso de fertilizantes importados y/o de síntesis química es una de las principales inquietudes de productores hortícolas de la Comarca Andina del Paralelo 42° en la Patagonia argentina. Este estudio evaluó el impacto de biofertilizantes, derivados de microorganismos de montaña recolectados de bosques nativos, sobre la colonización micorrícica y el rendimiento en cultivos de lechuga y zanahoria. Se evaluó el uso de “bioestimulante” y “supermagro” elaborados artesanalmente en comparación con la fertilización tradicional utilizada en tres chacras: una con manejo convencional y dos con manejo agroecológico. Los resultados mostraron que las chacras agroecológicas presentaron mayores niveles de colonización micorrícica en comparación con la convencional. En lechuga, la aplicación de supermagro incrementó la colonización micorrícica en las chacras agroecológicas, mientras que en zanahoria, los efectos de los distintos tratamientos fueron menos evidentes. El rendimiento de lechuga mostró una ligera disminución con supermagro respecto a la fertilización tradicional del productor o al bioestimulante; mientras que para zanahoria, el bioestimulante favoreció el rendimiento, especialmente en las chacras agroecológicas. El uso de biofertilizantes locales se perfila como una alternativa promisoria para mantener o mejorar la productividad de cultivos hortícolas intensivos. Estos bioinsumos no solo fomentan el funcionamiento del suelo, sino que también reducen la dependencia de insumos externos, contribuyendo a una transición hacia prácticas más sostenibles y resilientes.

Landscape complexity shapes insect spatiotemporal population dynamics and trophic interactions. In this context, understanding seasonal and environmental patterns of potential resident natural enemies of novel polyphagous herbivores, such as the globally invasive fruit fly pest Drosophila suzukii, is fundamental for developing effective landscape-scale pest management strategies. Here, we investigated for the first time in the Andean Patagonian region of Argentina the spatiotemporal dynamics and parasitism of three resident parasitoids—Leptopilina heterotoma, Pachycrepoideus vindemiae, and Spalangia endius—with the potential to attack D. suzukii across heterogeneous landscape including fruit crops and surrounding natural habitats. All three parasitoid species were recorded across all environments, although their seasonal dynamics differed. L. heterotoma peaked in spring, P. vindemiae in summer, while S. endius showed a non-significant tendency toward higher activity in autumn. We further provide the first field-based evidence in the region that S. endius successfully attacks and completes development in D. suzukii, and that D. suzukii exploits wild fruit species as alternative hosts. These findings highlight the need for further research on the pupal parasitoid S. endius to assess its potential as a suitable candidate for the development of biological control strategies.