Yerba mate (Ilex paraguariensis St. Hill.) is an important woody tree in South America, however the production of quality seedlings is a major problem. Microorganisms that promote plant growth have shown to be efficient biotechnologies in the production of seedlings. The arbuscular mycorrhizal fungi (AMF), it establishes symbiosis with several plant species and increases the accumulation of biomass and absorption of poorly mobile nutrients such as phosphorus. Here, we test the effects of two AMF species on growth, root architecture, phosphorus accumulation and gas exchange of yerba mate seedlings cultivated under different phosphorus levels. We used seedlings in a non-sterile soil, inoculated with AMFs Rhizophagus clarus SCT720A and Acaulospora colombiana SCT115A, and non-inoculated (control) treatment under five levels of phosphorus (0; 25; 50; 100 and 200% recommendation). After 90 days of AMF inoculation, plant dry biomass, root architecture and mycorrhizal colonization were determined and after 180 days, the same parameters plus photosynthetic rate, transpiration rate, stomatal conductance and P content were evaluated. AMF inoculation increased shoot and root dry biomass, total root length, root volume. Plants inoculated with AMF showed higher photosynthesis rate. Phosphorus content and mycorrhizal colonization were increased almost three times when inoculated with AMF. Our findings highlight the importance of AMF inoculation for Ilex paraguariensis seedlings production, reducing the time needed in nurseries to enhance tree performance. HIGHLIGHTS• Arbuscular mycorrhizal fungi (AMF) inoculation increases root development and photosynthesis of yerba mate.• The inoculation of AMF improves yerba mate growth and can reduce the time needed in nurseries.• No P supply was needed to produce I. paraguariensis seedlings inoculated with AMF.

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Pastures are of central importance in food production and provide multiple ecosystem services. The objective of this paper was to determine whether the intensification of pasture-based animal production systems, through practices such as fertilization and improved pasture species, has a higher capacity in the short-term (five years) to sequester carbon in the soil compared to (1) natural grassland without anthropogenic interactions, (2) natural grassland fertilized and overseeded with exotic species, and (3) annual pastures with frequent soil disturbance. The study assessed the organic carbon stock (OCS), total organic carbon (TOC), particle size, porosity, and density at different soil strata, as well as the root system and forage production. Forage dry matter (DM) production varied significantly with means ranging from 6615 to 13,000 kg ha–1 year–1 for natural grassland (NG) and permanent pasture (PP), respectively. Improved natural grassland (ING) and NG presented a higher density and root diameter than PP and annual pasture (AP). Forage systems significantly influenced soil porosity and density, with NG and ING showing lower soil densities and higher soil porosities. The OCS (0–100 cm) was similar between NG (270 Mg ha–1), ING (255 Mg ha–1), PP (274 Mg ha–1), and AP systems (256 Mg ha–1). Over a period of five years, the intensification of pasture-based animal production systems did not have a significant impact on OCS in the soils of a Brazilian subtropical highland.

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The conversion of natural grasslands to cultivated pastures can have a significant impact on the composition and structure of soil macro‐ and mesofauna groups, compromising the resilience of these organisms and the ecosystem services they provide. We studied the responses of these groups to increasing levels of soil disturbance across a gradient of four land management practices: Natural grassland (NG), Improved‐natural grassland (IG), Perennial‐cultivated pasture (PP), and Annual‐cultivated pasture (AP). The NG area had a higher abundance of macrofauna, greater dominance of certain groups, particularly Isoptera, and a lower abundance of mesofauna. On the other hand, the IG area had a higher abundance and diversity of macro‐ and mesofauna, with a lower dominance of specific groups. The PP area had a higher abundance of Coleoptera, Oligochaeta, and Hemiptera, whereas the AP area, despite soil disturbance, showed a higher abundance of mesofauna, particularly mites, Collembola, and Enchytraeidae, but lower diversity. Different grassland management practices have significantly altered the composition and structure of macro‐ and mesofauna groups, resulting in high dissimilarity between communities. We recommend IG as a more productive and sustainable alternative to the total replacement of natural vegetation (NG) with intensified converted pastures (PP and AP), as it maintains soil fauna diversity and ecosystem services.