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.

The objective of this work was to evaluate tiller dynamics and population stability of Andropogon lateralis in a natural pasture subjected to grazing height management under intermittent stocking method. The experiment was carried out in a randomized complete block design with four treatments and four replicates, in 16 experimental units of 875 m² each. The treatments consisted of four pre-grazing heights of A. lateralis (12, 20, 28, and 36 cm), which was grazed until its initial height was reduced by 40%. Dynamics of tiller birth and death were evaluated using the marked tiller technique over a period of 18 months, from October 2015 to March 2017. The results indicate that the use of different heights for the management of natural pastures does not affect the stability of the tiller population of A. lateralis and that, regardless of the management strategy, the persistent pathway of this species is mainly based on the maintenance of high-tiller survival rates.

Accurate greenhouse gas inventories require region-specific emission factors (EFs). Current nitrous oxide (N ₂ O) inventories often rely on IPCC Tier 1 defaults, which may not accurately represent subtropical grazing systems where field-based data remain scarce. This study aimed to evaluate how pasture intensification gradients interact with different nitrogen sources (urea fertilizer, cattle urine, and dung) to regulate N ₂ O emission factors in the Southern Brazilian Highlands, providing regionally calibrated data to assess their alignment with IPCC default values. Nitrous oxide emissions were measured over 100 days using static chambers in four systems: natural grassland (NG), improved natural grassland (ING), perennial pasture (PP), and annual pasture with soil disturbance (AP). Measured EFs suggested a trend toward lower values than IPCC defaults for most sources. Urea in AP was the only treatment exceeding the 1.6% default (EF = 1.7%), while urea-EFs in PP and ING averaged 0.77%. Urine-EFs averaged 0.71% in AP/ING and 0.23% in NG/PP, while dung consistently showed the lowest values (mean = 0.28%). These findings suggest that N ₂ O emissions are governed by two interacting hierarchies: management intensity (NG < ING ≈ PP < AP) and nitrogen source (urea > urine ≈ dung). Overall, these findings suggest that the monitored subtropical grazing systems with stable soil structures tended to exhibit lower N ₂ O emission factors than current IPCC Tier 1 default values. Disaggregating EFs by source and management intensity improves national inventories and informs mitigation strategies, such as reducing soil disturbance to preserve the naturally low N ₂ O emission potential of subtropical pastures.

IMPACT OF WEATHER CONDITIONS ON THE ENERGETIC QUALITY OF ACICULATED DRY BRANCHES OF Araucaria angustifolia (Bertol.) Kuntze PRODUCED THROUGHOUT A YEAR

As pastagens cultivadas de inverno são um importante componente dos sistemas pecuários no sul do Brasil, oportunizando a produção de carne e leite a custos competitivos. A qualidade de sementes é fundamental para o estabelecimento de pastos produtivos, com alto potencial e livre de contaminação de patógenos e plantas indesejáveis. O objetivo do trabalho foi avaliar a qualidade de sementes de forrageiras de inverno adquiridas por produtores rurais no Planalto Catarinense, no verão/outono de 2017 e 2019. Foram amostrados 78 lotes de sementes de forrageiras adquiridas no mercado local em 12 municípios da região. Parâmetros de germinação, pureza, outras sementes e material inerte foram analisadas em laboratório de análise de sementes credenciado no Ministério da Agricultura Pecuária e Abastecimento. A maior parte dos lotes de sementes analisadas estão abaixo do que preconiza a legislação vigente. Isto compromete o estabelecimento, produção e rentabilidade dos pecuaristas.