Edaphic fauna and physico-chemical atributes of soil in different phytophysionomies of Cerrado

ABSTRACT The edaphic community comprises several organisms that perform ecological functions in the environment, such as litter fragmentation, nutrient cycling, and modifications of soil structure, in addition to acting as food chain regulators. Thus, the objective of this study was to evaluate the composition of the edaphic fauna and the physical and chemical attributes of soil in different physiognomies of Cerrado in the Parque Estadual do Mirador (PEM). The study was carried out in two Cerrado formations (Sparse Cerrado and Typical Cerrado) in PEM, where 100 pitfall traps were installed. The edaphic organisms were screened and identified in terms of orders, suborders, subfamilies, families, abundance, richness, Shannon diversity, and Pielou’s equitability. A total of 4,149 individuals were collected from two experimental plots. The plot in the Typical Cerrado showed greater taxonomic richness (25 groups) and greater Shannon diversity (H’ = 1.65), while the plot in Sparse Cerrado presented 19 edaphic groups and Shannon diversity equal to H’ = 1.51. The factorial exploration explained 84.43% of the original data from the Sparse Cerrado and 90.84% from the Typical Cerrado. It is concluded that the plot in the Typical Cerrado showed greater differences in terms of richness and abundance due to the more favorable conditions for soil fauna, such as a high content of organic material and greater vegetation cover.

Chemical and microbiological changes in the soil mediated by different vegetative coverings in a Natal orange orchard

Proper soil cover management for citrus cultivation can contribute to increased productivity and improved soil quality. This study examined five different vegetative coverings [Urochloa brizantha; U. decumbens, U. ruziziensis, spontaneous vegetation, and herbicide application (glyphosate) in the total area] in the inter rows of a Natal orange orchard [Citrus sinensis (L.) Osbeck] grafted on the Swingle citrumelo (C. paradisi × Poncirus trifoliata). Their effects on the microbiological and chemical attributes of the soil and the vegetative development in the orchard were examined. Chemical (Ca2+, Mg2+, K+, P, pH, H+Al, CECpH7, base saturation, and OM) and microbiological (carbon and nitrogen of microbial biomass, basal respiration, and metabolic quotient) soil attributes in the rows and inter-rows were evaluated for the orchard in 2018 and 2019. There was a significant difference for most variables in the 2 years studied, emphasizing 2019 for microbiological parameters and OM, with the latter being 14.8% lower in the treatment with glyphosate in the total area compared to the treatment with spontaneous vegetation. The results showed the benefits of vegetation cover with brachiaria in inter-rows of the Natal sweet orange orchard in the chemical and microbiological attributes of the soil, especially in carbon and nitrogen of the microbial biomass.

Distributions and Risk Assessment of the Natural Radionuclides in the Soil of Shoubra El Kheima, South Nile Delta, Egypt

Due to heightening concern about radiation hazards protection, activity concentrations of 226Ra, 232Th, 40K in forty soil samples collected from Shoubra El Kheima in the South Nile Delta were measured using gamma-ray spectrometry. The mean activity concentrations of 226Ra and 40K were higher in 20% of the considered samples than the world average values. A comprehensive comparison with up-to-date data was carried out. Spatial distribution maps of the measured radionuclides and radiological parameters were generated. The distributions of natural radionuclides were influenced by the soil organic matter, clay content, and scavenger metals oxides, as well as differences in the physical and chemical attributes and solubility of these radionuclides. The results revealed that industrial activity and agricultural practices in the study area caused an incremental increase in 226Ra and 40K activity concentrations. It can be deduced that although there are intensive industrial activities in this area, the natural radiation that comes from the soil is normal and does not pose a significant radiological hazard to the public. The natural radioactivity of soil in this area needs to be monitored periodically to prevent unnecessary radiation exposure to inhabitants.

Occurrence and richness of arbuscular mycorrizal fungi in vineyards with grapevine decline and dieback symptoms

ABSTRACT: This research identified arbuscular mycorrhizal fungi (AMF) in rhizosphere soil of grapevines with Grapevine Death and Decline symptoms (GDD) or asymptomatic healthy (H) plants, and characterized the relationship of AMF communities with soil chemical attributes. The AMF spore number ranged from 287 to 432 spores 50 cm-3 in soil with GDD plants, and from 357 to 464 spores 50 cm-3 in H plants, with no differences among vineyards or between GDD and H plants within each vineyard. We detected 42 species and 17 genera, and most taxa belonged to Acaulosporaceae or Glomeraceae. Claroideoglomus etunicatum, Funneliformis mosseae, and Archaeospora trappei were the most frequent species in all vineyards. Soil chemical attributes were not determinant for the occurrence of most fungal species; although, Entrophospora infrequens, Diversispora sp1 and Diversispora sp2 were associated with a vineyard having high soil copper. Vineyards harbor highly diverse AMF communities, which are determined by location.

Interação dos atributos químicos do solo em área com floresta natural e com plantio de laranja (Citrus sinensis L Osb.)

Na região amazônica é comum a conversão de ambiente natural para o de cultivo, com isso o solo permanece em constantes modificações. As atividades agrícolas podem incrementar a heterogeneidade do solo provocando alterações nos atributos químicos do solo, decorrente principalmente das atividades de manejo e cultivo. Essas mudanças são mensuráveis e contribuem para caracterizar, avaliar e acompanhar as alterações ocorrida utilizando ferramentas estatísticas. Assim o estudo da variabilidade espacial dos atributos químicos dos solos é particularmente importante especialmente em áreas onde o solo está submetido a diferentes manejos, visando reduzir os efeitos da variabilidade na produção das culturas em função de determinadas práticas de manejo. Dessa forma, este trabalho tem por objetivo avaliar a variabilidade espacial dos atributos químicos em área de floresta natural e com cultivo de laranja em Colorado do Oeste, Rondônia. Foram selecionadas duas áreas de estudo, a primeira sendo a área de floresta nativa e a segunda sob cultivo de laranja em de Colorado do Oeste, Rondônia. Em cada área foi delimitada uma malha com 1.260 m² (42 x 30 m), com 48 pontos e espaçamento regular entre pontos de 6 m. Nos pontos de cruzamento da malha foram coletadas amostras em três profundidades (0,00-0,05; 0,05-0,10 e 0,10-0,20 m), correspondente ao horizonte diagnóstico do solo, perfazendo uma somatória de 144 amostras por área, logo, um total de 288. Serão determinados dos atributos químicos de pH em água, acidez potencial, alumínio trocável, fósforo e potássio disponível, e carbono orgânico. Com a obtenção dos dados, estes foram avaliados por meio de estatística descrita com teste de médias e a realização da análise multivariada. Houve diferença entre as duas áreas, a substituição da vegetação nativa por sistema de cultivo, ocasionou alterações nos atributos químicos do solo. O uso das técnicas multivariadas mostrou-se eficiente na distinção dos ambientes estudados. Interaction of the chemical attributes of the soil in an area with natural forest and with planting of orange (Citrus sinensis L. Osb.) A B S T R A C TIn the Amazon region it is common to convert from a natural environment to that of cultivation, with this the soil remains in constant modifications. Agricultural activities can increase the heterogeneity of the soil causing changes in the chemical attributes of the soil, mainly due to management and cultivation activities. These changes are measurable and contribute to characterize, evaluate and monitor the changes that have occurred using statistical tools. Thus, the study of the spatial variability of the chemical attributes of soils is particularly important, especially in areas where the soil is subjected to different managements, in order to reduce the effects of variability in the production of crops due to certain management practices. Thus, this work aims to evaluate the spatial variability of chemical attributes in an area of natural forest and with orange cultivation in Colorado do Oeste, Rondônia. Two study areas were selected, the first being the native forest area and the second under orange cultivation in Colorado do Oeste, Rondônia. In each area, a mesh of 1,260 m² (42 x 30 m) was delimited, with 48 points and regular spacing between points of 6 m. At the crossing points of the grid, samples were collected at three depths (0.00-0.05; 0.05-0.10 and 0.10-0.20 m), corresponding to the soil diagnostic horizon, making a sum of 144 samples per area, therefore, a total of 288. The chemical attributes of pH in water, potential acidity, exchangeable aluminum, available phosphorus and potassium, and organic carbon will be determined. Once the data were obtained, they were evaluated using statistics described with the means test and the multivariate analysis. There was a difference between the two areas, the replacement of native vegetation by a cultivation system, caused changes in the chemical attributes of the soil. The use of multivariate techniques proved to be efficient in distinguishing the studied environments.Keywords: Amazon soils, Use and management, Soil occupation.

Ethoxy acetalated dextran-based nanocarriers accomplish efficient inhibition of leukotriene formation by a novel FLAP antagonist in human leukocytes and blood

Leukotrienes are pro-inflammatory lipid mediators generated by 5-lipoxygenase aided by the 5-lipoxygenase-activating protein (FLAP). BRP-201, a novel benzimidazole-based FLAP antagonist, inhibits leukotriene biosynthesis in isolated leukocytes. However, like other FLAP antagonists, BRP-201 fails to effectively suppress leukotriene formation in blood, which limits its therapeutic value. Here, we describe the encapsulation of BRP-201 into poly(lactide-co-glycolide) (PLGA) and ethoxy acetalated dextran (Ace-DEX) nanoparticles (NPs), aiming to overcome these detrimental pharmacokinetic limitations and to enhance the bioactivity of BRP-201. NPs loaded with BRP-201 were produced via nanoprecipitation and the physicochemical properties of the NPs were analyzed in-depth using dynamic light scattering (size, dispersity, degradation), electrophoretic light scattering (effective charge), NP tracking analysis (size, dispersity), scanning electron microscopy (size and morphology), UV–VIS spectroscopy (drug loading), an analytical ultracentrifuge (drug release, degradation kinetics), and Raman spectroscopy (chemical attributes). Biological assays were performed to study cytotoxicity, cellular uptake, and efficiency of BRP-201-loaded NPs versus free BRP-201 to suppress leukotriene formation in primary human leukocytes and whole blood. Both PLGA- and Ace-DEX-based NPs were significantly more efficient to inhibit leukotriene formation in neutrophils versus free drug. Whole blood experiments revealed that encapsulation of BRP-201 into Ace-DEX NPs strongly increases its potency, especially upon pro-longed (≥ 5 h) incubations and upon lipopolysaccharide-challenge of blood. Finally, intravenous injection of BRP-201-loaded NPs significantly suppressed leukotriene levels in blood of mice in vivo. These results reveal the feasibility of our pharmacological approach using a novel FLAP antagonist encapsulated into Ace-DEX-based NPs with improved efficiency in blood to suppress leukotriene biosynthesis.