Consulta: creatorFacets:"Barros,Felipe Martins do Rêgo"
Registros recuperados: 4
Data/hora: 12/06/2024 07:04:30

Acidez Potencial Estimada pelo Método do pH SMP em Solos do Estado da Paraíba
Provedor de dados: 90
Autores: Almeida Júnior,Agenor Bezerra de; Nascimento,Clístenes Williams Araújo do; Barros,Felipe Martins do Rêgo.
O método do pH SMP, em virtude de sua praticidade analítica, tem sido amplamente utilizado na estimativa da acidez potencial (H+Al), em substituição à solução de acetato de cálcio 0,5 mol L-1 a pH 7,0, em laboratórios de análise de solo no Brasil. No entanto, tornam-se imprescindíveis estudos regionalizados para estimar com segurança os valores da acidez potencial. Este trabalho objetivou ajustar uma equação de regressão com boa capacidade preditiva dos valores de H+Al, a partir da medida do pH(SMP), para solos do Estado da Paraíba, visando sua utilização em análises de rotina para estimar a acidez potencial. Foram utilizadas 90 amostras de solo coletadas nas várias regiões do Estado. Essas amostras foram analisadas para pH(H2O), pH(SMP), H+Al e pH do...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: PH do solo; Reação do solo; Análise de solo; Solução-tampão.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000300767

Background and Reference Values of Metals in Soils from Paraíba State, Brazil
Provedor de dados: 90
Autores: Almeida Júnior,Agenor Bezerra de; Nascimento,Clístenes Williams Araújo do; Biondi,Caroline Miranda; Souza,Adailson Pereira de; Barros,Felipe Martins do Rêgo.
ABSTRACT Soil contamination by heavy metals threatens ecosystems and human health. Environmental monitoring bodies need reference values for these contaminants to assess the impacts of anthropogenic activities on soil contamination. Quality reference values (QRVs) reflect the natural concentrations of heavy metals in soils without anthropic interference and must be regionally established. The aim of this study was to determine the natural concentrations and quality reference values for the metals Ag, Ba, Cd, Co, Cu, Cr, Mo, Ni, Pb, Sb and Zn in soils of Paraíba state, Brazil. Soil samples were collected from 94 locations across the state in areas of native vegetation or with minimal anthropic interference. The quality reference values (QRVs) were (mg...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Geochemistry; Soil pollution; Micronutrients; Trace elements.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100509

Free-living diazotrophs drive castor bean nitrogen input in tropical semiarid soils
Provedor de dados: 65
Autores: Fracetto,Felipe José Cury; Fracetto,Giselle Gomes Monteiro; Barros,Felipe Martins do Rêgo; Lira Junior,Mario de Andrade; Siqueira Neto,Marcos.
ABSTRACT:  There are few studies of microbial diversity in castor bean soils in tropical semiarid environmental. Castor bean products have been widely used around the world justifying the commercial importance of ricinoculture in Brazil’ northeastern semiarid. There is no fertilization or maintenance of litter on the soils from the present study, so we hypothesized that the free-living diazotrophs microorganisms drive the nitrogen (N) input into these soils. We evaluated the communities’ structure and diversity of diazotrophs in tropical semiarid soils with i-Castor bean 50 years of cultivation intercropping with maize (CB-50); ii-Only Castor bean 10 years of cultivation (CB-10) and iii-soil under Caatinga vegetation (CAA). Nitrogenase enzyme activity was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: NifH; Microorganism diversity; Ricinoculture; Caatinga dry forest.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019001200252

Silvopastoral systems drive the nitrogen-cycling bacterial community in soil
Provedor de dados: 64
Autores: Barros,Felipe Martins do Rêgo; Fracetto,Giselle Gomes Monteiro; Fracetto,Felipe José Cury; Mendes Júnior,José Petrônio; Araújo,Victor Lucas Vieira Prudêncio de; Lira Junior,Mario Andrade.
ABSTRACT Intercropping tree legumes with forage grasses in a silvopastoral system can avoid pasture degradation benefiting the soil. In such a system, nitrogen (N) is supplied by symbiosis between legumes and bacteria. However, the pasture quality determines the action of free-living nitrogen-fixing bacteria, which possess nifH genes, which encode nitrogenase enzyme. Ammonium-oxidizing bacteria (AOB), involved in the nitrification step, can be evaluated by specific regions of the 16S rRNA corresponding to AOB. Thus, we investigated the influence of the introduction of tree legumes into a silvopastoral system on the community structure and abundance of total bacteria, diazotrophic bacteria and ammonium-oxidizing bacteria by DGGE (denaturing gradient gel...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tree legumes; Brachiaria; 16 rRNA; AOB; NifH.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542018000300281