Consulta: creatorFacets:"Camacho,Rafael"
Registros recuperados: 2
Data/hora: 16/06/2024 00:45:07

A model to explain high values of pH in an alkali sodic soil
Provedor de dados: 63
Autores: Guerrero-Alves,José; Pla-Sentís,Ildefonso; Camacho,Rafael.
For alkali sodic soils (pH&gt;8.5), the "hydrolysis of exchangeable sodium" has been used as a possible explanation for the alkalinity production and rise in pH of these soils. As an alternative to this hypothesis, a model was developed to simulate and to explain that the alkalinity production and rise in pH is possible in a soil that accumulates alkaline sodium salts and CaCO3. Several simulations were performed by using different combinations of CO2 partial pressures (P), presence or absence of MgCO3, along with experimental values of exchangeable sodium percentage (ESP) and ion concentrations in saturation extracts from an alkali sodic soil (named Pantanal). A hypothetical system with similar conditions to the Pantanal soil but with a Gapon selectivity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gapon selectivity coefficients; Calcium carbonate; Sodium bicarbonate; Alkaline hydrolysis.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000400021

Vegetative growth of grain sorghum in response to phosphorus nutrition
Provedor de dados: 63
Autores: Camacho,Rafael; Malavolta,Eurípedes; Guerrero-Alves,José; Camacho,Tomás.
Morphological variables such as phytomass, plant height, leaf area, number of leaves, have been used to express the influence of mineral nutrients on plant growth patterns, since the vegetative development responds, in general, favorably to fertilizer applications. This work evaluates the effect of P on both, some morphological characteristics and total [P] in the shoot of eight grain sorghum (Sorghum bicolor L. Moench) genotypes. Genetic materials were grown in nutrient solution under three concentrations of P (0; 0.5 and 1.0 mmol L-1). Plants were harvested 41 days after sowing, and leaf area per plant (LA), number of leaves (NL) per plant, root volume (RV), plant height (PH), root dry matter (RDM), shoot dry matter (SDM), total dry matter (TDM), RDM/SDM...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sorghum; Phosphorus; Leaf area; Plant height; Root volume.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000400022