Time filter

Source Type

Pedron F.A.,Federal University of Santa Maria | Fink J.R.,Federal University of Rio Grande do Sul | Rodrigues M.F.,Federal University of Santa Maria | de Azevedo A.C.,Escola Superior de Agricultura Luiz de Queiroz ESALQ
Revista Brasileira de Ciencia do Solo | Year: 2011

Leptosols and Regosols are soils with a series of restrictions for use, mainly related to the effective depth, which have been poorly studied in Brazil. These soils, when derived from sedimentary rocks should be treated with particular care to avoid environmental damage such as aquifer contamination. The purpose of this study was to verify the behavior of hydraulic conductivity and water retention capacity in profiles of Leptosols and Regosols derived from sandstone of the Caturrita formation in Rio Grande do Sul state. The morphology, particle size distribution, porosity, soil density (Ds), saturated hydraulic conductivity (K s), basic water infiltration in the field (BI) and water retention were determined in soil and saprolite samples of six soil profiles. High Ds, low macroporosity and high microporosity were observed in the profiles, resulting in a low K s and BI, even under conditions of sandy texture and a highly fractured saprolite layer. The variation coefficients of data of K s and BI were high among the studied profiles and between replications of a same profile. Water retention of the studied soils was higher in Cr layers than in the A horizons and the volume of plant-available water greater and variable among A horizons and Cr layers.

de Araujo Pedron F.,Federal University of Santa Maria | Fink J.R.,Federal University of Rio Grande do Sul | Dalmolin R.S.D.,Federal University of Santa Maria | de Azevedo A.C.,Escola Superior de Agricultura Luiz de Queiroz ESALQ
Revista Brasileira de Ciencia do Solo | Year: 2010

The use of the shallow Neossolos (Leptosols and Regosols) is limited in view of the small depth and rock fragments on the surface. There is a lack of information about the definition of the contacts between soil, saprolite and rock in this soil class, as well as tools that would facilitate the morphologic field identification. The objectives of this research were an evaluation of the morphology of the contact between soil, saprolite and rock in the Neossolos derived from the sandstones of the Caturrita Formation, in the central area of Rio Grande do Sul State; to test and to adapt the weathering classes of Pedron et al. (2009) to the conditions of sedimentary rock; and to verify the correlation of the weathering classes with penetration resistance. It was stated that the morphology of the saprolithic layers of the Neossolos Litólicos (Leptosols) and Neossolos Regolíticos (Regosols) derived from sandstone are similar to the same soil classes derived from volcanic rocks in the State, allowing the adaptation of the same weathering classes proposed by Pedron et al. (2009). The tests with the impact penetrometer showed high correlation with the weathering classes adapted in this study. The following contacts were identified in the studied profiles: lithic contact, lithic fragmentary contact, and saprolithic fragmentary contact. The authors suggest, considering its importance, the inclusion of this latter in the Brazilian soil classification system.

Rabelo F.H.S.,Escola Superior de Agricultura Luiz de Queiroz ESALQ | de Rezende A.V.,University of Jose do Rosario Vellano | Rabelo C.H.S.,Sao Paulo State University | Amorim F.A.,Institute Ciencias Agrarias UNIFENAS
Revista Ciencia Agronomica | Year: 2013

The aim was to evaluate levels and forms of application of potassium on the agronomic and alimentary characteristics of corn used for silage. The experiment was carried out at UNIFENAS during the agricultural year of 2008/2009. Fertilization at planting and sowing was performed manually using 120kg ha-1 P2O5 and 30kg ha-1 N, the potassium being applied according to the treatments. The experimental design used was of randomized blocks in a 4 x 2 factorial arrangement with four replications, using four amounts (0; 60; 90 and 120 kg ha-1) and two formsof application of K (100% at planting and 50% at sowing+50% coverage). The interaction between the factors of amount and forms of application of the potassium was not significant (p>0.05) for the variables studied: the main effect of each factor was then investigated. There was no effect (p>0.05) for K levels on the percentage of drymatter (DM) and bedded plants, DM and grain productivity and grain participation in the mass. The highest grain yield was obtained when using K at planting (p<0.05). High doses of potassium did not produce changes in DM, percentage of bedded plants, DM production, grain yield or grain percentage of the plant. The different levels and forms of application of potassium do not alter the alimentary characteristics of corn silage.

Modro A.F.H.,Federal University of Rondonia | Marchini L.C.,Escola Superior de Agricultura Luiz de Queiroz ESALQ | Moreti A.C.C.C.,Institute Zootecnia Of Nova Odessa
Ciencia Rural | Year: 2011

This study aimed to identify the botanic origin of pollen loads collected by Africanized honeybees. In Piracicaba (SP), during four seasons of the year, five honeybee colonies were installed with a frontal pollen collector in each one. The palinological preparation was done by the use of acetolysis and identified and counted approximately 900 pollen grains per sample. From the pollinic composition, the richness, diversity indexes and equitability were calculated. Throughout the year, 81 pollinic types were found, belonging to 32 botanic families, being Fabaceae, Asteraceae and Malvaceae the ones with the biggest frequency of pollinic types (5 pollinic types) and, Myrtaceae, the family with two pollinic types (Eucalyptus sp. and Myrcia sp.), among the nine most common types in the samples (> 10%). The biggest richness of pollinic types was during summer, and the biggest diversity and equitability was during spring. Fabaceae, Asteraceae, Malvaceae and Myrtaceae are the most important botanic families as polliniferous sources in Piracicaba - SP.

Salgado J.M.,University of Sao Paulo | Bombarde T.A.D.,University of Sao Paulo | Mansi D.N.,University of Sao Paulo | Piedade S.M.S.,Escola Superior de Agricultura Luiz de Queiroz ESALQ | Meletti L.M.M.,Instituto Agronomico Of Campinas Iac
Ciencia e Tecnologia de Alimentos | Year: 2010

Diabetes mellitus, an endocrine disorder, is the major cause of morbidity in developing countries, and it is considered the fourth leading cause of death worldwide. The conventional therapy for diabetes is insulin treatment. The peel of the Passion fruit is rich in fiber and prevents the absorption of carbohydrates, and thus can control and reduce the blood sugar rate. The objective of this study was to analyze the effect of the passion fruit peel flour on the glicemia of diabetic rats, as well as to study the probable action mechanisms. Wistar rats were used in the experiment and were offered the flours of the passion fruit peel in three concentrations: 5, 10, and 15%, and a casein diet as control. The most significant effect on the reduction of the glicemic rate was obtained with the 5% diet. The best values of hepatic glycogen were found in the 5 and 10% diets. The results of this study suggest that the 5% passion fruit flour diet was the one that provided the best reduction of blood glucose levels (59%) and the higher increase of the hepatic glycogen level (71%). The conversion of blood glucose into hepatic glycogen was considered the probable action mechanism involved.

Discover hidden collaborations