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Barwald Bohm G.M.,Instituto Federal Sul Rio Grandense IFSul | Rombaldi C.V.,Federal University of Pelotas | Castilhos D.,Federal University of Pelotas | Rodrigues Alves B.J.,Embrapa Agrobiologia | Gouvea Rumjanek N.,Embrapa Agrobiologia
Crop Science | Year: 2014

Genetically-modified soybean [Glycine max (L.) Merr.] resistant to glyphosate (N-phosphonomethyl- glycine) herbicide (GR) has turned out to be one of the most highly-used products of plant engineering. The impacts of the soybean, genetically transformed for glyphosate resistance, on the environment under Brazilian soil and climatic conditions are still unknown. For this purpose, two soybean genotypes, one genetically modified (GR BRS 244 RR) and a conventional isogenic genotype were grown under different weed-control methods: hand weeding and glyphosate or imazethapyr herbicide application. The study was performed in Rio Grande do Sul State with evaluations of soil microbial biomass and respiration, biological nitrogen fixation, isoflavone content in seed and glyphosate, and aminomethylphosphonic acid (AMPA) residues in seeds and soil. The use of GR did not affect soil microbial population, biological nitrogen fixation, or plant yield or isoflavone contents in seed. However, even though we used the recommended application doses, the glyphosate residues in the seeds were above levels permitted by Brazilian law. Also, AMPA residues were detected in the soil and the seeds. © Crop Science Society of America.

Vieira G.D.,Instituto Federal Sul Rio Grandense IFSul | Castilhos D.D.,Federal University of Pelotas | Castilhos R.M.V.,Federal University of Pelotas
Revista Brasileira de Ciencia do Solo | Year: 2011

The residue of the process of parboiling rice contains high amounts of elements such asnitrogen, phosphorus and others which, once incorporated into the soil, could serve as a sourceof utrients. Accordingly, the present study evaluated some properties of an Ultisol, the dry matter production and nutritional status of corn grown after applying an anaerobic sludge originated from the process of parboiling rice. The experiment was conducted in 4 kg pots filled with soil, in four replications. The following treatments were studied: control, NPK fertilization, 2.15, 4.31, 8.62, 12.93, and17.24 g kg -1 sludge. Sludge application from parboiled rice increased the maize dry matter yield, as well as pH, electrical conductivity and the concentration of N, P, K and Na in the soil. The sludge also increased the concentration of N, P and K and decreased Ca and Mg in the maize shoots.

Vieira G.D.,Instituto Federal Sul Rio Grandense IFSul | Castilhos D.D.,Federal University of Pelotas | Castilhos R.M.V.,Federal University of Pelotas
Revista Brasileira de Ciencia do Solo | Year: 2011

Rice, grown in all Brazilian regions, is particularly important in the southern region, where 60 % of the total production of this cereal is raised. The rice parboiling process is a hydrothermal treatment of partially cooking the grains in the husk, improving the nutrition al value. This process results in an effluent rich in organic matter and nutrients, which can be used as organic fertilizer in agriculture. In this sense, this study aimed to evaluate the quality of a soil based on changes of some microbial properties arising from the addition of anaerobic sludge from an effluent treatment plant of parboiled rice. Two experiments were conducted. The first in a greenhouse, with corn grown on an Ultisol enriched with anaerobic sludge of parboiling rice at doses of: 2.15; 4.31; 8.62; 12.93; and 17.24 g kg -1. Soil organic carbon and nitrogen and the microbial biomass were evaluated. The second experiment was developed in the laboratory using respirometric vessels with the same soil and treatments as in the previous experiment; the microbial activity was determined by basal respiration. Soil without fertilization and NPK fertilized soil constituted control treatments. Treatments were arranged in a completely randomized design with four replications. The sludge increased soil microbial activity, and the carbon and nitrogen contents of the microbial biomass, and decreased the soil metabolic quotient. Sludge application did not affect the ratios COT/NT, CM/NM, CM/ COT and NM/NT in comparison to the NPK treatment. Sludge increased the contents of soil organic carbon and caused a decrease in the levels of mineral N (NH 4 + and NO 3 -), compared to the NPK treatment. The sludge originated from rice parboiling can be applied to soil at the recommended doses, with benefits for the microbial activity and biomass.

De Souza A.L.K.,Empresa de Pesquisa Agropecuaria e Extensao Rural de Santa Catarina | Pereira R.R.,Federal University of Pelotas | Camargo S.S.,Federal University of Pelotas | Fisher D.L.O.,Instituto Federal Sul Rio Grandense IFSul | And 3 more authors.
Ciencia Rural | Year: 2014

The blueberry (Vaccinium ashei Read) pruning system currently used is based on studies performed at edaphoclimatic conditions different of our reality. Thus, it was assessed the effects of different fructification pruning intensities on production and fruit quality of two blueberry genotypes. The trial was performed in a commercial orchard in Pelotas - RS. The experimental design was a complete randomized block, in a factorial design (2x4) with four replications. Seven year old plant of Rabbiteye group, cultivars ‘Briteblue’ e ‘Woodard’, were undergone to the pruning intensities light, moderate drastic and no pruning (control) during the winter of 2010 and 2011 (first two weeks of august). The parameters assessed were average plant yield, estimated yield per area, fruit fresh weight, fruit diameter, soluble solids, pH and titratable acidity. According to the results, pruning intensity affects harvest anticipation. As the pruning intensity increased, there was a trend of increased fruit size. The productivity of Briteblue blueberries decreases as pruning intensity increases. Briteblue are more productive and show greater fresh fruit weight than Woodard blueberries. © 2014, Universidade Federal de Santa Maria. All rights reserved.

Taira D.E.,Instituto Federal Sul Rio Grandense IFSul | Schettini E.B.C.,Federal University of Rio Grande do Sul | Silvestrini J.H.,Grande Rio University
Procedia IUTAM | Year: 2015

The purpose of this numerical work is focused on the dynamics of a stably stratified inclined mixing layer. Both effects, stratifi- cation and slope, are considered through relevant flow parameters. Chebyshev's approximations and Direct Numerical Simulation (DNS) are used in the context of linear stability analysis for different Richardson numbers and slopes. Two-dimensional temporal and spatial simulations are employed to examine baroclinic layer and the evolution of primary and secondary Kelvin-Helmholtz instabilities. In three-dimensional configuration, only stratification effects are considered. The numerical results show persistence of the translative instability with formation of intense longitudinal vortices highly influenced by the Richardson number. © 2015 The Authors.

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