Embrapa Arroz e Feijao Cnpaf

Barra de Santo Antônio, Brazil

Embrapa Arroz e Feijao Cnpaf

Barra de Santo Antônio, Brazil
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Cooper M.,University of Sao Paulo | Medeiros J.C.,Embrapa Arroz e Feijao CNPAF | Rosa J.D.,Embrapa Arroz e Feijao CNPAF | Toma R.S.,National University of Rio Cuarto
Revista Brasileira de Ciencia do Solo | Year: 2013

Studies of soil-water dynamics using toposequences are essential to improve the understanding of soil-water-vegetation relationships. This study assessed the hydro-physical and morphological characteristics of soils of Atlantic Rainforest in the Parque Estadual de Carlos Botelho, state of São Paulo, Brazil. The study area of 10.24 ha (320 × 320 m) was covered by dense tropical rainforest (Atlantic Rainforest). Based on soil maps and topographic maps of the area, a representative transect of the soil in this plot was chosen and five soil trenches were opened to determine morphological properties. To evaluate the soil hydro-physical functioning, soil particle size distribution, bulk density (ρ), particle density (ρs), soil water retention curves (SWRC), field saturated hydraulic conductivity (Ks), macroporosity (macro), and microporosity (micro) and total porosity (TP) were determined. Undisturbed samples were collected for micromorphometric image analysis, to determine pore size, shape, and connectivity. The soils in the study area were predominantly Inceptisols, and secondly Entisols and Epiaquic Haplustult. In the soil hydrophysical characterization of the selected transect, a change was observed in Ks between the surface and subsurface layers, from high/intermediate to intermediate/low permeability. This variation in soil-water dynamics was also observed in the SWRC, with higher water retention in the subsurface horizons. The soil hydro-physical behavior was influenced by the morphogenetic characteristics of the soils.


Rosa J.D.,Embrapa Arroz e Feijao CNPAF | Cooper M.,University of Sao Paulo | Darboux F.,French National Institute for Agricultural Research | Medeiros J.C.,Embrapa Arroz e Feijao CNPAF
Revista Brasileira de Ciencia do Solo | Year: 2013

On the soil surface, rainfall modifies the soil surface structure promoting crust development. This study evaluated the dynamics of soil crusting, through description and micromorphological analysis of thin sections in 2009 and 2010. In 15 × 30 m plots, the management systems conventional tillage (CT), reduced tillage (RT) and no tillage (NT) were assessed. Within the plots, 1×1 m micro-plots were installed to test different levels of simulated rainfall (0, 27, 54, and 80 mm) at an intensity of 80 mm h-1. From these micro-plots, an undisturbed sample (soil block of 0.07 × 0.05×0.12 m) was taken. The blocks were resin-impregnated and after hardening and drying, thin sections (4.5×8 cm) were prepared and described using optical microscopy. One thin section was prepared per rainfall level and soil tillage system. Crusts were formed in all tillage systems, however, the process of crust formation was different in each system. Under conventional tillage, crusting was observed after 27 mm rain. A higher rain level increased the degradation of the surface structure and thickness of the crust layer. Under reduced tillage and no-tillage the surface conditions were irregular after the applied rainfall, i.e., the changes in the soil surface and in crust formation were not constant with increasing rain levels, unlike under conventional tillage. The analysis of thin sections and micromorphological description allowed satisfactory conclusions on the processes and dynamics involved in crust formation.


HEINEMANN A.B.,Embrapa Arroz e Feijao CNPAF | RAMIREZ-VILLEGAS J.,University of Leeds | RAMIREZ-VILLEGAS J.,International Center for Tropical Agriculture | NASCENTE A.S.,Embrapa Arroz e Feijao CNPAF | And 3 more authors.
Experimental Agriculture | Year: 2016

Upland rice (Oryza sativa L., UR) could be an option under soybean–maize crop rotation system. However, the recommended row spacing for UR (0.30 m) is shorter than that recommended for soybean and corn (0.40 m), limiting the use of UR in this rotation. We hypothesize that cultivar adaptation to wider than recommended row spacing and local environmental conditions harbour significant potential for overcoming the yield constraints of wider row spacing. We evaluated the row spacing effects on rice grain yield and their components in UR cultivars grown under different water deficit conditions. The experiments were designed as a randomized block in a split–split-plot scheme with sites (the cities of Santo Antônio de Goiás, Porangatu and Formoso) as main plots, row spacing (0.25, 0.35, 0.45 and 0.55 m) as the subplots and UR cultivars (one old and two modern genotypes) as the sub-subplots. We found that, in the less stressful environments, the modern cultivars, BRSMG Curinga and BRS Primavera, presented the highest grain yield. By contrast, in environments with moderate to intense water stress, the traditional cultivar, Douradão, presented the best performance, regardless of row spacing used. We conclude that UR is a viable option for soybean–maize rotation systems, as the UR cultivars tested presented no noticeable yield losses when sown with the same row spacing used for soybean and maize crops (0.40 m). In terms of impact, it can lead to an increase in UR cropped area in Brazil, and decrease in dependence on flooded rice harvested in the south of the country. Copyright © Cambridge University Press 2016


Silva A.C.F.,Federal University of Goais | Melo P.G.S.,Federal University of Goais | Melo L.C.,Embrapa Arroz e Feijao Cnpaf | Bassinello P.Z.,Embrapa Arroz e Feijao Cnpaf | Pereira H.S.,Embrapa Arroz e Feijao Cnpaf
Bragantia | Year: 2013

The objective was to compare breeding methods referring to genetic variability and the efficiency in obtaining superior progenies for crude fiber content and grain yield in common bean plants. The progenies were obtained by crossing Carioca in bredlines CNFC 7812 and CNFC 7829 in 2003. The segregating population was conducted by bulk, bulk within F2 and SSD until the F7 generation. In 2008, 64 progenies were chosen randomly according to each breeding method for evaluation in Goiás and Paraná States. The estimates of variance component, genetic and phenotypic parameters, means and indexes of superior progenie generations were obtained during this study. The progenies obtained by bulk and SSD methods presented significant differences for grain yield and crude fiber content along with larger genetic variance. The bulk within F2 presented higher indexes of superior progenies generation and larger averages for both characters as compared to the other methods, being recommended for breeding programs of common beans.

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