Fortaleza, Brazil
Fortaleza, Brazil

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do Nascimento P.C.,Federal University of Rio Grande do Sul | Bissani C.A.,Federal University of Rio Grande do Sul | Levien R.,Federal University of Rio Grande do Sul | Losekann M.E.,INCRA | Finato T.,Secretaria de Desevolvimeto Rural Governo do Estado do Rio Grande do Sul
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2014

Lower northeast hillside region, in Rio Grande do Sul state, Brazil, shows, in agricultural activities, variability in soil use and production systems, which can result in change of soil attributes and degradation processes. With the aim to evaluate particle size distribution and chemical attributes and to compare them in different soil use and management system, soil samples from 78 areas, performing eight diverse types of soil use in conventional and organic production systems, were sampled for the study, between 2009 and 2010. Soil samples were collected at 0 to 20 cm depth, and a series of attributes were determined. Results showed pH, electrical conductivity, zinc and phosphorus contents with higher values in areas of conventional vegetable production, while sulphur showed higher values in soil under grape cultivation. Discriminate analysis indicated that 67% of the areas were classified in the same use defined at the time of sampling (original use), and principal component analysis showed more similar behavior among uses in organic system, besides conventional crop. Some elements showed very high contents, indicating potential contamination and environmental risk.

Marangon L.C.,University of Pernambuco | Soares J.J.,Federal University of São Carlos | Feliciano A.L.P.,University of Pernambuco | Lani J.L.,Federal University of Viçosa | Matos L.V.,INCRA
Revista Arvore | Year: 2013

The Mata do Paraíso is originated in regeneration, making up secondary vegetation whose typology is Semidecídua Estacional Forest. In the Zona da Mata from Minas Gerais State, the Latosols predominate and this category is, also, the most present in the Viçosa's region where the soils are, generally, nutritive poor. Thus, it was looked for associating some characteristics of soils from "Mata do Paraíso" in specified order to relationate them with the evolution of different kinds of toposequences, presents in the studied area, and the local arboreous vegetation. Samples were gathered inside the 40 parcels, the same ones utilized for the vegetation study. Samples weretaken away from 0 to 20cm, 20 to 50cm and 50 to 100cm of depth in three different points. TFSA textural analysis of the soil was performed, as well as, density of soil, pH, total organic carbonic, Ca, Mg, Al, K and P. Based on the results achieved, the sum of the basis was calculated (SP), the cationic change capacity (T) and effective (t), saturating for basis (V) and saturating for Al. The remainders P were also determinated. Using the vegetation as the best ambient indicator, it can be perceived more species at the hillside, but with small plants and, following, the Ravine, with bigger trees. On the Hillside, the soil is poorer than the Ravine's and more subordinate to laminar erosion. In this case, the natures' option would be increase the recycledefficiency by the diversity, what the species would be doing by its self benefit. The Top is too poor, that limits individuals of bigger size and diameter, as well as its self diversity. The pioneer species, in this case, would have a fundamental role in maintaining or in the "formation" of this soil fertility. The texture, it is perceived that is possible separating on the 3 depths, 2 ambient groups: on Plan e the Top present a texture more homogeneous and Ravine and Hillside more heterogeneous.

de Sousa L.B.,Federal University of Uberlandia | Silva E.M.,INCRA | Gomes R.L.F.,UFPI | Lopes A.C.A.,UFPI | Silva I.C.V.,Ciencia e Tecnologia de Alimentos
Revista Brasileira de Fruticultura | Year: 2012

The characterizations have been performed in germplasm collections to generate information about the description and classification of collected materials, to discriminate more important characters and, mainly, to subsidize genetic breeding program by identifying desirable individuals as well as quantifying the available diversity. This study aimed to characterize and quantify the genetic divergence among accessions of Passiflora edulis and P. cincinnata based on physical and chemical characteristics of the fruits. The genetic material consisted of six accessions from the Germoplasm bank of UNESP in Jaboticabal. The fruits were evaluated with respect to the following physical characteristics: weight, length and fruit diameter, rind thickness, seed number and juice yield; and chemical: total soluble solids contents and total acidity. The six accessions differed with respect to all traits, indicating the presence of genetic variability and hence the possibility of obtaining genetic gains with selection of superior genotypes. The genetic diversity among the accessions was estimated by Tocher's grouping method, and used Mahalanobis' distance as a measure of dissimilarity, forming two groups. The estimates of higher positive genetic correlations associated with the juice, were with the number of seeds/fruit, fruit diameter, fruit length and fruit weight. The method of Singh, used to estimate the relative contribution of each character in the expression of genetic divergence among the six accessions, indicated that the size of the fruit and juice yield were the characteristics that contributed most, and total acidity showed a least contribution.

Machado R.L.,Ceres | Ceddia M.B.,Federal Rural University of Rio de Janeiro | de Carvalho D.F.,Federal Rural University of Rio de Janeiro | da Cruz E.S.,INCRA | Francelino M.R.,Ceres
Bragantia | Year: 2010

Knowledge of maximum daily rain and its return period in a region is an important tool to soil conservation, hydraulic engineering and preservation of road projects. The objective of this work was to evaluate the spatial variability of maximum annual daily rain considering different return periods, at the Rio de Janeiro State. The data set was composed by historical series of 119 rain gauges, for 36 years of observation. The return periods, estimated by Gumbel distribution, were 2, 5, 10, 25, 50 and 100 years. The spatial variability of the return periods was evaluated by semivariograms. All the return periods presented spatial dependence, with exponential and spherical model fitted to the experimental semivariograms. The parameters of the fitted semivariogram model were very similar; however, it was observed the presence of higher nugget effects for semivariograms of longer return periods. The values of maximum annual daily average rain in all the return periods increased from north to south and from countryside to the coast. In the region between the Serra do Mar range and the coast, besides increasing in magnitude, an increase in the spatial variability of the studied values with increasing return periods was also noticed. This behavior is probably caused by the orographic effect. The interpolated maps were more erratic for higher return periods and at the North, Northeast and Coastal Plain regions, in which the installation of new pluviometric stations are recommended.

Mendes A.M.S.,Embrapa Semiarido | Duda G.P.,Federal Rural University of Pernambuco | do Nascimento C.W.A.,Federal Rural University of Pernambuco | Lima J.A.G.,INCRA | Medeiros A.D.L.,Secretaria Municipal de Agricultura
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

Soil cultivation using agrochemicals may increase the concentration of availability of heavy metals to plant and cause contamination of the trophic chain as well. This work was carried out to evaluate the influence of length of time under cultivation with melon (Cucumis melo L.) on the heavy metals accumulation and chemical alterations in Ultisol. Melon plantations of one, two and three years were studied. A benchmark area under natural vegetation was used to compare the data obtained. The results showed that the lengthiest time under cultivation altered the chemical characteristics of the soil. An increase in pH and contents of N, P and K was observed for the two soil layers evaluated. On the other hand, Ca contents were decreased by cultivation. The larger the cultivation time the higher the concentration of N, Pb, Cu, and Mn in the soil surface layer, whereas the Fe and Zn concentrations were diminished in both analyzed soil layers, though available concentrations are still regarded as low in soil.

Andrade Neto R.C.,INCRA | Miranda N.O.,DCA UFERSA | Duda G.P.,Federal Rural University of Pernambuco | Goes G.B.,DCA UFERSA | Lima A.S.,DCA UFERSA
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

The effect of green manure on growth and yield of forage sorghum BR 601 was studied in a trial carried out at the UFERSA, Mossoró, RN, Brazil. The experimental design was completely randomized blocks in a scheme of split plots in time, with three replications. Treatments tested were seven legume species, Mucuna aterrima, Canavalia ensiformis, Cajanus cajan, Dolichos lab-lab, Crotalaria juncea, Crotalaria spectabilis, and Vigna unguiculata, a mixture of the legumes plus corn, sorghum and sunflower, and spontaneous vegetation as a control. For each treatment the amount of fresh mass, dry mass and contents of N, P, K, Na, Ca and Mg in shoots were determined, from which the amount of nutrients accumulated per hectare was calculated. Fresh mass of shoot, dry mass of shoot, plant height and number of leaves of sorghum, sowed after incorporation of green manures, were evaluated at 20, 40, 60, 80 and 100 days after seeding. Mucuna aterrima was the best option as a green manure because of its better performance in all characteristics evaluated at the end of sorghum cycle. Also recommended are Crotalaria juncea, and Dolichos lab-lab which had the higher dry mass and amount of nutrients in shoots.

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