Marcus M. Corrêa

Interceptação das chuvas em um fragmento de floresta da Mata Atlântica na Bacia do Prata, Recife, PE

The Dois Irmaos forest is one of the few remaining areas of the Atlantic Forest in the State of Pernambuco. The dams of Meio, Prata and Dois Irmaos, which belong to the Prata Basin, are in it. The objective of this work was to study the rainfall partitioning in a fragment of the Atlantic forest in the Prata basin, in Recife, PE. 24 raingouges were installed in the interior of the forest to measure the throughfall and 20 trees of superior extract and 10 of the sub-forest were selected to determine the stemflow. The results showed values of loss interception of 208,3 mm, net precipitation of 1431,7 mm, throughfall of 1392,4 mm, stemflow by superior stratum of 6,6 mm and stemflow by sub-forest of 32,8 mm, corresponding to 12,7%, 87,3%, 84,9%, 0,4% and 2%, respectively.

Desempenho de gotejadores autocompensantes com diferentes efluentes de esgoto doméstico

A B ST R A C T This study had the objective of evaluating the hydraulic performance of dripper Katif, brand Plastro Brazil, external type, auto compensating using effluent from three different treatments of domestic sewage. The experiment was conducted under field and laboratory conditions. The field test consisted in the evaluation of a drip irrigation system by uniformity tests which were conducted on three occasions. In the laboratory, the study aimed to compare the hydraulic performance of used emitters with a lot of new emitters in four pressure ranges: 100, 150, 200 and 250 kPa. The values were obtained for the Christiansen Uniformity Coefficient (CUC), Distribution Uniformity Coefficients (CUD), and of Manufacturer Variation Coefficient (CVf). The results showed that the use of domestic sewage treated with decant digester associated with a filter digester and a stabilization pond provided the best results in distribution uniformity and, in general, the continuous use of wastewater provided losses in the hydraulic performance of emitters.

Comportamento hídrico e crescimento do feijão vigna cultivado em solos salinizados

Soil salinization reduces the capacity of plants to absorb water, and in general causes decrease in plant growth. Plant responses to salt stress are better correlated with osmotic potential compared to electrical conductivity of soil saturation extract. In order to evaluate the effect of salt stress on growth, water use and leaf osmotic potential of cowpea [Vigna unguiculata L. (Walp.)], an experiment was carried out in a greenhouse of the Federal Rural University of Pernambuco (Recife-PE, Brazil). The Treatments were in a factorial arrangement of 2 x 4, comprising of two soil textures and four levels of soil salinity (4, 8 and 12 dS m-1 at 25 °C, and the control without salt addition) with five replications. It was concluded that soil salinity causes reduction in water consumption, leaf osmotic potential, plant height, number of leaves and dry biomass of shoot of cowpea.

Zoneamento agroclimático para a cultura do pinhão-manso no estado de Pernambuco

This study aimed to realize the agroclimatic zoning of Jathopra curcas L. crop in the State of Pernambuco. For this, climatic data of air temperature and mean rainfall of 146 meteorological stations and 73 series with historical data over 30 years and another 73 with less than 30 years but more than 20 years of observations were used. The choice of Jatropha has been motivated by the potential of this crop as a source of renewable energy to replace fossil fuels as well as for its rusticity and a new option for regions of semi-arid climate, as it occurs in the Northeast region. The selection of the study area is related to climate variability in the State and the potential that this crop has in regions where there is low precipitation. According to the study, the State of Pernambuco has 14.92% of areas suitable for production of Jatropha, 44.26% of the restricted areas by water deficit, and 40.82% of unsuitable areas.

Transporte do paclobutrazol em colunas de solos

Paclobutrazol (PBZ) is a post-emergence plant growth regulator used in agricultural systems with the objective of vegetative control growth, thereby increasing the reproductive capacity of the plant. This growth regulator remains active in the soil for several years being detrimental to subsequent tillage and contamination of groundwater through leaching. The objective of this work was to study the mechanisms involved in the transport and sorption of PBZ in an Ultisol and a Vertisol, both of the San Francisco Valley, Brazil. Column breakthrough experiments were performed with a water tracer (Bromide) and with PBZ at 0.4 e 1.6 cm3.min-1 in the two soils. Hydrodispersive parameters of both soils were obtained by fitting the tracer breakthrough curves (BTC) with the convection-dispersion (CDE) model, whereas the parameters of PBZ reactive transport were obtained with the CDE-2 sorption sites model, through the CXTFIT code. PBZ presents a lower retardation factor in the Vertisol than in the Ultisol. The water flow was found to strongly affect PBZ mass balance, mainly because of sorption/desorption hysteresis, suggesting partial irreversible sorption of the chemical. The two sites model fitted well the tracer and PBZ breakthrough curves. The results showed that PBZ transport is strongly influenced by its interactions with the soil matrix through rate-limited sorption. The determined transport parameters indicate that PBZ applied to the two tropical soils cultivated with Mango presents an important leaching potential and contamination risk of the groundwater of the San Francisco Valley.

Hydrodispersive characterization of two soils in the irrigated region of São Francisco Valley

The hydrodispersive characterization of a Latosol and a Quartzarenic Neosol, both in the irrigated region of Sao Francisco Valley, was carried out in laboratory by means of assays of displacement of miscible liquids in columns of deformed soil. The assays consisted of the displacement of a pulse of 1.0 volume of pores of the solution of KBr in the outflows of 2.4.10-5, 4.8.10-5, 7.2.10-5, 9.6.10-5 and 1.2.10-4 m3 h-1 and in concentrations of 11.89, 59.49 and 118.99 g L-1, and three repetitions for each assay, under conditions of saturation and flow in stationary condition. By means of program CXTFIT 2.0 that adjusts the analytical solution of the equation of the convection-dispersion (CDE) to the points of the experimental breakthrough curve, it was possible to obtain the hydrodispersive parameters of the retardation factor (R) and coefficient of hydrodynamic dispersion (D). The model CDE carried out a good adjustment to the points of the experimental breakthrough curve, with the values of determination coefficients varying from 98 to 99% for both soils. The values of R are near 1.0 for both the soils, indicating that the KBr does not interact with the soil and the dispersivity of the Neosol is greater than that of the Latosol due to distribution of the size of the pores being greater in the Neosol.The hydrodispersive characterization of a Latosol and a Quartzarenic Neosol, both in the irrigated region of São Francisco Valley, was carried out in laboratory by means of assays of displacement of miscible liquids in columns of deformed soil. The assays consisted of the displacement of a pulse of 1.0 volume of pores of the solution of KBr in the outflows of 2.4.10-5, 4.8.10-5, 7.2.10-5, 9.6.10-5 and 1.2.10-4 m3 h-1 and in concentrations of 11.89, 59.49 and 118.99 g L-1, and three repetitions for each assay, under conditions of saturation and flow in stationary condition. By means of program CXTFIT 2.0 that adjusts the analytical solution of the equation of the convection-dispersion (CDE) to the points of the experimental breakthrough curve, it was possible to obtain the hydrodispersive parameters of the retardation factor (R) and coefficient of hydrodynamic dispersion (D). The model CDE carried out a good adjustment to the points of the experimental breakthrough curve, with the values of determination coefficients varying from 98 to 99% for both soils. The values of R are near 1.0 for both the soils, indicating that the KBr does not interact with the soil and the dispersivity of the Neosol is greater than that of the Latosol due to distribution of the size of the pores being greater in the Neosol.

Potencialidades hídricas superficiais de Fernando de Noronha, PE, e alternativas para incremento da oferta

A disponibilidade de recursos hidricos para usos multiplos, com enfase no abastecimento publico, e questao da mais alta relevância e depende de aspectos edaficos, hidrologicos, ambientais e de gestao. Avaliou-se o potencial hidrico de bacias hidrograficas da Ilha de Fernando de Noronha, com vistas a dar suporte a gestao da agua no arquipelago; para isto se delimitaram e caracterizaram cinco bacias representativas e se estimou a precipitacao efetiva atraves do metodo da Curva Numero. Adicionalmente, foram investigadas as caracteristicas de infiltracao dos principais solos do arquipelago. Verifica-se que, em geral, as bacias hidrograficas tem limitada infiltrabilidade e elevado potencial de escoamento, constatando-se o potencial de incremento de oferta de agua superficial superior a 90%, desde que se contemple a utilizacao racional das principais bacias existentes. Dentre os solos analisados, os Cambissolos Haplicos Vertissolicos e os Vertissolos sao os solos de menor infiltrabilidade e, portanto, de maior contribuicao a macrodrenagem do arquipelago. Sugere-se a utilizacao das bacias estudadas no abastecimento domestico da Ilha, de modo a incrementar a disponibilidade de agua no local.

Análise de risco e otimização de recursos hídricos e retorno financeiro em nível de fazenda

Este trabalho teve como objetivo analisar padroes de cultivo em uma propriedade rural, visando a otimizacao do uso de recursos hidricos e a maximizacao do retorno financeiro, para um estudo de caso no Agreste Meridional Pernambucano. O modelo de programacao linear com horizonte de planejamento de tres anos utilizado, foi implementado na planilha Microsoft® Excel. Este modelo visou a maximizacao do valor presente liquido total do empreendimento. Para a analise de risco foram utilizadas duas tecnicas complementares: a simulacao de risco, procedida com o programa @Risk, e a analise de sensibilidade. No primeiro padrao de cultivo, PC1, com restricao hidrica mensal para irrigacao de 8.500 m3, o maximo valor presente liquido total, VPLt , foi de R

Potassium adsorption in soil cultivated with sugarcane

8.771,10 (ha ano)-1; no segundo padrao de cultivo, PC2, com restricao hidrica mensal de 4.000 m3, o VPLt foi de R

Morphometric characterization and assessment of water quality Hydrographic Basin of Bita, Ipojuca-PE

8.228,77 (ha ano)-1. Na analise de risco, observou-se que os valores encontrados do VPLt foram positivos e proximos para os dois padroes de cultivo evidenciando a nao expectativa de fracasso financeiro, mas com consideravel reducao da demanda de agua para irrigacao para o PC2, indicando o potencial da metodologia aplicada a gestao de recursos hidricos na regiao.