Spawning and parental care in Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae) in the Southern Pantanal, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An extraordinary new species of Melanophryniscus (Anura, Bufonidae) from southeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Potencial de lixiviação de herbicidas utilizados na cultura do algodão em colunas de solo

O intenso uso de herbicidas implica a necessidade de determinar o potencial dessas substâncias em contaminar fontes aquáticas subsuperficiais. Diante dessa preocupação, o objetivo deste trabalho foi avaliar o efeito de diferentes lâminas de água sobre o potencial de lixiviação de quatro herbicidas utilizados em pré-emergência na cultura do algodão, em dois solos provenientes de Campo Novo do Parecis-MT (RQ - textura arenosa) e Tangará da Serra-MT (LV - textura argilosa). No desenvolvimento deste trabalho utilizouse a técnica de bioensaio em colunas de solo, nas quais foram simuladas irrigações de 0, 20, 40, 60, 80 e 100 mm, após a aplicação de alachlor (RQ 2,40; LV 3,36 kg ha-1), oxyfluorfen (RQ 0,48; LV 0,72 kg ha-1), prometryne (RQ 0,75; LV 1,50 kg ha-1) e S-metolachlor (RQ 1,20; LV 1,44 kg ha-1). Nas amostras de solo com textura arenosa (RQ), evidenciou-se que lâminas de 80 e 100 mm de água proporcionaram lixiviação até a profundidade de 10-15 cm do alachlor e até 15-20 cm do S-metolachlor. Independentemente da lâmina de água aplicada, nas amostras de RQ oxyfluorfen não ultrapassou a camada de 5-10 cm, e o prometryne movimentou-se até a camada de 10-15 cm somente na lâmina de 100 mm de água. Nas amostras de solo com textura argilosa (LV), o oxyfluorfen não se movimentou além da camada superficial, mesmo sob as maiores lâminas de irrigação, e o prometryne atingiu 5-10 cm de profundidade sob lâminas de 80 e 100 mm. Os herbicidas alachlor e S-metolachlor atingiram 10-15 cm de profundidade sob lâminas de 80 e 100 mm no LV. Evidenciou-se uma maior movimentação efetiva das moléculas de herbicidas nas amostras de solo com textura arenosa (RQ), em relação às amostras de solo com textura argilosa (LV).

Efeito residual de herbicidas aplicados em pré-emergência em diferentes solos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nodulation, arbuscular mycorrhizal colonization and growth of some legumes native from Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

População de Metarhizium anisopliae em diferentes tipos e graus de compactação do solo

Este trabalho objetivou investigar a influência do tipo e compactação do solo na sobrevivência do fungo Metarhizium anisopliae. A sobrevivência do fungo foi determinada em quatro tipos de solos: Latossolo Vermelho textura argilosa, Latossolo Vermelho textura média, Argissolo Vermelho Amarelo textura arenosa média e Argissolo Vermelho Amarelo textura areno-argilosa, com maior teor de matéria orgânica. Para determinar o efeito da compactação na sobrevivência do fungo usaram-se os três primeiros tipos de solos nas densidades de 1,12, 1,32, 1,50g cm-3; 1,22, 1,44, 1,65g cm-3; 1,30, 1,50, 1,70g cm-3, respectivamente. Por meio da contagem de unidades formadoras de colônias (UFC) em placas de Petri, fizeram-se avaliações da sobrevivência do fungo, após zero, 20, 40, 60, 80, 100 e 120 dias de incubação a 27 ± 1ºC. Houve influência significativa do tipo de solo e do grau de compactação na sobrevivência do fungo, obtendo-se maior quantidade de UFC no solo textura areno-argilosa. Entre os demais solos, a maior sobrevivência ocorreu no solo textura arenosa e a menor no solo textura argilosa. O efeito da compactação foi significativo para o tipo de solo, exceto no solo textura arenosa. Independentemente do tipo de solo, a maior sobrevivência foi observada nos valores médios de densidade. A compactação teve maior impacto no solo textura média, onde ocorreu queda mais acentuada na quantidade de UFC em todas as densidades.

Influência dos constituintes do esgoto no colapso de um solo arenoso

Este trabalho analisa o comportamento colapsível de um solo tropical arenoso inundado com diferentes fluidos de saturação que constituem o esgoto doméstico. Para tal análise, foram levados em consideração parâmetros físicos e químicos e aspectos estruturais do solo no âmbito do fenômeno da colapsibilidade dos solos, assim como as principais características dos fluidos de inundação de água destilada, esgoto doméstico e algumas soluções à base de substâncias que compõem os esgotos e as deformações axiais do solo a um metro de profundidade em ensaios edométricos. As propriedades físicas e químicas dos fluidos de inundação e dos solos, bem como a combinação entre tais propriedades, desempenham relevante papel na compreensão do fenômeno do colapso, mostrando que a sua ocorrência não pode ser atribuída a um ou outro parâmetro do solo ou do fluido isoladamente.

Doses e fontes alternativas de nitrogênio no milho sob plantio direto em solo arenoso

The objective of this work was to evaluate the effect of nitrogen sources and rates on maize nutrition and grain yield under no-tillage system in sandy soil. The experiment was conducted in a Typic Quartzipsamment, in the city of Cassilandia, State of Mato Grosso do Sul, Brazil. A completely randomized block design was used in a factorial array 3x4 with four replicates. Treatments consisted of three sources [urea, extruded urea with starch (Starea), and ammonium sulfonitrate with nitrification inhibitor of 3,4-dimethylpyrazole-phosphate (Entec (R) 26)] and four rates (0, 45, 90 and 180 kg ha(-1)) of nitrogen, applied in side-dressing when the plants presented four and six expanded leaves. The nitrogen source affected N, K, and S concentration in the leaf, but did not interfere in the components of production and maize grain yield. Nitrogen application like ammonium sulfonitrate promoted higher concentrations of N, K and S in the maize leaf in relation to the urea, especially in the larger rates studied. Side-dressing nitrogen fertilization increased the number of ears per plant, number of grains per ear and grain yield, grown under no-tillage system in sandy soil, independent of the used source.

Growth, nodulation and nitrogen fixation of cowpea in soils amended with composted tannery sludge

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Manejo de brachiaria decumbens e seu reflexo no desenvolvimento de Eucalyptus grandis

A field trial was carried out in Santa Rita do Passa Quatro, SP, on sandy soil, between February 1993 to February 1995, aiming to study the effects of fertilizer doses and brachiaria grass control on the growth of E. grandis. In the field the plots (9×9 plants, spacing 2×3 m) were located following a randomized block experimental design with four repetitions. The treatments were arranged in a factorial design with four systems of brachiaria grass control in the space between the Eucalyptus rows: mowing, cultivation, chemical control with glyphosate (2,08 kg eq. ác./ha) and hand hoeing were developed when the population reached the early flowering stage and four doses of the fertilizer 20-05-20: 0, 115, 230 and 345 kg/ha, handled at 3, 6 and 12 monthes after the transplantation. The hand hoeing was the most effective method of brachiaria grass control. However the hand hoeing controlled plots showed a decrease on the E. grandis growth exhibiting slower growth rate, shorter plants, thinner stems, smaller leaf area results and reduction on dry matter accumulation than the plants from the other plots under different weed control management's. The glyphosate promoted an excellent brachiaria grass control while the E. grandis plants grow better. Both remainder weed control management systems were intermediary in terms of efficacy. The mowing management was the most similar method as compared to the hand hoeing one and the cultivation treatments to the chemical control method. The growth rate differences observed between the hand hoeing and chemical control treatments were not caused directly by late fertilizations. There were no significative interactions among the weed control systems and the fertilization doses. Considering the brachiaria grass that grew between the E. grandis rows there were detected benefits to the crop and these effects increased when the chemical control was used for weed management.

Monitoramento sanitário de um sistema integrado de tratamento de águas residuárias da suinocultura

Objective. To assess the potential for contamination of wastewaters from pig farming. Methods. Wastewaters from pig farming were stored in a tank. After 0, 30, 60, 90, and 120 days of hydraulic retention, they were added to lysimeters filled with argillaceous, sandy, or medium soil. Finally, these lysimeters were submitted to simulations of either a rainy season or a dry season. The number of colony-forming units (CFUs) of total coliforms, fecal coliforms, and fecal streptococci was measured in the effluents of the storage tank (for the various periods of hydraulic retention), in the percolate from the lysimeters, and in the three types of soil. The microbiological analyses were carried out using the membrane filter technique. The pH analyses were done potentiometrically. Results. For the three microorganisms, the largest decrease in bacterial counts in the storage tanks occurred with 90 or 120 days of retention. There was a marked decrease in the bacterial count in the percolates of the three soils. For the three soil types the greatest reduction in bacterial counts was found in medium soil, due to its acidity (pH < 7.0). Hydraulic retention was not sufficient to ensure the sanitary adequacy of the wastewaters and their use for irrigation, given that fecal coliform values were above 1 000 CFU per 100 mL. Therefore, adding the residues to the soil was considered a second stage of treatment. Conclusions. The retention of wastewaters followed by adding them to soil was effective in minimizing the contaminating effect of pig farming residues. The storage time for wastewaters from pig farming could be decreased from 120 to 90 days.

Parâmetros geotécnicos e previsão da capacidade de carga de estacas apiloadas em solo tropical arenoso obtidos com o Pressiômetro Ménard

This paper presents and discusses Ménard Pressuremeter test results used to predict bearing capacity of pounded piles installed in a tropical sandy soil. Fifteen pre-bored pressuremeter tests were carried out at the Experimental Research Site from Unesp - Bauru up to 15 m depth, one test per meter. Several laboratory and in situ tests were carried out in this research site as well as load tests on plates and on piles. Pressuremeter test results were firstly analyzed to determine geotechnical soil parameters based on empirical methods, emphasizing the estimative of the earth pressure coefficient at rest (K0). After that, bearing capacity prediction of pounded piles with 4 m, 7 m and 10 m were made and compared with test results from instrumented load tests. Pressuremeter test results allowed a very good estimative of bearing capacity for the pile with 4 m length and underestimated in 25,7% and 20,0% the bearing capacity for the pile with 7 and 10 m length, respectively. The back analysis of the test results suggests that the appropriate value for the bearing capacity factor for the tested soil-pile system on this soil is equal to 2.

Resistivity (DC) method applied to aouifer protection studies

Resistivity (DC) method using vertical electrical soundings (Schlumberger array) are conducted In the vicinity of Canoas/RS, applied to environmental studies with the objective of Investigating groundwater conditions, The present paper shows a geoelectrlcal Identification of the lithology and an estimate of the relationship between the resistivity and Dar Zarrouk parameters (transverse unit resistance and longitudinal unit conductance) with the properties such as aquifer transmlssivlty and protection of ground water resources, In the saturated sediments, resistivity values defined the following sequence: clay layers (resistivity < 40 ohm-m) and sand layers (resistivity > 40 ohm-m), Two sand layers were identified; one corresponding to the unconfined aquifer and another to the confined aquifer between two clay layers, In the map of the transverse unit resistance of the unconfined aquifer, the tendencies of high values can be associated with the zones of high transmissivity; hence, these zones are suggested for the installation of monitoring wells, The map of longitudinal conductance Illustrates the Impermeability of the confining clay layer, Values of S > 1.0 siemens would indicate zones in which the confined aquifer would be protected; In comparison, values of S < 1.0 siemens would indicate zones of probable risks of contamination. © 2006 Sociedade Brasileira de Geofísica.

Emprego da sondagem elétrica vertical com o método da eletroresistividade no estudo do lixão de Macapá-Ap

Vertical electrical soundings using eletroresistivity method were carried out in the public waste landfill in Macapá - AP, having as a goal to investigate the geoelectrical and hidrogeologic characteristics of the ground. The results of geophysics interpretation allowed obtaining a model of five geoelectrical layers until the depth of 14,6 m. This model is correlated to a sedimentary sequence of clay-silt-sandy with laterite. The main flow of the water table, also determined, is concordant to the topographical gradient.

Efecto de la fertirrigación con n y k en el crecimiento de la palma de coco enano Verde de jiqui

The coconut palm crop has increased with the use of the fertigation technique in Brazil in the last years. The objective of this work was to evaluate the influence of N and K rates via fertigation, on vegetative growth of three year old palms, cultivated in the littoral region of the Ceará State, Brazil, with tropical rainy climate. The study was conducted in a sandy soil using the variety of green dwarfed Jiqui coconut palm. The experimental design was a randomized complete block, with 10 treatments, including five nitrogen and five of potassium rates, according to the model of the experimental matrix Plan Puebla III. The nitrogen and potassiun applications via fertigation influenced significantly the plant height, stem perimeter, and the number of leaves and folioles. © 2009 Universidad Centroccidental Lisandro Alvarado (UCLA).