13 research outputs found
Recommended from our members
Implication of Urban Occupation Patterns in the Natural Infiltration
The article aims to contribute to the study of urban form and hydrological impacts relations, especially with regard to a recharge of the aquifers. The focus on the natural water infiltration and recharge of aquifers is due to the similarities between the characteristics of the physical environment conducive to aquifer recharge and urbanization, which lead to urban occupation of recharge areas. To address the proposed objective, the study developed a methodological framework that relates elements of the urban form, intervening factors of urban infiltration and water sensitive urban design guidelines. To accomplish this, recent literature were reviewed in urban drainage, water-sensitive urbanism and urban morphology, seeking to organize and identify the links between them. The intervening factors of natural infiltration found in the literature were: (i) Sealing of the soil; (ii) soil compaction; and (iii) reduction of tree cover. The urban morphological elements related to these factors were: (i) streets; (ii) public spaces; and (iii) lots. The analysis characteristics of each of these morphological elements were identified from the revised intervening factors and urban design guidelines. The use of the framework for the analysis of the Lago Paranoá Basin in the DF – Distrito Federal, Brazil, demonstrated the validity of the identified analysis criteria for the study of the urban form hydrological impact. In addition, it confirmed the premise of the study that more details about the urban occupation form are needed, besides the percentage of impervious surfaces, for the evaluation and planning of water sensitive cities
Microhabitats occupied by Myxomycetes in the Brazilian Atlantic Forest: Heliconiaceae inflorescences
Myxomycetes ocorrentes em áreas de caatinga e brejo de altitude no sertão de Pernambuco, Brasil
Yield performance of upland rice cultivars at different rates and times of nitrogen application
Nitrogen is the most important nutrient for rice (Oryza sativa L) yields. This study aimed to evaluate the response of upland rice cultivars to N rate and application times in a randomized block design, in subdivided plots with four replications. The studied factors were five rice cultivars (BRS MG Curinga, BRS Monarca, BRS Pepita, BRS Primavera, and BRS Sertaneja), three application times (100 % at planting, 50 % at planting - 50 % at tillering and 100 % at tillering) and four N rates (0, 50, 100, and 150 kg ha-1). All cultivars responded to increased rates and different times of N application, especially BRS Primavera and BRS Sertaneja, which were the most productive when 50 % N rates were applied at sowing and 50 % at tillering. The response of cultivar BRS Monarca to N fertilization was best when 100 % of the fertilizer was applied at tillering
Dry matter production and nutrient accumulation after successive crops of lettuce, tomato, rice, and andropogongrass in a substrate with zeolite Produção de matéria seca e acúmulo de nutrientes após cultivos sucessivos com alface, tomate, arroz e capim andropogon em substrato com zeólita
Zeolites are hydrated crystalline aluminosilicate minerals of natural occurrence, structured in rigid third dimension net that can be used as slow release plant-nutrient source. The main objective of this study was to evaluate the effects of plant growth substrate under zeolite application, enriched with N, P and K, on dry matter yield and on nutrient contents in consecutive crops of lettuce, tomato, rice, and andropogon grass. The experiment was carried out in a greenhouse, with 3 kg pots with an inert substrate, evaluated in a randomized block design with three replications. Treatments consisted of four types of enrichment of concentrated natural zeolite: concentrated zeolite (Z) only, zeolite + KNO3 (ZNK), zeolite + K2HPO4 (ZPK) and zeolite + H3PO4 + apatite (ZP), and a control grown in substrate fertilized with a zeolite-free nutrient solution. Four levels of enriched zeolite were tested: 20, 40, 80, and 160 g/pot. Four successive crops were grown on the same substrate in each pot: lettuce, tomato, rice, and andropogon grass. Results indicated that N, P and K enriched zeolite was an adequate slow-release nutrient source for plants. The total dry matter production of above-ground biomass of four successive crops followed a descending order: ZP > ZPK > ZNK > Z.<br>Zeólitas são minerais aluminossilicatos cristalinos hidratados de ocorrência natural, estruturados em redes cristalinas tridimensionais rígidas que podem ser usados como fonte de liberação lenta de nutrientes para as plantas. O objetivo deste trabalho foi avaliar o efeito da adição de zeólita enriquecida com N, P e K ao substrato de cultivo sobre a produção de matéria seca e o acúmulo de nutrientes pelas culturas sucessivas de alface, de tomate, de arroz e de capim-andropogon. O experimento foi conduzido em vasos em casa de vegetação, em vasos contendo 3 kg de substrato inerte. O delineamento experimental foi o de blocos ao acaso, com três repetições. A zeólita natural estilbita foi concentrada e enriquecida com nutrientes N, P e K obtendo-se os seguintes tratamentos: zeólita concentrada (Z), zeólita + KNO3 (ZNK), zeólita + K2HPO4 (ZPK) e zeólita + H3PO4 + apatita (ZP), além de um tratamento testemunha sem adição de zeólita, mas com solução nutritiva. Utilizaram-se quatro doses de zeólita enriquecida: 20, 40, 80 e 160 g/vaso. Foram realizados quatro cultivos sucessivos no mesmo substrato de cada vaso: alface, tomate, arroz e capim-andropogon. Os resultados indicaram que a zeólita enriquecida com N, P e K funcionou como fonte de nutrientes de liberação lenta. A produção de matéria seca total da parte aérea dos quatro cultivos sucessivos seguiu a seguinte ordem decrescente: ZP > ZPK > ZNK > Z
Myxomycetes occurring on Cecropia adenopus (Cecropiaceae) in fragments of Atlantic Rainforest Myxomycetes ocorrentes em Cecropia adenopus (Cecropiaceae) em fragmentos de Floresta Atlântica
Cecropia adenopus (Ambay pumpwood) is a frequent native species on the edges of woods and clearings and is considered a pioneer species in re-colonized areas. Despite its distribution from Mexico to Argentina, this substrate has never been examined in detail regarding the presence of Myxomycetes. In the present study, the myxobiota associated with leaf debris of C. adenopus was investigated in two Atlantic Rainforest conservation units located in the Brazilian state of Rio Grande do Norte. Five specimens and one plasmodium were obtained directly from the field and 87 were developed in 43.7% of 200 moist-chamber cultures set up separately with blades and petioles. Fifteen species were identified and illustrated. The two predominant groups were representatives of Trichiales and Physarales. Didymium columella-cavum was recorded for the second time in Brazil and in the world.<br>Cecropia adenopus (embaúba) é uma espécie nativa, frequente em bordas de matas e clareiras e tida como espécie pioneira em áreas recolonizadas. Apesar de ocorrer desde o México até a Argentina este substrato nunca tinha sido examinado com detalhe quanto à presença de Myxomycetes. No presente estudo, a mixobiota associada a folhas mortas de C. adenopus foi investigada em duas Unidades de Conservação da Floresta Atlântica, situadas no estado do Rio Grande do Norte. Cinco espécimes e um plasmódio foram obtidos diretamente no campo e 87 desenvolveram-se em 43,7% de 200 câmaras-úmidas, montadas com lâminas foliares e pecíolos separadamente. Quinze espécies de Myxomycetes foram identificadas e ilustradas. Os dois grupos predominantes pertencem às ordens Trichiales e Physarales. Didymium columella-cavum foi encontrado pela segunda vez no Brasil e no mundo