oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

4 ( 1 )

2019 ( 766 )

2018 ( 1186 )

2017 ( 1113 )

Custom range...

Search Results: 1 - 10 of 636579 matches for " Ivandro de Fran?a da;Amorim Neto "
All listed articles are free for downloading (OA Articles)
Page 1 /636579
Display every page Item
Avalia??o de métodos de determina??o de água disponível em solo cultivado com algod?o
Souza, Carlos Cleide de;Oliveira, Francisco Assis de;Silva, Ivandro de Frana da;Amorim Neto, Malaquias da Silva;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000300015
Abstract: the main objective of this work was to evaluate two methods of determination of soil available water (a direct method and other in laboratory) and the effect of three levels of available water (10, 25 and 40%) in cotton crop (gossypium hirsutum l. r. latifolium hutch). this work was developed in green house condition in the departamento de solos e engenharia rural/centro de ciências agrárias/universidade federal da paraíba, located in areia, pb, brazil. a completely randomized block was utilized in a 2 x 3 factorial arrangement, with three replications. the variance analysis showed that the values of the available water in soil using the direct method were significantly (p £ 0.05) bigger than the lab method. the management of irrigation in the cotton crop using 40% of available water determinated through the direct method showed the better results of evapotranspiration, leaf area, aboveground biomass. there was interaction of methods x levels of available water for all variables studied.
Avalia??o de métodos de determina??o de água disponível e manejo da irriga??o em terra roxa sob cultivo de algodoeiro herbáceo
Souza, Carlos Cleide de;Oliveira, Francisco Assis de;Silva, Ivandro de Frana da;Amorim Neto, Malaquias da Silva;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2000, DOI: 10.1590/S1415-43662000000300006
Abstract: this study was conducted in greenhouse conditions at the dser/cca/ufpb, located in areia, pb, brazil. the main objective was to evaluate two methods of determination of available soil water, a direct method (dm) and a laboratory method (lm), and the effect of three levels of available water, 10, 25 and 40% as indicative of irrigation management in cotton crop (gossypium hirsutum l. r. latifolium hutch). a completely randomized block was utilized in a 2 x 3 factorial scheme, with three replications. the variance analysis showed that the values of the available soil water using the direct method were significantly (p < 0.01) higher than the laboratory method. the management of irrigation in the cotton crop using 40% of available water by dm, showed better results of evapotranspiration, leaf area and above ground biomass. interaction of methods versus levels of available water for all variables studied was also found.
Avalia o de métodos de determina o de água disponível em solo cultivado com algod o
Souza Carlos Cleide de,Oliveira Francisco Assis de,Silva Ivandro de Frana da,Amorim Neto Malaquias da Silva
Pesquisa Agropecuária Brasileira , 2002,
Abstract: O objetivo deste trabalho foi avaliar dois métodos de determina o de água disponível no solo (um direto e outro de laboratório), e o efeito de três níveis de água disponível (10%, 25% e 40%) na cultura do algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch). O trabalho foi realizado em casa de vegeta o do Departamento de Solos e Engenharia Rural/Centro de Ciências Agrárias/Universidade Federal da Paraíba, Município de Areia, PB. O delineamento experimental adotado foi o de blocos ao acaso, com distribui o em esquema fatorial 2 x 3, com três repeti es. Conforme a análise de variancia, a faixa de água disponível no solo, encontrada mediante a utiliza o do método direto, supera significativamente (p £0,05) a obtida pelo método de laboratório. O manejo das irriga es do algodoeiro com base em 40% da água disponível, determinado pelo método direto, proporcionou os maiores resultados de evapotranspira o, de área foliar e acumula o de fitomassa na parte aérea da cultura. Observou-se ainda intera o métodos x níveis de água disponível em todas as variáveis estudadas.
Efeito de leguminosas nos atributos físicos e carbono organico de um Luvissolo
Nascimento, Jo?o Tavares;Silva, Ivandro de Frana da;Santiago, Roberval Diniz;Silva Neto, Luiz de Frana da;
Revista Brasileira de Ciência do Solo , 2005, DOI: 10.1590/S0100-06832005000500018
Abstract: soil degradation under cultivation results mainly from the inadequate management and it reflects in low crop yields. with the purpose of evaluating the effect of legumes on physical attributes and organic carbon content of an alfisol, an experiment was conducted in the alagoinha county-pb, brazil, between 1997 and 1999, with the following species: crotalaria juncea l, cajanus cajan l, cajanus cajan (l) millsp, calopogonium mucunoides l, canavalia ensiforme l, dolichos lab lab l, pueraria phaseoloides l, macroptilium atropurpureum l, leucaena leucocephala l, clitoria ternatea l, styzolobium aterrimum l, styzolobium cinereum piper and tracy, besides a plot with spontaneous vegetation as control treatment. a randomized split plot design was used with thirteen treatments in the main plot (12 legumes + 1 control treatment) and three split-plot treatments were represented by the three soil sampling depths 0.00-0.10; 0.10-0.20; and 0.20-0.30 m, with three replications. under the experimental climate and soil conditions during the three years of study, it was observed that the cultivation of legumes in the plots did not affect the organic carbon content, density, total porosity, water-dispersible clay, and aggregate stability of the soil in comparison to the control treatment.
Semeadura direta na produ??o do milho em agricultura de sequeiro na regi?o Nordeste do Brasil
Silva, Antonio Sousa;Silva, Ivandro de Frana da;Silva Neto, Luís de Frana da;Souza, Cícero de;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011000900011
Abstract: when efficiently introduced, no-tillage system benefices soil and crops. in brazil, no-tillage studies are concentrated in south and center-west regions, being necessary information about it in northeast region. the aim of this study was to evaluate the no-tillage influence on maize yield under rainfed agriculture in northeast brazil, in an experiment conducted during seven years. the crops of maize (zea mays) and pigeon pea (cajanus cajan) were used in three soil management systems: maize in conventional tillage (cc), maize in no-tillage (sd), maize in no-tillage plus pigeon pea sowed in the interrow (sg), with presence and absence of mineral n, p and k fertilization. soil samples were collected at the beginning and the end of the experiment to determine soil bulk density, soil particle density, total porosity, dry and wet mean weight aggregate diameters and aggregate stability index. it was also quantified soil cover rate and maize yield. the soil porosity and aggregate stability were lower after the study period. soil coverage increased significantly, about 96 % of the area under sd and sg systems, early in the culture development. mineral fertilization and no-tillage systems highly influenced the maize yield. the rainfall was the factor that caused greater variability on the results of this study.
Atributos físicos e químicos de agregados pedogênicos e de coprólitos de minhocas em diferentes classes de solos da Paraíba
Silva Neto, Luís de Frana da;Silva, Ivandro de Frana da;Inda, Alberto Vasconcellos;Nascimento, Paulo César do;Bortolon, Leandro;
Ciência e Agrotecnologia , 2010, DOI: 10.1590/S1413-70542010000600002
Abstract: the soil structure is composed by pedogenic and biogenic aggregates, formed respectively by aggregate hierarchy and macrofauna activity, especially by earthworms. the objective of this study was to compare soil aggregates and earthworm casts with different aggregate-size classes and soil classes. the sampling of undisturbed soil and earthworm casts (pontoscolex corethrurus, muller, 1857) was made in four soils of different classes in the state of paraíba (oxisol, ultisol, alfisol and nitisol). the chemical and physical evaluations of aggregates and earthworm casts were determined after dry and split into three aggregate-size classes (20.0 to 9.52, 9.52 to 6.35 and 6.35 to 4.76 mm). the particle-size distribution was similar to aggregates and earthworm casts, independent of aggregate-size classes. earthworm casts had higher proportions of clay, silt and fine sand, lower coarse sand, higher physical stability and more organic carbon and cations contents than the pedogenic aggregates. these results show a peculiar genetic process that makes biogenic aggregates an important indicator of soil quality.
Disponibilidade hídrica de dois solos e diferentes idades de corte no comportamento agron?mico da Jureminha
Diniz Neto, Manoel Alexandre;Vasconcelos, Rossana Carla Montenegro de;Cavalcante, Lourival Ferreira;Pimenta Filho, Edgard Cavalcanti;Silva, Ivandro de Frana da;
Revista Ciência Agron?mica , 2013, DOI: 10.1590/S1806-66902013000100004
Abstract: the study was developed to evaluate the effects of two soil-types under different levels of water availability and cropping ages on the components of vegetative growth and chemical composition of jureminha plants (desmanthusvirgatus l. willd.). the treatments were distributed in a 2 x 4 factorial in a completely randomized block design with twelve replications of the factors: two soil types, one being from the humid region of the town of alagoinha, and other from the semi-arid region of the town of s?o jo?o do cariri, both in the state of paraíba; four levels of water availability (40, 60, 80 and 100% of the available water) and four cropping ages (60,; 90; 120 and 150 days after the emergence of seedlings), the study being carried out in a greenhouse at cca / ufpb,in areia, paraíba. an increase in the water available in the soil stimulates plant growth but inhibits gross protein production in jureminha. plants grew more, and produced less protein in the soil from s?o jo?o do cariri in relation to that from alagoinha.
Componentes de produ??o de mamona em fun??o de níveis de aduba??o nitrogenada e desfolha
Diniz Neto, Manoel Alexandre;Silva, Ivandro de Frana da;Diniz, Belísia Lúcia Moreira Toscano;Pereira, Adelaido de Araújo;Pereira, Alécio Rodrigues;
Revista Ciência Agron?mica , 2012, DOI: 10.1590/S1806-66902012000300018
Abstract: the objective of this study was to evaluate the growth and yield components of castor beans subjected to nitrogen fertilization combined with the artificial defoliation of the plant. the experiment was carried out at the experimental station of the paraiba state agricultural company (emepa-pb) located in the town of alagoinha-pb, between the months of april and october, 2009. five levels of n-fertilizer (00, 30, 60, 90, 120 kg ha-1) were used, combined with four levels of artificial defoliation (00, 20, 40, 60%), distributed in a randomized-block design, in a 4 x 5 factorial arrangement, with four replications. plant height, stem diameter, number of nodes, 100-grain mass and grain yield were evaluated. growth variables increase with the levels of n-fertilizer at defoliation levels of up to 20%. from this level on, there is a tendency for greater vegetative growth with the application of lower doses of nitrogen. both the 100-grain mass and grain yield increase at n-fertilizer doses of less than 120 kg ha-1 and defoliation levels of up to 40%, showing that there is a positive correlation between these yield variables of the castor bean. artificial defoliation, when combined with nitrogen fertilisation, causes changes in the growth and yield components of the castor bean, it being important to assess to what extent the application of n-fertilizer is economically viable, and the possibility of using alternative sources of this nutrient.
Avalia??o quantitativa e qualitativa da fitomassa de leguminosas para uso como cobertura de solo
Nascimento, Jo?o Tavares;Silva, Ivandro de Frana da;
Ciência Rural , 2004, DOI: 10.1590/S0103-84782004000300047
Abstract: twelve species of tropical legumes (crotalaria juncea l, cajanus cajan l, cajanus cajan (l) millsp, calopogonium mucunoides l, canavalia ensiformis l, dolichos lab lab l, pueraria phaseoloides l, macroptilium atropurpureum l, leucaena leucocephala l, clitoria ternatea l, styzolobium aterrimum l, styzolobium cinereum piper and tracy) was evaluated for use as green manure or cover crops in an experiment in alagoinha-pb, brazil. the used experimental design was a ramdomized complete block design, with 12 treatments in plots of 20m2, with three repetitions .the largest biomass quantities were produced for leucaena leucocephala, cajanus cajan, styzolobium aterrimum, pueraria phaseoloides, canavalia ensiformis and clitoria ternatea, while crotalaria juncea, produced the smallest biomass. the biomass of pueraria phaseoloides, was shown with better quality for the incorporation.
Avalia o quantitativa e qualitativa da fitomassa de leguminosas para uso como cobertura de solo
Nascimento Jo?o Tavares,Silva Ivandro de Frana da
Ciência Rural , 2004,
Abstract: Para uso como adubo verde em um experimento em Alagoinha-PB, avaliaram-se doze espécies de leguminosas: crotalária (Crotalaria juncea L), guandu (Cajanus cajan L), guandu an o (Cajanus cajan (L) Millsp), calopog nio (Calopogonium mucunoides L), feij o-de-porco (Canavalia ensiformis L), lab-lab (Dolichos lab lab L), kudzu tropical (Pueraria phaseoloides L), siratro (Macroptilium atropurpureum L), leucena (Leucaena leucocephala L), cunh (Clitoria ternatea L), mucuna preta (Styzolobium aterrimum L), e mucuna cinza (Styzolobium cinereum Piper e Tracy), no DBC com 12 tratamentos, em parcelas de 20m2, com três repeti es. Constataram-se as maiores produ es de fitomassa para leucena, guandu, mucuna preta, kudzu tropical, feij o-de-porco e cunh , enquanto que para a crotalária, a menor produ o. A fitomassa do kudzu tropical mostrou-se com melhor qualidade para a incorpora o.
Page 1 /636579
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.