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Search Results: 1 - 10 of 1779 matches for " Ad?nis; "
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Fertilidade, matéria organica e substancias húmicas em solos antropogênicos da Amaz?nia Ocidental
Moreira, Adnis;
Bragantia , 2007, DOI: 10.1590/S0006-87052007000200015
Abstract: the objective of this work was to evaluate the variations of the carbon stock and quality and the chemistry alterations of soils of anthropogenic formation with high fertility occurring in scattered patches throughout the amazon, called "terra preta do índio" (amazonian dark earths - ade). twenty-one samples of different depths taken from eleven archeology sites, and four representative soil classes of the region (oxisol, inceptsol, ultisol and spodsol) were used. the eutrophic character of amazonian dark earths contrast with these representative soils and despite its high fertility, the sites present a great heterogeneity concerning the concentration of total n, organic c, available and organic p, available k and exchangeable ca and mg. the ancient antropic action in amazonian soils resulted in increase of humic acids and humin content and decrease of the fulvic acids, with consequent improvement of the soil organic matter quality. the use of walkley-black method presented limitations for the carbon in the anthropogenic soils as compared to the chns analyzer.
Prote??o de cachos de bananeira com sacos de polietileno nas condi??es edafoclimáticas do estado do Amazonas
Moreira, Adnis;
Ciência e Agrotecnologia , 2008, DOI: 10.1590/S1413-70542008000100019
Abstract: the purpose of this work was to evaluate the effect of bunch protection on yield, ripening period and fruit quality of four banana cultivars [thap maeo (aab), fhia 18 (aaab), nanic?o 2001 (aaa) and prata zulu (aab)]. a randomized experimental design was employed in a 4x2 factorial comprising the four cultivars and two procedures (bagged and not bagged bunches), with four replicates. bunches were conditioned in bags impregnated with organophosphorated insecticide. variables analyzed were bunch weight, number of bands per bunch, bunch size, band weight, number of fruits per band, fruit length, pulp diameter, and fruit rind thickness. in local edaphoclimatic conditions, results showed that bag enclosure reduce bunch yield and pulp diameter on prata zulu cultivar. protection of bunches on nanic?o 2001 increased fruit length. number of bands per bunch, band weight, fruit thickness, number of fruits per band, and bunch size were not influenced by bag enclosure, and differences were detected only among cultivars. time elapsed between emergence of inflorescence and fruit harvest showed significative correlation with bagged bunch yield only.
Dinamica da matéria organica na recupera??o de clareiras da floresta amaz?nica
Moreira, Adnis;Costa, Danielle Gon?alves;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004001000009
Abstract: the removal of native forest as well as of the surface soil horizons causes a significant decrease of microbial biomass and soil fertility. a slow and continuous recovery of the amount and of the quality of organic matter occurs in these areas, with reforestation. the objective of this work was to evaluate the fertility, organic matter and microbial biomass dynamics in areas reforested at different ages. the reforested clearings were set up in 2003, 2002, 2001, 1999 and 1993, with native regional species. the soil fertility was associated to soil organic matter content. the reforestation increased significantly the organic matter and the microbial biomass after the fourth year, and this indicates the need of an initial soil supply of carbon content, which can be provided by grasses or legumes used for forage.
Dinamica da matéria organica e da biomassa microbiana em solo submetido a diferentes sistemas de manejo na Amaz?nia Ocidental
Moreira, Adnis;Malavolta, Eurípedes;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004001100008
Abstract: the objective of this work was to evaluate the alterations of the microbial biomass activity as an indicator of c and n dynamics in a soil submitted to the succession of plant cover and management in the western amazon. the work was carried out in two chronosequences: ca - a succession from primary forest to a three years old cupua?u (theobroma grandiflorum) plot - and cb - a succession from primary forest to an eight years old brachiaria humidicola pasture and a three years old cupua?u plot. the succession primary forest-pasture-cupua?u affects negatively the stock of the soil carbon, with significant decrease of organic matter and c of the soil microbial biomass. the primary forest presents lower metabolic quotient and higher c/n ratio of the biomass, which results in less carbon loss. the n of the microbial biomass found in the 0-10 cm layer irrespective of the management adopted, increases significantly in the cupua?u plot and the total n decreases. ammonium concentration decreases according to soil depth, but this does not occur with nitrate.
Fontes, doses e extratores de fósforo em alfafa e centrosema
Moreira, Adnis;Malavolta, Eurípedes;
Pesquisa Agropecuária Brasileira , 2001, DOI: 10.1590/S0100-204X2001001200009
Abstract: the objective of this work was to study the effect of four rates and four sources of p on dry matter production, and of phosphorus content in alfalfa and centrosema grown in pots containing a red-yellow latosol (oxisol), and to evaluate soil phosphorus by three extractants. the treatments were completely randomized in a 4 x 4 x 6 factorial design, with three replicates. four sources of p were used at the rates of 0, 50, 100 and 200 mg kg-1, supplied as triple superphosphate (tsp), arad rock phosphate (arp), north caroline rock phosphate (ncrp) and yoorin magnesium thermophosphate (ytp), and six monthly harvests were made. the various rates of phosphorus applied increased both dry matter and p content in dry matter, alfalfa being more responsive. ytp ranked first in the total dry mater production: in six cuttings 50.17 g and 70.89 g were obtained, respectively with alfalfa and centrosema when 200 mg kg-1 was used. the extractants mehlich 1 and 3 and resin presented each other a high correlation in the evaluation of the available phosphorus. considering the average of the three rates of application and all cuttings, total p taken up obeyed the following decreasing order: ytp > tsp > ncrp > arp.
Liming influence on soil chemical properties, nutritional status and yield of alfalfa grown in acid soil
Moreira, Adnis;Fageria, Nand Kumar;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000400022
Abstract: alfalfa is an important forage crop with high nutritive value, although highly susceptible to soil acidity. liming is one of the most efficient and prevailing practices to correct soil acidity and improve alfalfa yield. the objective of this study was to evaluate response to liming of alfalfa grown in a greenhouse on a typic quartzipsamment soil. the treatments consisted of four lime rates (0, 3.8, 6.6 and 10.3 mg ha-1) and two cuts. alfalfa dry matter increased quadratically with increasing lime rates. in general, dry matter yield was maximized by a lime rate of 8.0 mg ha-1. except for the control, the dry matter nutrient contents in the treatments were adequate. the positive linear correlation between root and nodule dry matter with lime rates indicated improvement of these plant traits with decreasing soil acidity. the soil acidity indices ph, base saturation, ca2+ concentration, mg2+ concentration, and h + al were relevant factors in the assessment of alfalfa yield. the magnitude of influence of these soil acidity indices on yield as determined by the coefficient of determination (r2) varied and decreased in the order: base saturation, h + al, ph, ca and mg concentrations. optimum values of selected soil chemical properties were defined for maximum shoot dry matter; these values can serve as a guideline for alfalfa liming to improve the yield of this forage on acid soils.
Reparti??o e remobiliza??o de nutrientes na bananeira
Moreira, Adnis;Fageria, Nand Kumar;
Revista Brasileira de Fruticultura , 2009, DOI: 10.1590/S0100-29452009000200036
Abstract: the banana tree demands large quantities of fertilizers to maintain its nutritional requirements and achieve high productivity, but large percentage applied are not available, since it gets lost mainly by fixation, leaching and volatilization. the objective of this study was to evaluate the rate of remobilization and repartition of nutrients in banana tree, cultivar thap maeo, cultivated in the western amazon. the results showed that the highest proportion of k, na, mg, s, b, cu, fe and zn was found in the pseudostem. the remaining flowers represent a strong drain of nutrients. the biomass that comes from the culture residues represents a significant source of nutrients. the nutrient remobilization index was higher with n and k. the inverse was observed with fe and mn.
Fontes, doses e extratores de fósforo em alfafa e centrosema
Moreira Adnis,Malavolta Eurípedes
Pesquisa Agropecuária Brasileira , 2001,
Abstract: O objetivo deste trabalho foi estudar o efeito de quatro fontes e quatro doses de fósforo na produ o de matéria seca e nos teores de P em alfafa e centrosema, cultivadas em vasos com Latossolo Vermelho-Amarelo distrófico, e avaliar a disponibilidade de fósforo no solo, por três extratores. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 4 x 4 x 6: quatro doses de P (0, 50, 100 e 200 mg kg-1), quatro fontes de P (superfosfato triplo - SFT, termofosfato Yoorin - TY, fosfato natural da Carolina do Norte - FNCN e fosfato natural de Arad - FNA) e seis épocas de corte das plantas com intervalos de 30 dias, com três repeti es. As doses de P aumentaram a produ o de matéria seca total (MS) e o teor de P na MS, sendo que a alfafa apresentou maior resposta. O termofosfato Yoorin proporcionou a maior produ o de MS: em seis cortes foram obtidos 50,17 e 70,89 gramas, respectivamente, com a alfafa e centrosema na dose de 200 mg kg-1. Os extratores Mehlich 1, Mehlich 3 e resina apresentaram alta correla o entre si na avalia o do P disponível. Considerando a média das três doses aplicadas e de todos os cortes, a quantidade total de P absorvido obedeceu a seguinte ordem: TY > SFT > FNCN > FNA.
Ensacamento de cachos na produ??o, matura??o e qualidade dos frutos de bananeiras cultivadas no Estado do Amazonas
Silva Filho, Luis Pereira da;Moreira, Adnis;
Acta Amazonica , 2005, DOI: 10.1590/S0044-59672005000400004
Abstract: the objective of this work was to evaluated the effect of bag enclose on the yield, ripening period and fruit quality of bananas cultivars (thap maeo, fhia 18, nanic?o 2001 and prata zulu). a randomized experimental design was employed, in a 4x2 factorial, comprising the four cultivars and two procedures (bagged and not bagged bunches), with four replicates. the bagging was done with bags impregnated with organophosphorated insecticide. the variables analyzed were the time elapsed between the emergence of the inflorescence and the fruit harvest; bunch yield, hand yield; pulp diameter; fruit diameter; pulp/rind ratio; ph; texture and soluble solids. in the edaphoclimatic conditions, the results showed, on an average for all cultivars, that the baggin had no significative effect on the emergence of the inflorescence, pulp diameter, fruit diameter, pulp/rind ratio, ph, texture and soluble solids. it is noteworthy that even without significant difference, it was verified that, irrespective of cultivar, there was a decrease of the ripening period and a reduction of the bunch weight. the bags enclose reduced by cultivar prata zulu yield.
Efficiency of boron application in an Oxisol cultivated with banana in the Central Amazon
Moreira, Adnis;Castro, César de;Fageria, Nand K.;
Anais da Academia Brasileira de Ciências , 2010, DOI: 10.1590/S0001-37652010000400030
Abstract: in the amazon region, there is no information on the fertilization of banana plants with boron (b). besides this, the extractant (hot water) currently used to test b concentrations has many limitations. the aim of this work was to study the effect of b on the fruit yield and quality of banana plants of the cavendish (aaa) sub-group, grown in dystrophic yellow latosol (oxisol or xanthic ferralsol), in the amazonas state, brazil. the experimental design was completely randomized split plot in a 4 x 2 factorial scheme, composed of four b rates (0, 4, 8 and 12 kg ha-1) and two harvest cycles (sub-treatments), with four replicates. the b availability in the soil was determined by three extractants: mehlich 3, hot water and kcl 1.0 mol l-1. the application of b influences the fruit yield, pulp/peel ratio, pulp resistance and b content in the leaves and fruits. the kcl 1.0 mol l-1 extractant was similar to the hot water in the evaluation of available b. to obtain maximum yield, it is necessary to apply 4.1 and 6.1 kg ha-1 of b in the first and second cycles, respectively.
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