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Registros recuperados: 257 | |
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Labry, Claire; Youenou, Agnes; Delmas, Daniel; Michelon, Pascale. |
The speciation of particulate phosphorus (TPP) into inorganic (PIP) and organic phosphorus (POP), has been scarcely investigated in suspended particulate matter (SPM), contrary to numerous sediment studies. This work evaluates the actual capacity of methods for TPP, POP and PIP determination in SPM to measure efficiently and specifically each pool. Methods were tested on a range of plankton-associated organic and inorganic P compounds, on microalgal cultures and estuarine samples. Then results are specifically discussed reviewing P speciation in phytoplankton. For TPP analysis, the method of Solorzano and Sharp (1980) is recommended compared with that of Aspila et al. (1976), originally dedicated to sediment, as there is one step less, the protocol is more... |
Tipo: Text |
Palavras-chave: Phosphorus; Speciation; Waters; Phytoplankton; HTC; CWO. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00149/26046/26385.pdf |
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Araújo,Adelson Paulo. |
Plant growth analysis presents difficulties related to statistical comparison of growth rates, and the analysis of variance of primary data could guide the interpretation of results. The objective of this work was to evaluate the analysis of variance of data from distinct harvests of an experiment, focusing especially on the homogeneity of variances and the choice of an adequate ANOVA model. Data from five experiments covering different crops and growth conditions were used. From the total number of variables, 19% were originally homoscedastic, 60% became homoscedastic after logarithmic transformation, and 21% remained heteroscedastic after transformation. Data transformation did not affect the F test in one experiment, whereas in the other experiments... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: ANOVA model; Statistic; Phosphorus; Common bean; Rice. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2003000100001 |
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Guimarães,Igo Gomes; Pezzato,Luiz Edivaldo; Barros,Margarida Maria; Fernandes,Rosângela do Nascimento. |
Apparent digestibility coefficients (ADC) of gross energy and dry matter (DM) and mineral availability were evaluated for eight protein-rich ingredients (corn gluten meal, soybean meal, cottonseed meal at 280.0 and 380.0 g/kg, poultry by-product meal, meat meal, fish meal and feather meal) in compound diets for Nile tilapia. Chromic oxide was used as inert digestibility marker. Higher ADC values of DM and energy were, respectively, 0.862 and 0.881 for corn gluten meal, 0.811 and 0.888 for poultry by-product meal; 0.729 and 0.731 for feather meal; 0.666 and 0.754 for fish meal; 0.578 and 0.642 for soybean meal; 0.476 and 0.652 for meat meal at 450.0 g/kg; 0.352 and 0.449 for cottonseed meal at 380 g/kg; and 0.251 and 0.324 for cottonseed meal at 280.0 g/kg.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium; Feed evaluation; Gross energy; Nutritional value; Oreochromis niloticus; Phosphorus. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000800001 |
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Kampas, Athanasios; Mamalis, Spyridon. |
Although the initial allocation of pollution permits is neutral in terms of efficiency, it does have a significant impact on distributive equity. In this paper, we examine the two main categories of permit allocation rules, the distributive and the reductive, for controlling phosphorus pollution in a small catchment in South West England. Based on the premise that the regulatory choice compromises efficiency and equity, the main result of this paper is that an allocation of permits in proportion to the intensity of environmental preferences is a “win-win” choice. The reason is that it simultaneously achieves two goals. First, it is efficient (or cost-effective) since a permit system achieves a prespecified target at a minimum abatement cost, while second,... |
Tipo: Journal Article |
Palavras-chave: Pollution permits; Phosphorus; Nutrient management; Export coefficient model; Water quality; Distributive justice; Income inequality; Atkinson Index; Environmental Economics and Policy. |
Ano: 2006 |
URL: http://purl.umn.edu/44115 |
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Van Langenhove, Leandro; Verryckt, Lore T.; Bréchet, Laëtitia; Courtois, Elodie A.; Stahl, Clement; Hofhansl, Florian; Bauters, Marijn; Sardans, Jordi; Boeckx, Pascal; Fransen, Erik; Peñuelas, Josep; Janssens, Ivan A.. |
Atmospheric deposition is an important component of the nutrient cycles of terrestrial ecosystems, but field measurements are especially scarce in tropical regions. In this study we analysed 15 months of precipitation chemistry collected in an old growth tropical forest located in French Guiana. We measured nutrient inputs via bulk precipitation and throughfall and used the canopy budget model to estimate nutrient fluxes via canopy exchange and dry deposition. Based on this method we quantified net fluxes of macronutrients and compared their contribution to internal cycling rates via litterfall. Our results suggest that while atmospheric deposition of nitrogen was relatively high (13 kg ha−1 year−1), and mainly in organic forms, the N inputs via litterfall... |
Tipo: Text |
Palavras-chave: Throughfall; Litterfall; Nutrient cycling; Nitrogen; Phosphorus; Potassium. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74123/73572.pdf |
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Hirzel,Juan; Walter,Ingrid. |
Poultry litter (PL) is an organic matter source used as soil amendment. Besides its important nutrient content, it is a cheap alternative to conventional fertilizers in crop production. The efficient use of PL also helps reduce the environmental problems normally associated with its disposal near poultry production farms. This article reports the relative effects of PL and conventional fertilizers on the availability of soil N, P and K, dry matter (DM) production and total nutrient content in silage corn (Zea mays L.). The field experiment was carried out in a soil derived from volcanic ash (Tipic Melanoxerands) of Central South Chile. Corn was grown for three seasons (2002-2005) and PL and conventional fertilizers were applied in the first two years. The... |
Tipo: Journal article |
Palavras-chave: Poultry litter; Soil fertility; Corn; Nitrogen; Phosphorus; Potassium. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000300006 |
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Saraiva,Alysson; Donzele,Juarez Lopes; Oliveira,Rita Flávia Miranda de; Abreu,Márvio Lobão Teixeira de; Silva,Francisco Carlos de Oliveira; Vianna,Rafael Alves; Lima,Anderson Lazarini. |
With the objective to evaluate levels of available phosphorus (aP) in diets for pigs selected for meat deposition by maintaining the calcium and available phosphorus ratio, it was used 50 commercial hybrid female pigs with initial weight of 30.32 ± 0.29 kg, distributed in a complete randomized experimental design, with five treatments, five replicates, and two animals per experimental unit. Treatments were composed of a corn-soybean meal basal diet and four diets obtained by supplementation of basal diet with dicalcium phosphate, resulting in diets with 0.144; 0.224; 0.304; 0.384 and 0.464% of aP. Calcium levels were adjusted by varying the quantities of limestone in the diets. There was no effect of aP on both daily feed intake and feed conversion. Levels... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Growth phase; Phosphorus; Performance; Requirement. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000300017 |
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Davaran-Hagh,Elnaz; Mirshekari,Bahram; Reza-Ardakani,Mohammad; Farahvash,Farhad; Rejali,Farhad. |
Integrated nutrient management is a major agronomic practice which brings together all methods to support plants nutritional requirement. However, the interaction of these methods together is very complex and needs to be studied in different climatic conditions. So, the effect of nitrogen fertilizer and Azospirillum lipoferum inoculation on maize (Zea mays L.) growth, yield and nutrients uptake was determined in this study. The hypothesis was that the bacterial inoculation decreases the need for N fertilizer application without reducing plant yield. Therefore, we carried out a factorial experiment in a randomized complete block design with three replications. Nitrogen at 0, 25, 50, 75 and 100 % concentrations of the recommended dose, i.e. 150 kg N ha-1... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biofertilizer; Iron; Nitrogen; Phosphorus; Zinc. |
Ano: 2015 |
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952015000800006 |
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Huang, Bing; Marchand, Justine; Thiriet-rupert, Stanislas; Carrier, Gregory; Saint-jean, Bruno; Lukomska, Ewa; Moreau, Brigitte; Morant-manceau, Annick; Bougaran, Gael; Mimouni, Virginie. |
Nitrogen (N) and phosphorus (P) limitations induce neutral lipid accumulation and membrane lipid remodeling in the domesticated oleaginous microalga Tisochrysis lutea. This study compared growth, photosynthetic activity, biochemical and transcriptional responses of T. lutea throughout batch cultures under N or P limitation compared with non-limiting nutrient condition (NP). The results show that, under N limitation, the breakdown and re-use of cellular N-containing compounds contributed to carbohydrates and further triacylglycerol (TAG) accumulation, where the accumulation of docosahexaenoic acid (DHA) in neutral lipids might mainly be derived from the recycling of membrane polar lipids. Conversely, P limitation did not hinder the photosynthetic capacity;... |
Tipo: Text |
Palavras-chave: Tisochrysis lutea; Phosphorus; Nitrogen; Lipid remodeling; Betaine lipid; Polyunsaturated fatty acid. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00492/60409/64776.pdf |
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Registros recuperados: 257 | |
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