Consulta: subjectFacets:"Nitrate"
Registros recuperados: 58
Data/hora: 05/06/2024 08:08:09

Relaciones  NH4+/NO3- y Ca2+/K+ en la producción de fresa (Fragaria x ananassa Duch.) en hidroponia.
Provedor de dados: 32
Autores: Campos García, Tonatiu.
El objetivo de la presente investigación fue estudiar el efecto de las relaciones (en la solución nutritiva) amonio/nitrato (NH4+/NO3-) y calcio/potasio (Ca2+/K+) en plantas de fresa Fragaria x ananassa cv. Festival, cultivadas en fibra de coco en un sistema hidropónico. Los tratamientos de NH4+/NO3- fueron 100/0, 75/25, 25/75 y 0/100 en porcentaje de nitrógeno total y 58/42, 75/25, 50/50, 25/75 de Ca2+/K+. Los resultados obtenidos indicaron que las plantas con mayor crecimiento vegetativo y área foliar fueron las que se cultivaron con el tratamiento 100/0 donde se adicionó el 100% de nitrógeno en forma de amonio. También se observó que la corona es el órgano de la planta que concentra la mayor cantidad de NH4+ y NO3-. La concentración de azúcares y...
Palavras-chave: Fresa; Amonio; Nitrato; Relaciones; Producción; Strawberry; Ammonium; Nitrate; Ratio; Yield; Edafología; Maestría.
Ano: 2014
URL: http://hdl.handle.net/10521/2306

Spatial and temporal trends in the distribution of macronutrients in surface waters of the Drake Passage
Provedor de dados: 67
Autores: Paparazzo,Flavio E.; Alder,Viviana A.; Schloss,Irene R.; Bianchi,Alejandro; Esteves,Jose L.
The Drake Passage (DP) links the Southern Pacific and Atlantic Oceans, and acts as a physical narrowing for the largest current of the World Ocean, the Antarctic Circumpolar Current (ACC). This result in a constriction of the main circumpolar fronts related to the ACC: the Subantarctic Front, the Polar Front, the Southern Antarctic Circumpolar Current Front and the Continental Water Boundary Front. Previous studies showed that the DP is a high-nutrient low-chlorophyll (HNLC) region, but studies on the interannual and seasonal macronutrients' fluctuations in relation with chlorophyll and frontal areas in the DP are scarce. This study analyzes the spatial and temporal trends of nitrate, phosphate, and silicate on surface samples from 113 oceanographic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Phosphate; Silicate; Chlorophyll-a; Temperature; Salinity; Antarctic fronts; Antarctic zones; Seasonal variation; Interannual variation.
Ano: 2016
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2016000100004

STABILITY OF PARTIAL NITRITATION OF POULTRY SLAUGHTERHOUSE WASTEWATER IN A SEQUENTIAL BATCH REACTOR
Provedor de dados: 70
Autores: Assis,Tatiane M. de; Schilichting,Marcos V.; Lopes,Carla L.; Kunz,Airton; Gomes,Simone D.
ABSTRACT The aim of this study was to monitor the stabilization of a sequential batch reactor (SBR) regarding the partial nitritation of poultry slaughterhouse wastewater, aiming at preparing it for a reactor with bacteria that promote anaerobic ammonia oxidation (anammox). A cylindrical reactor with a useful volume of 3.5 L, mechanical agitation (50 rpm), and suspended biomass was used in the experiment. The strategies adopted for nitrite-oxidizing bacteria (NOB) inhibition were cycle time (CT: 24, 16, 6, 5, 4 h and real-time monitoring), free ammonia accumulation, alkalinity restriction and low concentrations of dissolved oxygen (DO). The ammonification process, observed at all experimental phases, negatively influenced the control of partial nitritation...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anammox; Deammonification; Nitrite; Nitrate; Nitrafying.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000200323

A review of the chemistries of redox sensitive elements within suboxic zones of oxygen minimun regions
Provedor de dados: 72
Autores: Kenneth W,Bruland.
This presentation is a review of the chemistries of redox sensitive elements within suboxic regions of extreme oxygen minimum zones. Suboxic regions are defined as extreme oxygen minimum zones with dissolved oxygen &lt; 10 µmol kg-1 (and likely &lt;5 µmol kg-1), and with clear evidence of nitrate reduction, but not sulfate reduction. These are regions with nitrate deficits &gt; 10 µmol kg-1 or N* values of _10 µmol kg-1. Suboxic regions predictably occur in the tropical and subtropical eastern Pacific and the Arabian Sea. These suboxic zones are important in the global biogeochemistry of nitrogen and act as an important sink for fixed nitrogen. Minor and trace element redox couples such as iodate/iodide and leachable particulate Mn/dissolved Mn undergo...
Tipo: Journal article
Palavras-chave: Nitrate; Iodine; Manganese; Iron.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300003

NITROGEN FLUXES IN THROUGHFALL AND LITTERFALL IN TWO NOTHOFAGUS FORESTS IN SOUTHERN CHILE
Provedor de dados: 73
Autores: Staelens,Jeroen; Godoy,Roberto; Oyarzún,Carlos; Thibo,Karen; Verheyen,Kris.
Nitrogen return by leaf litterfall was compared with atmospheric nitrogen deposition for two deciduous Nothofagus stands in southern Chile, located in areas with contrasting land use. The litterfall return of nitrogen in a Nothofagus alpina (Poepp. et Endl.) Oerst. stand at San Pablo de Tregua, in the Cordillera de los Andes, was similar to the litterfall return in a Nothofagus obliqua (Mirb.) Oerst. stand at Paillaco, in the Central Depression. In contrast, the net throughfall and stemflow deposition differed significantly between the two stands. At San Pablo de Tregua, the annual bulk deposition of NH4+ and NO3- was significantly higher than the throughfall and stemflow deposition reaching the forest floor. This demonstrates an uptake of inorganic...
Tipo: Journal article
Palavras-chave: Ammonium; Atmospheric deposition; Canopy interactions; Nitrate; Nutrient cycling; Amonio; Ciclos de nutrientes; Depositación atmosférica; Interacciones del dosel; Nitrato.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200002

NITROGEN FLUXES IN A NOTHOFAGUS OBLIQUA FOREST AND A PINUS RADIATA PLANTATION IN THE CENTRAL VALLEY OF SOUTHERN CHILE
Provedor de dados: 73
Autores: Oyarzún,Carlos; Godoy,Roberto; Staelens,Jeroen; Aracena,Claudia; Proschle,Juan.
Forest structure and tree species can have a significant impact on total atmospheric nitrogen (N) deposition; for example, deciduous forests have higher N requirements than coniferous forests. However, knowledge about the effect of the conversion of native Chilean vegetation cover by exotic plantations on N cycling is scarce. The aim of this study was to determine the effect of the replacement of a Nothofagus obliqua native forest by a Pinus radiata plantation in southern Chile on the chemistry of throughfall, stemflow, soil water infiltration and percolation. Pinus radiata stemflow was more acidic (pH 4.7) than precipitation (pH 5.2) and throughfall (pH 5.6), while in the Nothofagus forest stemflow and throughfall pH were 6.3 and 6.1, respectively. In the...
Tipo: Journal article
Palavras-chave: Ammonium; Infiltration; Nitrate; Soil percolation; Throughfall.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200004

NITROGEN RUNOFF AND LEACHING LOSSES IN BEEF PRODUCTION SYSTEMS UNDER TWO DIFFERENT STOCKING RATES IN SOUTHERN CHILE
Provedor de dados: 73
Autores: Alfaro,Marta; Salaza,Francisco; Iraira,Sergio; Teuber,Nolberto; Ramírez,Luis.
The Lakes Region of Chile produces 60% of the country's milk and 45% of its meat. Production is expected to increase in the near future, yet there are few data on the environmental impact of local livestock systems. A field experiment was carried out during 2004 to measure nitrogen (N) runoff and leaching losses in beef cattle-grazing production systems near Osorno. Grazing was carried out with Holstein-Friesian steers of 220 kg of initial live weight, with stocking rates of 3.5 and 5 steers ha-1. Water samples were collected during 6.5 months with surface lysimeters and ceramic cups, and were analyzed for nitrate and ammonium. Total losses were calculated as the product of N concentration and accumulated drainage at each sampling date. A significant...
Tipo: Journal article
Palavras-chave: Andisol; Ammonium; Nitrate; Livestock production.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200008

Vermicompost and biochar substrates can reduce nutrients leachates on containerized ornamental plant production
Provedor de dados: 75
Autores: Alvarez,José M; Pasian,Claudio; Lal,Rattan; López,Rafael; Fernández,Manuel.
ABSTRACT Containerized ornamental plant production is facing several environmental challenges. One of them is to replace the widely used, but with questionable sustainability, peat based substrates and another is to avoid water contamination by chemicals leaching from the nursery. Therefore, as have been verified that petunia and pelargonium plants can be produced in peat-based growing media partially replaced by vermicompost (V) and biochar (B) without decreasing commercial quality, this study has focused on analyzing the leachate from a standard peat-based substrate as a control, used for producing these two ornamental species, and those from the same substrate to which different proportions in volume of V (10% and 20%) and B (4% and 12%) have been...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Petunia hybrida; Pelargonium peltatum; Peat replacement; Water contamination; Nitrate; Phosphate.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362019000100047

Пространственное распределение флуоресценции хлорофилла в южной части  Чёрного моря в поздне-весенний период.
Provedor de dados: 13
Autores: Кривенко, О. В.; Геворгиз, Н. С.; Финенко, З. З.
На основе материалов междисциплинарной базы океанографических данных по Чёрному морю проанализированы пространственная структура и изменения вертикального распределения интенсивности флуоресценции хлорофилла (ИФ) в зависимости от гидрологических, гидродинамических и гидрохимических условий в южной половине моря в апреле – мае 1994 г. Показано, что вертикальное распределение ИФ в этот период в 80 % случаев носит одномодальный характер. Максимум ИФ в основном залегает в ХПС: в низкоградиентной зоне между термоклином и основным пикноклином. Только на трети профилей его положение связано с градиентами плотности в слое температурного скачка. Максимумы ИФ, расположенные в ХПС, близки по величине и на основной части исследованной акватории наблюдаются в узком...
Tipo: Journal Contribution
Palavras-chave: Флуоресценция; Хлорофилл "а"; Нитраты; Чёрное море; Fluorescence; Chlorophyll "a"; Nitrate; Black Sea; Флуоресценція; Хлорофіл "а"; Нітрати; Чорне море.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/797

Содержание и потребление неорганических соединений азота в Чёрном море.
Provedor de dados: 13
Autores: Кривенко, О. А.
На основе материалов по потреблению нитратов и аммония в Чёрном море в различные сезоны проанализирована зависимость между концентрацией неорганических соединений азота в среде и скоростями их поглощения фитопланктоном. Показано, что эта зависимость описывается кривой насыщающего типа, а её параметры изменяются в соответствии с сезонной динамикой гидрохимических условий. Константы полунасыщения, рассчитанные для процессов потребления нитратов и аммония, близки к среднемесячным концентрациям соответствующих неорганических соединений азота в поверхностном слое. В среднем скорости потребления достигают половины максимального значения, т.е. содержание неорганических соединений азота в среде лимитирует скорость потребления только в два раза. Летом, по сравнению...
Tipo: Journal Contribution
Palavras-chave: Нитраты; Аммоний; Скорости потребления нитратов и аммония; Константа полунасыщения; Чёрное море; Nitrate; Ammonium; Uptake rates; Half-saturation constant; Black Sea; Нітрати; Амоній; Швидкості споживання; Константа напівнасичення; Чорне море.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/828

Вертикальное распределение флуоресценции хлорофилла в Чёрном море в тёплый период
Provedor de dados: 13
Autores: Кривенко, О. В.
На основе обобщения материалов шести экспедиций, выполненных в Чёрном море в летний и осенний периоды с 1991 по 2005 гг., проанализировано изменение вертикального распределения интенсивности флуоресценции хлорофилла (ИФ) в зависимости от гидрологических, гидродинамических и гидрохимических условий. Показано, что одномодальные профили ИФ доминируют в Чёрном море на протяжении всего тёплого периода. В 90% случаев максимум ИФ фиксируется в слое термоклина в среднем на глубине 22 ± 7 м. Пик ИФ залегает преимущественно на глубине максимального градиента плотности при величине последне- го ~ до 0.6 кг·м-3·м-1, а при его увеличении заглубляется на 5 – 7 м. Около 40 % всех профилей характеризуются высокими значениями ИФ и в ХПС. Показано, что полуширина максимума...
Tipo: Journal Contribution
Palavras-chave: Чёрное море; Флуоресценция; Хлорофилл а; Нитраты; Чорне море; Флуоресценція; Хлорофіл а; Нітрати; Black Sea; Fluorescence; Chlorophyll a; Nitrate.
Ano: 2010
URL: http://repository.ibss.org.ua/dspace/handle/99011/1932

Solução nutritiva com adição de N mineral para estudos relacionados à fixação biológica de nitrogênio.
Provedor de dados: 14
Autores: LIMA FILHO, O. F. de; RAMOS, L. da L.; MERCANTE, F. M.
bitstream/item/108002/1/BP672014-CPAO.pdf
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Hidroponia; Nitrate; Amônio; Amoniun; Nodule.; Nitrato; Nódulo.; Nitrogênio; Hydroponics; Nitrogen.
Ano: 2014
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/994570

Herbicide and nitrate residues in surface and groundwater from sugarcane area in Brazil.
Provedor de dados: 14
Autores: CERDEIRA, A. L.; GOMES, M. A. F.; QUEIROZ, R. C.; BONATO, P. S.; FERRACINI, V. L.; LANCHOTE, V. L.
Various studies have demonstrated the presence at high levels of pesticides and nitrate in soil, surface, and groundwater. Prior studies have identified a watershed area in Brazil with a high risk of soil, surface, and groundwater contamination by pesticides at the region of Riberao Preto, SP. Surface and groundwater were collected at the area during the period of October 1995 to November 1998. By means of gas chromatography-mass spectrometry (GC-MS) technique the herbicides tebuthiuron, diuron, simazine, atrazine, and ametryne, and nitrate were analyzed according to the protocols established in literature. The recovery obtained in the extraction procedure was higher than 95% for all herbicides except simazine for which the recovery was 85,6%. Due to the...
Tipo: Fôlder / Folheto / Cartilha (INFOTECA-E)
Palavras-chave: Herbicide; Nitrate; Herbicidas; Nitrato de resíduos; Sugarcane.
Ano: 1999
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/13142

Efeito da proporcao NH4+/NO3- na distribuicao de nitrato e na atividade in vitro da redutase do nitrato de plantas de Panicum maximum.
Provedor de dados: 14
Autores: ANDRADE, S. R. M.; SANT'ANNA, J.; MOSQUIM, P. R.
O objetivo deste trabalho foi estudar os efeitos da nutricao nitrica e amoniacal na distribuicao de nitrato e na atividade in vitro da redutase do nitrato em plantas de capim coloniao ( Panicum maximum Jacq.). as plantas receberam 7 mM de nitrogenio nas forma N- NH4 +, N-NO3- ou combinadas nas seguintes proporcoes 0/100, 25/75, 50/50, 75/25 e 100/0. A extracao enzigmatica foi feita em Tris-HCI 50mM pH 7,5, EDTA 0,5 mM e b-mercaptoetanol 10mM, e para o ensaio utilizou-se 200 mmoles de Tris-HCI pH 7,5, 20 mmoles KNO3, 0,1 mmol NADH e 0,1 mL de Triton X-100 1% no volume final de 2,0 mL. A concentracao de nitrato foi levemente superior na parte aerea quando as plantas receberam ambas as formas de nitrogenio, e na raiz seta decresceu com o aumento da proporcao...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Assimilacao de nitrogenio; Amonio; Nitrogen assimilation; Nitrate; Ammonium; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrogênio; Nitrato; Panicum Maximum.; Plant physiology.
Ano: 2001
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567071

Assimilacao do nitrogenio pelas plantas de panicum maximum, cv. Vencedor, submetidas a diferentes proporcoes NH4+/NO3-.
Provedor de dados: 14
Autores: ANDRADE, S. R. M.; SANT'ANNA, R.; MOSQUIM, P. R.; CAMBRAIA, J.
Visando a elucidar alguns aspectos do metabolismo do nitrogenio por plantas de Panicum maximum, estudaram-se os efeitos da proporcao NH +4/NO-3 na variacao do pH das solucoes nutritivas de tratamento, no acumulo de materia seca e na distribuicaoo de nitrogenio na planta. Para tal, as plantas foram cultivadas em camara de crescimento na solucao nutritiva (pH 5,5) completa, contendo nitrogenio somente na forma nitrica. Aos 25 dias depois da germinacao, as plantas foram submetidas a 100 ppm de nitrogenio fornecido nas formas nitrica e amoniacal ou amonical, nas seguintes proporcoes 0/100,25/75,50/50,75/25 e 100/0, durante quatro dias. O pH das solucoes nutritivas foi medido e corrigido diariamente. Os resultados demostraram que o pH aumentou na presenca...
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E)
Palavras-chave: Amonio; Absorcao de nitrogenio; Nitrogen uptake; Ammonium; Nitrate; Fisiologia vegetal: Nutricao mineral.; Capim Colonião; Cerrado; Fisiologia Vegetal; Nitrato; Nitrogênio; Panicum Maximum.; Plant physiology.
Ano: 2001
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567073

Carbon and Nitrogen Acquisition in Shallow and Deep Holobionts of the Scleractinian Coral S. pistillata
Provedor de dados: 5
Autores: Ezzat, Leila; Fine, Maoz; Maguer, Jean-francois; Grover, Renaud; Ferrier-pages, Christine.
Reef building corals can host different symbiont genotypes (clades), and form distinct holobionts in response to environmental changes. Studies on the functional significance of genetically different symbionts have focused on the thermal tolerance rather than on the nutritional significance. Here, we characterized the nitrogen and carbon assimilation rates, the allocation patterns of these nutrients within the symbiosis, and the trophic condition of two distinct holobionts of Stylophora pistillata: one associated with Symbiodinium Glade A in shallow reefs and the other one associated with Glade C in mesophotic reefs. The main findings are that: (1) Glade C-symbionts have a competitive advantage for the acquisition of carbon at low irradiance compared to...
Tipo: Text
Palavras-chave: Light acclimation; Carbon isotopes; Nitrogen isotopes; Clades; Nitrate; Ammonium; Scleractinian coral; Mesophotic coral.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00602/71414/69897.pdf

Uptake of Inorganic and Organic Nitrogen Sources by Dinophysis acuminata and D. acuta
Provedor de dados: 5
Autores: García-portela, Maria; Reguera, Beatriz; Gago, Jesus; Le Gac, Mickael; Rodríguez, Francisco.
Dinoflagellate species of Dinophysis are obligate mixotrophs that require light, nutrients, and prey for sustained growth. Information about their nitrogenous nutrient preferences and their uptake kinetics are scarce. This study aimed to determine the preferred nitrogen sources in cultures of D. acuminata and D. acuta strains from the Galician Rías Baixas (NW Spain) and to compare their uptake kinetics. Well-fed versus starved cultures of D. acuminata and D. acuta were supplied with N15 labeled inorganic (nitrate, ammonium) and organic (urea) nutrients. Both species showed a preference for ammonium and urea whereas uptake of nitrate was negligible. Uptake rates by well-fed cells of D. acuminata and D. acuta were 200% and 50% higher, respectively, than by...
Tipo: Text
Palavras-chave: Dinophysis; Nitrate; Ammonium; Urea; Uptake rates; N-15 incubations; Antibiotic treatment.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00606/71770/70250.pdf

Simulation de l'effet sur l’eutrophisation côtière bretonne de 3 scénarios de réduction des teneurs en nitrate et phosphate de chaque bassin versant breton et de la Loire
Provedor de dados: 5
Autores: Dussauze, Morgan; Menesguen, Alain.
This study commissioned by the Région Bretagne and the Agence de l'Eau Loire Bretagne aimed at assessing on a mathematical modelling basis the marine influence of most of watersheds in Brittany, and the impact of 4 scenarios of reduction of the loadings of each of these watersheds on the phytoplanctonic biomass and ulva mass proliferation. The ecological 3D model ECOMARS3D has been applied to a domain containing Brittany (which is also used in an operational mode for putting everyday the 2dayforecasts on the website: http://www.previmer.org/previsions/production_primaire/modele_eco_mars3d_bretagne) and to 6 zooms which enabled a finer representation of coastal waters. This study highlighted the fact that: •a nitrate reduction for any river has no effect on...
Tipo: Text
Palavras-chave: Bretagne; Bassins versants; Eaux côtières; Nitrate; Phosphate; Marée verte; Ulve; Diatomée; Dinoflagellé; Modèle mathématique; Brittany; Watersheds; Coastal waters; Nitrate; Phosphate; Green tide; Ulva; Diatom; Dinoflagellate; Mathematical model.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00097/20804/18429.pdf

L'eutrophisation des eaux marines et saumâtres en Europe, en particulier en France
Provedor de dados: 5
Autores: Menesguen, Alain; Aminot, Alain; Belin, Catherine; Chapelle, Annie; Guillaud, Jean-francois; Joanny, Michel; Lefebvre, Alain; Merceron, Michel; Piriou, Jean-yves; Souchu, Philippe.
In order to be able to count the cases of coastal eutrophication and to propose methods to monitor as well as to reduce these phenomena, first of all it is necessary to precisely define the word eutrophication itself. Instead of the strict etymological definition, that is to say a progression of the enrichment of a medium, we will rather retain the concept of a state enriched at a point such as it causes harmful effects on the ecosystem, and nuisances to man's activities. Based on the average chemical equations of the organic matter synthesis/degradation in the sea, this operational definition thus puts forwards the harmful consequences of enrichment, i.e. the production of an excessive algal biomass, sometimes unbalanced from the point of view of...
Tipo: Text
Palavras-chave: Alexandrium; Phaeocystis; Monostroma; Ulva; Dilution plume; Water trapping; Anoxia; Nitrogen and phosphorus loadings; Red tides; Phytoplankton blooms; Green tides; Eutrophication; Alexandrium; Phaeocystis; Monostroma; Ulva; Panache de dilution; Confinement; Anoxie; Phosphate; Nitrate; Apports terrigènes; Eaux colorées; Blooms phytoplanctoniques; Marées vertes; Eutrophisation.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/rapport-22.pdf

Nutrient fluxes to the Bay of Biscay from Cantabrian rivers (Spain)
Provedor de dados: 5
Autores: Prego, R; Vergara, J.
Nutrient fluxes to the Bay of Biscay from the Cantabrian basin have been quantified for the first time. Data between 1981 and 1995 of the main 16 Cantabrian rivers from the COCA monitoring programme have been used. Values of water flow and dissolved inorganic nitrogen (DIN), phosphate and silicate concentrations have been taken. Equations are proposed to quantify the fluvial nutrient contributions to the Cantabrian Sea. The annual average of continental outputs to the Bay of Biscay from the Cantabrian basin is 16.1 x 10(9) m(3) of freshwater, 1.0 x 10(9) mol of N in DIN, 0.062 x 10(9) mol of phosphate and 1.2 x 10(9) mol of silicate. In comparison with the French rivers, those of the Cantabrian have small fluxes and their outflow is very disperse, not...
Tipo: Text
Palavras-chave: Nitrate; Phosphate; Silicate; Fleuve; Côte Cantabrique; Nitrate; Phosphate; Silicate; River; Cantabrian coast.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00326/43685/43190.pdf

Inventaire des Ulves en Bretagne année 1998 - rapport de synthèse
Provedor de dados: 5
Autores: Merceron, Michel.
The 1998 survey of green tides on the Brittany coast was performed in the same way as that of 1997 in order to allow comparison. 11 includes an inventory ofail the concerned sites, and a precise assessment ofthirteen ofthem, the most loaded. On these ones, nitrogen fluxes were surveyed during the critical period, and the green seaweed stock on the beach and in the first waves was quantified. The climatic conditions were opposite between the two years, very dry in spring and summer 1997, and wet in 1998. The irradiance contrast was inverse, and less pronounced. The nitrate contents and mostly the flows were more important in 1998. They generated nitrogen fluxes about 3.3 times those of 1997. The total number of sites concerned in 1998 is clearly higher than...
Tipo: Text
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/rapport-2665.pdf

Effects of pH and Nutrients (Nitrogen) on Growth and Toxin Profile of the Ciguatera-Causing Dinoflagellate Gambierdiscus polynesiensis (Dinophyceae)
Provedor de dados: 5
Autores: Longo, Sébastien; Sibat, Manoella; Taiana Darius, Hélène; Hess, Philipp; Chinain, Mireille.
Ciguatera poisoning is a foodborne disease caused by the consumption of seafood contaminated with ciguatoxins (CTXs) produced by dinoflagellates in the genera Gambierdiscus and Fukuyoa. Ciguatera outbreaks are expected to increase worldwide with global change, in particular as a function of its main drivers, including changes in sea surface temperature, acidification, and coastal eutrophication. In French Polynesia, G. polynesiensis is regarded as the dominant source of CTXs entering the food web. The effects of pH (8.4, 8.2, and 7.9), Nitrogen:Phosphorus ratios (24N:1P vs. 48N:1P), and nitrogen source (nitrates vs. urea) on growth rate, biomass, CTX levels, and profiles were examined in four clones of G. polynesiensis at different culture age (D10, D21,...
Tipo: Text
Palavras-chave: Gambierdiscus polynesiensis; French Polynesia; Ciguatera; Ciguatoxins; LC-MS; MS; Toxin profile; Nitrate; Urea; Culture medium acidification.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00662/77382/78981.pdf

Transformation de la phase solide à travers l’estuaire de la Loire en relation avec son environnement chimique et biologique
Provedor de dados: 5
Autores: Thibault De Chanvalon, Aubin.
Before reaching the ocean, riverine particles from the Loire watershed undergo important chemical transformations in the estuary. This study aims to identify and characterize main processes involving iron (and to a lesser extent Al, Mn, PO4 3- and rare earths elements). Suspended particulate matter data show that 15% of their iron is lost through the estuary. Reductive iron dissolution during deposition periods is likely to explain most of this loss. However, estuarine sediments are characterized by high spatial heterogeneity due to macrofaunal activities. To overcome this difficulty, new methodologies of high resolution and two-dimensional analyses and calculation of pore water, sediment and benthic meiofauna were developed. These developments enable to...
Tipo: Text
Palavras-chave: Estuaire; Fer; Phosphore; Nitrate; Foraminifère benthique; Diagenèse précoce; Loire; Bioturbation; Estuary; Iron; Phosphorus; Nitrate; Benthic foraminifera; Precocious diagenesis; Loire; Bioturbation.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60932/64325.pdf

Phased oscillations in cell numbers and nitrate in batch cultures of Alexandrium tamarense (Dinophyceae)
Provedor de dados: 5
Autores: Collos, Yves; Hadjadji, Imene; Plisson, Benoit; Cecchi, Philippe; Laabir, Mohamed; Bechemin, Christian; Masseret, Estelle.
Alexandrium tamarense (M. Lebour) Balech strains isolated in spring 2007 from a single bloom in Thau lagoon have been grown in nonaxenic artificial media. For three strains showing large oscillations in biomass (crashes followed by recoveries) on a scale of several days, a significant relationship was observed between changes in cell densities (as in vivo fluorescence) and changes in nitrate concentrations. Increases in cell densities were accompanied by decreases in nitrate, while decreases in cell densities corresponded to increases in nitrate, presumably due to nitrification. Net increases in nitrate could reach up to 15 mu mol N . L(-1) . d(-1) indicating a very active nitrifying archaeal/bacterial population. However, following population crashes,...
Tipo: Text
Palavras-chave: Alexandrium tamarense; Archaea; Bacteria; Decay; Growth; Nitrate; Nitrification; Oscillations.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00049/16046/13585.pdf

Simulation de l'effet de 3 scénarios de réduction des teneurs de l'Elorn en nitrate sur l'eutrophisation de la rade de Brest
Provedor de dados: 5
Autores: Menesguen, Alain.
This study commissioned by the Syndicat de l'Elorn et de la Rivière de Daoulas aimed at assessing on a mathemical modelling basis the impact of 3 scenarios of reduction of the loadings of Elorn river (imposed concentrations : 20, 15 et 10 mg/L NO3) on the status of ulva mass proliferation in the Moulin Blanc cowe (Bay of Brest). An ecological 3D model of N, P and Si cycling in the bay of Brest has been applied to a "reference situation": 2004 meteorological forcing combined to recent loadings of the new sewage plant. This model showed that: · the 3 reduction scenarios did not reduce significantly the early summer biomass of ulvae, but allowed to slightly reduce the subsequent summer and autumn levels of biomass (up to 20% reduction for 10 mg/L NO3). The...
Tipo: Text
Palavras-chave: Mathematical model; Dinoflagellate; Diatom; Ulva; Green tide; Nitrate; Moulin Blanc cowe; Elorn river; Bay of Brest; Modèle mathématique; Dinoflagellé; Diatomée; Ulve; Marée verte; Nitrate; Anse du Moulin Blanc; Elorn; Rade de Brest.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/rapport-6327.pdf

Inventaire des ulves en Bretagne. Année 1997. Rapport de synthese
Provedor de dados: 5
Autores: Merceron, Michel.
The yearly study of Ulva in Brittany aims at building a time series of its proliferations and corresponding nutrient loadings. The goal is to detect results of wilful loading reductions, and to distinguish them from natural variations. This first actually quantified study is the starting bench-mark of the process. Forty-five concerned sites were listed in 1997. They are nearly the same as in 1988, 1991 and 1994 (previous rough census). The Côtes d'Armor and then the Finistère are the most affected departments. The Morbihan is less and file et Vilaine not at all. Ulva biomass was precisely quantified in about fifteen locations during the growing season, along with nitrogen loadings of local streams (mostly nitrate). The fluxes of nitrogen - the limiting...
Tipo: Text
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/rapport-1580.pdf

Relation concentration-débit et évolution temporelle du nitrate dans 25 rivières de la région Bretagne (France)
Provedor de dados: 5
Autores: Guillaud, Jean-francois; Bouriel, Luc.
The study of the twenty-five largest rivers of Brittany showed that nitrate concentrations are positively correlated with river flow, in 90 % of the cases. The hydrogeological characteristics of the watersheds had an influence on these relationships. In this respect, river basins characterized by prevalent surficial water runoff exhibited higher correlation coefficients and lower lag times between river flow sequences and nitrate concentrations.  The multi-year trend in riverine nitrate concentrations indicated a fourfold increase over 30 years. Nevertheless, 80% of rivers exhibited a recent decrease in nitrate concentrations, independent of inter-annual river flow fluctuations. The highest annual rates of nitrate decrease corresponded to river basins for...
Tipo: Text
Palavras-chave: Eutrophication; River flow; Multiple regression analysis; Multi year trend; Nitrate; Brittany; Eutrophisation; Débit fluvial; Régression multiple; Évolution pluriannuelle; Nitrate; Bretagne.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2568.pdf

Macroalgae delta N-15 values in well-mixed estuaries: Indicator of anthropogenic nitrogen input or macroalgae metabolism?
Provedor de dados: 5
Autores: Raimonet, Melanie; Guillou, Gael; Mornet, Francoise; Richard, Pierre.
Although nitrogen stable isotope ratio (delta N-15) in macroalgae is widely used as a bioindicator of anthropogenic nitrogen inputs to the coastal zone, recent studies suggest the possible role of macroalgae metabolism in delta N-15 variability. Simultaneous determinations of delta N-15 of dissolved inorganic nitrogen (DIN) along the land sea continuum, inter-species variability of delta N-15 and its sensitivity to environmental factors are necessary to confirm the efficiency of macroalgae delta N-15 in monitoring nitrogen origin in mixed-use watersheds. In this study, delta N-15 of annual and perennial macroalgae (Ulva sp., Enterommpha sp., Fucus vesiculosus and Fucus serratus) are compared to delta N-15-DIN along the Charente Estuary, after...
Tipo: Text
Palavras-chave: Nitrogen isotopes; Nitrate; Ammonium; Primary producers; Indicators; Land-sea continuum.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00134/24558/23645.pdf

Combined effects of global climate change and nutrient enrichment on the physiology of three temperate maerl species
Provedor de dados: 5
Autores: Qui-minet, Zujaila Nohemy; Coudret, Jérôme; Davoult, Dominique; Grall, Jacques; Mendez‐sandin, Miguel; Cariou, Thierry; Martin, Sophie.
Made up of calcareous coralline algae, maerl beds play a major role as ecosystem engineers in coastal areas throughout the world. They undergo strong anthropogenic pressures, which may threaten their survival. The aim of this study was to gain insight into the future of maerl beds in the context of global and local changes. We examined the effects of rising temperatures (+3°C) and ocean acidification (−0.3 pH units) according to temperature and pH projections (i.e., the RCP 8.5 scenario), and nutrient (N and P) availability on three temperate maerl species (Lithothamnion corallioides, Phymatolithon calcareum, and Lithophyllum incrustans) in the laboratory in winter and summer conditions. Physiological rates of primary production, respiration, and...
Tipo: Text
Palavras-chave: Calcification; Maerl; Nitrate; Ocean acidification; Ocean warming; Phosphate; Photosynthesis; Respiration.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00595/70722/68955.pdf

Détermination des "bassins récepteurs" marins des principaux fleuves français de la façade Manche-Atlantique, et de leurs rôles respectifs dans l'eutrophisation phyto-planctonique des masses d'eau DCE et des sous-régions DCSMM. Phase 1 (2013) : Calcul de scénarios optimaux à partir des " bassins récepteurs". Phase 2 (2014) : Simulation de scénarios imposés et des scénarios optimaux
Provedor de dados: 5
Autores: Menesguen, Alain; Dussauze, Morgan.
- This study (granted up to 50% by the French Office for Water and Aquatic Environments ONEMA) aimed at determining by modelling (hydrodynamical/biogeochemical ECOMARS3D model) the marine "receiving basins" of the main tributaries to the French waters of the English Channel and the Bay of Biscay. Knowing the respective part of each of these marine "receiving basins" in winter nutrient distribution, some optimal scenarios of nutrient loading reduction can be computed for nitrate or phosphate in order to bring back any marine water to the Good Ecological Status regarding eutrophication, at the best efficiency/cost ratio. - The study encompasses 45 watersheds (or clusters of neighboring watersheds) which have been retained because of their sizes and flow...
Tipo: Text
Palavras-chave: Zone Manche-Atlantique; Modélisation 3D; Bassins versants; Bassins récepteurs marins; Nitrate; Phosphate; Réduction d'apports; Situation "pristine"; Production primaire; Oxygène dissous; Classement DCE; Bon Etat Ecologique; Optimisation linéaire; Simplexe; Optimisation quadratique; Méthode de Beale.; English Channel; Bay of Biscay; 3D modelling; Watersheds; Receiving basins; Nitrate; Phosphate; Nutrient loading reduction; Pristine situation; Primary production; Dissolved oxygen; WFD classification; Good Ecological Status; Linear optimisation; Simplexe method; Quadratic optimisation; Beale's method.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00333/44422/44083.pdf

A mid-Holocene transition in the nitrogen dynamics of the western equatorial Pacific: Evidence of a deepening thermocline?
Provedor de dados: 5
Autores: Kienast, M.; Lehmann, M. F.; Timmermann, A.; Galbraith, E.; Bolliet, T.; Holboum, A.; Normandeau, C.; Laj, C.
Sedimentary delta(15)N records from the oligotrophic western equatorial Pacific (WEP) off Mindanao show that late Holocene sedimentary delta(15)N is substantially lower than that of the early Holocene, following a gradual &gt;3 parts per thousand decrease that occurred between 7 and 3 kyrs ago. Analyses of modem day nitrate isotope profiles from the same region indicate the sensitivity of the WEP N pools towards (1) the advection of (15)N-enriched nitrate from the Eastern Equatorial Pacific (EEP) by the North Equatorial Current (NEC) and the Mindanao Current in subsurface waters and, (2) at shallow depths, the input of new and (15)N-depleted nitrate through N, fixation. We suggest that the Holocene decrease in sedimentary delta(15)N reflects a diminished...
Tipo: Text
Palavras-chave: Tropical Pacific; El Nino; Surface temperature; Fresh water; Nitrate; Mindanao; Ocean; Variability; Holocene; Seawater.
Ano: 2008
URL: https://archimer.ifremer.fr/doc/00207/31843/30257.pdf

Les "marées vertes" en Bretagne, la responsabilité du nitrate
Provedor de dados: 5
Autores: Menesguen, Alain.
Since 25 years, an increasing number of beaches and coves along the Britanny coast are invaded from spring until autumn by proliferating green macroalgae (free ulvae, fixed enteromorphae). This typical case of eutrophication, which has been well studied in the bays of Saint-Brieuc, Lannion, Douarnenez and Brest, could be explained by the conjunction of a natural containment of shallow water masses with a recent enrichment of them by nitrate river loadings. In the naturally confined sites, field measurements of summer biomass showed a good correlation with the spring nitrate river loadings ; furthermore, the summer rarefaction of these loadings explains the fall of the nitrogen content of the ulvae, which induces the summer stop of the algal growth.  The...
Tipo: Text
Palavras-chave: Intensive farming; Biogeochemical models; Coastal eutrophication; Nitrate; Ulva; Green tide; Agriculture intensive; Modèles biogéochimiques; Eutrophisation côtière; Nitrate; Ulve; Marée verte.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/rapport-143.pdf

Plankton community composition in relation to availability and uptake of oxidized and reduced nitrogen
Provedor de dados: 5
Autores: Berg, Gm; Balode, M; Purina, I; Bekere, S; Bechemin, Christian; Maestrini, Serge.
Trends in nitrogen utilization, determined with N-15-labeled substrates, were related to blooms of distinct phytoplankton groups in the Gulf of Riga, Baltic Sea, during May, June and July 1999. The dominant phytoplankton groups included diatoms, cryptophytes, dinoflagellates, and filamentous cyanobacteria. As the water column became progressively more stratified over the growing season, diatoms comprised a smaller proportion of the total phytoplankton assemblage and almost disappeared by late summer. Their disappearance correlated with undetectable surface-water nitrate concentrations and low nitrate uptake rates (5 to 8% of total nitrogen uptake). Diatoms were the only phytoplankton group significantly associated with the uptake of oxidized nitrogen...
Tipo: Text
Palavras-chave: Nitrogen uptake; DON; Nitrate; Diatoms; Cyanobacteria; Cryptophytes; Baltic Sea; Gulf of Riga.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00000/10207/7595.pdf

Variabilité hydrologique et biologique du golfe du Lion. II. Productivité sur le bord interne du courant
Provedor de dados: 5
Autores: Conan, P; Pujo-pay, M; Raimbault, P; Leveau, M.
An estimation of the annual productivity in the Gulf of Lions has been made in the 0-100 m layer using a Let-Go system, with monthly measurements at a fixed station. A value of 140 to 150 g m(-2) a(-1) of C is found, of which around 75 % occurs in the upper 50 m. The seasonal production is described according to three distinct patterns during the two hydrological seasons: (1) variable production in winter; (2) surface bloom in late winter; (3) homogeneous and mean production in summer with a clear Deep Chlorophyll Maximum. The hydrological winter phase represented 60 % of total annual production. The seasonal duality of the hydrodynamic system and the mesoscale variations of the Northern Mediterranean Current account for the variability and the evolution...
Tipo: Text
Palavras-chave: Production primaire; Bilan; Nitrate; Chlorophylle; Cycle saisonnier; Primary production; Budget; Nitrate; Chlorophyll; Seasonal cycle.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43639/43248.pdf

Genotoxic effect of high nitrate water consumption in men and woman from northern Mar del plata, Argentina
Provedor de dados: 46
Autores: Poli,M.N; López Miranda,L.A; Fernández Iriarte,P.J; Zanier,G.J; Iúdica,C.E.
Previous research has shown connections between the exposure to different agents and mutations in germinal and somatic cells. One of such agents, nitrate (NO3), can be potentially genotoxic for individuals who drink high nitrate well water, and may cause a subsequent impact on their health and on the whole ecosystem. The aim of this research was to conduct genotoxicity assays in somatic cells from people living in the northern area of Mar del Plata city, Argentina. The purpose of these experiments was, in turn, to establish the possible relationships between mutagenic effects and high nitrate water consumption. To this end, different diagnostic tests were carried out to detect potential genetic and/or chromosomal alterations. A non-exposed population equal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mutagenic agents; Nitrate; Chromosomal aberrations; Genotoxicity; Micronuclei.
Ano: 2012
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1852-62332012000100001

Nitrogen recycling for sustainable agriculture
Provedor de dados: 19
Autores: Takahashi, Junichi; 高橋, 潤一.
2004年8月5日とかちプラザで開催､日本ユネスコ国内委員会主催の帯広農村開発教育国際セミナー(OASERD)国際連合ユネスコアジア太平洋地域教育開発計画事業(APEID)シンポジウム「地球にやさしい農業をめざして : 家畜ふん尿，資源としての有効利用」講演資料
Palavras-chave: Synthetic ammonia; Harber-Bosch; Nitrogen recycling; Nitrate; Biomass.
Ano: 2004
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1899

Germination and emergence of Stachytarpheta cayennensis and Ipomoea asarifolia
Provedor de dados: 87
Autores: Dias Filho,M.B.
Understanding how weed seed germination and emergence respond to environmental factors is critical to determining their adaptive capabilities and potential for infestations, and could also aid in the development of effective control practices. Germination of Ipomoea asarifolia (Desr.) Roem. &amp;amp; Schultz and Stachytarpheta cayennensis (Rich) Vahl. decreased linearly with decreasing osmotic potentials. Also, increasing osmotic stress delayed germination of Ipomoea more than that of Stachytarpheta. Ipomoea germination was insensitive to light, while Stachytarpheta showed a positive photoblastic behavior. Nitrate had a negative effect on germination of Ipomoea seed under both light and dark conditions but stimulated dark germination of Stachytarpheta....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Light; Osmotic stress; Depth of planting.
Ano: 1996
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83581996000200005

Calibration and Validation of SWAT for the Upper Maquoketa River Watershed
Provedor de dados: 31
Autores: Kanwar,   Ramesh S.; Reungsang,   Pipat; Jha,   Manoj K.; Gassman,   Philip W.; Ahmad,   Khalil; Saleh,   Ali.
A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which...
Tipo: Working or Discussion Paper
Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy.
Ano: 2005
URL: http://purl.umn.edu/18440

Effects of Nutrient Restrictions on Confined Animal Facilities: Insights from a Structural Model
Provedor de dados: 31
Autores: Baerenklau,   Kenneth A.; Nergis,   Nermin; Schwabe,   Kurt A.
Nutrient emissions from animal feeding operations continue to degrade water and air quality.  New regulations will limit the amounts of nutrients that can be locally applied to land.  In this article, a structural-dynamic model of a livestock-crop operation is calibrated with data from a representative farm and is used to predict the effects of nitrogen regulations.  Policy simulations clarify the importance of dynamic elements and demonstrate three main results: (1) cost estimates are relatively high; (2) cross-media pollution effects are potentially large; and (3) improved input management appears most promising for reducing both emissions and waste management costs.  Implications for policy and future research are discussed.
Tipo: Conference Paper or Presentation
Palavras-chave: Ammonia; Animal feeding operation; Cross-media pollution; Dairy; Dynamic optimization; Groundwater; Nitrate; Nitrogen; Nutrient management plan; Livestock Production/Industries.
Ano: 2007
URL: http://purl.umn.edu/10253

Effect of nitrate and ammonium on the growth and protein concentration of Microcystis viridis Lemmermann (Cyanobacteria)
Provedor de dados: 88
Autores: Rückert,Gabriela Von; Giani,Alessandra.
Cyanobacteria are a very important group in aquatic systems, particularly in eutrophic waters. Therefore studies about their success in the environment are essential. Many hypotheses have tried to explain the dominance of Cyanobacteria, and several emphasized the importance of various nitrogen sources for the success of the group. In this study, we measured the effect of ammonium and nitrate on the growth and protein concentration of Microcystis viridis (Cyanobacteria). This species is well-known because bloom formation in eutrophic waters. The study was carried out, in experimental batch cultures, using the WC medium with different nitrogen sources: ammonium, nitrate, ammonium + nitrate (50% ammonium + 50% nitrate) and ammonium at different concentrations...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Cyanobacteria; Eutrophication; Growth; Nitrate; Protein concentration.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042004000200011

Emissions of Nitrous Oxide and Methane in a Subtropical Ferralsol Subjected to Nitrogen Fertilization and Sheep Grazing in Integrated Crop-Livestock System
Provedor de dados: 90
Autores: Piva,Jonatas Thiago; Sartor,Laércio Ricardo; Sandini,Itacir Eloi; Moraes,Anibal de; Dieckow,Jeferson; Bayer,Cimélio; Rosa,Carla Machado da.
ABSTRACT Brazilian agriculture contributes significantly to nitrous oxide (N2O) and methane (CH4) emissions, so the understanding of such emissions at the field is crucial for mitigation strategies. This study quantified the impact of N application and sheep grazing on the N2O and CH4 emissions from a subtropical Ferralsol under an integrated crop-livestock (ICL) management system. In a long-term experiment in southern Brazil, gaseous fluxes were measured during a year-long cycle of ryegrass (Lolium multiflorum) plus oats (Avena sativa) winter pasture and a summer crop of common beans (Phaseolus vulgaris). Three rates of urea-nitrogen (0, 75, and 150 kg ha-1) were applied to the winter-pasture, which was subjected to two sheep grazing levels (continuously...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Ammonium; Water filled pore space; Sheep.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832019000100520

Upland rice under no-tillage preceded by crops for soil cover and nitrogen fertilization
Provedor de dados: 90
Autores: Moro,Edemar; Crusciol,Carlos Alexandre Costa; Cantarella,Heitor; Nascente,Adriano Stephan.
The grain yield of upland rice under no-tillage has been unsatisfactory and one reason could be the nitrate/ammonium balance in the soil. Cover crops and nitrogen fertilization can be used to change the nitrate/ammonium relation in the soil and improve conditions for the development of upland rice in the no-tillage (NT) system. The aim was to study the effect of cover crops and nitrogen sources on grain yield of upland rice under no tillage. The study was carried out on the Fazenda Experimental Lageado, in Botucatu, State of São Paulo, Brazil, in an Oxisol area under no-tillage for six years. The experiment was arranged in a randomized block split-plot design with four replications. The plots consisted of six cover crop species (Brachiaria brizantha, B....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa; Ammonium; Nitrate; Millet; Brachiaria; Crotalaria spectabilis; Nitrogen.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600023

Brachiaria species affecting soil nitrification
Provedor de dados: 90
Autores: Fernandes,Adalton Mazetti; Andrade,Gabriel José Massoni de; Souza,Emerson de Freitas Cordova de; Rosolem,Ciro Antonio.
Nitrification can lead to substantial losses of the applied N through nitrate leaching and N2O emission. The regulation of nitrification may be a strategy to improve fertilizer N recovery and increase its agronomic efficiency. The objective of this study was to evaluate the inhibiting capacity of nitrification in soil by Brachiaria species. The greenhouse experiment was conducted using pots with 10 dm³ of a Red Latosol sample. The treatments consisted of the cultivation of three forage species (Brachiaria brizantha, B. ruziziensis and B. decumbens) and four n rates (0, 100, 200, and 300 mg/pot), and the control (without plants). In the absence of the forage plants, all N fertilization levels raised the N-NO3- soil levels, as a result of nitrification. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Nitrogen.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000500024

Temporal variability of nitrogen and phosphorus concentrations in a German catchment: water sampling implication
Provedor de dados: 91
Autores: Pott,Cristiano A.; Jadoski,Sidnei O.; Schmalz,Britta; Hörmann,Georg; Fohrer,Nicola.
Daily time series were used to verify the temporal variability and to characterize the nitrogen (N) and phosphorus (P) pollution in a 462 km² catchment of the Stör river, a typical rural lowland catchment in Germany. Also, this study aimed to identify the best sampling frequency of pollution by N and P. Total phosphorus (TP), soluble orthophosphate-phosphorus (PO4-P), particulate-phosphorus (PP), total nitrogen (TN), nitrate-nitrogen (NO3-N) ammonium-nitrogen (NH4-N) and total suspended sediment (TSS) were analysed. Daily monitoring from August 8, 2009 until August 10, 2011 was conducted with an automatic water sampler at the outlet of the catchment. The results show a seasonal variability of water quality parameters with more N and P concentration in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water quality; Nitrate; Phosphate; Autocorrelation; Automatic water sampler; Seasonal variability.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662014000800005

Evidence of nitrogen and potassium losses in soil columns cultivated with maize under salt stress
Provedor de dados: 91
Autores: Lacerda,Claudivan F. de; Ferreira,Jorge F. da S.; Suarez,Donald L.; Freitas,Emanuel D.; Liu,Xuan; Ribeiro,Aureliano de A.
ABSTRACT The aim of this study was to evaluate the accumulation of salts in the soil from irrigation water and of N and K from fertilization. The experiment was conducted in PVC columns (20 cm in diameter and 100 cm in height), filled with non-saline soil, and cultivated with maize. A completely randomized block design in a 4 x 4 factorial was used, with four levels of salinity (0.5, 2.5, 5.0 and 7.5 dS m-1), four N rates, and five replicates. Nitrogen was applied as urea and potassium nitrate at the following rates: N1: N recommendation for maize (2.6 g column-1); N2: 0.3 times (0.78 g column-1) the recommended N1 dose; N3 and N4 with N based on N1 and N2 doses, respectively, reduced proportionally based on the evapotranspiration reduction caused by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salinity; Nitrate; Nutrients leaching.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000800553

Effects of fruiting on the growth of Arabica coffee trees as related to carbohydrate and nitrogen status and to nitrate reductase activity
Provedor de dados: 93
Autores: AMARAL,JOSÉ A.T.; DA MATTA,FÁBIO M.; RENA,ALEMAR B.
Active vegetative and reproductive growth in field-grown trees of Coffea arabica L. in Viçosa (20º45’S, 650 m altitude), south-eastern Brazil, occur concurrently. The overall patterns of branch growth and leaf area gain were to a certain extent altered by fruit removal, with growth rates being remarkably greater in de-fruited trees. The content of N-NO3 was not affected by fruiting, whilst that of amino-N was greater in de-fruited than fruiting trees most of the time, but the differences were not large enough to have significantly contributed to the increased growth rates in de-fruited trees. Leaf nitrate reductase activity was greater in plants bearing fruit than in non-bearing ones most of the time; activity was roughly inversely associated with growth....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acids; Ammonium; Coffea arabica; Nitrate; Starch; Sugars; Temperature.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000100008

MOVEMENT OF N0(3)-N AND NH4-N IN AN ANDISOL AND ITS INFLUENCE ON RYEGRASS PRODUCTION IN A SHORT TERM STUDY
Provedor de dados: 127
Autores: Mora,María de la Luz; Cartes,Paula; Núñez,Pedro; Salazar,Mauricio; Demanet,Rolando.
In acids soils, the use of ammonium fertilizers accelerates the acidification processes and decreases both the production and persistence of the pastures. Nitrogen (N) is the most limiting factor for plant growth in most agricultural systems, but also it is one of the major environmental issues worldwide. In Chile, neither systematic studies in the first period of pasture growth and nor N leaching losses associated have been reported. The aims of this study were: (i) to evaluate the effect of the N sources at increasing rates of application on the yield and quality of ryegrass (Lolium perenne) and (ii) to quantify in the short-term the N potential leaching losses and the pH changes throughout the soil profile under field conditions. A field experiment was...
Tipo: Journal article
Palavras-chave: Ammonium; Leaching; Nitrate; Nitrogen; Pasture.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912007000200005

Cations extraction of sandy-clay soils from cavado valley, portugal, using sodium salts solutions
Provedor de dados: 63
Autores: Silva,João Eudes da; Castro,Fernando.
Cases of contamination by metals in the water wells of the Cavado Valley in north-west Portugal can be attributed to the heavy leaching of clay soils due to an excess of nitrogen resulting from the intensive use of fertilisers in agricultural areas. This work focuses on the natural weathering characteristics of soils, particularly the clay material, through the study of samples collected near the River Cavado. Samples taken from various sites, after physico-chemical characterisation, were subjected to clay dissolution tests, using sodium salts of different ionic forces, to detect the relationship between certain physico-chemical parameters of water, such as pH, nitrate, chloride and sulphate content, in the dissolution of clay and the subsequent extraction...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate; Sandy clay material; Natural weathering.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000200024

Root extracts of Bracchiaria humidicola andSaccharum spontaneum to increase N use by sugarcane
Provedor de dados: 63
Autores: Kölln,Oriel Tiago; Franco,Henrique Coutinho Junqueira; Ferreira,Danilo Alves; Vargas,Vitor Paulo; Castro,Saulo Augusto de Quassi; Cantarella,Heitor; Caldana,Camila; Trivelin,Paulo Cesar Ocheuze.
ABSTRACT Retaining the mineral N in the form of NH4+ in the soil for a lengthy period is desirable for reducing losses. Furthermore, there is evidence that sugarcane prefers NH4+-N in place of NO3−-N. This study aimed firstly, to evaluate the potential of root extracts of Bracchiaria humidicola andSaccharum spontaneum, in contrast with the DCD (Dicyandiamide) inhibitor, to increase absorption of N by plants fertilized with ammonium sulfate, and secondly, to quantify the emission of N2O fluxes with the use of this inhibitor. The experiment was developed in a glasshouse in an entirely randomized design where four treatments were applied: AS) ammonium sulfate (control); AS+DCD) ammonium sulfate associated with dicyandiamide; AS+BCH) ammonium sulfate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Dicyandiamide; Nitrification; Nitrous oxide.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000100034

Resilience of soil microbial activity and of amino acid dynamics to the removal of plant carbon inputs during winter
Provedor de dados: 63
Autores: Avramides,Elizabeth J.; Christou,Matina; Jones,David L.
Many temperate agricultural soils have prolonged periods in the winter when plant carbon inputs to the soil are low. Soil maintained at low temperature in the absence of plants was used to simulate the conditions in a vineyard soil during winter. In a four month simulated overwintering period we showed that the concentration of dissolved organic carbon and nitrogen in soil solution slowly declined alongside heterotrophic soil respiration. Measurements of free amino acid concentrations and turnover indicated that the amino acid pool in soil was rapidly depleted but readily replenished throughout the four-month period. This indicates that the soil contained intrinsic reserves of labile C that was capable of supporting the soil microbial community in times of...
Tipo: Info:eu-repo/semantics/report
Palavras-chave: DOC; DON; Microbial activity; Mineralization; Nitrate; Storage.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000100019

COMPARATIVE GROWTH AND BIOCHEMICAL COMPOSITION OF FOUR STRAINS OF Nostoc AND Anabaena (CYANOBACTERIA, NOSTOCALES) IN RELATION TO SODIUM NITRATE
Provedor de dados: 37
Autores: ROSALES LOAIZA,Néstor; VERA,Patricia; AIELLO-MAZZARRI,Cateryna; MORALES,Ever.
Nitrogen concentration is an essential parameter in cyanobacterial cultures to produce enriched biomass with biotechnological purposes. Growth and biochemical composition of Nostoc LAUN0015, Nostoc UAM206, Anabaena sp.1 and Anabaena sp.2 were compared at 0, 4.25, 8.5 and 17 mM NaNO3. Cultures under laboratory conditions were maintained for 30 days at a volume of 500 mL. Anabaena sp.1 yielded the highest value of dry mass of 0.26 ± 2.49 mg mL-1 at 8.5 mM NaNO3. For chlorophyll, phycocyanin and phycoerythrin, maximum values were achieved at 17 mM NaNO3 with 18.09 ± 1.74, 102.90 ± 6.73 and 53.47 ± 2.40 μg mL-1, respectively. Nostoc LAUN0015 produced its maximum value of protein 644.86 ± 19.77 μg mL-1, and 890 mg mL-1 of carbohydrates in the absence of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anabaena; Biochemical composition; Biomass; Culture; Nitrate; Nostoc.
Ano: 2016
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2016000200003

N sources affect growth, nutrient content, and net photosynthesis in maté (Ilex paraguariensis St. Hil.)
Provedor de dados: 52
Autores: Gaiad,Sérgio; Rakocevic,Miroslava; Reissmann,Carlos Bruno.
The influence of different N sources on the growth of maté (Ilex paragurariensis St.Hil.) seedlings grown in greenhouse was studied. All seedlings received a base fertilization of 10 mg N.kg-1 soil as NH4NO3, 60 mg P2O5.and 40 mg K2O.kg-1 soil as KH2PO4 15 days before treatments application. Treatments were as follow: Control, with no extra N added; Urea = 100 mg N.kg-1 soil as Urea; NO3- = 100 mg N.kg-1 soil as Ca(NO3)2; and NH4+ = 100 mg N.kg-1 soil as (NH4)2SO4. It was concluded that: 1) increasing N content in leaves alone was not able to promote gain in biomass production of maté seedlings; 2) seedlings receiving N-NH4 showed a higher accumulation of P and Mg on shoot biomass; and 3) an increase in leaf area, leaf number and net photosynthesis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Soil pH.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000600001

Growth of Crotalaria juncea L. supplied with mineral nitrogen
Provedor de dados: 52
Autores: Mendonça,Elenira Henrique Miranda; Schiavinato,Marlene Aparecida.
Plants of Crotalaria juncea inoculated with Rhizobium were treated with nutrient solution containing 10 or 20mg of either N/NO3 or N/NH4.plant-1.week-1 . The control plants received nutrient solution without N. An investigation was conducted on the effect of these sources of N on growth and nitrogen fixation of plants with 30, 60 and 90 days after sowing (DAS). Those that received mineral N presented higher growth than -N plants, but the presence of nodules occurred in all the treatments. Plants treated with NH4 presented higher N content until 60 days. The highest concentrations of leghemoglobin and protein in nodules were found at 30 DAS and there was no difference in leghemoglobin content between treatments for any age and in protein from 60 DAS....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Nitrate; Rhizobium; Nitrogen fixation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000200003

Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension
Provedor de dados: 56
Autores: Moriel,P.; Sevanian,A.; Ajzen,S.; Zanella,M.T.; Plavnik,F.L.; Rubbo,H.; Abdalla,D.S.P.
The objective of the present study was to identify disturbances of nitric oxide radical (·NO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of·NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 ± 9.7 years; blood pressure, 148.3 ± 24.8/90.8 ± 10.2 mmHg) and in 11 healthy subjects (N: 48.4 ± 7.0 years; blood pressure, 119.4 ± 9.4/75.0 ± 8.0 mmHg).Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrotyrosine; S-nitrosothiols; Nitrate; Oxidized LDL; Lipid peroxidation; Endothelin-1.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001100007

Effects of different nitrogen sources on growth, chlorophyll concentration, nitrate reductase activity and carbon and nitrogen distribution in Araucaria angustifolia
Provedor de dados: 61
Autores: Garbin,Mário L.; Dillenburg,Lúcia R.
The southern Brazilian highland plateau is a mosaic of two contrasting plant communities, Araucaria forests and grasslands, which differ in the relative abundances and spatial patterns of soil nitrate and ammonium. However, we still do not know the inorganic N preferences of one key species in this mosaic, Araucaria angustifolia, the dominant tree species in the Araucaria forests and an important tree species invading the adjacent grasslands. Growth responses measured in a greenhouse study demonstrated that the species prefers NH4+ over NO3- as an inorganic N source. When provided alone, NO3- induced N deficiency symptoms: increases in root: shoot ratio, root branching and leaf mass per area, thickening of the shoot apexes and decreased mass-based...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Araucariaceae; Ammonium; Inorganic nitrogen; Nitrate; Nitrogen deficiency.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400005

Nitrogen Losses under Different Cattle Grazing Frequencies and Intensities in a Volcanic Soil of Southern Chile
Provedor de dados: 117
Autores: Núñez,Pedro A.; Demanet,Rolando; Misselbrook,Tom H.; Alfaro,Marta; Mora,María de la Luz.
Chilean livestock production systems have intensified over the last years, with increasing amounts of N fertilizer inputs creating the potentiality for environmental damage through N pollution of water and air, so that alternative production strategies have been developed to reduce such environmental impacts. This study assesses N losses under different grazing frequencies and intensities on permanent pasture (Lolium perenne L., Festuca arundinacea Schreb., Dactylis glomerata L., and Trifolium repens L.) on an Andisol in Southern Chile. Four grazing strategies were evaluated: frequent-heavy (FH), frequent-light (FL), infrequent-heavy (IH), infrequent-light (IL), and a no grazing control (C) treatment, and each with three replicates in a randomized complete...
Tipo: Journal article
Palavras-chave: Ammonium; Grazing; Leaching; Nitrate; NH3 volatilization.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000200007

Mitigating effect of salicylic acid and nitrate on water relations and osmotic adjustment in maize, cv. Lluteño exposed to salinity
Provedor de dados: 118
Autores: Escobar,Hugo; Bustos,Richard; Fernández,Felipe; Cárcamo,Henry; Silva,Herman; Frank,Nicolás; Cardemil,Liliana.
We analyzed the mitigating effect of NO3 - and salicylic acid (SA) on the detrimental effects of salt stress by studying the water status of plants of maize grown in Hoagland's medium with NaCl 100 mM as the saline component, to which SA and NO3 - were added in different concentrations as mitigating agents. We evaluated water potential &amp;#936;w, osmotic potential &amp;#936;s, relative water content (RWC), turgor potential (&amp;#936;p ), and the osmotic adjustment (OA) of leaves and roots. SA 0.5 mM mitigated the effects of salinity by increasing the &amp;#936;w of the leaf, the &amp;#936;sof theroot, the &amp;#936;pof the leaf, RWC and OA of the leaf; while NO3 was only effective in combination with SA, mitigating the effects of salinity by increasing...
Tipo: Journal article
Palavras-chave: Nitrate; Osmotic potential; Osmotic adjustment; Salinity mitigation; Salicylic acid; Water potential; Water relative content.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202010000300006

Nitrogen availability in an apple orchard with weed management
Provedor de dados: 65
Autores: Brunetto,Gustavo; Oliveira,Bruno Salvador; Ambrosini,Vítor Gabriel; Couto,Rafael da Rosa; Sete,Paula Beatriz; Santos Junior,Elano dos; Loss,Arcângelo; Silva,Lincon Oliveira Stefanello da; Gatiboni,Luciano Colpo.
ABSTRACT: Weed management in apple orchards (Malus domestica) can affect the leaching of nitrogen (N) in soil. The study aimed to evaluate the potential leaching of N forms in soil of an apple orchard with different weed management treatments. The experiment was conducted in an apple orchard implanted in 2008. In October 2011, 80 plants were selected and the following treatments were implemented: no weed management (NM), desiccation of weeds on the tree row with herbicide use (DR) and mechanical mowing of weeds on the tree row (MR). Yield was evaluated in the 2011/2012, 2012/2013 and 2013/2014 crop seasons. In May 2012 porous cup lysimeters were installed in the NM, DR and MR treatments. In the solution collected at 0.20m, NH4 +-N and NO3 --N were analyzed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mineral N; Nitrate; Ammonia; Malus domestica.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000500251