|
|
|
| Registros recuperados: 58 | |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| 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 Ψw, osmotic potential Ψs, relative water content (RWC), turgor potential (Ψp ), and the osmotic adjustment (OA) of leaves and roots. SA 0.5 mM mitigated the effects of salinity by increasing the Ψw of the leaf, the Ψsof theroot, the Ψpof 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 |
| |
|
|
| 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 |
| |
| Registros recuperados: 58 | |
|
|
|
