Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Salinity tolerance of halophyte Atriplex nummularia L. grown under increasing NaCl levels
Araújo, Sandro A.M. de;Silveira, Joaquim A.G.;Almeida, Tania D.;Rocha, Iza M.A.;Morais, Déborah L.;Viégas, Ricardo A.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2006, DOI: 10.1590/S1415-43662006000400010
Abstract: the current study reports effects of salt stress on growth, k+ nutrition and organic composition of atriplex nummularia. the upper limit of the nacl gradient imposed on the plants was close to seawater salinity (600 mm). an external nacl of 150 mm improved the growth of this species, which corroborates its halophytic nature. evidence show that atriplex nummularia was responsive to nacl, but the mechanisms of this response are still not known. in such stress condition, na+ and cl- accumulation in leaves was far greater than that in roots; therefore salinity tolerance of atriplex nummularia is not due to ion exclusion mechanism. in spite of a reduction of k+ content of tissues under salinity conditions, no corresponding physiological relevance of this in terms of growth was found. the high affinity of root cells for na+ during uptake and, probably, its subsequent sequestration into cell vacuoles and structures of protection seems to contribute to osmotic adjustment as an increase in relative water content (rwc) of leaves was observed. nacl caused a decrease in total soluble proteins and chlorophylls; the relevance of this is discussed in terms of mechanisms of salinity tolerance. the ability of atriplex nummularia plants to keep na+ and cl- away from enzymes and cytosolic structures, together with an effective osmotic adjustment, is suggested as having a role in its tolerance to high salinity.
Fitorremedia??o de solo salino s ódico por Atriplex nummularia e gesso de jazida
Leal, Isaac Gomes;Accioly, Adriana Maria de Aguiar;Nascimento, Clístenes Williams Araújo do;Freire, Maria Betania Galv?o dos Santos;Montenegro, Abelardo Ant?nio de Assun??o;Ferreira, Fabiana de Lima;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000300015
Abstract: the cultivation of atriplex nummularia on saline-sodic soils is economically attractive because it can be used as a forage crop as well as in landscape projects. the potential of atriplex nummularia for phytoextraction of na+ from a saline-sodic soil irrigated with saline water was evaluated. additionally, gypsum was tested for improving phytoremediation. the experiment was set up as a randomized block design, in a 2 x 3 factorial scheme. the treatments consisted of: no gypsum and 50 % of the regularly recommended gypsum dose, and three salinity levels of irrigation water: c1 = 175 μs cm -1; c2 = 500 μs cm -1; c3 = 1,500 μs cm -1. the na concentration in plant tissues and soil were evaluated 40, 70, 100 and 130 days after a nummularia transplanting. the results showed that there was a 96 % increase in root dry matter as a result of gypsum application. sodium accumulation in shoots increased significantly in the third (90.1 g kg-1) and fourth (109.7 g kg-1) sampling period. this effect was magnified by gypsum application. after 100 days, the soil na+ content had decreased by 31 and 26 %, with and without gypsum addition, respectively. our results indicate that a. nummularia is a na+ accumulator species. gypsum was effective as a phytoextraction enhancer. a. nummularia irrigation aiming at na phytoremediation is possible with saline water varying from 175 to 1,500 μs cm-1.
Atividade microbiana em solo do semi-árido sob cultivo de Atriplex nummularia
Pereira, S?nia Valéria;Martinez, Cosme Rafael;Porto, Everaldo Rocha;Oliveira, Beatriz Regina Brito;Maia, Leonor Costa;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004000800005
Abstract: methods used to estimate the soil microbial activity are important to environmental monitoring of degraded areas. the objective of this research was to investigate the microbial activity of a semiarid soil cultivated with atriplex nummularia lindl. in a field receiving saline waste during one and three years, in comparison with an area without crop and irrigation. soil cultivated during three years presented, during the dry season, values of ph, ce, and activity of fda hydrolyses higher than those registered in other areas. however, a negative correlation between the microbial carbon and values of qco2 was observed. the microbial biomass and the alkaline phosphates were also higher in the three years cultivated soil, in comparison with the native soil, non irrigated, confirming the role of halophytes for enhancing quality of soils under saline stress. thus, the cultivation of a. nummularia is an alternative for using saline waste from the desalinization process.
Atividade biológica em solo salino sódico saturado por água sob cultivo de Atriplex nummularia
Santos, Karen Cristina Fialho dos;Silva, Marina Steffane Lopes da;Silva, Luís Eduardo da;Miranda, Marcelo Alves;Freire, Maria Betania Galv?o dos Santos;
Revista Ciência Agron?mica , 2011, DOI: 10.1590/S1806-66902011000300007
Abstract: the salinity constitutes a serious limiting factor for agriculture, because most crops are sensitive to salinity, being much affected by the harmful effects of salts./ halophyte species of the genus atriplex are characterized by high tolerance to drought and soil salinity, a viable alternative to reduce negative impacts of salinity, associated with the microbial biomass./ therefore, the aim of this study was to assess the microbial activity in saline sodic soil of the agreste of pernambuco, in the presence and absence of plants of atriplex nummularia./ for that, there were samples of soil to 20 cm depth in different situations: 1 and 2) in the proximity of roots (20 cm from the stem of each plant) in treatments with and without pruning, 3 and 4) at the midpoint of plant spacing (125 cm) in treatments with and without pruning, 5) bare soil (control treatment), in the rainy season./ these samples were analyzed for c and n microbial biomass, basal respiration and c and n content of soils./ it was observed that the control treatment had different results compared with other treatments, indicating that without plants of atriplex the soil microbiota is highly affected by the high salt concentrations. there was also a tendency for increased microbial activity with proximity of pruned plant roots of atriplex, showing that, besides being a viable plant for phytoremediation of salinized soils, still promotes an improvement of soil microbes.
Atriplex Nummularia (Old Man Saltbush) : A Potential Forage Crop for Arid Regions of Botswana  [PDF]
A. A. Aganga,J. K. Mthetho,S. Tshwenyane
Pakistan Journal of Nutrition , 2003,
Abstract: Atriplex nummularia (Old man saltbush) is widely planted on salt affected land to provide a vegetative cover, which can be used as fodder reserve. Such plantations are also perceived as having the capacity to use saline groundwater and hence affect the extent of shallow water tables. Atriplex spp. contains high concentrations of nitrogen (N) in winter as compared to summer when it has high concentrations of sodium. The sum of soluble protein-N, amino acid-N, nucleic acid-N and nitrate-N is about half of the total nitrogen. The remainder includes non-soluble protein-N and other N associated with cell membranes and walls. Phosphorus is known to uniformly distribute among pools of inorganic-P, phytate-P, nucleic acid-P and other (residual) fractions. This paper reviews the potentials of A. nummularia as a forage for arid areas of Botswana with saline ground water.
Dinamica de íons em solo salino-sódico sob fitorremedia o com Atriplex nummularia e aplica o de gesso Dynamics of ions in saline-sodic soil under phytoremediation with Atriplex nummularia and gypsum applications  [cached]
Monaliza A. dos Santos,Maria B. G. dos S. Freire,Brivaldo G. de Almeida,Cíntia M. T. Lins
Revista Brasileira de Engenharia Agrícola e Ambiental , 2013,
Abstract: Desenvolveu-se este trabalho em um Cambissolo salino sódico do Perímetro Irrigado Cachoeira II, Serra Talhada, PE, com o objetivo de avaliar a dinamica de cátions e anions básicos em um solo salino sódico submetido a fitorremedia o com Atriplex nummularia e corre o com aplica o de gesso. Realizaram-se amostragens semestrais com quatro coletas de solo (0, 6, 12 e 18 meses). O delineamento experimental utilizado foi de blocos ao acaso avaliando-se quatro tratamentos: controle (sem nenhum manejo do solo), corre o química com gesso (sem cultivo) e dois com cultivo de Atriplex nummularia Lindl (espa amentos 1 x 1 m e 2 x 2 m), com quatro repeti es. Os resultados das análises do solo revelaram a contribui o da aplica o de gesso, especialmente do cultivo de plantas de atriplex na redu o dos teores de sais no solo. The study was conducted in a saline-sodic Inceptisol from the Cachoeira II Irrigation Perimeter, Serra Talhada (PE), with the objective of evaluating the dynamics of basic cations and anions in a saline-sodic soil subjected to phytoremediation with Atriplex nummularia and correction with application of gypsum. Samples were taken every six months, at four times (0, 6, 12 and 18 months). The experimental design was in randomized blocks, the four Treatments evaluated were: control (without any management practice), chemical correction with gypsum (no crop) and two Atriplex nummularia cultivation (1 x 1 m and 2 x 2 m plant spacing), with four replications. The results of soil analysis revealed the contribution of gypsum application and especially the cultivation of Atriplex plants in reducing the levels of salts in the soil.
Fitoextra??o de sais pela Atriplex nummularia lindl. sob estresse hídrico em solo salino sódico
Souza, Edivan R. de;Freire, Maria B. G. dos S.;Nascimento, Clístenes W. A. do;Montenegro, Abelardo A. de A.;Freire, Fernando J.;Melo, Hidelblandi F. de;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2011, DOI: 10.1590/S1415-43662011000500007
Abstract: this study aims to evaluate the growth, production and extraction of salts by atriplex grown on saline-sodic soil under water stress conditions and to compare soil properties before and after their cultivation. the experiment was carried out in a greenhouse during 134 days growing atriplex nummularia in pots with 20 kg of saline sodic soil with four levels of soil moisture (35, 55, 75 and 95% of field capacity) with a control (soil without plant). the experiment was performed in a randomized block with eight replications. the high concentrations of ca2+, mg2+, k+, and especially na+ and cl- in leaves of atriplex nummularia, associated with high dry matter production characterizes this species as phytoextraction of salts, extracting through leaf and stem: 644, 758, 1059 and 1182 kg ha-1 at 35, 55, 75 e 95% of field capacity, respectively. the variables of the exchangeable cations (ca2+, mg2+, k+, sum of bases) and total organic carbon remained stable between the beginning and end of the experiment in all treatments, while na+ and exchangeable sodium percentage decreased after cultivation of the plant. the atriplex responded to soil moisture with respect to biomass production and salts extraction.
Uso do rejeito da dessaliniza??o de água salobra para irriga??o da erva-sal (Atriplex nummularia)
Porto, Everaldo R.;Amorim, Míriam C.C. de;Silva Júnior, Luis G. de A.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2001, DOI: 10.1590/S1415-43662001000100020
Abstract: looking forward to reducing environmental impacts resulting from desalting brackish water in the region of the crystalline rocks in the semi-arid tropic of brazil, saltbush (atriplex nummularia) was cultivated during one year in an experimental field of embrapa semi-arid. the plants were irrigated with the brine from the desalting plant which presented a salt concentration of 11.38 ds m-1. each plant received 75 l of water per week, during 48 weeks. the soil salinity, at the depth of 0-90 cm, of the cropped area averaged 0.64 ds m-1 before starting the irrigation process. after the plants were harvested, the soil salinity in the same profile averaged 12.74 ds m-1. the saltbush yield was 6,537.00 kg ha-1 of dry matter with 18.4% crude protein in the foliage. the atriplex presented a great potential for extracting salt from the soil profile. however, when irrigated with concentrated brine, the amount of extracted salt from the soil profile by saltbush plants is in the order of 3.93% of the total amount of salt added by the irrigations. this implies that, for sustainable water management, it is necessary to generate more information about soil and water relationships for saltbush plants in the arid zones of brazil.
Rendimento da Atriplex nummularia irrigada com efluentes da cria??o de tilápia em rejeito da dessaliniza??o de água
Porto, Everaldo R.;Amorim, Miriam C. C. de;Dutra, Maria T.;Paulino, Renata V.;Brito, Luiza T. de L.;Matos, Ana N. B.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2006, DOI: 10.1590/S1415-43662006000100015
Abstract: looking forward to reduce environmental impacts resulting from desalinization of brackish water in the region of the crystalline rocks in the semi-arid brazil, saltbush (atriplex nummularia) was cultivated during one year with four different volumes of aquiculture effluent generated from an intensive tilapia (oreochromis sp) raising system, with a mean salinity of 8.29 ds m-1, in an experimental field of embrapa semi-arid. a completely randomized block design, with four treatments and three replications was used. the treatments t1, t2, t3 and t4 corresponded, respectively, to the weekly volumes of irrigation of 75, 150, 225 and 300 l of water per plant. the mean soil salinity of the cropped area, in the depth of 0 - 90 cm, was 0.40 ds m-1 before starting the irrigation process. after the plants were harvested, the mean soil salinity in the profiles was 8.02, 6.09, 4.97, and 4.60 ds m-1 for treatments t1, t2, t3 and t4, respectively. the saltbush dry matter yields were 9.75, 12.26, 14.49 and 13.81 t ha-1 for treatments t1, t2, t3 and t4, respectively. the highest dry matter production per unit of applied water was for treatment t1, which yielded 4.84 g l-1 of effluent. the same treatment had the best relation input/output of salt by the saltbush, removing 13.84% of the total salt incorporated into the soil.
Morphometry, Carcass Yield and Traits of Mexican Creole Goat Kids Slaughtered and Packed in a Federal Inspection Plant  [PDF]
M. Becerril-Herrera,O. Guzman-Pina,M. Alonso-Spilsbury,E.V. Dorsey-San Vicente
Journal of Biological Sciences , 2006,
Abstract: The objective of the present study was to evaluate the morphometry and carcass traits of Creole goats sacrificed and packed in a Federal Inspection Plant (FIP). The study was carried out in a FIP abattoir during May and June 2004. Fifty Creole male goats, 40 to 50 days old were used, brought form nearby family farms. Goats were transported without stops and they were not fed, nor provided with water. Carcasses were graded and 11 indicators were measured: both hot and cold carcass yields, cold carcass temperature, viscera weight, morphometry and pH, among others. When comparing the hot carcass weight with and without viscera (5.03 vs. 4.55), the values measured indicated that viscera represented 20.22% of the animals weight. The difference observed between hot carcass and cold carcass weight was 4.55 vs. 4.28 kg, respectively. Positive correlations were determined (R = 0.96) between hind-limbs (R = 0.65) and forelimbs (R = 0.69), as well as the one registered of both limbs with the hind and fore canes` perimeters. On the other hand, the abdominal and thoracic regions were highly correlated (R = 0.9). This is an indicator of the animal biotype, which shows that these animals are long linear with highly developed limbs. The pH mean of the hot carcass and the cold carcass was 6.06 and 5.97, respectively.
Page 1 /100
Display every page Item

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