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| Registros recuperados: 115 | |
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| Cartes,Paula; Jara,Alejandra A; Demanet,Rolando; Mora,María de la Luz. |
| Incubation studies were carried out to evaluate the effect of temperature and urea supply level on both the urease activity and the kinetics of N mineralization in two Andisols of Southern Chile. Our results showed that urease activity was higher in Piedras Negras soil (PNS) than Freiré soil (FS) at 24 and 48 h, and the enzyme was activated when the temperature increased from 5 to 21 °C. Urease activity followed a simple Michaelis-Menten kinetics. In PNS, the Michaelis Menten constant (Km) decreased, whereas the maximum enzyme reaction velocity (Vmax) and the catalytic efficiency increased when the temperature was raised up to 21 °C at 24 and 48 h of soil incubation. In FS, urease activity was the highest at 24 h, and it decreased at 48 h as a consequence... |
| Tipo: Journal article |
Palavras-chave: Urease activity; N mineralization; Urea; Andisols. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000100006 |
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| Sepulveda-Cuevas,Luisa A; Contreras-Villacura,Elsa G; Palma-Toloza,Carolyn L. |
| Colour abatement is a complex problem because the synthetic origin of the dyes used in the industry. The purpose of this study is to evaluate the feasibility of using Magellan peat (Sphagnum magallanicum) as an adsorbent of textile dyes, determining the physical-chemical characteristics of the peat by measuring the adsorptive capacity of the dyes as well as exploring the degrading potential of the native microorganisms they contain. The results obtained indicate that the peat has a specific surface area (BET) and a volume of 144.3 m² g-1 and 60% of meso- and macropores, respectively. The basicity of the peat surface is superior to acidity and the pH in which the neutrality is reached is about 3.1. Equilibrium concentrations for the basic, acid and reactive... |
| Tipo: Journal article |
Palavras-chave: Adsorption; Dyes; Textile effluents. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000200005 |
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| Cea,M; Cartes,P; Palma,G; Mora,M.L. |
| Atrazine, a herbicide used for the control of broadleaf weeds of different crops, was incorporated in ethylcellulose controlled release formulations (CRFs) by using the solvent evaporation technique. Allophanic clays and nanoclays were incorporated as matrix modifying agents. The formulations were characterized by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), and their behavior was determined in aqueous phase. Dissipation studies and soil columns experiments with CRFs were also carried out, and compared with commercial formulations (CFs). In addition, a short-term bioassay was performed to evaluate the effect of CRFs and CFs on the emergence and growth of field mustard (Brassica campestris L.) under greenhouse conditions. The matrix... |
| Tipo: Journal article |
Palavras-chave: Atrazine; Natural clays and nanoclays; Controlled release; Soil; Herbicidal activity. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912010000100007 |
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| Ribera,Alejandra E; Mora,Maria de la Luz; Ghiselini,Vanessa; Demanet,Rolando; Gallardo,Felipe. |
| We studied the phosphorous (P) and molybdenum (Mo) relationship in soil and red clover (Trifoliumpratense L.) in a non limed and limed acid Andisol of Southern Chile. In soil, we evaluated the effect of different liming (0 and 2000 mg kg-1), P (0, 200 and 400 mg kg-1), and Mo (0, 0.58 and 0.96 mg kg-1) doses supply on soil available Mo. In addition, the availability of P and Calcium (Ca) in treated soils was determinated. In red clover, we studied the Mo and P shoot concentrations and dry matter yield in response to the different treatments applied to the soil. Also, we measured the changes produced by Mo uptake in shoot Cu concentrations. The results showed that both, lime and more strongly P and Mo additions significantly (P ≥ 0.05) increased... |
| Tipo: Journal article |
Palavras-chave: Phosphorous; Molybdenum; Andisol; Red clover. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912010000100008 |
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| Alberto Ruiz,Hugo; Arruda Sampaio,Regynaldo; Oliveira,Maurício de; Afonso Ferreira,Paulo. |
| O objetivo deste trabalho foi avaliar a influência do parcelamento da lâmina de lixiviação sobre as características físicas de solos salino-sódicos. Cilindros foram preenchidos com amostras de solos: NEOSSOLO FLÚVICO (Ae1); NEOSSOLO FLÚVICO, coletado a 0-20 cm (Ae2-s) e 20-50 cm (Ae2-i) de profundidade, e VERTISSOLO (V). O gesso foi incorporado até 15 cm de profundidade, numa quantidade equivalente a 100% da necessidade de gesso para substituição do sódio trocável. O manejo de água consistiu na aplicação de solução de lixiviação com CaCl2 e MgCl2 de uma única vez e do mesmo volume parcelado em duas, quatro e seis vezes, respectivamente, com intervalos de 22 dias entre cada aplicação. Verificou-se que o gesso e a lâmina de lixiviação diminuíram a dispersão... |
| Tipo: Journal article |
Palavras-chave: Salinidade; Lixiviação de sais; Recuperação de solos. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912006000300001 |
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| Nissen M,Juan; Quiroz S,Cristian; Seguel S,Oscar; Mac Donald H,Roberto; Ellies Sch,Achim. |
| El objetivo principal de esta investigación fue determinar la conductividad hidráulica en fase no saturada en tres Andisoles bajo dos manejos bosque y praderas en s series Bramadero, Pemehue y Osorno, localizados en la VIIª, IXª y Xª Regiones de Chile, respectivamente. En muestras de suelo no alteradas se determinó la conductividad hidráulica en fase no saturada a distintas profundidades, mediante la metodología propuesta por Becher (1970), que combina la medición del potencial mátrico en el suelo y la aplicación de las ecuaciones de continuidad y de Darcy. Mediante mediciones de potencial mátrico, se monitoreó durante 95 días en laboratorio el proceso de secado en perfiles de suelo no alterados y en ausencia de un nivel freático artificial. Paralelamente,... |
| Tipo: Journal article |
Palavras-chave: Conductividad hidráulica no saturada; Movimiento de agua; Andisol. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912006000100003 |
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| Dec,Dorota; Dörner,José; Horn,Rainer. |
| In order to determine the effect of soil management on its thermal properties, undisturbed soil samples were taken from two tillage treatments (conventional and conservation treatment) at two depths (0-30cm and 30-60cm) of a Stagnic Luvisol (silt loam) before and after directly wheeling. The experimental field, located in Harste/Goettingen, Germany, was cultivated with sugar beet (Beta vulgaris). To calculate thermal properties of the soil, the volumetric water content (TDR needles) and temperature (pT 100 thermistors) during the simulation of the daily fluctuation of temperature were registered in laboratory and then the thermal conductivity, volumetric heat capacity and heat diffusivity were calculated following the damping depth method and the... |
| Tipo: Journal article |
Palavras-chave: Heat capacity; Heat conductivity; Thermal diffusivity; Tillage system. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000100003 |
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| Cosio G,Fernando; Negrón B,Mary; Gastó C,Juan; Villate G,Juan Luis. |
| En la Provincia Templada Secoestival Nubosa o Valparaíso, Secano de la Costa Central, se determinaron y caracterizaron los Distritos y Sitios, mediante el Sistema de Clasificación de Ecorregiones, propuesto por Gastó et al. (1993) y antecedentes adicionales presentados por Silva (1991) y Vallejos (2001), entre otros. La Capacidad de Uso en el área varía de: V en el Distrito Depresional (1,8%), de I a IV en el Distrito Plano (25%), de IV a VI en el Distrito Ondulado (32,4%), de VII a VIII en el Distrito Cerrano (39,6%) y, finalmente, VIII en el Distrito Montano (1,3%). Los Sitios del Distrito Depresional, son en su mayoría profundos con hidromorfismo permanente y alta salinidad-sodio; los Sitios del Distrito Plano son, en general, media-profundo con drenaje... |
| Tipo: Journal article |
Palavras-chave: Distrito geomorfológico; Sitio. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912007000100004 |
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| Curaqueo,Gustavo; Acevedo,Edmundo; Cornejo,Pablo; Seguel,Alex; Rubio,Rosa; Borie,Fernando. |
| Arbuscular mycorrhizal fungi (AMF) and their product glomalin (GRSP) play a decisive role in the soil aggregation, affecting the carbon (C) dynamics in agroecosystems. Tillage affects the AMF activity and GRSP content, influencing the stability and the soil C forms as well. The aim of this study was to compare the effect of no tillage (NT) and conventional tillage (CT) on: i) arbuscular mycorrhizal hyphal length and GRSP content; ii) the nature of soil organic matter by means of physical fractionation (free paniculate organic matter [fPOM]; occluded paniculate organic matter [oPOM] and mineral-associated soil organic matter [Mineral]), as well as chemical fractionation (fulvic acid, humic acid and humin), and iii) the relationships between AMF parameters,... |
| Tipo: Journal article |
Palavras-chave: Agroecosystem Glomalin Related Soil Protein; Mollisol Organic Matter Fractions Soil Aggregates. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912010000100002 |
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| Zhang,Y.L; Sun,Cc.X; Chen,L.J; Duan,Z.H. |
| An incubation test with black soil (Phaeozem), Albic soil (Albic Luvisols), brown soil (Cambisols), and cinnamon soil (Chromic Luvisol) from Northeast China was conducted under the conditions of 10%, 20% and30 % field capacity, and the kinetic parameters of soil urease, phosphatase, and arylsulphatase were determined, aimed to study the changes in the catalytic potential of these enzymes under different soil moisture conditions. All test enzymes exhibited typical Michaelis-Menten kinetic behaviors. The test enzymes exhibited the highest enzyme-substrate affinity (l/Km) at 20% or 30% field capacity. With increasing soil moisture content, the Fmax of test soil urease decreased, while that of soil phosphatase and arylsulphatase increased, with the maximum... |
| Tipo: Journal article |
Palavras-chave: Soil enzymatic kinetic parameters; Soil hydrolase; Soil moisture condition. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000200003 |
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| Alfaro,Marta; Salazar,Francisco. |
| In developed countries, intensive grazing has been related to water pollution. The results of several projects carried out on a volcanic soil of the Osorno soil series on beef grazing production systems have shown that grazing management did not increase total nitrogen (N) and phosphorus (P) transfer and losses. Due to the high water infiltration capacity of the soil, runoff was <1% of total drainage, therefore, N and P losses in runoff were small. Nitrogen leaching losses were high (3 up to 71 kg N ha-1 yr-1). Nitrogen loss in runoff was mainly lost as DON (c. 50%) while N leaching losses were mainly as nitrate (c. 70%). Total P losses ranged between 1 and 22 g P ha-1 yr-1 and they increased with increasing field slopes. Phosphorus was mainly lost as... |
| Tipo: Journal article |
Palavras-chave: Nitrogen; Phosphorus; Dairy production; Beef production; Environmental impact. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000200002 |
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| Hernández,Marcela; Morgante,Verónica; Flores,Cecilia; Villalobos,Patricio; González,Myriam; Miralles,Pola; Dinamarca,Alejandro; Seeger,Michael. |
| The extensive use of s-triazine herbicides in diverse countries causes environmental and health concern. Simazine and atrazine are s-triazines widely used in agriculture and forestry. Although, natural dissipation of s-triazines in soils by physicochemical processes has been described, the main mechanism for their removal is biological degradation by microorganisms. Bioremediation is a successful strategy for the removal of i-triazines in soil. For bioaugmentation processes, s-triazine-degrading bacteria are required, which isolation from agricultural soils was described in this report. Studies of s-triazine adsorption and leaching in soil are useful to determine the bioavailability of these herbicides. The detection of s-triazine-degrading catabolic... |
| Tipo: Journal article |
Palavras-chave: Í-triazine; Simazine; Biodegradation; Bioremediation; Herbicide. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000200004 |
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| Pérez,Aridio; Céspedes,Carlos; Núñez,Pedro. |
| Los beneficios de la aplicación de enmiendas orgánicas en la agricultura son conocidos a nivel mundial; sin embargo, existen muy pocos estudios sobre los contenidos nutricionales y actividad biológica de estos fertilizantes orgánicos. En República Dominicana estas enmiendas son aplicadas en la agricultura hace más de dos décadas; pero no han sido estudiadas. El objetivo de la investigación fue determinar las características física-químicas y microbiológicas de las enmiendas orgánicas de mayor uso en República Dominicana, así como las fuentes utilizadas para su preparación. Las muestras de enmiendas orgánicas fueron recolectadas en las localidades de Jarabacoa, Espaillat, La Vega y Montecristi durante el periodo enero del 2005 a julio 2006. En total se... |
| Tipo: Journal article |
Palavras-chave: Propiedades físicas; Químicas; Biológicas; Suelo; Enmiendas orgánicas; Compost. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912008000300002 |
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| Mello Prado,Renato de; Ferreira Frade Junior,Elízio; Rinaldi Mouta,Ernesto; Cássia Gomes São João,Andréia de; Savério Souza Costa,Roberto. |
| Objetivou-se avaliar o desenvolvimento inicial e a nutrição da cultura do trigo ( Triticum aestivum L.) em função da aplicação de zinco (Zn) via sementé. O delineamento experimental foi o de blocos inteiramente casualizados, com fatorial 4 x 2+1, sendo [quatro doses de Zn, 100; 200; 400 e 800 g por 100 kg de sementé e duas Zn fontes, ZnS0(4) e ZnO] e tres repeticoes. Avaliou-se o índice de velocidade de emergencia, a altura media das plântulas, a materia seca em folhas e raizes e o teor e o acumulo de Zn das plântulas e o índice de eficiencia de absorção. A aplicação de zinco ñas sementes de trigo afetou o estado nutricional e a produção de materia seca das plântulas. As plântulas apresentaram maior eficiencia de absorção quando o Zn foi fornecido na forma... |
| Tipo: Journal article |
Palavras-chave: Triticum aestivum L.; Micronutrientes; Tratamento de sementes; Nutrição mineral de plantas. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912007000200003 |
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| Registros recuperados: 115 | |
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