3290 results

Chemical and microbiological attributes of an oxisol treated with successive applications of sewage sludge

José Rafael Pires Bueno, Ronaldo Severiano Berton, Adriana Parada Dias da Silveira, Marcio Koiti Chiba, Cristiano Alberto de Andrade, Isabella Clerici De Maria

01/Aug/2011

Studies on sewage sludge (SS) have confirmed the possibilities of using this waste as fertilizer and/or soil conditioner in crop production areas. Despite restrictions with regard to the levels of potentially toxic elements (PTE) and pathogens, it is believed that properly treated SS with low PTE levels, applied to soil at adequate rates, may improve the soil chemical and microbiological properties. This study consisted of a long-term field experiment conducted on a Typic Haplorthox (eutroferric Red Latosol) treated with SS […]

Water retention in a peatland with organic matter in different decomposition stages

José Ricardo da Rocha Campos, Alexandre Christófaro Silva, José Sebastião Cunha Fernandes, Mozart Martins Ferreira, Daniel Valladão Silva

01/Aug/2011

Peatlands are ecosystems formed by successive pedogenetic processes, resulting in progressive accumulation of plant remains in the soil column under conditions that inhibit the activity of most microbial decomposers. In Diamantina, state of Minas Gerais, Brazil, a peatland is located at 1366 m asl, in a region with a quartz-rich lithology and characteristic wet grassland vegetation. For this study, the peat area was divided in 12 transects, from which a total of 90 soil samples were collected at a distance […]

Chemical dispersion in particle size analysis of latosols

Jocimar Mauri, Hugo Alberto Ruiz, Raphael Bragança Alves Fernandes, João Carlos Ker, Luiz Rogério Martins Rezende

01/Aug/2011

The complete sample dispersion and maintenance of stability in the dispersed phase are fundamental for a greater accuracy in soil texture analysis. For this purpose, Na+ and Li+ compounds were tested as alternative chemical dispersants, compared to a 10 mmol L-1 NaOH solution, for the possibility of a more effective dispersion and to minimize the presence of pseudo components, basically pseudo-silt, in the particle size analysis of Oxisols. Eight samples of Oxisols from the State of Minas Gerais, selected for […]

Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems

Ben-Hur Costa de Campos, Telmo Jorge Carneiro Amado, Cimélio Bayer, Rodrigo da Silveira Nicoloso, Jackson Ernani Fiorin

01/Jun/2011

Soil organic matter (SOM) plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years) of tillage (CT-conventional tillage and NT-no tillage) and crop rotations (R0-monoculture system, R1-winter crop rotation, and R2- intensive crop rotation) on total, particulate and mineral-associated organic carbon (C) stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa […]

Attributes of irrigated rice as affected by soil sodicity and potassic fertilizer application

Felipe de Campos Carmona, Ibanor Anghinoni, Marquel Jonas Holzschuh, Amanda Posselt Martins

01/Jun/2011

Soils of the coastal plains of Rio Grande do Sul, Brazil, are affected by salinization, which can hamper the establishment and development of crops in general, including rice. The application of high doses of KCl may aggravate the crop damage, due to the high saline content of this fertilizer. This study aimed to evaluate the effect of K fertilizer management on some properties of rice plant, grown in soils with different sodicity levels, and determine which attribute is best related […]

Decomposition and nutrient release from millet and sorghum biomass

Michelle Barbosa Teixeira, Arcângelo Loss, Marcos Gervasio Pereira, Carlos Pimentel

01/Jun/2011

Millet can be used as cover crop and enhance nutrient cycling in low-fertility soils. The aim of this study was to evaluate the decomposition rate and nutrient release from shoot residues of millet and sorghum left on the soil surface. The treatments consisted of pearl millet (cultivars ENA 2 and BRS 1501), and sorghum (hybrid BRS 310) plants. After cutting, at the end of the cycle, the shoot samples were placed in decomposition bags distributed on the plot surface. Plant […]

Sunflower production under saline stress and nitrogen fertilization

Reginaldo Gomes Nobre, Hans Raj Gheyi, Frederico Antonio Loureiro Soares, José Alberto Ferreira Cardoso

01/Jun/2011

The limited availability of low-salinity water in Brazilian semiarid region causes producers to use water of moderate to high salinity for irrigation. In view of the increasing importance of sunflower (Helianthus annuus L.) in this region as a potential source of renewable energy, this study was conducted to evaluate sunflower crops irrigated with different water salinity levels (ECw) and fertilized with nitrogen. The experiment was conducted in a greenhouse of the Federal University of Campina Grande (UFCG), from July to […]

Nitrogen fertilizer use efficiency, recovery and leaching of an alexandergrass pasture

Laércio Ricardo Sartor, Tangriani Simioni Assmann, André Brugnara Soares, Paulo Fernando Adami, Alceu Luiz Assmann, Christiano Santos Rocha Pitta

01/Jun/2011

Nitrogen usually determines the productive potential of forage crops, although it is highly unstable in the environment. Studies on recovery rates and use efficiency are important for more reliable fertilizer recommendations to reduce costs and avoid environmental pollution. The purpose of this study was to evaluate N use efficiency and recovery rate of Alexandergrass pasture (Brachiaria – Syn. Urochloa plantaginea) as well as N-NO3– and N-NH4+ soil concentrations using different levels of N fertilization under two grazing intensities. The experiment […]

Soil and water losses by erosion after land use change, in relation to two tillage methods and two fertilization types

Tatiane Bagatini, Neroli Pedro Cogo, Luciléia Gilles, Jeane Cruz Portela, Gustavo Portz, Henrique Thomas Queiroz

01/Jun/2011

A change in the type of land use, if not properly planned and conducted, may result in soils with diminished production capacity and increased erosion susceptibility, which will reduce crop yields and hamper soil and water conservation. This study had the purpose of investigating the soil erosion caused by rainfall in an originally native pasture area, in the second and third year of cultivation of two annual row crops (respectively, cowpea – Vigna unguiculata – and shorgum – Shorgum bicolor), […]

Computer-assisted cartography using topographic properties: precision and accuracy of local soil maps in central Mexico

Gustavo Cruz-Cárdenas, Carlos Alberto Ortiz-Solorio, Enrique Ojeda-Trejo, Juan Felipe Martínez-Montoya, Erasto Domingo Sotelo-Ruiz, Atenogenes Leobardo Licona-Vargas

01/Jun/2011

Map units directly related to properties of soil-landscape are generated by local soil classes. Therefore to take into consideration the knowledge of farmers is essential to automate the procedure. The aim of this study was to map local soil classes by computer-assisted cartography (CAC), using several combinations of topographic properties produced by GIS (digital elevation model, aspect, slope, and profile curvature). A decision tree was used to find the number of topographic properties required for digital cartography of the local […]

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