280 results

Characterization of Exopolysaccharides Produced by Rhizobia Species

Tereza Cristina Luque Castellane, Alda Maria Machado Bueno Otoboni, Eliana Gertrudes de Macedo Lemos

01/Dec/2015

ABSTRACT Increasing attention has been given, over the past decades, to the production of exopolysaccharides (EPS) from rhizobia, due to their various biotechnological applications. Overall characterization of biopolymers involves evaluation of their chemical, physical, and biological properties; this evaluation is a key factor in understanding their behavior in different environments, which enables researchers to foresee their potential applications. Our focus was to study the EPS produced by Mesorhizobium huakuii LMG14107, M. loti LMG6125, M. plurifarium LMG11892, Rhizobium giardini bv. giardini […]

Herbicide use in Degraded Forest Areas in Restoration: Effects on Soil Invertebrate Biota

Rafael Nogueira Scoriza, Alessandro de Paula Silva, Maria Elizabeth Fernandes Correia, Paulo Sérgio dos Santos Leles, Alexander Silva de Resende

01/Dec/2015

ABSTRACT Chemical control of weeds is an effective method used in planted forests and in forest restoration, which plays an important role in development of forest seedlings and reduces costs of intervention. However, when this strategy is not properly applied, it may have negative impacts on soil organisms and on the ecological processes in which they take part. The goal of this study was to evaluate the effects of herbicide use on soil biota through sampling of the soil fauna […]

Microbiological Indicators of Pasture Soil with Successive Applications of Pig Slurry

Danni Maisa da Silva, Zaida Inês Antoniolli, Rodrigo Josemar Seminoti Jacques, Andressa de Oliveira Silveira, Diego Armando Amaro da Silva, Magnus Maurício Rache, [...]

01/Dec/2015

ABSTRACT Pig slurry use as soil fertilizer is a common practice in southern Brazil. In spite of the benefits of reusing waste, this practice poses serious environmental risks. Microbiological indicators of soil quality are very sensitive and allow soil environment conditions to be monitored. The aim of this study was to evaluate the microbiological quality of pasture soils with different histories of successive use of pig slurry. Determinations were made of C content in the microbial biomass, soil microbial respiration, […]

Initial Development of Two Sugarcane Varieties Inoculated with Diazotrophic Bacteria

Valfredo Almeida Chaves, Silvana Gomes dos Santos, Nivaldo Schultz, Willian Pereira, Jailson Silva Sousa, Rafael Cassador Monteiro, [...]

01/Dec/2015

ABSTRACT Sugarcane is one of the most important crops in the economy due to production of sugar, ethanol, and energy. Technologies are necessary to improve its yield and quality with minimum damage to the environment. We evaluated the indole acetic acid production and germination in the sugarcane varieties RB867515 and IACSP95-5000 after inoculation with five strains of diazotrophic bacteria. The production of indole acetic acid was assayed through the colorimetric method using the Salkowski reagent. To evaluate germination, an experiment […]

Least Limiting Water Range and Load Bearing Capacity of Soil under Types of Tractor-Trailers for Mechanical Harvesting of Green Sugarcane

Antonio Higino Frederico Pereira, Antonio Carlos Tadeu Vitorino, Eber Augusto Ferreira do Prado, Anderson Cristian Bergamin, Munir Mauad, Heverton Ponce Arantes

01/Dec/2015

ABSTRACT The expansion of the sugarcane industry in Brazil has intensified the mechanization of agriculture and caused effects on the soil physical quality. The purpose of this study was to evaluate the limiting water range and soil bearing capacity of a Latossolo Vermelho distroférrico típico (Rhodic Hapludox) under the influence of different tractor-trailers used in mechanical sugarcane harvesting. The experiment was arranged in a randomized block design with five replications. The treatments consisted of green sugarcane harvesting with: harvester without […]

Influence of Organic Matter on Mean Size of Clay Minerals in Basalt Soils in Southern Brazil

Daniel Hanke, Vander de Freitas Melo, Jeferson Dieckow, Deborah Pinheiro Dick, Itamar Antônio Bognola

01/Dec/2015

ABSTRACT The interaction of organic compounds with clay minerals can change the size of crystals. However, in soils this effect is still unclear because of limitations in separation of pure mineral phases for conducting dissolution experiments. In this study, the relationship between soil organic matter (SOM) and mean crystallite size (MCS) of clay minerals from surface and subsurface horizons of soils from a toposequence in Southern Brazil was evaluated. Soil C and N contents were determined and the nature of […]

Carbon and Nitrogen Dynamics under Eucalyptus Plantations in Southern Brazil

Charlote Wink, Dalvan José Reinert, Carlos Gustavo Tornquist, Ivo Ribeiro Silva

01/Dec/2015

ABSTRACT The expansion of eucalyptus plantations in southern Brazil, especially over regions with natural grasslands, which occurred in the last decade potentially changes total organic carbon and nitrogen in soil. The aim of this study was to test the Century model 4.5 in the simulation of changes in inventories of TOC and TN in the surface layer (0.0-0.2 m) soil in Eucalyptus sp. com different ages in three municipalities in Rio Grande do Sul State, Brazil. Areas adjacent to grasslands […]

Water Balance Components in Covered and Uncovered Soil Growing Irrigated Muskmelon

Paulo Leonel Libardi, Jaedson Cláudio Anunciato Mota, Raimundo Nonato de Assis, Alexsandro dos Santos Brito, Joaquim Amaro

01/Sep/2015

ABSTRACT Knowledge of the terms (or processes) of the soil water balance equation or simply the components of the soil water balance over the cycle of an agricultural crop is essential for soil and water management. Thus, the aim of this study was to analyze these components in a Cambissolo Háplico (Haplocambids) growing muskmelon (Cucumis melo L.) under drip irrigation, with covered and uncovered soil, in the municipality of Baraúna, State of Rio Grande do Norte, Brazil (05º 04’ 48” […]

Estimate of Groundwater Recharge Based on Water Balance in The Unsaturated Soil Zone

Davi de Carvalho Diniz Melo, Edson Wendland, Rafael Chaves Guanabara

01/Sep/2015

ABSTRACT Groundwater management depends on the knowledge on recharge rates and water fluxes within aquifers. The recharge is one of the water cycle components most difficult to estimate. As a result, despite the chosen method, the estimates are subject to uncertainties that can be identified by means of comparison with other approaches. In this study, groundwater recharge estimates based on the water balance in the unsaturated zone is assessed. Firstly, the approach is evaluated by comparing the results with those […]

Filter Paper Method for the Determination of the Soil Water Retention Curve

Eurileny Lucas de Almeida, Adunias dos Santos Teixeira, Francisco Chagas da Silva, Raimundo Nonato de Assis, Raimundo Alípio de Oliveira Leão

01/Sep/2015

ABSTRACT High cost and long time required to determine a retention curve by the conventional methods of the Richards Chamber and Haines Funnel limit its use; therefore, alternative methods to facilitate this routine are needed. The filter paper method to determine the soil water retention curve was evaluated and compared to the conventional method. Undisturbed samples were collected from five different soils. Using a Haines Funnel and Richards Chamber, moisture content was obtained for tensions of 2; 4; 6; 8; […]

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