Risk of land salinization in baixo Acaraú, Ceará
01/Aug/2012
Certain conditions of relief, climate and use can lead to the formation of saline and sodic soils, also called salt-affected soils. With a view to establish guidelines for management practices and land use in the region of Baixo Acaraú, Ceará, the purpose of this work was to generate a map of salinization risk. To classify levels of vulnerability, the pedology, geology, geomorphology and land use/cover were evaluated as well as slope altimetry information, treated in a GIS environment with an […]
Heavy metals in soils and plants in mango orchards in Petrolina, Pernambuco, Brazil
01/Aug/2012
The monitoring of heavy metal concentrations in areas under intensive agriculture is essential for the agricultural sustainability and food safety. This paper evaluates the total contents of heavy metals in soils and mango trees in orchards of different ages (6, 7, 8, 9, 10, 11, 14, 16, 17, 19, and 26 years) in Petrolina, Pernambuco, Brazil. Soil samples were taken from the layers 0-20 cm and 20-40 cm, and mango leaves were collected in the growth stage. Areas of native […]
Magnetic susceptibility to identify landscape segments on a detailed scale in the region of Jaboticabal, São Paulo, Brazil
01/Aug/2012
The agricultural potential is generally assessed and managed based on a one-dimensional vision of the soil profile, however, the increased appreciation of sustainable production has stimulated studies on faster and more accurate evaluation techniques and methods of the agricultural potential on detailed scales. The objective of this study was to investigate the possibility of using soil magnetic susceptibility for the identification of landscape segments on a detailed scale in the region of Jaboticabal, São Paulo State. The studied area has […]
Evaluation and quantification of the fractions silt, sand and clay by diffuse reflectance spectroscopy
01/Aug/2012
Routine tests to determine physical and chemical soil properties have been used for several years. However, due to economic and environmental problems, new assessment methods must be developed. In this context, diffuse reflectance spectroscopy is a promising and quick tool in the determination of these properties. The objective of this work was to study the spectral behavior of the silt, sand and clay fractions and evaluate the possibility of quantifying these properties with regression models generated for each individual element. […]
Isolation and identification of endophytic and epiphiytic bacteria in sugarcane in areas with and without termiticide
01/Aug/2012
The exploration and knowledge of bacteria-plant interaction mechanisms may be used for a more sustainable production of several crops, e.g., of sugarcane. The objective of this paper was to isolate bacteria associated with sugarcane with the ability to fix nitrogen and solubilize inorganic phosphate in areas with and without the application of termiticide. Endophytic bacteria were isolated from leaves and roots and from the rhizoplane, four months after planting of three commercial sugarcane varieties (RB 92579, RB 867515 and RB […]
Nitrogen balance in soil under eucalyptus plantations
01/Aug/2012
An understanding of the role of organic nitrogen (N) pools in the N supply of eucalyptus plantations is essential for the development of strategies that maximize the efficient use of N for this crop. This study aimed to evaluate the distribution of organic N pools in different compartments of the soil-plant system and their contributions to the N supply in eucalyptus plantations at different ages (1, 3, 5, and 13 years). Three models were used to estimate the contributions of […]
Critical slope length for water erosion for three crop residue types and rates in two sowing directions in no-till
01/Aug/2012
Under conservation tillage systems, the effectiveness of crop residues in reducing water erosion decreases if the mulch is carried away by runoff and/or if the runoff furrows the soil. This phenomenon is called mulch failure, characterizing the critical slope length, i.e., the distance on the ground after which the runoff shear stress is sufficient to overcome the resistance of the mulch to be carried away and/or the resistance of the soil to furrowing. The objective of this study was to […]
Replication of an IVG protocol to estimate bioaccessible arsenic in materials from a gold mining area in Brazil
01/Aug/2012
Tests for bioaccessibility are useful in human health risk assessment. No research data with the objective of determining bioaccessible arsenic (As) in areas affected by gold mining and smelting activities have been published so far in Brazil. Samples were collected from four areas: a private natural land reserve of Cerrado; mine tailings; overburden; and refuse from gold smelting of a mining company in Paracatu, Minas Gerais. The total, bioaccessible and Mehlich-1-extractable As levels were determined. Based on the reproducibility and […]
Variability and spatial correlation among micronutients and organic matter and yield of black pepper
01/Aug/2012
Studies on the spatial variation of soil properties associated with the response of crop yields may contribute to a rational application of inputs, enabling economic and environmental gains. The purpose of this work was to evaluate the variability and spatial correlations among soil Fe, Cu, Zn, Mn, and organic matter contents and yield of black pepper grown on a Yellow-Red Latosol. The study was carried out on a black pepper plantation under microsprinkler irrigation, in São Mateus, State of Espirito […]
Mineralogy and genesis of argisols (ultisols) from Serra do Tabuleiro/Itajaí, Santa Catarina state, Brazil
01/Aug/2012
The crystalline shield rocks that outcrop in the central-east and north-east of the state of Santa Catarina lie in a strong and wavy relief characterizing the northern Santa Catarina Coastal Mountains. The irregular surface results from the magmatic metamorphic cycles of the crust, responsible for the reworking of ancient rocks formed from the Archean to the Proterozoic. This compartment consists of metamorphic rocks while information about genesis and mineralogical composition of the soils derived from it are scarce, motivating this […]