Volume 39, Number 2, 2015

Biochar (carbonized biomass for agricultural use) has been used worldwide as soil amendment and is a technology of particular interest for Brazil, since its “inspiration” is from the historical Terra Preta de Índios (Amazon Dark Earth), and also because Brazil is the world’s largest charcoal producer, generating enormous residue quantities in form of fine charcoal and due to the availability of different residual biomasses, mainly from agroindustry (e.g., sugar-cane bagasse; wood and paper-mill wastes; residues from biofuel industries; sewage sludge […]

Ironstones or petroplinthites are common materials in soils under humid tropical climate, generally defined as the result of Fe oxide accumulation in areas where the water table oscillates, and may exhibit considerable morphological variability. The aim of this study was to examine the internal structure and porosity of an ironstone fragment from a Petroferric Acrudox in Minas Gerais, Brazil, by computed tomography (CT) and conventional techniques. The sample analyzed had total porosity of 59.5 %, with large macropores in the […]

In a soil survey, a detailed description of a set of soil properties is important for analyzing and understanding the interactions of several soil forming processes. Thus, multivariate analysis may be an important statistical tool to better interpret and understand the relationships and similarities between pedons. The aim of this study was to differentiate and group similar pedons based on physical and chemical properties using multivariate statistics. The study was carried out in Lages, SC, Brazil, at 27º 48’ S […]

The olive tree is a temperate climate plant, whose fructification requires low temperatures before flowering. The production of good quality seedling material is essential for establishing an orchard, and association with arbuscular mycorrhizal fungi (AMF) can be very important in this respect. In Brazil, there are no studies related to the use of AMF in olive seedling production. The aim of this study was to evaluate the effect of the use of different AMF species on the development of seedlings […]

Biological N fixation in forage legumes is an important alternative to reduce pasture degradation, and is strongly influenced by the inoculant symbiotic capability. This paper evaluates the effectiveness of Calopo (Calopogonium mucunoides) rhizobial isolated from soil under three vegetation covers of an Argissolo Vermelho-Amarelo of the Dry Forest Zone of Pernambuco. An experiment was conducted evaluating 25 isolates, aside from 5 uninoculated controls with 0; 309; 60; 90 and 120 kg ha-1 N, and a treatment inoculated with the SEMIA […]

Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to […]

Sorghum bicolor (L.) Moech is an important high production forage crop that is increasingly used in Brazil, though still slow in replacing growing of second crop maize. Growing sorghum during the dry season would be an alternative for silage production and its use in the rainy season. However, plant growth and development will be affected if alterations occur in the texture, porosity, and structure of the soil. The objective of this study was to analyze the spatial variability and linear […]

Under field conditions in the Amazon forest, soil bulk density is difficult to measure. Rigorous methodological criteria must be applied to obtain reliable inventories of C stocks and soil nutrients, making this process expensive and sometimes unfeasible. This study aimed to generate models to estimate soil bulk density based on parameters that can be easily and reliably measured in the field and that are available in many soil-related inventories. Stepwise regression models to predict bulk density were developed using data […]

Soil compaction has been recognized as a severe problem in mechanized agriculture and has an influence on many soil properties and processes. Yet, there are few studies on the long-term effects of soil compaction, and the development of soil compaction has been shown through a limited number of soil parameters. The objectives of this study were to evaluate the persistence of soil compaction effects (three traffic treatments: T0, without traffic; T3, three tractor passes; and T5, five tractor passes) on […]

To run a consolidation test, it is necessary to use a consolidometer. This equipment, however, had not been produced and sold in Brazil until some years ago. Non-automatic models available for import, although of low cost, are nevertheless rustic and need continuous calibration of pressure levels during the consolidation test. The exclusiveness and intervention of a technician throughout the test, associated with the precarious acquisition of data in these models, are still major factors that have made consolidation of this […]