ABSTRACT The use of fire to prepare agricultural areas is a technique still used by small farmers in eastern Amazon. This type of management changes the dynamics of soil nutrients, especially phosphorus, which constitutes the most limiting nutrient for crop production in tropical soils. This study was carried out to evaluate changes in phosphorus forms in an Argissolo Amarelo Distrófico (Ultisol) submitted to burning and trituration of secondary forest in eastern Amazon. The evaluated systems were: slash-and-burn of vegetation; slash-and-mulch […]

ABSTRACT Diffuse reflectance spectroscopy (DRS) is a fast and cheap alternative for soil clay, but needs further investigation to assess the scope of application. The purpose of the study was to develop a linear regression model to predict clay content from DRS data, to classify the soils into three textural classes, similar to those defined by a regulation of the Brazilian Ministry of Agriculture, Livestock and Food Supply. The DRS data of 412 soil samples, from the 0.0-0.5 m layer, […]

ABSTRACT Increasing attention has recently been given to sweet sorghum as a renewable raw material for ethanol production, mainly because its cultivation can be fully mechanized. However, the intensive use of agricultural machinery causes soil structural degradation, especially when performed under inadequate conditions of soil moisture. The aims of this study were to evaluate the physical quality of a Latossolo Vermelho Distroférrico (Oxisol) under compaction and its components on sweet sorghum yield forsecond cropsowing in the Brazilian Cerrado (Brazilian tropical […]

ABSTRACT The study of soil chemical and physical properties variability is important for suitable management practices. The aim of this study was to evaluate the spatial variability of soil properties in the Malhada do Meio settlement to subsidize soil use planning. The settlement is located in Chapadinha, MA, Brazil, and has an area of 630.86 ha. The vegetation is seasonal submontane deciduous forest and steppe savanna. The geology is formed of sandstones and siltstones of the Itapecuru Formation and by […]

ABSTRACT Soil organic matter is an important primary source of nutrients for plants and influences infiltration, water retention, susceptibility to erosion, and soil aggregation. However, this process is conditioned on the quality and quantity of organic matter supplied. The objective of this study was to evaluate the influence of the environmental disaster caused by rain in areas of horticulture production in the mountainous region of Rio de Janeiro. The following areas were selected: A1- no impact (control); A2 – totally […]

ABSTRACT The removal of thick layers of soil under native scrubland (Cerrado) on the right bank of the Paraná River in Selvíria (State of Mato Grosso do Sul, Brazil) for construction of the Ilha Solteira Hydroelectric Power Plant caused environmental damage, affecting the revegetation process of the stripped soil. Over the years, various kinds of land use and management systems have been tried, and the aim of this study was to assess the effects of these attempts to restore the […]

ABSTRACT Conversion of a natural condition to agricultural use can impose changes in soil properties and processes and bring environmental consequences to the region this agricultural use encompasses. The aim of this study was to evaluate the physical quality of the soil in agricultural areas of municipalities around Sobradinho Lake, a semiarid region in the State of Bahia, using multivariate analysis statistical techniques as a tool. Initially, descriptive statistical analysis and correlation analysis techniques and the normality test were applied, […]

ABSTRACT Accumulation of nutrients and surface compaction have been reported after a long time under a no-tillage system. The aim of this study was to evaluate soil chemical properties, bulk density, and crop yield following a single mechanical intervention associated with liming in a clayey Oxisol under a NT system for 17 consecutive years in Pato Branco, southwestern Paraná, Brazil. A randomized block experimental design was used in a split-plot arrangement, with plowing and harrowing of the soil in the […]

In the Jalapão region, State of Tocantins, Brazil, there are large contiguous areas of Neossolos Quartzarênicos (Tropsamments). Golden grass (Syngonanthus nitens) is a native species widely used as material for handicrafts in the region, and it is therefore of great importance for the local economy. The aim of this study was to analyze the relationship between soil physical and chemical properties and golden grass yield in Campos Limpos Úmidos within Jalapão State Park (Parque Estadual do Jalapão). We collected soil […]

The number of machine passes, types of wheels, and high soil moisture during harvest operations affect the soil compaction process. The impacts of these factors and alternatives to reduce them must be better understood. This study evaluated the impact of different traffic intensities of a loaded forwarder and the effect of different management conditions of eucalyptus harvest residues on productivity, soil physical properties, and organic matter at the end of the subsequent rotation in two Oxisols in the State of […]