The phenomenon of dispersion of soil clay can be caused by the quality of irrigation water. This study investigated the effect of irrigation water with different electric conductivities (EC), combined with different Sodium Adsorption Relation (SAR) values on clay dispersion in soil commonly found in the state of Minas Gerais, with different mineralogies. The samples were collected from the B horizon of three soils (Oxisols) in Viçosa, Belo Horizonte and Barroso, respectively, with high levels of the clay minerals kaolinite, […]

Eucalyptus grandis and other clonal plantations cover about 3.5 million ha in Brazil. The impacts of intensively-managed short-rotation forestry on soil aggregate structure and Carbon (C) dynamics are largely undocumented in tropical ecosystems. Long-term sustainability of these systems is probably in part linked to maintenance of soil organic matter and good soil structure and aggregation, especially in areas with low-fertility soils. This study investigated soil aggregate dynamics on a clay soil and a sandy soil, each with a Eucalyptus plantation […]

Structural changes caused by management systems to soil can result in compaction and may change crop root development. With the aim to evaluate the effects of the farming systems on the soil structure by qualitative (cultural profile) and quantitative (soil density) methodologies, a field study was carried out in Maringá, state of Paraná, Brazil (23 º 29 ‘ S, 51 º 59 ‘ W). A conventional tillage system with crop succession of corn (Zea mays L.) and soybean (Glycine max) […]

The ability of a soil to keep its structure under the erosive action of water is usually high in natural conditions and decreases under frequent and intensive cultivation. The effect of five tillage systems (NT = no-till; CP = chisel plowing and one secondary disking; CT = primary and two secondary distings; CTb = CT with crop residue burning; and CTr = CT with removal of crop residues from the field), combined with five nutrient sources (C = control, no […]

The soil quality of a crop-livestock system can change according to the pasture and soil management. This research was carried out in Otacilio Costa, Santa Catarina State, southern Brazil, on a Humic Cambisol previously used with native grass pasture for 9 years, desiccated in May 2003, for use with ryegrass (Lolium multiflorum) pasture in the winter and corn in the summer. A split plot design was used, consisting of pasture management systems and soil tillage systems prior to the summer […]

The maintenance and improvement of soil quality are crucial to the stability, sustainability and productivity of natural ecosystems and agroecosystems. The understanding and quantification of the impact of tillage systems in their physical quality are fundamental in the development of sustainable agricultural systems. This study was carried out to evaluate the effects of management practices on physical properties and organic matter content of an Ultisol cultivated with cassava following the use of distinct cover crops. A field experiment was carried […]

The S index corresponds to the slope of the soil water retention curve at its inflection point. A high S value indicates the presence of structural pores, which are essential for a good soil physical condition. The objective of this study was to evaluate the sensitivity of the index of soil physical quality (S), as proposed in the literature for some physical properties of soils from Southern Brazil. In the seven soils used here, no relationship was found between clay […]

The soil compaction, induced by different traffic intensities, can cause damage in the soil structure, reducing the coffee plantation production. The objectives of this study was to develop a model of load support capacity for a Red Latosol (Oxisol) under Cerrado and under coffee and to investigate the effect of coffee plantation management on soil pore distribution and soil water retention, in different sampling positions in the coffee plantation. The stud site is located at 18 º 59 ‘ 15 […]

The identification of impacts of mechanized sugarcane harvesting on the structure in different soil classes can be an important strategy to minimize compaction effects. The objective of this study was to evaluate the structural changes, preconsolidation pressure and least limiting water range (LLWR) in a Red-Yellow Latosol (LVA) and a Haplic Cambisol (CX), due to harvest operations at different periods during the sugar cane harvesting season. Undisturbed soil samples were collected in the layer 0 to 0.05 m to determine […]

The physical, chemical and biological properties of soils of reconstructed areas after coal mining are altered. This study aimed to evaluate liming, mineral and organic fertilizers and revegetation effects on the physical properties of a reconstructed soil after open-pit mining. The experiment was carried out in a former mine in Lauro Müller County – SC, in southern Brazil, from 2001 to 2005. The site was mined in 1991 and reconstructed in 1995. A randomized complete block design was used, with […]