Both soil conservation and crop productivity may negatively be affected by changes caused to soil characteristics by management techniques. The objective of this study was to evaluate the influence of soil tillage on soil physical attributes and organic carbon contents. The experiment was carried out over a period of 17 years in Eldorado do Sul County (RS) in a loamy Acrisol under different management systems: conventional tillage, reduced tillage and no-tillage, using vetch-maize in crop succession. An area of native […]

Cover crops along with proper soil management recover or maintain soil physical properties such as aggregation. The objective of this study was to determine the effect of cropping systems, cover crops, and soil organic matter (SOM) content on the temporal variation of soil aggregation in an Hapludalf in its natural state and under different cropping systems. The experiment was conducted at the experimental station of the Soil Department of the UFSM, Brazil. Undisturbed soil samples were collected in 60 day-intervals throughout […]

Latosols (Oxisols) under cerrado vegetation have been intensively incorporated into the agricultural production process. However, studies involving soil quality in this environment are scarce. The objective of this work was to verify alterations on aggregation attribute indicators of soil quality, as a result of the management systems adopted for the native cerrado, and to select the best attributes indicating such alterations. The samples were collected at depths of 0-10, 10-20, and 20-40 cm from a typic Dystrophic Red Latosol (Oxisol) […]

The cellulose and paper industry discards residues of varied chemical composition on a large scale. Some of these residues are being used by farmers for the adjustment of soil acidity, since they contain hydroxide. However, there are no recommendations on quantities or reapplications. Possible consequences are clay dispersion, reduction of the aggregate stability and the imbalance of nutrients, degrading the physical and chemical soil properties. This study evaluated the physical and chemical properties of two soils incubated with alkaline residues […]

Tropical soils under continuous cultivation undergo fast degradation, leading to crop production decline, mainly due to erosion and reduction of soil organic matter levels. Soil protection with live mulching is one of the alternatives to alleviate these effects and to control soil degradation. This study was conducted to evaluate the root distribution and morphology of three perennial herbaceous leguminous species, as well as its effects on soil aggregation and organic carbon content when used as live mulching. The experiment was […]

The effects of different weed control methods in coffee (Coffea arabica L.) on some soil physical quality indicators were studied. The essay was installed in 1977 at the EPAMIG Experimental station in São Sebastião do Paraíso (MG), Brazil, in a coffee plantation on a Dusky Red Latosol. Coffee cultivar ‘Catuaí Vermelho’ LCH 2077-2-5-99 was planted at 4x1m spacing. Mower (RÇ), coffee tandem disk harrow (GR), rotary tiller (RT), post (HC) and pre-emergency herbicides (HR) and hand hoe (CM), were used […]

The objective of this paper was to study the effect of eight soil tillage systems on the aggregation status of an Albaqualf at a depth of 0-10 cm using the following parameters: distribution of water stable aggregates in different size classes and mean weight diameter aggregates. The field experiment was carried out at the “Empresa Brasileira de Pesquisa Agropecuária – Centro de Pesquisa Agropecuária de Clima Temperado” (EMBRAPA-CPACT) experimental station, in Pelotas (RS) in 1985. After ten years, the soil […]

This research was carried out in Rio Grande do Sul State, Southern Brazil, during the 1990/1991 summer harvest. The main objective was to evaluate the aggregation and aggregate stability of two clayey soils classified as Dusky Latosol (Haplorthox) and Dark-Red Podzolic (Paleoudult). Two treatments were used in the Haplorthox: grass (Setaria anceps L.); and crop rotation under conventional tillage (wheat (Triticum aestivum) soybean (Glycine max L.)). On the other hand, four treatments were used in the Paleoudult: grass (Digitaria decumbens […]

When calculating the mean weight-diameter (MWD) or the geometric mean diameter (GMD) of a soil sample, the arithmetic mean diameter (in the case of MWD) or the logarithmic mean (in the case of GMD) of cach class is weighed by the mass of aggregates retained in that class. The use of the arithmetic mean of each class, multiplied by the aggregate mass retained in that class is correct only if a symmetric distribution of aggregate sizes occurs within each class, […]