For aggregated soils the Mohr failure line can be separated into two straight lines, with different slopes and intercepts. In the range of low normal load, when the slope is very steep and the intercept is small, the failure line is defined by the friction and cohesion inter-aggregates, while for the higher load range the slope becomes smaller and intercept is larger, which defines the intra-aggregate friction and cohesion. Therefore, for aggregated soils the normal load range used in the […]

The effect of physical, chemical and biological soil attributes on the stability of wet aggregates of two Oxisols cultivated with annual crops under no tillage for over four years was evaluated. Soils samples were collected in the 0-10 cm layer of two areas in a 100 m square grid marked with a DGPS. One of the areas is located in Campos Novos Paulista county, SP, Brazil (22 º36 ‘ 11 ” latitude and 50 º00 ‘ 09 ” longitude) on […]

A new approach is discussed for adoption of criteria in the application of the cultural profile methodology for tropical soil conditions. The evolution of this methodology has been analyzed since its beginning in France in the 1960s, until its proposal for tropical soil management studies. The cultural profile approach can be used to make qualitative diagnosis of the physical state of soil in the field, as well as to help with soil sampling, to study the effect of agricultural machinery, […]