Volume 28, Number 6, 2004

In the clay and heavy clay soils, compaction of the surface layer represents one of the limitations under no-tillage. Under such conditions, periodic soil tillage has been adopted. Other techniques, such as crop rotation are indicated for the physical management of the soil due to a larger input of organic matter and bioporosity of the soil. The objective of this study was to quantify some soil physical properties in an eutroferric Red Latosol (rhodic Eutrudox), the organic carbon content and […]

Soil management influences surface cover and roughness, and it is the major factor that affects water erosion. A rotating-boom rainfall simulator operated at a constant rainfall intensity of 64 mm h-1 and 0.2083 MJ ha-1 mm-1 kinetic energy was used to investigate water erosion and related parameters in six management systems of corn and bean crops. The experiments were carried out on a clayey loam structured soil (Hapludox) with 0.165 m m-1 average slope, on the Southern Plateau of Santa Catarina State, Brazil, from March […]

Water erosion extracts nutrients from farming areas and causes soil impoverishment and environmental contamination outside the erosion site. A rotating-boom rainfall simulator operated at a constant rainfall intensity of 64 mm h-1 and 0.2083 MJ ha-1 mm-1 kinetic energy was used to investigate nutrient and organic carbon losses by water erosion and related parameters in six management systems in corn and bean crops. The experiments were carried out on a clayey loam structured soil (Hapludox) with 0.165 m m-1 average slope on the Southern Plateau of Santa […]

Gully erosion are very common in areas with gneiss basement rocks. Their development is strongly influenced by subsuperficial processes, although the surface ones are also important. This study aimed to investigate the subsuperficial erosion mechanisms of these gullies and to understand how mineralogy and texture could influence the saprolite erodibility. Some basic trials and erodibility tests were carried out in representative samples, with imphasis to especially the pin-hole test. The results showed that seepage erosion does not occur and that […]

Arbuscular mycorrhiza can be important for plant nutrition in acid and low fertility soils such as those of the Amazon. The present study evaluated the mycorrhizal colonization by native arbuscular mycorrhizal fungi (AMF) and nutrient concentrations of cupuassu and guarana leaves in an agroforestry system in Manaus, Amazonas State, Brazil. Ten plants of each species were selected, of which the roots, soil and leaves were sampled during the rainy and dry seasons. Guarana and cupuassu trees presented higher levels of […]

The objective of this research was to study the physical and chemical properties of substrates with different mixtures of biosolids (BIO) and carbonized rice chaff (CAC) in order to get an appropriate medium for seedling development. The experiment was established in the nursery of the Department of Natural Resources/Forest Sciences, College of Agronomic Sciences, State University of São Paulo-FCA/UNESP-Botucatu (SP), using BIO from SABESP/Franca-SP and CAC in the following ratios (BIO/CAC): 100/0, 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80, […]