Volume 26, Number 2, 2002

Independent of the runoff capacity to transport mineral and organic particles of soil, the assessment of rainfall erosive action, during its initial phase, would not be complete if the mechanisms of soil detachment and splash by raindrop impact were not appraised. Considering the lack of data on these mechanisms in soils of Ceará State, Brazil, the objectives of this work were: to compare collection methods of detached and splashed soil and to evaluate the correlations between rainfall erosivity and splash […]

The most interesting effect of introducing research into teaching is the assimilation of knowledge as a theoretical construction shared by the scientific community. The idea of temporary and subjective knowledge must be developed in the classroom. But, how can doubt arise during the study of a subject? At the Agricultural Microbiology Course at Faculty of Agricultural Sciences (Universidad Nacional de Entre Ríos) a team work has been conducted for five years, characterized by the use of problem-solving to motivate the […]

Brasilia’s urban growth has caused the increase of domestic sewage sludge, production generating a large volume of biosolid – a final product of sludge treatment – deposited at the Companhia de Saneamento de Brasilia (CAESB) sewage treatment plants. Although there is still a lack of technical data on health, environmental safety and economic viability, it has been used as a soil amendment and fertilizer by farmers in the neighbouring areas. The biosolid produced at one of the sewage treatment plants […]

The agronomic use of biosolid is considered an adequate alternative to its disposal and, although a technical knowledge about its fertilizing properties is already available, information on its qualitative, economical and practical aspects for its use on the field is also needed. The biosolid produced by the “Companhia de Saneamento de Brasília” (CAESB) showed an appreciable variability in nutrient concentration among each monthly sampling from August, 1995 to July, 1996 and among the sludge treatment plants (ETEs) where the biosolid […]

Repeated sewage sludge application to soils can cause changes in some soil chemical properties. The goal of this paper was to evaluate changes in soil organic carbon content, electric conductivity, pH and CEC after sewage sludge application during two years in a row. The soil used was as a Typic Hapludox and, after the sludge application, was planted with sugarcane. The experiment had five treatments: lime + inorganic fertilization, control and sewage sludge in three levels: 33, 66 and 99 […]

The accumulation of herbicides in the environment as a consequence of their intensive usage associated to their high persistance is a matter of principal concern due to their harmful effects on the fauna and flora. Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is one of the worldwide mostly used herbicides, and is being detected in considerable amounts in aquatic and soil ecosystems. The goal of this study was to evaluate the sorptive behaviour of atrazine in a Humic Cambisol under its natural form and in […]

Azospirillum amazonense is a widespread N2 fixing bacterium, occurring mainly in association with grasses and palm trees roots. Aiming to study its occurrence in species of other families not yet studied and the efficiency of media. Fam and LGI for its detection, these were used for rhizosphere soil counting or for enrichment cultures of rhizosphere soil, ecto and endorhizosphere. A. amazonense was detected in rhizosphere soil, ecto and endorhizosphere of many species belonging to monocotyledons, including Orchidaceae and dicotyledons with. […]

Paty do Alferes in the State of Rio de Janeiro, Brazil, is a county with agricultural tradition, whose main economical source is horticulture. Topography and rainfall regime of the region are favorable for erosion. Due to the lack of an appropriate soil management, besides excessive application of agrochemicals, physical and chemical soil degradation processes are favored, causing serious environmental impacts. With the objective to evaluate accumulated heavy metals in soil and in tomato plants (Lycopersicon esculentum Mill), raised in different […]

Soil and water loss data under natural rainfall in Lages, Santa Catarina State (Brazil), from November 1992 to October 1998, were utilized to calculate the soil loss ratio (SLR) and C factor for the Universal Soil Loss Equation (USLE) under three soil tillage systems for corn and oat in rotation with other crops. The studied treatments were: plowing followed by disking twice (P + D), chiseling plus disking (C + D) and no-tillage (NT)/direct sowing, cultivated with corn (Zea mays) […]

The point of zero salt effect (PZSE) of soil samples is usually determined by a graphic method where the PZSE corresponds to the pH value observed at the crossing point of drafted potentiometric titration curves. Although the use of graphic software decreases the personal bias that normally occurs when the titration curves are drafted by hand, this determination method can be time-consuming when there is a great number of soil samples. The present work aimed to develop a software to […]