Volume 32, Number 2, 2008

Maize root growth is negatively affected by compacted layers in the surface (e.g. agricultural traffic) and subsoil layers (e.g. claypans). Both kinds of soil mechanical impedances often coexist in maize fields, but the combined effects on root growth have seldom been studied. Soil physical properties and maize root abundance were determined in three different soils of the Rolling Pampa of Argentina, in conventionally-tilled (CT) and zero-tilled (ZT) fields cultivated with maize. In the soil with a light Bt horizon (loamy […]

Soil porosity influences plant development since root growth and crop yield are determined by the root depth. The objective of this study was to investigate the linear and spatial variability and correlations between common bean yield and soil porosity. The bean grain yield of the irrigated cultivar Carioca IAC was analyzed in the growing season 2004/2005, in Selviria-MS, as well as macroporosity (MA), microporosity (MI) and total porosity (TP), in a Dystroferric Red Latosol, at four depths: 1 (0.0-0.10 m), 2 (0.10-0.20 m), 3 (0.20-0.30 m) […]

Brazil is the world’s largest sugarcane producer, so changes in sugarcane management in Brazil can affect the environment to a great extent. During almost one century, studies were carried out in cropping systems involving pre-harvest burning of aerial sugarcane residues. Nowadays the green trash management of sugarcane residues has become a common practice, although the effects are still poorly documented. The objective of this work was to compare topsoil carbon and nitrogen stocks, aggregation and bulk density in Brazilian sugarcane […]

Accelerated soil erosion is a serious global problem that degrades agriculture lands. Since erosion research is normally expensive and time-consuming, the use of models allows to estimate soil losses at locations and under conditions not represented directly in the research. The objective of this study was to estimate the soil erosion in an area intensively cultivated with sugarcane near the city of Piracicaba, São Paulo, contributing to diagnose the current land uses aimed at controlling erosion. The study was carried […]

Accelerated soil erosion, a process basically induced by human activities contributes greatly to the degradation of arable land quality throughout the world, and is the main non-point source of surface water resource pollution. Considering the effective demand for developing indicators to evaluate the impact of soil erosion on soil quality in agriculture production systems, the objective of this study was to develop an index with a predictive value to be applied as a planning tool for interpreting soil loss tolerance […]

Rainfall erosivity represents the potential of rainfall causing soil erosion. The EI30 index is a method to determine rainfall erosivity and is calculated by the product of the total kinetic energy of rainfall and the maximum intensity in 30 min. The objective of this study was to calculate rainfall erosivity in Uruguaiana, RS, Brazil, for practical applications in soil conservation, based on daily rainfall charts. For each rainfall chart, segments with the same intensity were separated, registered in worksheets, digitalized and […]

Intensive soil mobilization in the conventional tillage system has caused soil structure degradation, soil compaction below the arable layer, and decreased macroporosity. These changes resulted in reduced soil water infiltration rate and increased runoff, soil erosion and sedimentation in rivers and reservoirs. In the no tillage system the water erosion from the soil surface is practically controlled, and the terraces were eliminated by the farmers. Nevertheless, the surface flow is higher than it was in the conventional tillage system. With […]

With the prevalence of no-till systems in Central-Western Brazil, a more in-depth knowledge about cover crops for straw production is necessary. The objective of this study was to evaluate the green and dry biomass production, the percentage of soil cover, as well as the dynamics of residues decomposition of three cover crop species, in the second growing season of the cropping year: amaranth (Amaranthus cruentus L. BRS Alegria), pearl millet (Pennisetum glaucum L. var. ADR500) and finger millet [Eleusine coracana […]

Plant nutrient extraction has been used to remove inorganic ions from soil or other polluted media. In this study, the nutrient extraction capacity of the macrophytes Typha sp. and Eleocharis sp., cultivated as monoculture and as consortium, was evaluated in a growing medium containing rubble and leachate of an urban landfill. The plants were grown in wooden boxes containing rubble and leachate as substrate, in a plastic greenhouse, for five months. The total concentration and amount of macro (N, P, […]

Nowadays, inoculant application in the sowing furrow of soybean is widely used, but there is little information underlying this practice, which would prove the efficiency in different environments under no-tillage systems. This study aimed to evaluate the viability of inoculant application to soybean, via seed and in-furrow, in soil never cultivated with soybean or previously cultivated with soybean. Two field experiments were carried out as of December 2004 in a Red Yellow Latosol (Oxisol), using the same methodology and applying […]