In the paper some results on the effects of chemo-physical evolution of clay-lime-water suspensions on the microstructure of a lime treated kaolin have been presented. A multi-scale investigation on the sedimentation behaviour of clay suspensions under different pore water chemistry has been developed highlighting the chemophysical mechanisms controlling particle arrangement and the soil fabric...

Johansson. T. 1995. Site index curves for Norway spruce plantations on farmland with different soil types. Studici Forestulia S~lecicu 198. 19 pp. ISSN 0039-3150, ISBN 91-576-5089-6. Growth data were collected from 157 Norway spruce (Picea abies (L.) Karst.) stands planted on farmland in Sweden. The stands ranged in latitude from 55'N to 66'N. The mean age of the stands was 41 years (range, 25-...

Clay fractions in soils from a transect of the Mazama ash deposit (6600-yr-old) contained more than 80% amorphous material. Instrumental neutron activation analysis was used to compare the trace element composition of the soil clay with the unweathered volcanic glass. The clay fractions had only 10% as much Na as the volcanic glass. Conversely, the rare earth element concentrations were about t...

The aim of this review is to examine the hypothesis that organic matter decreases the adsorption of radiocaesium on clay minerals. The factors that determine radiocaesium mobility and bioavailability in soil are briefly outlined to show why a relationship between soil organic matter content and enhanced Cs bioavailability is paradoxical. In all the investigations reviewed the ionic compositions...

The influence of direct current electric fields on the possible electrokinetic delivery of nano-iron slurry in clay for the purpose of fast and effective remediation of soil contaminants has been tested. Nano-iron can be introduced to soil hydraulically in slurry form, but in tight clay soil, delivery of a uniform distribution of the slurry may be difficult to achieve for effective remediation....

A controlled greenhouse experiment was conducted to study the fraction, uptake and fixation of phosphorus (P) and potassium (K) in three soils with contrasting characteristics. The experiment was carried out in two phases, viz., sorghum-Sudangrass depletion and test crop experiment with maize with three levels of fertility status (depleted, original and fertilized with 40 mg kg-1 P and K) and t...

The potential for lettuce field-coring harvesting knives to cross-contaminate lettuce heads with pathogens was evaluated. Rings and blades of the harvest knives artificially contaminated with Escherichia coli O157:H7 (EHEC), were used to core three successive heads of iceberg lettuce. The coring rings and blades were inoculated by dipping into soils containing EHEC at concentration ranges of 1-...

Soil surface texture is an important environmental factor that influences crop productivity because of its direct effect on soil water and complex interactions with other environmental factors. Using 30-year data, an agricultural system model (DSSAT-CERES-Wheat) was calibrated and validated. After validation, the modelled yield and water use (WU) of spring wheat (Triticum aestivum L.) from two ...

General guidelines to reclaim saline or sodic soils do not adequately consider variables such as pH and the presence of organic matter that are known to affect soil stability. Poor structural stability of sodic, saline-sodic, and high-pH soils adversely influences crop yields; promotes piping, tunneling, and slope erosion; and can accelerate the failure of water conveyance systems. We evaluated...