Cadmium (Cd) concentration in soil solution and its bioavailability is controlled by sorption-desorption reactions. The objective of this research was to compare Cd adsorption behavior in six calcareous and four acid soils. Soil samples were equilibrated with 0.01 M Ca(NO3)2 containing 25 to 3200 mg Cd L−1. Results showed that the tendency for adsorption was high at low Cd concentrations (0-400...

Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium (>/=80 mg/kg) and zinc (>/=3000 mg/kg) in leaves of will...

to determine the effects of vinasse on physicochemical properties of a calcareous and an acidic soil experiment was factorial and had a complete randomized design and three replications. factorial combinations of five vinasse levels (0, 5, 10, 20 and 40 t/ha) and three exposure times (10, 20 and 30 days) were considered as the treatments of this experiment. the result of experiment showed that ...

Iron availability in calcareous soils, and Fe uptake and translocation in plants are major factors limiting the agricultural use of land. The nutritional value of crops as Fe sources for humans is often reduced due to Fe-deficiency in plants. Agronomic approaches to overcome these shortcomings include: (i) methods aimed at increasing the availability of indigenous soil-Fe; (ii) soil and/or foli...

Adsorption of Cd(2+) on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts. Kinetics and thermodynamic parameters of the adsorption were calculated at two different electrolyte concentrations: 0.05 N and 0.15 N. The adsorption was described by Langmuir an...

The girdle epidermis of adult Mopalia muscosa secretes several types of structures, including calcareous spicules and innervated hairs. Newly metamorphosed chitons superficially resemble adult animals, but they lack the adult girdle ornaments, shell sculpture, and coloration. The morphogenesis of the adult girdle structures has not been described previously for any species. Juvenile Mopalia mus...

[1] A high-resolution record of exceptionally well preserved calcareous nannofossil assemblages from Tanzania is marked by two key transitions closely related to the climatic events of the Eocene-Oligocene transition (EOT). The first transition, at 34.0 Ma, precedes the first positive shift in dO and coincides with a distinct interval of very low nannofossil abundance and a cooling in sea surfa...

Biostratigraphic data provided by the sections of the Caravaca–Cehegı́n region, SE Spain, have contributed decisively to the lively debate that has taken place in recent years concerning the Berriasian/Valanginian boundary. This work presents the results from new integrated stratigraphic analyses of these sections, based on the distribution of ammonites, calpionellids and calcareous nannofossils...

Accumulation of heavy metals from agricultural soils contaminated by low levels heavy metals has important implications in the understanding of heavy metal contamination in the food chain. Through field experiments (1994-1996), the influence of thermal regime under different treatments on the accumulation of zinc, cadmium, copper, and lead in Chinese cabbage [Brassica pekinensis (Lour) Rupr. cv...

Calcareous dinophytes produce exoskeletal calcified structures during their life history (a unique character among the alveolates) and are subsumed under the Thoracosphaeraceae as part of the Peridiniales. We provide a brief synopsis about the taxonomic history of the group, from the first descriptions of fossils in the 19th century through to the results of molecular phylogenetics studies unde...