Citric acid (CA) was evaluated in terms of its efficiency as a biodegradable chelating agent, in removing zinc (Zn) from heavily contaminated soil, using a soil washing process. To determine preliminary ranges of variables in the washing process, single factor experiments were carried out with different CA concentrations, pH levels and washing times. Optimization of batch washing conditions fol...

The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha-1, applied once or d...

The effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper were investigated in a high concentration of sulfate with synthesized Fe(III) minerals and red earth soils rich in amorphous Fe (hydr)oxides. Batch microcosm experiments showed that red earth soil inoculated with subsurface sediments had a faster Fe(III) bioreduction rate than pure amorphous F...

The 2011 East Africa drought caused dire situations across several countries and led to a widespread and costly famine in the region. Numerous dynamic and statistical drought prediction models have been used for providing drought information and/or early warning. The concept of Ensemble Streamflow Prediction (ESP) has been successfully applied to univariate drought indicators (e.g., the Standar...

BACKGROUND The effectiveness of bioremediation systems for PAH-contaminated soil may be constrained by physicochemical properties of contaminants and environmental factors. Information on what is the most effective factor in bioremediation process is essential in the decision of what stimulations can be taken to assist the biodegradation efficacy. METHODS In this study, four factors of surfac...

The purpose of this research was to test the hypothesis that variability in 11 soil properties, related to soil texture and soil C and N, would increase from small (1m) to large (1 km) spatial scales in a temperate, mixed-hardwood forest ecosystem in east Tennessee, USA. The results were somewhat surprising and indicated that a fundamental assumption in geospatial analysis, namely that variabil...

Six seasons of experiments in Machakos, Kenya, revealed that above about 150 mm of rainfall, maize yields per row in alley cropped "replacement" agroforestry (AF) plots, of Cassia siamea Lam. and maize (Zea mays, cv. Katumani Composite B), may be expected to exceed those in the control (sole maize) plots. Such yields were insufficient to compensate for the area "lost" to the hedgerows. Below ab...

It has been pointed out that tobacco accumulates cadmium as well as other potentially toxic heavy metals. A three year study was carried out to provide information on the concentration of heavy metals in air-cured (Burley), flue-cured (Virginia) and sun-cured (Oriental-filling) tobacco produced in the Thessaly region of central Greece. During the years 1998, 1999 and 2000, 474 composite surface...

Three different forms of casts are produced by earthworm species of rubber plantation. These are tower-like casts (Metaphire houlleti, Eutyphoeus gammiei, Eutyphoeus gigas, Eutyphoeus scutarius, Eutyphoeus assamensis, Eutyphoeus callosus, Eutyphoeus comillahnus, Eutyphoeus turaensis, Eutyphoeus sp.), composite irregular casts (Pontoscolex corethrurus, Drawida papillifer papillifer) and large gl...

Nineteen taxa of Mucorales, belonging to Absidia, Apophysomyces, Cunninghamella, Fennellomyces, Lichtheimia, Mucor, Mycotypha, Rhizopus and Syncephalastrum were isolated from 36 composite soil samples in three semiarid areas in the State of Pernambuco (Triunfo, Cabrobó and Belém de São Francisco), Northeast Brazil, which are characterized by Caatinga vegetation. Triunfo is preserved, whereas Ca...