Microbial populations responsible for the oxidation and reduction of As were examined in unsaturated (aerobic) soil columns treated with 75 microM arsenite [As(III)] or 250 microM arsenate [As(V)]. Arsenite [As(III)] was rapidly oxidized to As(V) via microbial activity, whereas no apparent reduction of As(V) was observed in the column experiments. Eight aerobic heterotrophic bacteria with varyi...

The aim of this study was to evaluate P availability, P and C contained in the microbial biomass, and enzymatic activity (acid phosphatases and β-glucosidases) in a Nitisol with the application of mineral and organo-mineral fertilizers. The experiment was performed in a protected environment with control over air temperature and soil moisture. The experimental design was organized in a "5 x 4" ...

A leaching experiment was conducted on three level of total N soils transplanted with lettuce in packed soil columns. Nitrate content in the surface soil layer increased to 52.6, 92.8 and 92.1 mg kg-1 when 30 t ha-1 poultry manure was used alone in the low, medium and high level of total N soils. Measured leachate data showed that more nitrate was leached in the chemical fertilized soils in the...

Shallow Soil Mixing (SSM) is a sister technology to Deep Soil Mixing (DSM) developed to more economically improve soils within ten meters of the surface. SSM was recently utilized to provide a foundation for large effluent storage tanks as well as to contain foundation soils in the event of liquefaction from an earthquake. Two large storage tanks were required to be built in a pulp mill. The on...

The geospatial patterns of four species of native entomopathogenic nematodes in Florida were previously shown to be related to soil properties that affect soil water potential. Here we compared the responses to water potential of third stage, infective juvenile (IJ), Steinernema sp. (Sx), and Steinernema diaprepesi (Sd) in controlled conditions. The two species were selected because they are cl...

BACKGROUND The longevity, mobility and insecticidal activity of bifenthrin at the termiticidal application rate for perimeter treatment were investigated in packed-soil columns in the laboratory and greenhouse. RESULTS Bifenthrin was not detected in the eluates of packed-soil cones over a period of 6 months. In larger pipe plots incorporating bifenthrin into the top 15 cm of the soil, the com...

Field populations of Xiphinerna americanum around roots of Syringa vulgaris 'President Lincoln' were larger in Marshall silty clay loam, a medially developed loess soil, than in Monona silt loam, a minimally developed loess soil. Most X. amerieanum occurred in the top 15 cm of soil, with few below 30 cm. Maximum numbers occurred in August of both years in the Marshall soil, and in August 1969 a...

ABSTRACT-Application of models for simulation of solute and pollutants transport in soil can reduce time and costs for remediation process. HYDRUS-1D model was developed to simulate the one–dimensional flow of soil water, heat, solute and viruses in variably saturated–unsaturated porous media. The objective of this investigation is to determine the solute transport parameters in disturbed soil ...

Appropriate management of animal waste is essential for guaranteeing good water quality. A laboratory leaching study with intact soil columns was performed to investigate the risk of phosphorus (P) leaching from a clay loam and a loamy sand. The columns (0.2 m deep) were irrigated before and after application of pig slurry on the surface or after incorporation, or application of mineral P, each...

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their s...