Adsorption-desorption of arsenic is the primary factor that impacts the bioavailability and mobility of arsenic in soils. To examine the characteristics of arsenate [As(V)] adsorption-desorption, kinetic batch experiments were carried out on three soils having different properties, followed by arsenic release using successive dilutions. Adsorption of As(V) was highly nonlinear, with a Freundlic...

This study investigates time-dependent sorption of pesticides in soil aggregates. We tested if the sorption kinetics of pesticides in soil aggregates can be described by modeling diffusion into aggregates for a range of soils and pesticides. Our hypothesis is that the rate of sorption is negatively related to sorption strength due to retardated diffusion. Natural aggregates of 3-5 mm diameter w...

It has long been recognized that the minerals in the clay (<2 gm) fractions of soils play a crucial role in determining their major physical and chemical properties, and inevitably, questions concerning the origin and formation of these minerals have assumed some prominence in soil science research. This review considers some important aspects of these questions and is confined to clay minerals...

abstract time domain reflectometry (tdr) is a widely used method for measuring the dielectric constant (ka) and bulk electrical conductivity (σa) in soils. the tdr-measured σa and ka can be used to calculate the soil solution electrical conductivity, (σp). a theoretical model describing a linear relationship between bulk electrical conductivity, σa, and dielectric constant, ka, in moist soil wa...

Environmental conditions influence patterns of local-scale plant productivity and species richness. We sampled soils and plant communities at a topographicallydiverse, mid-successional old field site in Kansas to better understand the abiotic factors underlying a natural plant productivity gradient. We related soil texture, pH, percent nitrogen and carbon, and soil moisture to elevation, plant ...

In the present work, different methods were tested to evaluate the adsorption and desorption of metalaxyl in two acid soils with different organic carbon and clay contents. The three methods (batch, stirred flow chamber and column) that were examined produced similar findings when the two soils were compared: (a) the metalaxyl adsorption capacity was higher in the soil with higher organic matte...

Agrotain has shown in previous studies on silt loam soils to be much less prone to ammonia volatilization loss and to result in higher rice-grain yields compared to urea when the flood cannot be applied immediately after nitrogen (N) fertilizer application. However, no research has been conducted to determine if Agrotain is superior to urea as an N source for rice grown on clay soils, which vol...

Use of soft clay soils in construction activities has faced many problems. Some improvement, stabilization, and reinforcement methods is required to use these soils in body of roads, sub-foundations and embankments. In this research, the effect of chitin nanofiber and rice husk ash as additives on the behavioral properties and bearing resistance of soft clay soils by considering the processing ...