Labile fractions of soil organic matter (SOM) respond rapidly to land management practices and can be used as a sensitive indicator of changes in SOM. However, there is little information about the effect of agroforestry practices on labile SOM fractions in semiarid regions of China. In order to test the effects of land use change from monocropping to agroforestry systems on labile SOM fraction...

Sperm conjugation occurs when two or more sperm physically unite for motility or transport through the female reproductive tract. In many muroid rodent species, sperm conjugates have been shown to form by a single, conspicuous apical hook located on the sperm head. These sperm "trains" have been reported to be highly variable in size and, despite all the heads pointing in roughly the same direc...

ABSTR ACT: In a laboratory investigation, the effect of natural sunlight and UV light exposure on dissipation of fipronil insecticide from two soils (clay loam and sandy clay loam) and the effect of pH on the persistence of fipronil in aqueous medium were studied. Dissipation of fipronil insecticide under sunlight followed biphasic first order kinetics in both soils. The half-life of the insect...

a r t i c l e i n f o On aerial photographs, sandy tidal flats display (1) large sandy bedforms (N10 m long, N 3 m wide), indicating effects of strong hydrodynamics on sediment relief, and (2) beds of seagrass and mussels, indicating stable sediment conditions. These physical and biogenic structures have been mapped from aerial photographs taken in a back-barrier tidal basin of the North Sea co...

in this paper, the grouting ability of sandy soils is investigated by artificial neural networks based on the results of chemical grout injection tests. in order to evaluate the soil grouting potential, experimental samples were prepared and then injected. the sand samples with three different particle sizes (medium, fine, and silty) and three relative densities (%30, %50, and %90) were injecte...

The annual cycle of oxygen and nitrogen flux, denitrification and microphytobenthic variables (primary production, biomass, composition and calculated N demand) were studied for 2 shallow-water microtidal sediment sites in NE Kattegat, 1 sandy and 1 silty, by incubating undisturbed sediment in the laboratory in light and darkness. Both sites (2 stations within each) were characterised by low co...

Information on P release potential in relation to labile P and P fractions in sandy soils is limited. In this study, P release potential was determined by leaching, and labile P, soil P fractionation, and P adsorption capacity were measured in the laboratory using 96 Florida sandy soil samples to evaluate the relationship between P release in water and soil P status. The sandy soils had a very ...

In situ measurements of atmospheric NO3 and NH4 þ at Sandy Hook on the northern New Jersey (USA) coast and at Tuckerton on the southern New Jersey coast reveal significant temporal and spatial variations of these inorganic N constituents. The mean concentration of NO3 in precipitation was higher at Sandy Hook (44.6 lmol/L) than at Tuckerton (29.1 lmol/L). The mean concentration of NH4 þ in prec...

abstract disc infiltrometer is one of those devices that used in recent years in measurement of hydraulic conductivity of entire soil. in order to analyze the data taken by disc infiltrometer a variety of methods based on wooding’s base analyze have been introduced. the objective of this study was to compare the performances of ankeny and weir methods for predicting soil hydraulic properties us...

Earth slopes stabilization is one of the main issues focused on by are in geotechnical engineer. Use of stone columns is one of approaches well increasing the safety factor of earth slopes of the soil embankments; furthermore, it is economical besides the simplicity and ease it exhibits in implementation. . The present paper aims at an experimental comparison of the Ordinary Stone Column (OSC) ...