topography and climate are two important soil forming factors affecting genesis and clay mineralogy of soils. calcareous and gypsiferous soils are widely spread in arid and semiarid parts of iran and palygorskite is a dominant clay mineral in these soils. the objectives of the study were to: (1) determine soil genesis and classification along the climotoposequence and (2) investigate clay miner...

ABSTRACT- Paddy soils make up the largest anthropogenic wetlands on earth. Present study was performed to investigate and compare soil formation of paddy soils with long-term rice cultivation history with non-paddy soils and study the effect of waterlogging on soil pedogenesis. Soil samples were taken from paddy and non-paddy soils derived from the same calcareous parent materials. Some pedogen...

The extraction of nematodes from clay soil is difficult using flotation-sieving methods of soil-water suspensions. Aggregated soil particles trap nematodes and prevent them from passing through the top coarse sieves during decanting. Also, the soil aggregates clog the sieves which slows the decanting operation. In addition, clay particles are difficult to clean from centrifuge tubes that are us...

Laboratory soil column experiments were conducted to study the distribution of preferential flow paths resulting from removal of fine-size clay particles. These experiments specifically studied the influence of clay (kaolinite) percentage in sand-clay mixtures and the effect of hydraulic gradients on pore evolution. Analysis of the effluent during the experiments indicated that clay particles w...

Renewed focus on the sorption of hydrophobic organic chemicals (HOCs) onto mineral surfaces and soil components is required due to the increased and wider range of organic pollutants being released into the environment. This mini-review examines the possibility of the contribution and mechanism of HOC sorption onto clay mineral sorbents such as kaolinite, and soil organic matter and the possibl...

A first survey of entomopathogenic nematodes (EPN) was conducted in three agro-ecological zones of Southern Cameroon in 2007 and 2008. Entomopathogenic nematodes were recovered from 26 of 251 soil samples (10.4%). Three species, Heterorhabditis baujardi, Steinernema sp. A and Steinernema sp. B were found. The two steinernematids were considered unidentified species. Among the positive samples, ...

Adsorption and desorption characteristics of endosulfan in four Indian soils were studied extensively. The soils used were clayey soil (CL--lean clay with sand), red soil (GM--silty gravel with sand), sandy soil (SM--silty sand with gravel) and composted soil (PT--peat) as per ASTM (American Society for Testing and Materials) standards. Adsorption and desorption rates were calculated from kinet...

in this study argillic horizons in calcareous soils of a semiarid region, with xeric and mesic soil moisture and temperature regimes, in the west of urmia lake were studied. thus, a toposequence in different physiographic positions including piedmont plains, plateau, hills and mountains was investigated. in each land type, three soil profiles were dug and described and their morphological prope...

In this study we tested the feasibility of the thermal infrared (TIR) wavelength region (within the atmospheric window between 8 and 11.5 μm) together with the traditional solar reflective wavelengths for quantifying soil properties for coarse-textured soils from the Australian wheat belt region. These soils have very narrow ranges of texture and organic carbon contents. Soil surface spectral s...