a r t i c l e i n f o Here we analyze the past and present roles of the five soil-forming factors in USDA Soil Taxonomy. As opposed to the 7th Approximation of 1960, the factorial and genetic approach is clearly present in Soil Taxonomy. Soil climate is the most important factor in Soil Taxonomy. It is used at the highest level to define two of the 12 soil orders: Aridisols, the soils of the dr...

Pedogenesis and clay mineralogy of soils and rock samples were studied in a transect of calcareous, gypsiferous, saline soils and sediments of Bakhtegan lake bank in southern Iran. The main objectives of study were to determine the occurrence of clay minerals and factors controlling their distribution pattern and relative abundance in soils and parent materials. The soil parent material is high...

The aim of this work is to model the occurrence and intensity of calcium carbonate loss in calcareous forest soils under Mediterranean conditions. We have used 193 Spanish forest soils found on limestone parent material considered highly calcareous materials. This data set came from FOREDAF, a database containing 2200 complete soil profiles and all of them covered by forest stands (mainly domin...

Abtract The Mg +2 accumulation on the exchange complex of soils to a very high saturation levels affect their chemical, physical and biological properties. Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley ...

Accurately quantifying soil organic carbon (SOC) is considered fundamental to studying soil quality, modeling the global carbon cycle, and assessing global climate change. This study evaluated the uncertainties caused by up-scaling of soil properties from the county scale to the provincial scale and from lower-level classification of Soil Species to Soil Group, using four methods: the mean, med...

soils of the arid–semiarid karaj basin in north-central iran have formed on alluvium-colluvium derived from mixed calcareous-gypsiferous marls of miocene and basic igneous rocks of holocene age. in order to characterize and classify the soils and to determine the soil-landscape relationship in the area, sixteen pedons located on different physiographic positions have been described, sampled and...

introduction: parent materials as one of the main soil formation factors have a great impact on the concentration of heavy metals in the soil. heavy metals are released to the soil during weathering and pedogenic processes. ultrabasic rocks are known as the potential natural source of heavy metals, especially ni, cr and mn in the soil. average concentrations of ni and cr in the soils are 84 and...

owing to the proximity of certain locations to the thermal power stations, it has always been efforts of engineers to enhance the flyash utilization rate in various civil engineering constructions adopting suitable strategies. in the present study, a soilflyash interface mechanism has been evolved using different soil-flyash ratios to upgrade significantly stabilization of supporting medium bas...

OBJECTIVE The purpose of this study was to measure the readability and user-friendliness (clarity, complexity, organization, appearance, and cultural appropriateness of materials) of parent education brochures on newborn screening. METHODS We studied English-language versions of the brochures that state newborn screening programs prepare and distribute. We obtained brochures from 48 states an...