Nutrient limitation to primary productivity and other biological processes is widespread in terrestrial ecosystems, and nitrogen (N) and phosphorus (P) are the most common limiting elements, both individually and in combination. Mechanisms that drive P limitation, and their interactions with the N cycle, have received less attention than mechanisms causing N limitation. We identify and discuss ...

A total of 650 arable soil samples were collected from the suburbs of Liaocheng, Shandong Province, China to identify the concentrations and the sources of heavy metals and to assess the environmental quality of soil. Subsequently, the contents of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the samples were analyzed. The investigation revealed that the mean concentrations of As, Cd, Hg, Ni, Hg, and C...

In a semiarid region of central Iran, effects of parent materials, physiography and landscape position, land use, andmanagement practices on association of organic carbon with secondary (aggregates) particles and aggregate stability canhave important consequences in terms of carbon sequestration and budgeting, deciding on the proper land use strategy andsuitable soil conservation practices. It ...

I N T R O D U C T I O N T h e s t u d y o f c lay f o r m a t i o n i n soils m a y b e d i v i d e d i n t o t h r e e p a r t s : (1) a q u a n t i t a t i v e e v a l u a t i o n o f t h e a m o u n t o f c lay f o r m e d f r o m a g i v e n a m o u n t o f p a r e n t m a t e r i a l , (2) a q u a l i t a t i v e e v a l u a t i o n of t h e k i n d o f m i n e r a l s a n d o t h e r s u ...

In order to evaluate the effects of parent material on clay mineralogy in northface of the Elborz mountain area that is covered with deciduous trees, five mountain physiographical units with dolomite, sandstone, marl, limestone and conglomera parent material were selected and in each physiographical unit some soil profiles were studied. Soil samples were taken from different horizons and leyers...

The data on the heavy metal content at different soil depths derived from a multi-purpose regional geochemical survey in the Pearl River Delta (PRD) were analyzed using ArcGIS 10.0. By comparing their spatial distributions and areas, the sources of heavy metals (Cd, Hg, As and Pb) were quantitatively identified and explored. Netted measuring points at 25 ×25 km were set over the entire PRD acco...