the pull- out strength of the reinforcement has a significant role on the function of the most reinforced soil structures. since the coarse grain soils have a better interaction with the reinforcement, they are mostly used in these structures. in most situations, we have to transfer these granular soils from the borrow area, usually far from the site of the project. this will impose a considera...

Many studies at the regional scale have found either negative or hump-shaped relationships between productivity and diversity, and some theories propose that these occur because soil resource heterogeneity is either lower or less important in more productive environments. However, there have been few explicit tests of these theories in natural ecosystems. We evaluated the relationship between s...

Specific surface captures the combined effects of particle size and slenderness in a measurement that is independent and complementary to grain-size distribution. There are various methods to measure specific surface, including gas adsorption in dry conditions and selective molecular absorption in aqueous suspensions. The measurement procedure can have an important effect on measured values, ye...

This paper describes the findings of selenium measurement in three types of soil (semigley, pseudogley and hypogley) and in wheat grain cultivated in these types of soil in the vicinity of Koprivnica using hydrid atomic absorption spectrometry. The results showed relatively low selenium levels in all three types of soil (145-333 micrograms Se/kg dry weight) as well as the wheat grain (22-62 mic...

Cytokinins may reflect soil water status and regulate rice (Oryza sativa L.) grain filling. This study investigated the changes in cytokinin levels in rice plants and their relations with grain filling under alternate wetting and drying irrigation. Two 'super' rice cultivars were field grown. Three irrigation regimes, alternate wetting and moderate soil drying (WMD), alternate wetting and sever...

1991). These properties include soil bulk density and chemical properties. This study investigated the relationships between corn (Zea mays An objective of site specific management is to apply L.) grain yield and weather over a range of soil rooting depths with appropriate levels of agricultural inputs to localized areas. and without irrigation. The purpose was to test if variability of corn Si...

In years 2007-2008 field experiment with spring wheat was conducted on the parcels (14 m ) with 2m deep concrete walls, filled with six different soils. The goal of this experiment was to evaluate the influence of soil quality on yield and technological properties of spring wheat varieties. The results of the conducted experiment showed that the highest level of spring wheat yielding were obtai...

large areas of iran are under the influence of wind erosion thus it is important that we recognize three zones ofremoval, transportation and deposition. the deposition zone is very important due to more damages and tangibleeffects. in this study we try to obtain a comprehensive idea to persian desert with use of laboratory facilities, remotesensing, gis and field surveying. we survey 28 ergs in...