Silicon in Agriculture

Scientific articles its address ( Silicon in Agriculture (images/Silicon_in_Agriculture.docx))


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Genesis and Classification of Selected Soils in an Arid Region of Central Iraq

A.S. Muhaimeed,* S.R. al-Jeboory, K.A. Saliem, R. Burt, and J.V. Chiaretti

Five pedons were studied and sampled around Razazah Lake in central Iraq west of the city of Karbala.
This lake is a depression into which excess water from the Euphrates River is diverted by a controlled
escape channel. Razazah Lake is shallow, and water levels fluctuate seasonally. The climate of the
region is hot and arid with mean annual temperature of 22.5°C and mean annual precipitation of
150 mm. The pedons represent gypsiferous and calcareous soils that formed from different parent
materials overlying several geological formations and which have different groundwater levels. Soils
were described, sampled, and analyzed in USDA–Lincoln laboratory using standard USDA soil survey
methods, with some soil properties determined by Iraqi laboratories. The results indicate differences in
the morphological, chemical, physical, and mineralogical properties of the pedons. These differences
were related to local factors including age and type of their geological formation, topographic
location, and depth of groundwater. 

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origin of sulfur and mode of gypsum formation in central

Origin of Sulfur and Mode of Gypsum Formation in Central
Iraqi Soils

Abstract: The δ18O and δD values of gypsum
crystallization water together with δ18O and δ34S of
sulfates were used as reliable techniques to study
source of sulfur and mode of gypsum formation in
selected central Iraqi soils. Six representative pedons
on different geologic units were studied. The slope of
3.2 for δ18O and δD plot of gypsum crystallization
water showed that evaporation was the major process
of gypsum deposition in the study area. The mean
δ34S value of +17.58 ‰ showed that Cretaceous sea
sulfate followed by Tertiary is the source of sulfur in
studied soils. The heavier δ34S value (+17.58 ‰) of
the study area compared to central Iran (+13.5 ‰)
proved that gypsum in central Iraq soils has been
formed in the later stage of evaporation and that Iraqi
landforms were cut off from the Tethys seaway after
central Iran was evolved.

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