نتایج جستجو برای: soil formation

تعداد نتایج: 703087  

2016
Jianguo Zhang Yongdong Wang Ying Zhao Xinwen Xu Jiaqiang Lei Shengyu Li

Understanding the formation and spatial-temporal distribution of soil salt crusts (SSCs) is important for the sustainable management of the artificial shelterbelt and high-salinity groundwater utility in the Taklimakan Desert in Northwest China. The SSCs in this area were sampled, and their thickness and electrical conductivity (EC) were analyzed to examine the formation mechanism and the spati...

2014
Luis Alberto Morales Eva Vidal Vázquez Jorge Paz-Ferreiro

Proper and effective management of soil nutrients requires assessment of their variability at the field scale. We compare the effects of lime amendment rate on the spatial variability of three macronutrient forms (NH4 (+)-N, Olsen P, and Mehlich-1 K) in a paddy soil at three different dates during the growth period of a rice crop. The field work was carried out near Corrientes, Argentina. Lime ...

Journal: :Chemosphere 2003
H F Schöler F Keppler I J Fahimi V W Niedan

Trichloroacetic acid (TCA), in former times used as a herbicide in agriculture, is now ubiquitous and almost evenly distributed in precipitations of the Northern and Southern Hemisphere, despite larger emissions of the possible precursors tetrachloroethene and 1,1,1-trichloroethane in the Northern Hemisphere. The permanent input of a herbicidal compound into most vulnerable ecosystems might lea...

2017
Shirong Qiang Bin Han Xiaolan Zhao Yunbo Yang Dadong Shao Ping Li Jianjun Liang Qiaohui Fan

The sorption of Ni(II) on a calcareous aridisol (CA) soil, one of the major soil types in northwestern China, was investigated using batch and extended X-ray absorption fine structure (EXAFS) approaches in a 0.01 mol/L NaClO4 solution at different pH values (6.0-10.0), temperatures (25-60 °C) and contact times (2-15 days). Under alkaline conditions, EXAFS analysis showed that the interatomic di...

Journal: :FEMS microbiology ecology 2013
Felizitas Bajerski Dirk Wagner

Antarctic glacier forefields are extreme environments and pioneer sites for ecological succession. Increasing temperatures due to global warming lead to enhanced deglaciation processes in cold-affected habitats, and new terrain is becoming exposed to soil formation and microbial colonization. However, only little is known about the impact of environmental changes on microbial communities and ho...

Journal: :تحقیقات آب و خاک ایران 0
حمیدرضا اولیائی ابراهیم ادهمی عبدالکریم اجرائی مهدی نجفی قیری مجید رجائی

soil drainage conditions significantly affect the chemical properties of soil, particularly type and the extent of iron oxides. soil magnetic susceptibility (?) has a close relationship with drainage conditions. eight soil profiles, in four regions of fars province, with aquic and non-aquic soil moisture regimes were studied to determine the effect of drainage conditions on ? and on chemical fo...

2014

Improved computer models of erosion have been developed, considering soil hydraulic conductivity. The models deal with erosion of levees, dams and embankments due to overtopping. The simulations trace the formation of rills and gullies, beginning with initial overtopping and continuing to final breaching. Physical models performed at “1-g” and high “g” using a geotechnical centrifuge have been ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

ژورنال: علوم آب و خاک 2012
تورج هنر, , شیده شمس, , علی اکبر کامگار حقیقی, , علی ثابت سرورستانی, , علیرضا سپاسخواه, ,

In recent years, simulatiom modelling of yield has been the focus of attention for many researchers. Because, while reducing adminestrative costs, it can easily provide simulation models of different situations. In this study, while a subroutine on simulation of canola was added to CRPSM model, effect of different water treatments on canola was also investigated. In this research, canola (Talay...

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