نتایج جستجو برای: soil formation

تعداد نتایج: 703087  

2017
Oliver W. Moore Heather L. Buss Sophie M. Green Man Liu Zhaoliang Song

Soil degradation, including rocky desertification, of the karst regions in China is severe. Karst landscapes are especially sensitive to soil degradation as carbonate rocks are nutrient-poor and easily eroded. Understanding the balance between soil formation and soil erosion is critical for long-term soil sustainability, yet little is known about the initial soil forming processes on karst terr...

Soil erosion is one of the vital factors contributing to the loss of fertility and environmental degradation. Generally accepted diagnostics of eroded soils is based on comparison of the sloping soils profile depth with the watershed soils. In this case, there is a separate problem of slope soils with a naturally shortened profile and eroded soils. Formation of the soil’s natura...

2017
C. A. Igwe S. E. Obalum

Soil aggregate stability influences a wide range of physical and biogeochemical processes in the agricultural and natural environments, including soil erosion [3]. The relative prepon‐ derance of aggregates of various sizes in the soil and their stability to external forces are, therefore, an issue of major concern to soil scientists. By definition, an aggregate is a compo‐ site body or granule...

2013
Masakazu Yamashita Masato Hata

Seeking the possibility of the formation of benzoic acids from benzyl halides in natural soil, a model oxidation reaction of the halides was carried out in the presence of water and soil in an open air under UV light irradiation. Addition of TiO2 to soil raised the yield of the acid, implying such a metal oxide plays a real catalytic role in this oxidation. By these supplementary experiments, o...

Journal: :Journal of the Japan Society of Engineering Geology 1990

Journal: :journal of agricultural science and technology 2010
s. s. hashemi m. baghernejad h. khademi

gypsiferous soils occur in xeric, ustic, and aridic moisture regimes. environmental conditions affect the mode of gypsum formation. gypsiferous soils in fars province, southern iran, are found in piedmont plains, flood plains, and alluvial plains. the objective of this work was to investigate the micromorphology of gypsum crystals formed under different soil moisture regimes. the results indica...

Journal: :Letters in applied microbiology 2015
P Weigold A Ruecker M Jochmann X L Osorio Barajas S Lege C Zwiener A Kappler S Behrens

UNLABELLED The mechanisms and organisms involved in the natural formation of volatile organohalogen compounds (VOX) are largely unknown. We provide evidence that the common and widespread soil bacterium Sinorhizobium meliloti strain 1021 is capable of producing up to 3338·6 ± 327·8 ng l(-1) headspace volume of chloroform (CHCl3 ) and 807·8 ± 13·5 ng l(-1)  headspace volume of tetrachloroethene ...

2016
Shulan Zhang Renjie Wang Xueyun Yang Benhua Sun Qinghui Li

Soil aggregation was studied in a 21-year experiment conducted on an Anthrosol. The soil management regimes consisted of cropland abandonment, bare fallow without vegetation and cropping system. The cropping system was combined with the following nutrient management treatments: control (CONTROL, no nutrient input); nitrogen, phosphorus and potassium (NPK); straw plus NPK (SNPK); and manure (M) ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده جنگلداری و مهندسی چوب و کاغذ 1391

درک الگوی توزیع مکانی ماکروفون خاک بدلیل اثرات آن روی فرآیندهای اکوسیستم بسیار مهم است. لیکن اطلاعات کمی در این خصوص وجود دارد. درمورد تنوع زیستی ارگانیسم ها وجانداران خاکزی که ازاجزای مهم وکلیدی درهرسیستم اکولوژیکی هستند و در بهبود حاصلخیزی خاک و تولیدات زمین وپایداری اکوسیستم ها(ازطریق فرآیندهای بیولوژیک)نقش عمده دارند تحقیقات کمی انجام شده است. این تحقیق جهت بررسی الگوی مکانی پارامترهای تنوع...

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