نتایج جستجو برای: soil formation

تعداد نتایج: 703087  

2015
Karen M. Barry David P. Janos David M. J. S. Bowman

Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse....

2003
Douglas L. Karlen Craig A. Ditzler Susan S. Andrews

The soil quality concept evolved throughout the 1990s in response to increased global emphasis on sustainable land use and with a holistic focus emphasizing that sustainable soil management requires more than soil erosion control. The concept includes two areas of emphasis—education and assessment—both based soundly on principles of soil science. Soil quality test kits, farmer-based scorecards,...

2017
Xueqing Zhang Yasong Li Hui Li

This paper examines the potential value of phosphate-solubilizing bacteria(PSB) in the dissolution of soil phosphorus and in the subsequent immobilization of lead (Pb), both in bacterial growth medium and in soil. In growth medium, Pseudomonas chlororaphis showed both phosphate-solubilizing and Pb-immobilizing capability, the immobilization of Pb was attributed to pyromorphite formation, as ind...

2005
A. P. Kravets

A three–module ecological model for assessment of radiological consequences (EMARC) of accidental fallout was developed to estimate the internal dose. The model was adapted for ecological and economic conditions of Ukraine after the Chernobyl accident. The model takes into account the main natural mechanisms of changes in level of agricultural production pollution such as transformation of bioa...

2007
O. V. Kyrychenko

Modulation of the effect of wheat germ agglutinin (WGA) with hapten, N-acetyl-D-glucosamine (GlcNAc), in case of pre-sowing treatment of spring wheat (Triticum aestivum cv Rannyaya 93) seeds, on the biological components of the system ’’plant – soil – microorganisms” was studied. The application of WGA (100 nM) stimulated root formation, biomass production, total chlorophyll content and wheat g...

2009
Martin Werth Yakov Kuzyakov

Introduction Natural variations of the C/C ratio have been frequently used over the last three decades to trace C sources and fluxes between plants, microorganisms, and soil. Most of these studies have used the natural C labelling approach, i.e. natural δC variation after C3 – C4 vegetation changes. In this mini-review, we focus on C fractionation in processes at the interface between roots, mi...

Journal: :Applied and environmental microbiology 2002
Kuk-Jeong Chin Peter H Janssen

Propionate-forming bacteria seem to be abundant in anoxic rice paddy soil, but biogeochemical investigations show that propionate is not a correspondingly important intermediate in carbon flux in this system. Mixed cultures of Opitutus terrae strain PB90-1, a representative propionate-producing bacterium from rice paddy soil, and the hydrogenotrophic Methanospirillum hungatei strain SK maintain...

Journal: :Science 2009
P H Smith L K Tamppari R E Arvidson D Bass D Blaney W V Boynton A Carswell D C Catling B C Clark T Duck E Dejong D Fisher W Goetz H P Gunnlaugsson M H Hecht V Hipkin J Hoffman S F Hviid H U Keller S P Kounaves C F Lange M T Lemmon M B Madsen W J Markiewicz J Marshall C P McKay M T Mellon D W Ming R V Morris W T Pike N Renno U Staufer C Stoker P Taylor J A Whiteway A P Zent

The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5 degrees and 148 degrees ). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H(2)O ice...

Journal: :دانش آب و خاک 0
فهیمه محمدقاسمی کارشناس ارشد مرتع داری، دانشکده منابع طبیعی دانشگاه صنعتی اصفهان، ایران سید حمید متین خواه استادیار گروه مرتع و آبخیزداری، دانشکده منابع طبیعی دانشگاه صنعتی اصفهان، ایران عاطفه شهبازی دانشجوی دکتری علوم مرتع، دانشکده منابع طبیعی دانشگاه صنعتی اصفهان، ایران

plants have noticeable effects on soil resources distribution and its biochemical processes, and organic materials are naturally much more in the understory soil as compared to open areas. vegetation as one of the soil formation factors is not always an independent variable, so that the soil and vegetation can have interaction. the present study was conducted to investigate the effects of hedys...

2000
HUIMING BAO PAUL L. KOCH MARK H. THIEMENS

Low-temperature synthesis experiments on ferric oxide–water systems have resulted in disparate oxygen isotope fractionation–temperature (a-T) curves. In this study, recent ferric oxides, mostly goethites of Holocene age, were collected and analyzed from a variety of modern soil, stream, and marine environments, where formation temperature and the oxygen isotopic composition (dO) of the water fr...

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