نتایج جستجو برای: a 2000 small scale spatial soil plant relationship in semi arid gypsum environments

تعداد نتایج: 20655252  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده ادبیات و علوم انسانی 1391

with the introduction of communicative language teaching, a large number of studies have concerned with students’ oral participation in language classrooms. although the importance of classroom participation is evident, some language learners are unwilling to engage in oral activities. this passivity and unwillingness to participate in language classroom discussions is known as “reticence”. rev...

Journal: :Global change biology 2015
Martin Wiesmeier Sam Munro Frauke Barthold Markus Steffens Peter Schad Ingrid Kögel-Knabner

Organic carbon (OC) sequestration in degraded semi-arid environments by improved soil management is assumed to contribute substantially to climate change mitigation. However, information about the soil organic carbon (SOC) sequestration potential in steppe soils and their current saturation status remains unknown. In this study, we estimated the OC storage capacity of semi-arid grassland soils ...

ژورنال: علوم آب و خاک 2015
اسفندیارپور, عیسی, شیرانی, حسین, مصلایی, مریم, مظفری, وحید,

Salinity and ions toxicity are one of the main problems of agricultural lands in arid and semi-arid regions, such as Iran. In addition to the salinity problem, some other marks like boron toxicity in crops have been seen in Hossein Abad area as one of the main agricultural regions of Yazd. Therefore, this study intends to evaluate and analyze spatial variability of soil salinity as an aspect of...

حجتی, سعید, خادمی, حسین ,

Type of clay minerals determines the stage of soil evolution. Palygorskite is a dominant clay mineral in soils of arid and semi-arid regions. This study aims to identify the distribution and genesis of palygorskite in some soils developed on Tertiary parent materials in the Isfahan Province. Six soil profiles and their Tertiary parent materials were studied, described and sampled for X-ray diff...

ژورنال: علوم آب و خاک 2011
فایز رئیسی, , فخرالسادات موسوی, ,

Although the crucial function of earthworms in improvement of soil physical properties is well -know, but very little is known of the interactive influence of earthworms and organic materials on soil properties such as soil aggregate stability, particularly in arid and semi-arid soils. The low organic matter content and the significant role of earthworms in improving physical properties of arid...

2003
Benjamin L. Turner Barbara J. Cade-Menun Dale T. Westermann

the need to understand the nature of organic P in these soils. The organic P composition of semi-arid arable soils is largely unSoil organic P determination has traditionally been known, but such information is fundamental to understanding P dynamics in irrigated agriculture. We used solution 31P nuclear magnetic hampered by difficulties with the extraction, separation resonance (NMR) spectrosc...

2015
Ilja Sonnemann Hans Pfestorf Florian Jeltsch Susanne Wurst Cristina Armas

Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content ...

Journal: :journal of agricultural science and technology 2010
a. keyhani

to measure soil water content (or soil matric suction) in thin layers of about 30mm, conventional gypsum blocks are not suitable. to carry out the task, mini-gypsum blocks were constructed using plaster of paris in an innovative fashion. a power relationship was found between the soil water content and the mini-gypsum blocks’ readings in kω. the calibration results showed that readings of m...

Journal: :The New phytologist 2015
Sunil Mundra Rune Halvorsen Håvard Kauserud Eike Müller Unni Vik Pernille B Eidesen

Soil conditions and microclimate are important determinants of the fine-scale distribution of plant species in the Arctic, creating locally heterogeneous vegetation. We hypothesize that root-associated fungal (RAF) communities respond to the same fine-scale environmental gradients as the aboveground vegetation, creating a coherent pattern between aboveground vegetation and RAF. We explored how ...

Journal: :مرتع و آبخیزداری 0
محمد جعفری استاد دانشکدة منابع طبیعی دانشگاه تهران محمد طهمورث دانشجوی دکتری تخصصی آبخیزداری دانشکدة منابع طبیعی دانشگاه تهران محسن نقیلو کارشناس ارشد مرکز تحقیقات بین المللی بیابان دانشگاه تهران

the purpose of this research is investigation of relationship between vegetation cover and soil characteristics and determination of the most important soil factor that effects on quantity variations and kinds of vegetation cover in the study area. the study area is located in west of tehran province and south eastern of hashtgerd, next to najm-abad village. after field study, the index vegetat...

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