The thermal conductivity of dry soils is related closely to air pressure and the contact areas between solid particles. In this study, the thermal conductivity of two-phase soil systems was determined under reduced and increased air pressures. The thermal separation of soil particles, i.e., the characteristic dimension of the pore space (d), was then estimated based on the relationship between ...

Identification of global biodiversity hotspots is a leading conservation priority (Mittermayer et al. (1999) Hotspots. Conservation International, Washington, DC; Stein et al. (2000) Precious Heritage: The Status of Biodiversity in the United States. Oxford University Press, Oxford, UK), but we know little about the nature and structure of such hotspots. Botanical richness in one recently ident...

All humans are infected with bacteria (the normal flora) living on their external surfaces (including the skin, gut and lungs). We are constantly also exposed to bacteria (including air, water, soil and food). Normally due to our host defenses most of these bacteria are harmless. In compromised patients, whose defenses are weakened, these bacteria often cause opportunistic infectious diseases w...

Grass cropping in the rotation and the use of no-till seeding appear to be important components for developing sustainable cropping systems. Grass cropping and no-till seeding improve soil organic matter content, increase the soil microbial biomass, increase earthworm numbers, likely cause a buildup of fungivorous microarthropods and nematodes, and greatly increases the resistance of soil to er...

Rice (Oryza sativa L.) is the most important staple food crop in many developing countries, and is ranked third in Kenya after maize and wheat. Continuous cropping without replenishing soil nutrients is a major problem in Kenya resulting to declining soil fertility. The use of chemical fertilizers to avert the problem of low soil fertility is currently limited due to rising costs and environmen...

BACKGROUND Iron (Fe) deficiency in crops is a worldwide agricultural problem. Plants have evolved several strategies to enhance Fe acquisition, but increasing evidence has shown that the intrinsic plant-based strategies alone are insufficient to avoid Fe deficiency in Fe-limited soils. Soil micro-organisms also play a critical role in plant Fe acquisition; however, the mechanisms behind their p...

Recent studies on the speciation of Zn in contaminated soils confirmed the formation of Zn-layered double hydroxide (LDH) and Zn-phyllosilicate phases. However, no information on the kinetics of the formation of those phases under field conditions is currently available. In the present study, the transformation of Zn in a field soil artificially contaminated with ZnO containing filter dust from...

in order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. physical and chemical properties of soil are effective in distribution of plant species in local area. to determine the effects of some soil properties on species distribution of eurotia ceratoides and stipa barbata in baghedar summer region of bafgh, three ...

Estimates of numbers of micro-organisms occurring in three differently manured soils, made by a direct-counting and plating technique, were compared. No correlation was found between the two methods and reasons for the large discrepancy between them are discussed. Contradictory information of the effect of external factors on soil micro-organisms can be given by the two different methods of cou...

General Purpose (use of) Graphics Processing Units (GPGPU) is a promising technology for simulation upscaling; in particular for bottom–up modelling approaches seeking to translate micro-scale system processes to macro-scale properties. Many existing simulations of soil ecosystems do not recover the emergent system scale properties and this may be a consequence of “missing” information at finer...