Soils biological factors

The condition of any soil represents a stage in the changing process of soil evolution. Soils develop, mature and change with the passage of time. Whereas the time required for a true soil to develop from the parent rock of the earth may be thousands of years, rapid changes can result in a few years when soils are cultivated, irrigated, or otherwise subjected to man s manipulation. The type of soil that develops from the parent material will depend upon the various physical, chemical and biological factors of the environment. 

The behavior of technetium in soils is important from an ecological viewpoint, but is quite complicated and depends on many factors. Stalmans et al. [27] stated that it is ruled by a combination of chemical, physicochemical and biological factors and understanding of it is needed on two main accounts bioavailability and geochemical mobility . They also noticed that organic matter in soils and sediments play a significant role as a geochemical sink for technetium. 

Doi R (2004) Soil bacterial community profiling with Biolog kinetic and antibiotic resistance most probable number approaches showed multidimensionality of land degradation. Int J Agri Bio 6 284-288 Doi R, Sakurai K (2003) Soil environmental factors relating to diversity of culturable soil bacterial communities in the Sakaerat Environmental Research Station, Thailand. Tropics 12 185-200... 

Bushby, H.V.A. Marshall, K. C. (1977a). Some factors affecting the survival of root-nodule bacteria on desiccation. Soil Biology Biochemistry, 9, 143-7. 

Detrital processing can be thought of as a continuum from fresh litter to stabilized SOM (Agren and Bosatta, 2002). At different stages in this continuum, the relative importance of each of these environmental and biological factors that have been identified as controlhng decomposition dynamics will likely vary. The initial stages of mass loss are characteristically most affected by climate, resource quality, and, when abundant, soil macrofauna. The physical soil environment also needs to be considered as an important control on the turnover of more humified SOM in the mineral horizons. It is also evident from this literature review that observed correlations between decay rates and decomposition factors are often attributable to both the direct effects of that factor on microbial metabolism and to the indirect interactions with other factors. 

He has contributed to research on the interface between soil chemistry and mineralogy and soil biology. His special areas of research include the formation mechanisms of aluminum hydroxides and oxyhydroxides, the surface chemistry and reactivities of short-range-ordered precipitation products of Al and Fe, the influence of biomolecules on the sorption and desorption of nutrients and xenobiotics on and from variable charge minerals and soils, the factors that influence the sorption and residual activity of enzymes on phyllosilicates, variable charge minerals, organomineral complexes, and soils and the chemistry of arsenic in soil environments. 

Translocation in plant. The last step in elemental availability is translocation from roots to tops, a biological process that would seem outside the control of soil chemistry. A number of trace elements, especially those that take the form of cations in soils, do not readily translocate to plant tops. Therefore it is common for metals such as Cu, Pb, and Cd, after absorption from the soil, to accumulate in (or on) roots. Translocation behavior of plants is complex and not understood for many of the elements of environmental concern, but soil chemical factors (alkalinity, phosphate... 

Numerous physical, chemical and biological factors influence vims persistence and activity. Some of the primary physical factors involved in the persistence of vimses outside living hosts include temperature, ultraviolet light, moisture (or relative humidity) and pH. These factors may interact with each other, and their effect can be additionally altered by vimcidal chemicals, formulation additives, and a variety of substrates, including soil, fabrics and plant foliage. 

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