Soil Environment
From MicrobeWiki, the student-edited microbiology resource
List of Topics
Introduction
This page is a work in progress. We study the soil environment and physical factors controlling microbial activity.
Key Points
Physical Factors
Soil Texture Sand (0.05-2.0 mm) Silt (0.002-0.05mm) Clay ( < 0.002mm)
Soil Density
Soil Pores Soil pores play a major role in water and air movement. Also, soil microorganisms reside in pores. Pore Size Distribution Macropores ( >75um) Mesopores ( 30-70um) Micropores ( 5-30um) Ulltramicropores (0.1-5um) Crytopores ( <0.1um)
Soil structure Aggregation of primary soil particles is a critical determinant of soil structure.
Soil Environment
Abiotic factors
Soil water - Soil water is essential for soil microorganisms. Without some water, there is no microbial activity.
Soil aeration Soil aeration measures how well a soil is oxygenated. Ideally, a well-aerated soil would have sufficient oxygen for the respiration of plant roots and the function of most aerobic microorganisms.
Soil temperature Soil temperature greatly influences the rates of biological, physical, and chemical processes in the soil. Within a limited range, the rates of chemical reactions and biological processes double for every 10 degree increase.
Toxins poisonous substance produced by living cells or organisms that is active at very low concentrations.
Osmotic pressure Osmotic pressure is the hydrostatic pressure produced by a solution in a space divided by a semi-permeable membrane due to a differential in the concentrations of solute.
PH Soil pH is important because microorganisms and plants respond markedly to chemicals in their environment. Most soil microorganisms and plants prefer a near-neutral pH range of 6 to 7 because the availability of most soil nutrients is best in this pH range.
Bioavailability - Bioavailability is the amount of a contaminant that is absorbed from soil.
Biotic factors
Native vegetation
Microflora
Microfauna
Macrofauna
Anthropogenic (farming, ect.)
Current Research
References
Edited by students of Kate Scow
