Flashcards in Soil Deck (17):
What does SOM stand for and in which layer of soil is most of it contained?
Soil Organic Matter; topsoil
What is soil degradation?
The loss of topsoil and its nutrients through erosion or other processes
Describe the process of salinization
Water containing ions deposits these as salts after it evaporates from the soil, leaving higher concentrations of the salt in the soil
Name three processes that aid in soil degradation
Salinization, Nutrient Depletion, Soil Pollution
Describe Nutrient Depletion
Plants remove nutrients from the soil. If they themselves are removed, there is a net loss of nutrients to that environment
Name some sources of soil pollution
Fertilizer, pesticides, chemical dumping, chemical spillages, leaching from landfills
What are the primary components of SOM?
undecided plant and animal tissue, decomposition products, soil biomass (e.g. microorganisms)
What are non-humic substances?
Substances excreted directly from cells, such as proteins, polysaccharides, amino acids, and sugars
What are Fulvic and Humic acids?
Weak acids composed of complex mixtures of large molecules
To what extent is Fulvic acid soluble?
Soluble in basic and acidic solutions
To what extent is Humic acid soluble?
Soluble in basic solution but insoluble in acidic solution
To what extent is Humin soluble?
What are the physical properties of SOM?
Improves soil water retention, alters soil thermal properties, improves structural stability
What is the biological property of SOM?
Source of energy and nutrients
What is cation exchange capacity?
Measure of the amount of exchangeable cations in the soil
What are some examples of organic soil pollutants?
Petroleum hydrocarbons, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organotin compounds, VOCs, semi-volatile organic compounds (SVOCs)