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29 Cards in this Set
- Front
- Back
What three elements make up 80% of the soil?
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Oxygen, Silicon, Aluminium
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soil is a...
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...heterogeneous mixture of interacting materials
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Limestone weathering
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CaCO3+H2O+CO2 goes to
(Ca)2+ +(2HCO3)- |
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What are common soil pollutants?
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petroleum hydrocarbons, agrichemicals, VOCs, solvents, polyaromatic hydrocarbons, polychlorinated biphenyls, organotin compounds, semi-volatile compounds
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What is salinization? Why does salinization reduce plant growth?
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when water and salt molecules accumulate in the soil due to irrigation
The concentration of ions reduce the ability of roots to take up water - osmosis cannot take place efficiently |
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What 5 metals make up 5% of the soil?
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Calcium, Iron, Potassium, Magnesium and
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Formula for when 1 in every 4 tetrahedrons has Al3+
Formula for when 2 in every 4 tetrahedrons has Al3+ |
AlSi3O8 -
Al2Si2O8 2- |
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Sources of:
petroleum hydrocarbons agrichemicals |
discharges and accidents from the petroleum industrey (e.g. tanker, oil fields, pipelines)
agriculture: fertilizers, pesticides that leach into the ground |
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Equation for the chemical wethering of limestone
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CaCO3(s)+H2O(l)+CO2(g)-->(Ca)2+(aq)+2(HCO3)-(aq)
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Sources of semi-volatile organic compounds (SVOCs), those with boiling points greater than 200° such as PCBs, PAHs
Sources of VOCs |
Pesticides and fungicides in agriculture and chemicals used in preserving wood, propellatns, fuels
Household products, fuels from gasoline, cleaning and degreasing products, chemicals drom copiers and printers, glues, markers, paints |
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What is soil made up of?
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inorganic matter, water, air smaller amounts of organic matter
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Osmosis
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Water moces from low ion concentration in roots to high concentration in soil
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What happens to the organic matter in soil?
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It is converted into humus, a water insoluble mixture that consists 50% of carbon and 5% nitrogen, by bacteria and fungi
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Sources of :
solvents polyaromatic hydrocarbons Polychlorinated biphenyls |
dry cleaning, electronics industry, paint manufacture
tar, coal, crude oil spills, incomplete combustion of wood, vegetation, waste incineration, industrial emission incinerator stacks, leaks from enclosed electrical equipment, leaks from hydraulic fluids |
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Partial dissociation of humic acids present in SOM
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RCOOH <--> RCOO - + H +
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Chemical weathering of limestone, calcium carbonate
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CaCO3 (s) + H2O (l) + CO2 (g) --> Ca (2+) (aq) + 2HCO3 (-) (aq)
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what is SOM?
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SOM=Soil organic matter.
A mixture of non-living organic compounds in soil at various stages of decomposition through biological/chemical reactions on plant matter or dead organisms. |
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SOurces of :
organotin compounds semi-VOCs |
PVCs, ship paint used to stop marine life from attaching to the hull
pesticides and fungicides, chemicals used in preserving wood, propellants, fuel |
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What is mineralization?
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the slow process by which organic matter containing nitrogen and phosphorus is broken down to release them into roots.
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Changes in the nutrient concentration in soil are caused by...
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...acid deposition, water runoff from soil, pollution, pesticides, harvesting of crops
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What is nutrient depletion?
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Removal of essential nutrients from the soil food web by crops that lead to sil degradation
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How does salinization reduce plant growth?
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Due to the fact that increased concentrations of ions reduce the ability of roots to take up water, they can't grow that fast or can't grow at all and die. This phenomenon is called osmosis.
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What is inorganic matter made of?
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Silica, silicates and aluminosilicates
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What does SOM act as biologically?
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it acts as a nutrient reservoir for plants, which can take up the nutrients through their roots
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What salts are irigated in the soil?
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CaCl2+MgSO4+NaCl
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What are humic acids?
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Acids of diiferent composition with the functional groups ArOH and RCOOH or phemolic and carboxylic acid functional groups.
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List the factors that cause soil pollution or contamination
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pesticides, herbicides, fungicides, nitrate/phosphate fertilizers, domestic/industrial waste containing heavy metals and organic contaminants such as PCBs (polychlorobiphenyls) or PAHs (poly aromatic hydrocarbons)
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What are the elements present in the soil that have a 1% under 5%
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Calcium, Iron, Potassium, Magnesium and Sodium
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How is soil created?
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Through the weathering of rocks due its breakdown by biological decay of organic matter by microbial action due to bacteria and fungi in the soil and by physical and chemical means
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