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Unformatted text preview: s in soil (mycorrhizae), geological uplift Human intervention:
Mining phosphate rock for fertilizer;
Fishing; sewage, agricultural runoff, erosion Human intervention in phosphorous cycle – Fast‐growing, weedy (r‐selected) plants favoured
– Nitrate buildup in groundwater a hazard in agricultural areas – Eutrophication of coastal waters, anoxia Phosphorus chemistry 101
• No gaseous forms, so mostly in rocks • Made available through “weathering,” geological uplift, mining
• Atmospheric dust sometimes important input
• Phosphate (PO4‐3) technically soluble, but can be bound by soil components; mycorrhizal
fungi help pull it into solution so plant roots can get it Phosphate rock for fertilizer in agriculture
• Mostly sedimentary rock (old seabed, uplifted) • A sedimentary cycle (slow)
• We can’t make P fertilizer; must mine phosphate‐rich rock (also, guano deposits)
• Lost from terrestrial systems by runoff, erosion, over‐application of fertilizers: eutrophication of rivers and lakes
• Much ends up back in marine sediments • Biggest known reserves (in order): Morocco, USA, South Africa, Jordan, China, Russia, Senegal
• “Based on current...
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This note was uploaded on 03/31/2013 for the course BIO 101 taught by Professor Profans during the Spring '13 term at Case Western.
- Spring '13