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12 Cards in this Set
- Front
- Back
Entisols
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-soils of very recent origin
characterized by great diversity in environmental setting and land use many are found in steep, rocky settings |
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Inceptisols
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-minimum horizon development (more developed than Entisols)
-widely distrubuted |
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Andisols
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-soils formed in volcanic ash
-dominated by glassy and poorly crystalline collloidal materials -high OM, water holding capacity -naturally fertile -fix large quantities of P -least extensive soil order |
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Gelisols
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-soils of very cold climates that contain permafrost within 2m of the surface
limited to polar regions and high mountain elevations -soil formation is slow due to cold temps -high OM because very slow decomp |
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Histosols
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-composed mainly of organic materials
-have at least 20-30% OM -low bulk density -formed in wetland areas -contain large amounts of carbon |
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Aridisols
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-calcium carbonate containing soils or arid regions
-ochric epideon w/ light color and low OM -often have accumulation of calcium carbonate, gypsum, soluble salts or exchangeable sodium -widely distributed in desert regions |
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Vertisols
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-clay rich soils that shrink and swell with changes in moisture content
-shrink-swell causes mixing and prevents development of distinct, well-developed horizons -difficult to till, susceptible to erosion |
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Mollisols
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-dark, soft soils of grasslands
-most imporant ag soils in the world |
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Alfisols
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-moderately leached forest soils w? relatively high native fertility
-found in humid and subhumid regions of the world -generally very productive for ag |
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Ultisols
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-strongly leached forest soils w/ low native fertility
-found in humid and tropical regions on older stable landscapes -intensive weathering has leached most Ca, Mg, and K -strong yellow to red colors cause of iron oxides |
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Spodosols
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acid soils
-often from under coniferous forest vegetation -not naturally fertile |
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Oxisols
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-highly weathered soils found in humid tropical regions in stable landscape positions
-rixh in fe and al oxide minerals -extremely low native fertility, high p fixing capacity, low CEC, moderate acidity -usually well structured, resistat to compaction and erosion |