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Soil PowerPoint Presentation

Soil

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Soil

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  1. Soil November 7, 2013

  2. So, what is soil? • The end product of weathering • Loose mixture of small mineral fragments, organic material, water and air • 2 kinds: • 1. Residual soil – soil that is weathered from rocks found in soil called its parent rock • 2. transported soil – soil that has been weathered from rocks then moved to its current location by erosion

  3. Are all soils alike? • No, each have own unique properties • Texture – soil quality based on the proportions of soil particles • Sand – 2mm-.05 mm • Silt - .05m - .002 mm • Clay – less than .002 mm

  4. What about the organic material? • Important for the fertility of the soil • Humus – organic material formed from the decay of plants and animals • Only broken down by bacteria and fungi in soil • Allows the soil to hold nutrients and supply them to plants • Humus • Not hummus

  5. Is soil the same all the way all the way down? • No, soil forms distinct layers called horizons • A horizon – consists of topsoil, humus and sometimes litter from dead plants and animals • B horizon – collects the dissolved substances and nutrients deposited by the A horizon • C horizon – made mostly of bedrock that has little or no weathering

  6. What are some other properties? • pH – influences which nutrients will be available to plants from the soil • Certain nutrients are available in acidic (low pH) and others are available in basic or alkaline (high pH)

  7. Color – tells a lot about soil fertility • Black and dark – contain organic matter and is fertile • Reddish-yellow – often contain oxidized iron, somewhat fertile • Whitish – may contain salts that make soil unsuitable for life