Download soil study guide 2015

O = Litter
Horizon A = Topsoil = humus+ Loam
(sand/silt/clay)
Horizon B = subsoil (clay/washeddown particles from Horizon A.
Horizon C = Bedrock , partlyweathered rock material
Soil – the loose, weathered material on Earth’s surface which plants can
grow.
Litter – a loose layer of leaves and other plant material on top of the soil
Humus -decayed plant and animal remains
Soil horizon/profile – a layer of soil that differs from the layers above
and below it
Loam – soil made up of equal parts of clay, sand and silt = the best
mixture!
Decomposers – organisms that break down animal and plant remains
and wastes
Leaching – drain away from soil/organic matter removed from soil or
rock.
Why is soil valuable?????
• It provides minerals and other
nutrients for plants.
• all animals get their energy from
plants by either eating them or
eating animals that have eaten
plants.
• It provides homes (habitats) for
insects & animals.
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WAYS PEOPLE HELP THE SOIL:
Conservation of soil - a method to maintain the fertility of the soil by protecting the soil from
erosion and nutrient loss.
Contour plowing - forms ridges, slows the water flow and helps save precious topsoil.
Terraced farming - uses "steps" that are built into the side of a mountain or hill. Good for
when the farmer does not have room for crops.
No-till farming -dead weeds and stalks are left in the ground from year to year to prevent
wind /water erosion
Crop rotation - plant different crops in a field from year to year to slow nutrient depletion.
Cover crops – crops that are planted between harvests to replace the nutrients and keep the
soil from eroding. (ex. Cabbage grown in the winter time)
WAYS SOIL LOSES FERTILITY & becomes useless:
Desertification – when dryland areas become even dryer from lack of rain & overuse by
humans.
Erosion – when soil & sediments are carried away by wind, water or gravity.
Over-use – when humans farm too much, over-mining, building too much and over-watering.
Pollution – pollutants from mining, chemical spills, HUMANS