O Litter Horizon A Topsoil humus Loam sandsiltclay

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 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.

• • • 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 prevent wind /water erosion Crop rotation - plant different crops in a field from 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