Soil

• Mineral - a solid object formed in nature that has never been alive; they are identified by their hardness, color, and shape
• Rock - a hard object made of one or more minerals; these make up the majority of the Earth
• Soil - the loose material in which plants can grow in the upper layer of Earth
• made of weathered rock which contains minerals, humus, and water and air pockets
• Humus - a part of soil made up of decayed parts of once-living things; it is dark and soft and contains much of what plants need to grow
• Layers of Soil
• Topsoil - the top layer made of the smallest grains and containing the most humus
• Subsoil - layer under topsoil that is made of larger grains and some humus
• Bedrock - solid rock under soil; weathering breaks this down into soil
• Bedrock will be made of different minerals depending on where it is and this will affect what minerals are in the soil

• Different Types of Soil
• Clay soil - small grains, holds water and becomes sticky, dries up into hard clods that can be broken into powder
• Sandy soil - large grains, large spaces for water to easily pass through, less humus than others
• Loam - a type of topsoil that contains a lot of humus, water, and air which makes it ideal for growing plants
• Soil is an important resource, or material that is found in nature that living things use 
• Soil is used to grow food, and is held in place by the roots of plants 
• Many things humans do harms soil (i.e., cutting down too many trees without replanting)
• Soil Conservation
• Conservation - saving resources by using them carefully
• Strip Cropping - planting strips of thick grass or clover between strips of crops; this helps keep water in the soil and keeps the soil from being washed away
• Contour Plowing - planting rows of crops around the sides of hills instead of up and down; this keeps water from running off in straight lines, so the soil won't be washed away

The soil is washed away because there are not enough roots to keep it in place when heavy rain comes.

Strip Cropping used to produce more crops and prevent soil erosion

Contour Plowing keeps water from flowing down in straight lines and carrying away the soil.