O Horizon - Top layer of soil, has animal waste, dead organisms, and fallen leaves, microorganisms, protects from erosion

A Horizon - known as topsoil, layer contains organic humus, has a distinctive dark color, microorganisms

B Horizon - known as sub soil, has inorganic rock materials such as slit, clay and sand

C Horizon - sits on top of bedrock, made up of weathered fragments 

Typical loam made up of 20:40:40

clay, silt, sand 

Sandy Loam - percentage of sand is higher than the soil

Silty Loam - percentage of silt is higher than the soil

Soil porosity - measure of volume of spaces of pore spaces, between soil grains per volume and determines the water and air holding capacity of the soil 

Soil Permeability - average pore size the ease at which water can seep into them 

Primary macronutrients - nitrogen, potassium, phosphorus 

Secondary macronutrients - calcium, magnesium, sulfur 

Micronutrients - boron, chlorine, iron, maganese, copper, zinc, molybdenum 

Erosion - removes finer particles and nutrients from the water, mixture of wind and water

Salinization - when considerable amounts of salt accumulate in soil 

Wind Breaks - reduce wind speed,  at ground level by planting taller trees

Tillage - turning over the soil ( minimize this to prevent erosion)

No-till agriculture - land disturbed as little as possible, by leaving crop residue in the fields

Contour Farming - plowing and planting crop rows along the natural contours of gently sloping land 

Terracing - used to control water erosion on more steeply  sloped hills and mountains