Basic Soil Components Topic 2052 Developed By Amanda R. Moore

Overview  Introduction  Mineral Components  Organic Matter  Water  Air

Introduction  The Four Major Components are: Mineral Materials Organic Matter Water Air  Exist in a close mixed condition  Interactions among components yields variation in environment for plant growth

Mineral Materials  Variable in Size and Composition  Rock fragments are remnants of parent material  Colloidal clay particles  4 sizes of Inorganic(mineral)particles Gravel-very coarse Sands-coarse Silt-fine Clay-very fine

Organic Matter  An accumulation of plant and animal residues  Constantly being decomposed and replaced  Small percentage of soil – 2-6% by weight  Largely responsible for manageable characteristic of productive soil  Source of soil nitrogen, sulfur and phosphorus

Organic Matter  Increases water-holding capacity  Increases water availability for plants  Main source of energy for soil organisms

Water  Is held in pore spaces between soil particles  Soil water with its salts make up the soil solution  Supplies nutrients to growing plants  Only about ½ of the water is available to plants because of water-holding forces in the soil  Nutrients are exchanged between soil solids and soil solution and then between soil solution and plants

Air  Located in soil pores between soil particles  These pores are the passageways for oxygen movement  Aeration can be limited by water and compaction