Ch. 6 Organic Matter
Organic soil that contains slightly decayed plant remains
Peat
Another name for cohesion water
Capillary water
How rapidly excess water leaves soil
Drainage
Drains away under the force of gravity
Gravitational potential
Long chain structures
Proteins
Dictates the behavior of water in the soil
Soil-water potential
Moves excess underground water from the soil through buried drainage lines
Subsurface drainage
A pure inorganic compound in the earth’s crust. Often used in soil science to mean the inorganic solid particles of soil.
Mineral
Sugar molecules linked together to form various long chains that make more complex carbohydrates
Starches
Water around soil particles that is held so tightly it cannot move; cannot be removed by roots
Adhesion water
Collects and removes excess water from the soil surface
Surface drainage
Most roots occupy the upper ___ inches of soil; most roots do not extend deeper than five to six feet below the soil surface.
12
Rich in nitrogen and sulfur
Amino acids
The attraction of water to soil particles and to itself
Matric potential
In irrigating saline soil, the amount of water to be applied in excess of that needed to wet the root zone of the plant is called the ____ requirement.
leaching
Hardpans, water-logged soil, and ____ prevent roots from growing deeply.
bedrock
Mostly decayed plant materials in organic soil
Sapric
Held so tightly to soil particles that it can only be removed by drying soil in an oven
Hygroscopic water
A benefit of artificial drainage and irrigation
make otherwise difficult soil productive
Oxygen, carbon, and ____ are gases exchanged in soil.
nitrogen