Parent material- rock from which soil forms
Weathering- breaking rock down by biological, physical and chemical processes
Topography-surface features of the land
Humus- decomposed organic matter
Leaches- movement of water and dissolved chemicals through the ground
Illuviation- deposition of leached minerals in the lower layers of the soil
Soil Profile- vertical section of soil showing the soil horizons
O-Horizon- uppermost layer of the soil rich in organic matter
A-Horion- dark colored horizon containing organic matter mixed with mineral soil
E-Horizon- light-colored, heavily leached horizons sometimes present between A and B horizons
B-Horizon- lighter in color than the A horizon, the B horizon is rich in minerals that leached out of the upper layers. Usually high in iron, aluminum and clay
C-Horizon- contains weathered rock fragments and borders the unweathered parent material
Mycorrhizae- symbiotic relationship between roots of plants and fungi in the soil
Mycelium- thread-like body of fungi
Abiotic- nonliving
Texture- the relative proportions of sand, silt and cay in a soil
Sand- the coarsest mineral particles (0.05mm to 2 mm in diameter) It isn’t necessary to memorize the actual size range but you should know these are coarser than silt or clay.
Silt- medium-sized mineral (0.002 to 0.05 mm in diameter)
Clay- the finest mineral particles (less than 0.002 mm in diameter)
Loam- soil containing approximately 40% sand, 40% silt and 20% clay. Loam is excellent for most agricultural uses.
Erosion- movement of soil from one area to another
Salinization- the salinity of soil increases over time due to poor irrigation and soil management practices
Desertification- the conversion of productive land into unfertile desert
Shelterbelts- rows of trees planted to reduce erosion from wind
Agroforestry- simultaneously growing trees and other crops to improve