GEOG 3108 Lecture Notes - Lecture 2: Soil Texture, Aeration, Silt
30 Sep 2016
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Document Summary
Soil compaction: the process by which soil grains (particles) are rearranged to decrease pore space (primarily macropores) and bring grains in closer contact with one another thereby increasing the soil bulk density. Soil compaction cause roots to either stop growing, plow through the soil, or grow sideways. Some causes of compaction: wheel traffic compaction, tillage practices. Soil compaction is measured by 1) texture, 2) structure, and 3) moisture: soil texture: a key property of the mineral component of a soil describing the relative proportions of sand, silt, and clay. Analyze sample for sand, silt, and clay content and use triangular texture diagram. In the field, moisten sample and rub between fingers (sand is gritty, silt is smooth, clay is stick) Texture is easy to determine and allows prediction of many soil properties: soil structure: assemblage of soil particles to form aggregates (peds), which influence porosity and pore size distribution.
