Gravels > 2 mm are not included in evaluating texture, but should be noted in any description of the soil profile. Soils dominated by sand-sized particles typically have large pore sizes and rapid soil aeration and water percolation. However sand does not hold water or nutrients and may be droughty and infertile. Sand feels gritty when rubbed between the fingers. Silt sized soil particles generally offer adequate aeration and water penetration and reasonable water and nutrient holding capacities. Silt feels slippery when rubbed between the fingers, but is not sticky. Clay has the smallest grain size and pore size distribution. Clay generally offers high mosture and nutrient holding capacity. Clay soils that have not developed good structure do not allow good aeration or water penetration.

2) Soil structure is the aggregation of sand, silt and clay into larger structures called peds. Pore spaces between this aggregation promote water and air movement into soil, which is a highly desirable property of productive soils. Thus the presence of a clay texture in soils does not mean it will have low aeraton or water movement if the soil has a good structure. High degrees of soil structure are most common in finely-textured soils.

3) Soil and rooting depth is determined by the presence of bedrock or layers in soil that restrict root penetration into the soil. Very shallow soils are generally poorer for forestry because of lower nutrient and water availability for plant growth. When comparing similar soil material, forest growth is often strongly correlated with soil depth. Compacted or cemented horizons can restrict water penetration and aeration and can cause a soil with coarse textures to show slow water penetration and poor aeration.

4) Soil permeability is strongly related to soil texture and structure. Medium to coarse textured soils or soils with a high degree of structure generally show rapid water percolation and good aeration. This can be excessive in extreme cases. Fine textured soils with weak structure can have very slow permeability and low aeration.

5) Soil color can be an indication of depth to water table. Soils may be dry when pits are dug (this is certainly the case with NW summers), but the color of the soil may indicate a higher seasonal water table. Water tables restrict rooting depth and may indicate problems with trafficability in winter. Reddish colors indicate the horizon is drained during a large part of the year, while grayish hues denote presence of the water table. Mottling is the presence of both hues near each other, indicating a fluctuating water table.