PROF1 RATE = Soil Profile 1
The soil profile is the environment in which the crops' roots grow. Profile ratings are based on the depth, structure, texture and chemical make up of the soil. The highest ratings (maximum of 20 points) are given to those soil profiles in which the soil has developed to a depth of 12 inches or more; the soil has good structure, (not hard or blocky); the soil has favourable texture, ( is not gravelly or sandy); and the soil is not full of calcium carbonates or sodium.
Lighter textured soils have mainly large, continuous pores that transmit water very quickly. Rain water can move down through a sandy soil very quickly. A profile adjustment factor has been introduced to decrease the profile rating assigned to lighter textured soils . The profile adjustment factor is based on the moisture holding capacity of the soil texture that makes up the soil profile. It applies only to soils of texture lighter than a loam. The lighter the soil texture, the lower the profile adjustment factor and therefore the lower the profile rating will be. In this example the soil profile is developed to a depth of 10 inches and is calcareous (has calcium carbonate in the profile). The soil profile is a CAL10 which is rated at 8 points. The profile rating has been reduced by a profile adjustment factor due to its sandy texture. (The profile adjustment factors are not shown on the detail profile.)
On this particular sample field sheet no soil association 2 is present. When there are two soil associations present: the climate ratings, organic matter ratings, and texture ratings are all averaged.
On this particular field sheet there are two soil profiles for soil association 1. The second soil profile (PROF2 RATE) is usually the soil profile that is rated with the second soil association in the soil area. In this particular example, the soil profile is OR10. The soil development is to a depth of 10 inches and the profile rating is 11 points.
If more information is required on soil profile ratings, the reader should consult The Canadian System of Soil Classification.
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