Donald Series

Soils included in this series have distinct texture contrasts between hard setting surface soil horizons and moderately to strongly pedal clayey subsoils. Sporadically bleached A2 ‘subsurface' soil horizons are present. The uppermost subsoil layer, that is at least 15 cm thick, is whole colored and red. The soil reaction trend is alkaline.

In the current survey, three soil types and six phases comprise this series: Donald sandy loam, Donald sandy clay loam, and Donald fine sandy clay loam.


Donald Sandy Loam (DO sl)

Profile Morphology:

Surface Soil - A1 horizon

• 10-15 cm thick.
• Brown to dark reddish brown.
• Loamy sand to light sandy clay loam, commonly sandy loam.

Surface Soil - A2 horizon

• About 5 cm thick (range 2-10 cm).
• Reddish brown to dark reddish brown, sporadically bleached.
• Sandy loam.
• This horizon may occur only as nests of sporadic bleaching at the interface between the A and B horizons.

Subsoil

• Red to dark reddish brown, gradually becoming yellowish red at about 50 cm. Color mottling may occur in the deep subsoils.
• Medium to heavy clay.

Soil Inclusions:

• Trace to slight amounts of soft and /or hard CaCO3 usually occur at about 40 cm. Accumulations up to light amounts commonly occur in the deep subsoils.
• Slight to light amounts of weathered sandstone fragments may occur at about 80 cm.

Analytical Data for Selected Depths Down the Profile:

Depth	pH	Total Soluble Salts	Sodium Chloride	Moisture Retention @ 15-Bar	Moisture Retention @ 1/3-Bar
-	-	%	%	%	%
A	7.0	0.022	*	4.3	7.9
B C	8.4 9.2	0.095 0.184	0.049 0.095	20.2 18.2	30.7 28.7

* Sodium chloride contents were not measured and are expected to be very low (based on TSS < 0.05%).

Occurrence:

Donald sandy loam usually occurs on the level areas and gentle slopes.

Phases:

Deep surface:

• The overall depth to the clayey subsoil is about 30 cm (range 16-40 cm).
• A2 horizons comprise about 60-80% of the surface soils.
• Occurs mainly on level areas and foot slopes in the gently undulating plains.

Stony profile:

• Light to moderate amounts of ferruginous concretions and/or sandstone fragments occur throughout the soil profile.
• Occurs mainly on intermediate and upper slopes in the hilly areas.

Donald Sandy Clay Loam (DO scl)

Profile Morphology:

Surface Soil - A1 horizon

• 5-10 cm thick.
• Dark brown to dark reddish brown.
• Sandy clay loam.

Surface Soil - A2 horizon

• About 5 cm thick (range 2-9 cm).
• Brown to dark reddish brown, sporadically bleached.
• Sandy loam to sandy clay loam or loam.
• This horizon often occurs only as nests of sporadic bleaching at the interface between the A and B horizons.

Subsoil

• Reddish brown to dark reddish brown, gradually becoming yellowish red at about 40 cm. Mottled brown colors may occur at about 60 cm.
• Medium to heavy clay.

Soil Inclusions:

• Trace to slight amounts of soft and /or hard CaCO3 occur at about 40 cm. Usually increase up to light amounts at depth.
• Trace to slight amounts of quartz fragments may occur in the surface horizons.

Analytical Data for Selected Depths Down the Profile:

Depth	pH	Total Soluble Salts	Sodium Chloride	Moisture Retention @ 15-Bar	Moisture Retention @ 1/3-Bar
-	-	%	%	%	%
A	7.2	0.029	0.005	6.6	13.3
B C	8.5 9.2	0.077 0.224	0.036 0.078	23.0 23.8	41.1 42.6

Occurrence:

Donald sandy clay loam occurs on various topographical positions varying from slight depressions to intermediate and upper slopes in the undulating plains. It also occurs on some lunettes.

Phases:

Shallow surface:

• The depth to the clayey subsoil is about 6 cm (range 5-9 cm).
• Occurs mainly on crests and upper slopes of the ridges and low rises in the undulating plains.

Deep surface:

• The depth to the clayey subsoil is about 25 cm (range 16-35 cm).
• Trace to slight amounts of quartz fragments often occur in the surface, and/or the deep subsoil horizons.
• At depth, the degree of mottling usually increases and some gleyed colors may occur.
• Occurs mainly on intermediate and upper slopes of the undulating plains and lower outwash slopes. It also occurs in localized areas on the level and gently undulating plains.

Donald Fine Sandy Clay Loam (DO fscl)

Profile Morphology:

Surface Soil - A1 horizon

• 10-15 cm thick.
• Red to reddish brown.
• Fine sandy clay loam, occasionally clay loam.

Surface Soil - A2 horizon

• 3-5 cm thick.
• Brown to yellowish red, sporadically bleached.
• Clay loam to fine sandy clay loam.
• This horizon may occur only as nests of sporadic bleaching at the interface between the A and B horizons.

Subsoil

• Dark red to yellowish red, gradually becoming mottled and dominantly reddish yellow and/or brown at about 70 cm.
• Medium to heavy clay.

Soil Inclusions:

• Trace to slight amounts of soft and /or hard CaCO3 occur at about 50 cm. Amounts may increase with depth.
• Pockets of fine crystals of gypsum may occur sporadically in the deep subsoils.
• Trace to slight amounts of stone fragments, scattered on the surface, may occur in some localities.

Analytical Data for Selected Depths Down the Profile:

Depth	pH	Total Soluble Salts	Sodium Chloride	Moisture Retention @ 15-Bar	Moisture Retention @ 1/3-Bar
-	-	%	%	%	%
A	6.7	0.027	0.014	7.1	16.0
B C	8.2 8.8	0.079 0.228	0.035 0.087	20.8 20.4	36.4 36.4

Occurrence:

Donald fine sandy clay loam is usually found on intermediate and upper slopes in the undulating plains. It also occurs on some lunettes.

Phases:

Shallow surface:

• The depth to the clayey subsoil is about 6 cm (range 5-9 cm).
• Occurs mainly on level areas of the very gently undulating plains and on some parts of the flood plains.

Deep surface:

• The depth to the clayey subsoil is about 25 cm (range 16-35 cm).
• Occurs mainly on level areas of the gently undulating plains and on some parts of the flood plains.