Callawadda Series

Soils included in this series have distinct texture contrasts between hard setting surface soil horizons and moderately to strongly pedal clayey subsoils. Conspicuously 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 (Callawadda loam, Callawadda sandy clay loam, and Callawadda fine sandy clay loam) and one phase comprise this series:

Callawadda Loam (CA l)

Profile Morphology:

Surface Soil - A1 horizon

• 10 cm thick.
• Brown to dark reddish brown.
• Loam to light sandy clay loam.

Surface Soil - A2 horizon

• 10-15 cm thick.
• Reddish brown to yellowish red (moist) conspicuously bleached near white (dry).
• Light sandy clay loam to clay loam.

Subsoil

• Reddish brown to dark red, clearly changing to strong brown (occasionally mottled with grey) at about 60 cm.
• Medium to heavy clay.
• At about 70 cm, the subsoil usually changes into silty clay or fine sandy clay loam, massive to moderately pedal soil material.

Soil Inclusions:

• Trace to slight amounts of soft and /or hard calcium carbonate occur at about 60 cm.
• Trace amounts of quartz fragments may occur in the surface soils.

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	5.4	0.010	*	6.2	20.5
B C	7.6 8.3	0.103 0.110	0.055 0.077	16.9 10.5	29.3 23.5

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

Occurrence:

Callawadda loam usually occurs on the level and gentle slopes in the flood plains and plains with prior streams.


Callawadda Sandy Clay Loam (CA scl)

Profile Morphology:

Surface Soil - A1 horizon

• 6-12 cm thick.
• Dark brown to dark reddish brown.
• Sandy clay loam.
  

Surface Soil - A2 horizon

• 15-25 cm thick.
• Reddish brown to yellowish red (moist) conspicuously bleached near white (dry).
• Sandy clay loam.
  

Subsoil

• Reddish brown to red, gradually becoming slightly yellower with depth.
• Slight color mottling may occur in the deep subsoils.
• Medium to heavy clay.
  

Soil Inclusions:

• Trace to slight amounts of soft and/or hard calcium carbonate occur at various depths in the clayey subsoils.
• Occasional to trace 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	6.9	0.022	*	7.8	15.9
B C	8.5 9.0	0.030 0.057	* 0.009	25.6 25.2	40.5 39.7

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

Occurrence:

Callawadda sandy clay loam is usually found on the slight depressions, lower slopes and level parts of the undulating plains.


Callawadda Fine Sandy Clay Loam (CA fscl)

Profile Morphology:

Surface Soil - A1 horizon

• 8-15 cm thick.
• Dark reddish brown to red.
• Fine sandy clay loam to clay loam.
  

Surface Soil - A2 horizon

• About 20 cm thick.
• Sandy clay loam to fine sandy clay loam.
• Light reddish brown to yellowish red (moist) conspicuously bleached near white (dry).

Subsoil

• Red to yellowish red, gradually becoming slightly yellower with depth. Slight mottling may occur in the deep subsoils.
• Medium to heavy clay. Sandy clay material may occur at about 100 cm.
  

Soil Inclusions:

• Trace to slight amounts of soft and/or hard calcium carbonate occur at various depths in the clayey subsoils.

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	6.6	0.022	*	6.3	19.3
B C	7.7 8.1	0.055 0.071	0.036 0.037	18.9 17.2	34.7 31.9

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

Occurrence:

Callawadda fine sandy clay loam usually occurs on the slight depressions, lower slopes and level parts of the undulating plains.

Phases:

Deep surface:

• The overall depth to the clayey subsoil is about 50 cm (range 35-55 cm).
• A2 horizons comprise about 80% of the surface soils.
• Occurs mainly on level areas and lower slopes in the undulating plains.