Field texture
Code |
Texture | Behaviour of moist bolus | Approximate clay content (%) |
|---|---|---|---|
S |
Sand | Coherence nil to very slight, cannot be moulded; sand grains of medium size; single sand grains adhere to fingers | commonly less than 5% |
LS |
Loamy sand | Slight coherence; sand grains of medium size; can be sheared between thumb and forefinger to give minimal ribbon of about 5 mm | about 5% |
CS |
Clayey sand | Slight coherence; sand grains of medium size; sticky when wet; many sand grains stick to fingers; will form minimal ribbon of 5-15 mm; discolours fingers with clay stain | 5-10% |
SL |
Sandy loam | bolus coherent but very sandy to touch; will form ribbon of 15-25 mm; dominant sand grains are of medium size and are readily visible | 10-20% |
L |
Loam | bolus coherent and rather spongy; smooth feel when manipulated but with no obvious sandiness or 'silkiness'; may be somewhat greasy to the touch if much organic matter present; will form ribbon of about 25 mm | about 25% |
ZL |
Silty loam | coherent bolus; very smooth to often silky when manipulated; will form ribbon of about 25 mm | about 25% and with silt 25% or more |
SCL |
Sandy clay loam | strongly coherent bolus, sandy to touch; medium-size sand grains | about 20-30% |
CL |
Clay loam | coherent plastic bolus, smooth to manipulate; will form ribbon of 40-50 mm | about 30-35% |
CLS |
Clay loam, sandy | coherent plastic bolus; medium-size sand grains visible in finer matrix; will form ribbon of 40-50 mm | about 30-35% |
ZLS |
Silty clay loam | coherent smooth bolus, plastic and often silky to the touch; will form ribbon of 40-50 mm | about 30-35% and with silt 25% or more |
LC |
Light clay | plastic bolus; smooth to touch; slight resistance to shearing between thumb and forefinger; will form ribbon of 50-75 mm | 35-40% |
LMC |
Light medium clay | plastic bolus; smooth to touch; slight to moderate resistance to ribboning shear; will form ribbon of about 75 mm | 40-45% |
MC |
Medium clay | smooth plastic bolus; handles like plasticine and can be moulded into rods without fracture; has moderate resistance to ribboning shear; will form ribbon of 75 mm or more | 45-55% |
MHC |
Medium heavy clay | smooth plastic bolus; handles like plasticine; can be moulded into rods without fracture; has moderate to firm resistance to ribboning shear; will form ribbon of 75 mm or more | 50% or more |
HC |
Heavy clay | smooth plastic bolus; handles like stiff plasticine; can be moulded into rods without fracture; has firm resistance to ribboning shear; will form ribbon of 75 mm or more | 50% or more |
Source: National Committee on Soil and Terrain (2021). Australian Soil and Land Field Survey Handbook, 4th edition, CSIRO Publishing, Melbourne.