Soil texture is defined as ‘the relative proportion of the various size groups of individual soil particles; the individual size groups are referred to as soil separates. The following soil groups are recognized;
- Clay - particles smaller than 0.002 mm.
- Silt - particles between 0.002 mm and 0.02 mm.
- Fine sand - particles between 0.02 mm and 0.2 mm.
- Coarse sand - particles between 0.2 mm and 2.0 mm.
- Gravel - particles over 2.0 mm.
Depending on the proportion of soil separates, soils are classified into different soil classes which is defined as ‘a group of soils having same range in particle size and physical properties based on texture. The following table gives the composition of various soil classes:
||(%) limits of mixture
|Clay||<50||<50||30 or more||Homogenous, very sticky and plastic, compact and hard when dry.|
|Silt loam||<50||50 or more||<20||
|Loam||30-50||30-50||<20||Not homogenous, plastic when wet|
|Loamy sand||80-85||15-20||Sandy to touch|
|Sandy loam||50-80||20-25||Heterogenous, slightly plastic when wet|