Particle Sizes and Soil Texture Classes

Soil texture depends on the percent distribution of three groups of soil particles based on their sizes: sand (2000-50 μm), silt (50-2 μm) and clay (< 2 μm). Soil texture can be determined using a textural triangle presenting 12 classes. Sandy soils have high infiltration but poor nutrient retention, thus require frequent water and fertilizer application. Silty soils have moderate infiltration and nutrient retention. High silt can clog the soil. Clay soils have low infiltration but high nutrient retention. Equal distribution of sand, silt and clay is called loamy soil.