Which soil particle size is considered the smallest?

Clay is considered the smallest soil particle size, with particles measuring less than 0.002 millimeters in diameter. This fine texture contributes to clay's unique properties, such as high plasticity and the ability to retain moisture. Due to its small particle size, clay has a large surface area relative to its volume, allowing it to hold nutrients and water effectively. This characteristic makes clay crucial in various agricultural and environmental contexts.

In contrast, silt particles are larger than clay but still relatively small, ranging from 0.002 to 0.05 millimeters. Sand particles are coarser, varying from 0.05 to 2 millimeters, while gravel consists of even larger particles, typically ranging from 2 millimeters up to several centimeters. Understanding the various soil particle sizes is essential for grasping how soils behave in different conditions and impacts such as drainage, aeration, and nutrient availability.