Here's why:

* Sand particles are the largest: Sand grains are much bigger than silt or clay particles. This means they have a rougher surface area and feel gritty to the touch.

* Low surface area: Sand particles have a low surface area compared to smaller particles, which means they don't hold water or nutrients as well.

* Poor drainage: Sand drains water quickly, often leading to dry conditions.

While clay and silt can feel rough if they are very compacted, sand will always have the roughest texture due to the size and shape of its particles.