What is the term that describes the proportion and size of soil particles?

The term that describes the proportion and size of soil particles is "Soil Texture." Soil texture is determined by the relative amounts of sand, silt, and clay present in the soil. This composition is crucial because it influences a variety of soil characteristics, including water retention, drainage, aeration, and nutrient availability. Different textures can dramatically affect how soil behaves in terms of both plant growth and environmental interactions.

Soil pH refers to the acidity or alkalinity of the soil, which affects nutrient availability and microbial activity but does not directly describe particle size or proportion. Soil structure relates to how soil particles aggregate, influencing water movement and root penetration, yet it does not specifically address the size or proportion of the particles themselves. Soil fertility encompasses the overall health and nutrient content of the soil, including its ability to supply essential elements to plants, but again, it does not specifically refer to particle size or proportion. Thus, the correct answer highlighted the essential characteristic of soil texture accurately representing the composition of soil particles.