What does bulk density measure in soil?

Bulk density is a crucial measurement in soil science that reflects the weight of a soil sample relative to its volume, which includes both the solids and the pores within the soil. It is calculated by dividing the mass of dry soil by its volume. This measurement is important because it gives insights into several key soil properties.

When the bulk density is known, it can help infer soil compaction levels and porosity, influencing variables such as water retention, root penetration, and overall soil health. Bulk density can indicate how densely packed the soil particles are, which in turn affects the air and water movement through the soil.

While the other options discuss different soil properties—such as acidity levels, the amount of pore space, or nutrient status—they do not directly relate to the measure of weight in relation to volume, which is the specific focus of bulk density. Understanding bulk density aids in assessing how well the soil can support vegetation and how it can be managed for agricultural practices.