What characteristic of soil does the term 'capacity to hold water' refer to?

The term 'capacity to hold water' refers to porosity, which is a critical characteristic of soil. Porosity is defined as the percentage of the total volume of soil that consists of pore spaces, which can be filled with air or water. Soils with higher porosity can store more water, making it available for plants and microorganisms. This characteristic is essential because it influences the availability of water for crops, particularly during dry periods.

Soil texture, while related to water retention, focuses more on the size of soil particles (sand, silt, clay) rather than the spaces between them, which actually dictate how much water the soil can hold. Soil structure pertains to the arrangement of soil particles into aggregates, influencing water movement and root penetration but doesn't directly measure the volume of water held. Nutrient status refers to the availability of essential nutrients in the soil, which is distinct from water-holding capacity. Each of these other factors plays a role in overall soil health, but porosity is the specific characteristic that defines the ability to retain water in the soil.