What does the water retention property of loam primarily depend on?

The water retention property of loam is fundamentally influenced by the composition of its components: sand, silt, and clay. Loam is regarded as an ideal soil type for growing plants because it has an optimal balance of these three textural elements.

Sand particles are larger and create spaces that facilitate drainage, preventing water from being held too long. Silt particles are medium-sized and have good water retention abilities. Clay, being the smallest in particle size, is excellent at holding water due to its fine texture. The ideal mixture in loam allows it to retain moisture while still draining excess water, creating a conducive environment for plant roots to access both air and water.

In contrast, while factors like soil depth, organic matter content, or the addition of fertilizers can affect overall soil health and plant growth, they do not directly dictate the inherent water retention properties that stem from the composition balance of sand, silt, and clay. Thus, the composition of these particles is the primary determinant of how effectively loam retains water.