Which type of soil has the greatest percentage of porosity?

The type of soil with the greatest percentage of porosity is silt. Silt particles are smaller than sand particles but larger than clay particles. This intermediate size allows silt to hold more water and air in the spaces between particles compared to sand, which has larger particles and therefore larger but fewer pore spaces. Silt's structure provides a good balance of porosity, enabling it to retain moisture effectively while still allowing for some drainage.

Clay, in contrast, has very small particle sizes that create tiny pores, leading to high water retention but low permeability. While clay can exhibit high total porosity due to its fine particles, its ability to transmit water is limited, affecting its functional porosity differently than silt. Sandy soils have larger particles and lower total porosity, as they provide large pore spaces that do not hold water well. Loam is a balanced mixture of sand, silt, and clay, which gives it good fertility and drainage properties but does not surpass silt in terms of porosity.

Silt is favored in contexts where water retention and drainage balance are essential, making it significant for agricultural practices and natural ecosystems.