2-10 mm

2-10mm pumice can be used as a soil conditioner in soils that lack an ideal grain size composition and exhibit mild drainage or air permeability problems. Pumice makes heavy clay soils more porous, which improves drainage and reduces the average pore size of sandy soils and ultimately increases their water capacity, that is, their ability to retain water.

In addition, pumice increases the total porosity of sandy soils, which is very low by default (around 35-40%), improving their air permeability. In conclusion, incorporating pumice into soil does not directly affect its pH or fertility due to its natural, chemically inert properties.

Nevertheless, it indirectly improves soil fertility through

drainage and aeration, which in turn increases nutrient availability and facilitates extensive root growth within a larger volume of soil.