Why we like air in the soil

Roots.... it's what we live for as superintendents.  We are always chasing the dream of white, healthy roots, especially in the summer.  Air, glorious fresh air is what keeps roots alive and turf systems functioning even in the heat of summer.  Why is this so important, because we manage a playing surface that requires a lot of stress induced practices.  Mowing, rolling, topdressing, all require the plant to use those roots to regenerate growth.

So what about the air; well the soil on most of the greens has little pore space to make room for roots.  Those roots have to share that space with air and water, which tends to drain more slowly in soil, thus making less air available to the system.

In sand the pores are larger and varied, water drains freely.  As it drains it pulls air into the space which increases air for roots.

The photos below show the difference between rooting in soil and sand greens.  Shallow poa roots in soil, struggle when temperatures rise and too much water (natural or irrigation) is present.  The sand green with greater pore space and infilitration, generates longer roots.  This in turn creates a firmer putting surface using less water and chemicals since the natural process of air exchange for roots has been improved.

Poa roots in a soil green this week

bentgrass roots in sand this week