Solid tine aeration involves the simple punching of holes in the soil, while the hollow tine version captures and removes volumes of soil often referred to as cores. Hollow-tine or core aeration is arguably the best general-purpose method and is applicable in the widest range of situations. In terms of importance, aeration as a management practice falls somewhere just beyond the basic fundamentals of mowing, irrigation, and fertilization. One of the times when core aeration provides the greated benefits in most regions of the country is late summer and early fall.
Jason Lanier, extension educator with the University of Massachusetts Turf program, shared an overview of why this is so important in an article in UMass Turftalk. The article enumerates the many benefits of core aeration and may be useful to share with clients.
Relief of compaction – Compressive forces such as foot or vehicle traffic can lead to dramatic reductions in total pore space of the soil.
Improved gas exchange -Turfgrass root tissues require a sufficient supply of oxygen for respiration and growth. Beneficial soil microorganisms also require ample oxygen for proper functioning and robust population numbers. Aeration also promotes better moisture infiltration and drainage, reducing the potential for prolonged soil saturation and associated oxygen inhibition.
Improved microbial activity – Like turfgrass plants, soil microorganism populations normally benefit from aeration. Healthier microbial populations perform myriad functions including the breakdown of thatch and organic matter, and the recycling and retention of nutrients in the turf system.
Management of thatch – Thatch typically accumulates when resilient plant tissues, such as stolons and rhizomes, are produced faster than microbial populations are able to break them down. Improved soil conditions from aeration help to ‘tip the scales’ in favor of microbes and allow better control of the rate of thatch buildup.
Improved moisture infiltration – Because aeration helps to break up and reduce thatch and mat layers, and to disrupt any existing surface crusts, better site permeability and better infiltration of moisture into the root zone frequently results. While several aeration events per year may be appropriate for higher traffic areas, especially on golf courses or sports fields, once annually is a good general guideline for many lawn and grounds areas. Lower maintenance turf areas may be aerated even less frequently. It is important to apply aeration based on need and specific management goals, as research has demonstrated that aerating too frequently, especially at similar depths, can create a ‘cultivation pan’ in the soil profile over time. Remember also that core aeration is a disruptive process and somewhat of a shock to the system. Aeration should be carried out only when aesthetic considerations permit, and when favorable conditions for recovery exist.