AERATION GUIDELINES

These guidelines help groundstaff to use aeration effectively to improve the quality and performance of cricket pitches and outfields.  The guidelines take a close look at the effect of aeration on the square and pitch performance but the guidelines given for outfields can be applied to other sports such as football and rugby.

They are based on four-years of research at Cranfield University funded by the Institute of Groundsmanship (IOG) and the England and Wales Cricket Board (ECB), combined with experience

Strictly, ‘aeration’ in sports turf management means: ‘Increasing the volume of air in the soil’.  It often has a secondary meaning of ‘loosening the soil to remove compaction’, also known as ‘decompaction’.  The aim of increasing air content and removing compaction is to improve soil health, which slows the rate of thatch accumulation and encourages healthy, deep rooted, grass growth.

This is essential for good pitch performance.  Thatch accumulation in the soil profile slows pitch pace and bounce, good grass coverage helps pace and consistency and deep rooting helps grass growth and binds a pitch together.  Achieving low thatch content and good, deep rooted grass coverage helps to produce good, consistent pace and bounce.

Why is aeration necessary?

Rollers are used to produce hard pitches because this helps ball pace and bounce (see the ECB-Cranfield Rolling Guidelines) and rolling is an essential part of cricket pitch preparation.  But rollers make pitches harder by pushing the soil particles closer together, making the spaces, or ‘pores’ between them smaller and less inter-connected.  This means that air and water are squeezed out of the soil leading to stagnant conditions for grass growth.  It also means that the soil has very high strength, making it difficult for roots to penetrate through the profile.

In the majority of sports the turf manager would use tines to lift the surface and increase the volume of air, or punch through the surface to make holes which are then replaced with sand – however this is more difficult on cricket pitches because the soils are hard clays and surface smoothness and uniformity cannot just be ripped up.

In cricket, aeration methods are generally aimed at one of the following:

1.       Making holes in the surface to increase the volume of the air in the soil by decompaction.

2.       Making holes in the surface to decompact the soil to help deeper root growth.

3.       Making holes in the surface to increase infiltration of water into the soil.

4.       Scarification (sometimes called ‘Linear Aeration’) to remove thatch from the pitch.

5.       Making holes in the surface to reduce deeper thatch to increase microbial breakdown of thatch by getting more oxygen deeper into the pitch.

6.       Making holes in the surface to create holes to assist in seed germination.

7.       Making holes in the surface to bind upper layers to lower layers in the profile.

The research has shown that although these might be the intended outcomes, some of them are not achieved – in fact using solid tines doesn’t decompact the profile and doesn’t help microbes break down thatch, likewise linear aeration is effective at removing near-surface thatch (scarification), but isn’t effective at decompaction or increasing the oxygen content of the profile either.

What the research has shown is that the aeration method needs to be matched to the intended outcome and that timing is critical.  If you want to improve rooting depth then deep solid tines or deep drilling could be of benefit.  If you want to reduce thatch content then look at deep scarification.  If you want to decompact your soil – don’t worry about solid tines as these will not work, just let it wet and dry naturally and the shrink and swell will help to create natural channels and fissures and reduce compaction.  Don’t let it dry out too much though because deep, wide cracks can be a problem.

These Guidelines

These guidelines will help you select and use the right aeration method to help improve your pitches.  The guidelines are in two main sections:

1. Routine aeration to help prevent pitch problems.

2. Using aeration to help solve pitch problems.

These Guidelines have been written by Dr Iain James and Dr Simon Parsons.  Iain James is Technical Director at TGMS Ltd and formerly Senior Lecturer and head of the Centre for Sports Surface Technology at Cranfield University.  He is also co-author of the ECB-Cranfield Rolling Guidelines.  Dr Simon Parsons was a Research Engineer at Cranfield University, funded by the Engineering and Physical Sciences Research Council, the Institute of Groundsmanship and the ECB.

Prevention using Routine Aeration

Problem Solving with Aeration

 

Disclaimer : These guidelines are based on research data and experience from a project conducted at Cranfield University.  Neither Cranfield University or TGMS Ltd accept any liability for the results of that project or for the use or uses to which these are put or for the effects, consequences or otherwise of maintenance of any facilities, or the actions of any contractors employed, as a result of, or in connection with, any information provided in these guidelines.  Cranfield University and TGMS Ltd are independent organisations. No recommendation of any product or service supplier is made in this report whether implied or otherwise.  All costings in these guidelines are indicative and are not a current survey of market prices. All costs were current as per the date of these guidelines.