Oxygen addictions and how to control them..
During the year or playing season our sports turf surfaces will be trampled by feet and studs, have various machines and pieces of equipment pulled and driven over them and of course (depending on the sport) be played upon daily, weekly or bi-weekly. I work in Soccer, so this means, constant use throughout the Winter period.
Winter is a time of year that can be a real pain in the ‘…’ for a sports turf manager!
Being a weird kinda guy, I do find myself spending an awful lot of time worrying about the condition of my soil and what is happening beneath the lush green surface, let me explain why…
When the soil is wet even the weight of the operator walking while mowing the grass can begin to compact soil and Winter is a very wet time of year (nothing new here then).
We cannot modify the weather to suit our needs, so if a coach wants to train in the rain or snow, or a match day happens to coincide with heavy rain, then we need to bear in mind that damage is actually occurring, damage you cannot necessarily see.
The trick is to make sure the surface is managed well enough to allow the above to take place to minimise this. Ideally, starting with correct construction technique and materials and inevitably ending with proper and conscientious management of the area to ensure longevity. Correct construction, without proper aftercare is pointless in the long term.
Over time, all turf surfaces deteriorate due to the effects of soil compaction, new, old, well used and under used. I liken this inevitability to my impending baldness. It’s gonna happen. However, I can do something about compaction problems ☺
If the surface is managed with over exuberant fertiliser application it can/will deteriorate further due to the effects and consequences of excess thatch, poor root development and the poor soil conditions. Not to mention the affects this has on the grass plant itself — producing, as I like to call it, lazy and demanding grass. I once had a girlfriend with similar characteristics!
Even the best-presented surfaces will suffer from compaction, as it is a constant; they may be green and lush, but they are managed. If they are managed we can counter the visual affects of weak growth. For a while at least! Aeration should be regarded as a staple diet food for grass.
Aeration is the term used to describe the mechanical methods we use to combat the effects of excessive use (compaction) and/or thatch development.
Soil compaction can be described as the soil particles being squashed together leaving minute spaces or pores between them, the end result being little or no room for root development and growth and reduced levels of oxygen held in the soil that is so vital for initiating root growth and general plant health. The trick here is to start with a soil that has good compaction characteristics, the right shape of sand, the right amount of sand compared to other minerals, the right particle size diameters
This is where the choice of rooting medium (materials) is vital as small particles lead to small pore spaces that tend to hold water very tightly; making the soil prone to wetness whilst large pore spaces easily give up the water to the plant root and allow rapid drainage to occur and therefore give us higher levels of oxygen within.
Oxygen is also vital for the growth and development of billions of soil residents (bacteria and fungus to name two). Fungus populations will grow and develop seasonally too. If there is a heavy thatch layer that has been decomposing slowly over the years, expect a weak plant on the surface that will be susceptible to disease issues.
Thatch makes a great food source for problem fungi as well as beneficial types, once the populations develop and the weather conditions are ideal — .issues may arise. The host is the last piece of the jigsaw — the host for the disease being the grass plant you want to keep healthy.
Aeration is a task that should be carried out not to calendar dates but when necessary and will not only encourage and aid the growth of a dense, healthy turf but aid the grasses natural resistance to diseases, water logging, weed and pest infestations. Roots will and do develop in Winter, so for me, Winter is a time of year to aerate when the soil conditions allow me to. In fact, all year is aeration time for me and my little green friends.
Topsoil is intrinsically susceptible to compaction especially those consisting of clay, silt or those being organic by nature. As these soil types have extremely small mineral particles within them that are easily squashed to form hard, impenetrable barriers.
If your pitch is hard and suffers from slow drainage rates then it is probably suffering from either surface, localised or complete compaction.
Compaction will eventually lead to a stressed turf grass plant that cannot grow to its fullest potential. Most compaction occurring in any soil is likely to develop in the top two or three inches of the profile. However, it is not limited to this area.
The task of aeration aims to break open the soil and ‘lift’ it or ‘remove’ a portion of it and therefore ‘relieve the compression’ . If you are pushing It down and simply making holes you are moving compaction. You will be aerating sure, but not de-compactiing.
Aeration and decompaction allow water to drain through soils easily, oxygen can enter filling the voids that the drained water leaves behind and undesirable, root-inhibiting gases such as carbon dioxide and hydrogen sulphide can escape easily.
The gases mentioned above are two problematic types, there are more and these are the result of life processes from plants and soil life. So we could assume that any aid to ‘gas exchange’ between the soil and the upper atmosphere will reap benefits for all.
If you want to promote the fast, strong development of your plant, fertiliser is not the ‘only’ way forward. Especially if you, like I, want to decrease budget spend or maybe you have no budget to spend anyway ☺
Interestingly, a healthy soil (in terms of oxygen supply) will not only make better use of the feed you give but it will be a soil that requires less feeding in the long term as the now thriving soil life breaks down the organic content inside more efficiently, therefore releasing locked up and hidden nutrients for the plant and reducing thatch levels — all for free! So long as you are not giving the bugs a hard time.. with high input of fungicides. Liken this to buying a ferrari and feeding it 92 RON petrol. The true potential will be limited.
When to aerate
All turf surfaces require annual aeration (even cricket squares) of the entire surface the benefits of the operation can bring fantastic results if carried out correctly with the correct equipment.
Aeration benefits the surface and grass growth by:
(a) Prevents loss of water from the soil surface as more percolates into the soil.
(b) Increases the rooting depth of the plant improving drought resistance
(c) Breaks hard undesirable layers within the soil that can prevent root development
(d) Increases the levels of beneficial fungi and bacteria in the soil
(e) Increases the rates at which thatch is broken down
(f) Helping fertiliser and water to easily work their way into and out the soil profile
(g) When cutting through stems, stolons and rhizomes increases new shoot and root growth
Spring is almost here, the plant is about to naturally enter a strong growth phase, help it, get out and aerate. Think of Spring as the aeration time of year, not the fertiliser time of year and all will be well….Help the soil and the bugs and they in turn, will help you.
Good luck in your endeavours