0 Bug Trek: Soil - the Final Frontier

There is, undoubtedly, a growing interest in this country in 'growing your own', and it is spreading to golf clubs. I am not talking about vegetables though. No, I am talking about beneficial micro-organisms, the life in the soil that provides life on this planet. I have been asked a lot lately what I think about their part in management of golf greens, so here is where I'm at on the subject of bug life.

Before I go on, I am going to take it as given that you have some knowledge of the benefits of Mycorrhizal fungi, protozoa, nematodes etc. I say this, as I am not covering them in detail here. And there are people, whom I shall mention below, who are far better qualified to explain the soil food chain than me. The purpose of this article is to give my practical opinion on whether introducing and maintaining 'soil life' works in the golf green maintenance environment.

The Green men are not aliens!

As greenkeeping cleans up its act, in terms of intensive chemical and fertiliser usage, in particular on golf greens, there is a movement towards getting the good guys to help out. Before everyone tells me that greenkeeping is not that bad with chemical cures and that farming is much worse, I say it doesn't matter where farming is at, it is where you are at.

Quantities of chemical usage on golf courses are only relative to chemical usage on golf courses, not farms. It is what we do with our individual courses that matter, not what others in related 'fields' do or, for that matter, what other golf course managers do. As with all greenkeeping and course playing quality, it is down to the individual manager.

I was never one for high chemical or fertiliser usage, but there is no doubt that, in the past, I have been instructed to, or have, of my own free will, applied some nasty man-made stuff (legally) without a thought to the above ground environment and, less still, for the soil.

Until the late 1990s most of us regarded our rootzone 'soils' as simple, dare I say, inert mediums that were there to grow as much root as possible, as deep as possible, so as to support the desired fine grasses above. Little thought was given to what else was supported by those soils. Yes, we applied seaweed in topdressings and in liquid form. We also applied processed cow slurry (Farmura) and still do these things. In the early days some of us will remember applying composted leaf and turf wastes in topdressings, however I do not ever recall anyone saying that that will help the soil life to grow!

It is life Jim but not as you knew it!

Those of you that have Practical Greenkeeping by Jim Arthur as your bible will no doubt have read his teachings on topdressings, including 'Soil Conditioners' and 'Sources of Humus', and you will have found not one mention of soil life in any of this. This is not a slight on Jim, it is just a simple fact that, even at the time of his book's second revision in 1999, very little was known about life in our soils. Any benefit to soil life gained from sound greenkeeping practices would have been purely an accidental by-product, as long as you weren't applying straight Sulphate of Iron and Ammonia that is!

No, it is only in very recent times that mention of beneficial bacteria and, more importantly, fungi have become part of the greenkeeping language. I can hear Martin Ward of Symbio shouting "but I have been banging on about it for the past sixteen years". Yes Martin, but it always takes the masses some time to catch up with the pioneers. Not many of us have climbed Everest or been to the Moon yet either, but many of us have had penicillin.

So here we are, ten years on, and the boffins have been staring through their electron-microscopes in an effort to progress man's knowledge of soil microbial activity, as well as to make bent and fescue more competitive against Poa annua for the benefit of golf! Okay I know, but it does put it all into perspective. We do get a bit carried away in our little golf world at times.

If you are well into this subject you will have read research articles on the topic by Dr Alan Gange, you should have come across the name of Dr Elaine Ingham and her 'Soil Food Web', if not Google her, it will be well worth it. And you may have even heard of the bug counting lab at one time F1 world champion Jody Schekter's, Laverstoke Park.

If you have seen all of this, and have managed to retain 20% of the technical information, you are doing well. Now that you have this information, and remembering that you are a greenkeeper which, in turn, makes you a natural sceptic, does all this really help?
Mr Spock like mind control

If you are going to put energy, time and cost into a programme that promotes fungal rich rootzones you have to have the right mind focus. Evaluation of what impact your next greens maintenance task is going to have on your 'underground movement' is required at all times. This is no bad thing as it focuses your management approach further. It is no good applying a beautifully brewed fungal rich tea and then allowing it to bake on the green surface, or applying a touch of Sulphate of Iron to "give them a green up" post "tea time". In past reports on the subject I have referred to it as "whole system thinking", that is to say, giving full consideration to the complete biomass that the grass plant occupies, and not just the turf itself.

You need to prepare you rootzones to be good hosts to a healthy soil life. There is little point in adding soil conditioners, such as seaweed as food for micro-organisms, if you have none to start with! An aerobic environment is vital to maintain soil life and vital to the success of any quality composted tea application programme.

If you are already reducing your fertiliser inputs, cutting out high salt index feeds and going organic, as well as aerating and topdressing on a regular basis, then promotion of beneficial soil life is a 'shoe in' for your programme and can only tip the balance further in your favour or, should I say, the favour of bent/fescue swards.

As with a lot of greenkeeping practices, and even theory, much of the positive evidence for soil life is anecdotal, born out of practical application. There are many out there brewing compost teas and applying them to their greens ten times a season, who swear by the improvements made. The benefits claimed and recorded include improvements in species type toward bent/fescue, sward density and health, reduction in incidences of fungal attack and even soil rootzone drainage improvements through particle flocculation by the microbes (I have witnessed the latter at The RAC club's Woodcote Park where Bob Wiles has been using compost teas for over five years).

The key to achieving these objectives is to evolve a microbial enhanced rootzone, which utilises the nutrients locked up in any organic thatch layer as food for plant growth, not for fungal pathogens.

To bodly go where no researcher has gone before

I believe that it will take a very long time before the research catches up with the practical world on this one. Someone has said that the life in our soils is far more complex and diverse than the universe outside of it. As we are nowhere near understanding the universe I would get on with practical application. Apply compost teas and see the beneficial anecdotal results quicker than waiting for research results.

Although there is still much to learn on this subject, it is undeniably clear that a healthy balanced life in the soil is the key element of the plant/soil association. In modern terminology it has been described as the connective interface, the lubricant, stimulant and antibiotic of plant life.

It is fact that introducing competition for fungal pathogens, and reduction in available food source via thatch digestion, leads to healthy, more consistent and less disease affected turf.

Most fungal related turf problems are caused by a single factor, namely adverse environmental conditions. For example, soil compaction, high moisture levels (above and below ground), consistent warm temperatures and traffic/machine damage, all of which result in plant stress.

What many turf managers don't factor into this equation is that the life below ground is also stressed out by these factors, or just plain dead because of them!

Most turf pathogens are just opportunists that are able to capitalise on a situation that is tipped in their favour. They pick on the weak and stressed because they are able to. Under the adverse environmental conditions that we maintain golf greens, the fungi that would naturally eat or control these causal pathogens are missing from the food chain.

In simplistic terms, a healthy soil equals a healthy plant. I am not talking just about the physical composition of the soil (rootzone), I am talking about the life that is supported in that soil. An active soil biomass, full of equal quantities of fungi and bacteria, will ensure a 'below ground' food chain that will provide the plant with the natural growing environment it requires. An environment that does not need excessive additional nutrient or irrigation for the desirable grasses to thrive.

Beam them down Scotty

Therefore, in summary, I believe that a regular quality compost tea programme, in the right hands, will further tip the balance in favour of the desired finer grasses. In fact, I would go as far as to say that it should form the backbone of any greens management programme geared towards reduced chemical inputs and species conversion to bent/fescue swards. If you want, or do, manage in this way, why wouldn't you want to get this type of help below ground? I like to think of it as increasing your greenstaff by a few trillion, without the wage bill to match.

Kevin Munt
KMgc Golf Consultants

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