JHA & soil biology

FineGolf was given advice by one of its Advisory Panel, the late  Nick Park (who spent 25 years on The R&A’s various ‘course’ committees and who was an enormous loss to golf when he died at only 62), to stay away from technical matters and focus on reviewing courses.

This was easy advice for an amateur golfer with wide experience of playing all the finest running courses in GB&I over a period of 55 years to take, and agronomy is a subject that the golf media, TV pundits and even course architects shy away from.

Nevertheless, it was not always like that, for example in the 1980s magazines like Golf Monthly had regular articles on the dichotomy in greenkeeping between weed and fine grass, led of course by Jim H. Arthur and by the likes of Eddie Park – (see Real Golf)

FineGolf  recognises that golf exists within a wider society that today is keener on conservation than ever before. We contend that if the traditional values of Running-Golf and Conservation Greenkeeping are to be the future for the game then the key issues confronting Chair of Greens, Secretaries, greenkeepers and educated, interested golfers could do with an independent platform to help explore them dispassionately in a transparent, open manner, highlighting the different points of view.

We decided therefore, spurred on by supportive readers, to take advantage of this wide interest in conservation and have developed a ‘Conservation Series’ of articles. Do you know, I just think Nick would be pleased that we have ignored his well meant advice and below is our latest offering.

A question that has been increasingly asked of late is the efficacy of changing the soil biology…

..beneath greens in temperate climates (i.e. in GB&I) while helping to tilt the balance in greenkeeping away from ‘feed and water’ annual meadow grasses (Poa annua) and towards low input fine perennial grasses (bents and fescues).

Therefore this article has three elements to it:

  • A simple explanation of soil biology by an expert
  • An analysis of what Jim Arthur had to say about it
  • A summary of what is happening on our golf courses influenced by the STRI and The R&A.

To discuss the positive input that soil biology can have FineGolf has invited Dr Deidre Charleston, the research manager of Symbio (the leading provider of soil biology products across Europe) to explain her company’s research and why they are seeing increasing uptake and success in the use of compost teas and mychorrizal fungi.

Dr Deidre Charleston

She starts: “Greenkeepers and golfers alike are starting to recognise the need for a more sustainable approach to managing turf. Recently articles in FineGolf have promoted the practice of conservation greenkeeping to create firm surfaces dominated by perennial grasses which provide the finest performing greens. The quality of the grass surface on putting greens has an important influence on the enjoyment of the game.

By working with the soil biology beneath our feet we can help create the conditions that encourage the growth of fine grass species and enhance the enjoyment of the game.”

Before she continues, readers will want to know what the ‘authorities’ have to say on the soil biology subject and here we are helped by the fact that The R&A published Practical Greenkeeping in 1997.

goswick golf club, george thompson, james braid, frank pennink, the flying scotsman

Jim Arthur’s Bible of conservation greenkeeping

This book that has become known as the ‘bible of greenkeeping’, was written by renowned greenkeeping advisor, the late Jim Arthur, The R&A’s Open Championship course advisor for some twenty five years.

It was reviewed, updated by The R&A’s Director of Sustainability, adding his name, Steve Isaac, as a co-author and reprinted in 2014. The R&A’s logo has always appeared on every page and they continue to publish, promote (for example see HERE Steve Isaac at FineGolf’s ‘Running-Golf Day’ in 2017) and sell it from their online bookshop.

On the opening page it is called: “An invaluable guide for enthusiasts of traditional golf, especially those whose concern is the care, maintenance, management and long-term welfare of golf courses.” One can assume therefore, that:

Practical greenkeeping’ is The R&A’s authorised version of the greenkeeping methods they wish to promote within temperate climates.

So, FineGolf has done an analysis of what Jim Arthur had to say in ‘Practical Greenkeeping’ at a time when research into the science of ‘golf soil biology’ was only just starting. Like any good scientist he was generally skeptical of new products.

He reminds us: “The needs of the grasses we want to favour and which give the best golfing turf have not altered in a thousand years, so why should their basic management? This in no way implies we should ignore or neglect new methods, especially if they speed up operations (to keep Greenkeepers ahead of golfers) or are cheaper or more effective” (p269).

What runs through all of Jim Arthur’s writings is that correct greenkeeping is more of an art than a science and “it is a study of living things” (p.46).  A crucial quote is: “It is a study in botany, not in chemistry and only marginally in soil physics. It is an art. It hinges on husbandry, not chemical soil analysis. Greenkeeping is a study of soil infertility, not agriculture” (p.304).

Jim Arthur explains how topdressing, of all the five greenkeeping principles, has changed most over the years (p.76) and he considered the best topdressings to be sand with a humus rich additive to assist in drought resistance and soil structuring, though ‘continuity’ within a site’s policy was important to stop layering and potential root break (p.86).

He noted that pure sand greens may give excellent drainage but through leaching require higher inputs of water and fertiliser, and do not contain the humus that holds the micro-organisms that provide healthy soil biology (p.86).

He understood the importance of saprophyte organisms (p.288), especially fungi and bacteria, that live on and get their nourishment from dead organisms or decaying organic material (thatch) and that naturally break thatch down to organic matter (humus). (See HERE FineGolf’s article on the difference between organic material/matter).

Jim Arthur is clear:  “It is the humus content of soil which creates satisfactory root zones and healthy soils, that is, those with thriving populations of soil macro- and micro-organisms” (p.58).

He also recognised that some biological products can inhibit turf grass disease (p.176) but I cannot find any comment concerning there being a correct balance between bacteria and fungi, nor is mycorrhizal fungi specifically mentioned. We might surmise that his understanding of soil biology was instinctive and from the depth of his enormous experience. As with much of his practical advice it was given without explicit explanation.

So to better understand and give reason to how soil biology works let us reintroduce Deidre again with Symbio’s thirty years of research and some 500 golf course customers across Europe, behind her.

She continues: “The biology in the soil is intricately connected with the ecosystem and its processes above the ground and adapts alongside the changing environment, through a process of ecological succession. A bare patch of ground is initially colonised by soft annual plants and weeds. Within the soil, the microbial population is dominated by bacteria, able to break down these soft tissues and produce nitrates allowing these short rooted annual grasses to thrive particularly if extra water and inorganic fertiliser is artificially added.

Nevertheless, if the environment is left to nature, then over time, the plants above the ground will change to a more perennial deeper rooting population. In the soil, fungi will start to appear. Fungi have adapted to break down more complex carbohydrates like lignin formed from perennial bent/fescue roots. During this process they produce ammonium, that in this environment, is favoured by perennial plants. If left unmanaged, then eventually the bare patch of ground will become a forest and microbial life in the soil will be dominated by fungi.

We can use this information to help us in managing our turf and we can shape the soil conditions to encourage the species we want to grow. Both bacteria and fungi are important in the soil ecosystem, but one group is likely to be more abundant than the other, depending on the plants above the ground. Weeds and Poa annua tend to thrive if the soil is dominated by bacteria, whereas the fine grass species such as bents and fescues grow better if there is a balanced bacterial to fungal ratio in the soil.

Professor Alan Gange

Marcel Van der Hejiden

Research has shown that by increasing soil fungal populations, particularly those of arbuscular mycorrhizal (AM) fungi, Poa annua populations start to decline, whilst the growth of desirable perennial grass species increases (Gange, 1998; Gange et al., 1999). Arbuscular Mycorrhizal fungi form symbiotic relationships with perennial plants, enhancing their growth (van der Heijden et al., 1998). Therefore, if it is possible to manipulate fungal and bacterial populations in the soil, it should be possible to encourage the growth of fine grasses.

Poa annua as an annual plant regenerates itself and survives by creating abundant seed heads and fast-growing roots which die quickly and become thatch resulting in soft surface target-golf. Fine grass species on the other hand are associated with firm surfaces and the running game of golf.

Comparison showing growth of healthy perennial grasses with mycorrhizal.

When soil biology is healthy, populations of beneficial microorganisms keep thatch levels low, converting thatch to humus, increasing plant nutrient uptake and improving soil structure. However, where soil microbial activity is low this can lead to a build-up in thatch. Excessive thatch decreases playability, increases disease pressure and reduces water infiltration, creating soft turf.

Different soil profiles that need avoiding.

Management of thatch using biological degradation can reduce the need for disruptive physical practices (deep scarification and hollow coring) and means that play can continue uninterrupted. In a healthy balanced soil food web, bacteria will consume the excess carbohydrates that are released by the roots, while fungi will consume some of this, most fungi prefer the woody cellulose and lignin found in thatch and are excellent at converting thatch into humus, improving soil function. By encouraging beneficial fungal populations thatch degradation can be improved.

Within the soil, the bacteria and fungi, in turn, become food for other predatory microorganisms such as protozoa and nematodes. In healthy soil the cycle continues uninterrupted, with members of the soil food web feeding off each other, excreting, dying, decomposing and returning nutrients to the soil to feed the next generation, and support the growth of plants above the ground. 

By encouraging a return to conservation greenkeeping (see HERE Jim Arthur’s five principles from ‘Practical Greenkeeping’ with explanation by Gordon Irvine), and creating the soil conditions to promote the growth of fine perennial grasses we can reduce chemical and water inputs and lower maintenance costs.

To achieve this, management activity needs to focus on encouraging a healthy soil food web, with a balanced bacterial and fungal population. Practices to encourage the spread of bents and fescues can be achieved by:

  • using organic slow-release nitrogen fertilisers that are inoculated with mycorrhizal fungi, and by only fertilising when necessary, for example to aid recovery from winter wear and tear;
  • by carrying out activities to boost fungal populations for thatch degradation, such as the use of compost teas;
  • by creating soil conditions that encourage active healthy aerobic soil populations, such as frequent non-disruptive aeration using a sarrel spike roller.
  • Once thatch levels are low, judicious over-seeding of fine grass using mycorrhizal seed coatings can speed the conversion process.
  • by creating the correct conditions to encourage healthy soil biology there is less need for intensive and disruptive maintenance practices, and a reduced need for fertiliser and fungicide inputs.”

So, FineGolf summarises:

It seems the Symbio soil biology explanation fits well with Jim Arthur’s methods, which his heir and protégé, Gordon Irvine MG, says creates naturally the right balance of good micro-organisms in a healthy, aerobic, humus-rich soil if the principles of conservation greenkeeping are followed.

Out on the golf courses greenkeepers are picking up on golfers’ increasing preference for firm surfaces and many who manage Poa annua dominated greens have followed the management policy promoted by some consultants in emphasising organic material (thatch) reduction through physical methods, combined with the addition of a large tonnage of pure inert sand topdressing.

This policy certainly physically helps to artificially firm-up Poa annua dominated greens. But some observers who call this a ‘peak sand’ policy argue that this may also hinder the transition to a healthy microbe/fungal-rich soil biology with low fertiliser, fungicide and water inputs.

Taking into account wider society’s conservation wishes, few can disagree that a move to these more sustainable low input management practices is what is needed. Low inputs also encourage fine grasses, which in turn give natural firmness all year round for more enjoyable golf.

The R&A’s ‘GolfCourse2030’ project has also recognised the issues that may arise from this high sand technique because the right type of sand resources are running out.

The Open Championship venues should be at the apex of GB&I golf course husbandry and the R&A has tightened up control of greenkeeping policy requiring more objective measurement and setting of standards (see HERE how different it was in the 1980s at Royal St George’s!). Nevertheless, nobody would argue these days that the heart of all Open Championship greens are dominated by bents and fescues rather than Poa annua and there is much work still to do, not helped by some golf TV coverage.

Therefore, the question arises, as to whether The R&A policy on topdressing and soil biology has now diverged from what Jim Arthur advised in ‘Practical Greenkeeping’?

Everybody recognises that the effect of ‘soil biology’ on the dichotomy between Poa annua and fine grasses is complex and difficult to fully understand and might well differ from one site to another. Though many are now moving to fine grasses, the majority of GB&I greens are still dominated by Poa annua. We should never forget that traditional running-golf in GB&I is most enjoyably played across bents and fescues.

Therefore, it is important to have a transparent, open discussion with all interested parties about current turf management policy and the use of soil biology.

This would be helped by an independent analysis of the empirical evidence from what is happening on golf courses, together with increased research into new technologies and management techniques.

The R&A is invested in the GC2030 projects and an important project for inclusion is the investigation of the fundamental question in GB&I greenkeeping, namely, what is the best way of replacing Poa annua with fine grasses, including the role that soil biology could play in this process.

This clear identification of the ‘elephant in the room’ is unlikely to be welcomed by everyone as there are many vested interests, some of whom would like to pretend that the game has moved on from Jim Arthur’s era of fighting for fine grasses.

However, FineGolf will continue to campaign for the running game, as it is so much more enjoyable and should not only be the heritage, but also the future, for GB&I golf.

Gordon Irvine speaking in America.

To finish on a positive note, it is pleasing that there is now more discussion surrounding the topic of Conservation Greenkeeping as evidenced by FineGolf in 2020 and Greenkeeping Magazine in March 2021 both publishing Gordon Irvine’s summary of the five principles of Jim Arthur’s methods.

We expect to see this topic become more central to greenkeeping and the management of fine running-golf courses. Gordon says that he hopes to explain more detail at a discussion conference when the pandemic allows.

Published April 2021.

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