As many of you more mature turf managers will know and remember well, compost has been used on sports and golf areas for many years, once being the organic of choice for those making their own dressings and divot mixes in the sheds during winter.
Compost was, in those days, very much a DIY operation with no real informed research into what it offered, and no ideas what the end product was of months of storage and wetting and occasional turning of the compost heap would be.
The main source of this compost was grass clippings and some leaf mulch with a small amount of branches etc as a bulking agent. What the result was, most of the time, would be a high nitrogen, unstable organic material which would, most likely, still contain harmful pathogens and, in many cases, would be the cause of disease and fungal attacks.
Unstable composts also tend to draw nutrients from the surface they are applied to as they are still in the feeding stage, thereby, rather than adding benefits, they had quite the opposite affect.
So, what is so different now?
As much as anything, it is the rigorous regulation that has changed, certainly in the case of green composts that are able to achieve PAS100/2005 Certification. These composts have to be consistent, batch after batch, ensuring that Certified Green Compost is the most consistent organic amendment to use above topsoil, sphagnum moss peat or any other organic materials.
The secret to producing a Class A green compost is to maintain a temperature at the centre of the windrow of at least 55OC for a minimum of fifteen consecutive days. Composting of this standard reduces bacterial and vial pathogens to non detectable levels - and it has also been demonstrated that virus and helminth ova do not re-grow after thermal inactivation.
Composting at this standard is not a sterilisation process, and a properly composted product maintains an active population of beneficial micro and macro organisms that compete against the pathogenic members.
Addition of green composts to turf has been shown to increase the soils phosphorous, potassium and nitrogen levels alongside increasing organic carbon content.
Also, seen over prolonged use of compost amended topdressing and rootzones, is a reduction in diseases - and it has also shown to ward off turf pests.
So, back to the future or simply look to the future?
The future - As the recession bites (despite us being told it is now over), all turf managers are having to find real-time cost savings from their already tight budgets; We have been informed over the last 7-10 years, by many of our customers who changed their top dressings, divot mixes and, when constructing new tees and greens, their rootzones, to sand/green compost blends, that they are seeing real savings in terms of fertiliser applications, irrigation requirement, fungicide and pesticide applications - and they are also seeing substantially less need to use wetting agents.
To illustrate the potential savings by switching your materials to incorporate certified green compost, I am taking an average 18 hole golf course as an example:
Traditional sand/soil topdressing application:
100 tonnes over the season @ £35 per tonne delivered (loose bulk density 1.7t/m3)
Total cost: £3,500
Typical irrigation cost per year:
Total cost £20,000
Fertiliser programme - Tees and greens: 60 bags @ £30 per bag
Total Cost £1,800
Total Spend per year £25,300
Sand/compost topdressing @ £38 per tonne delivered ( loose bulk density 1.45t/m3)
84 tonnes required to cover the same area
Total cost: £3,192.00 - saving £308
Irrigation saving: Typically 40%
Total cost: £12,000 - saving £8,000
Fertiliser programme saving: Typically 25-40 %
Total cost @ 25% saving: £1,350 -saving £450
Total spend per year: £16,542
Saving £8,758 per year - a massive 34% reduction!!
This example does not take into account any savings on fungicide, pesticide or labour.
One last word, as I hope that the aforementioned has at least sparked some interest from you. In the words of an agronomist who I had the good fortune to meet on a recent research trip to the States, with in excess of thirty years experience of composting and compost benefits, "do not ever go for the easy route with green compost, if its screened or milled too small, below 3/8", it has lost most of its benefits".
We live in an age where the job of a turf manager is like that of a child in the 19th century - be seen but not heard. You have to do your job without disruption to the members. However, when it comes to topdressing, you are not just levelling the surface, you are also putting something back.
Using dressings, divot mixes and rootzones with certified green compost as the organic amendment is, without doubt, the future!
Andy Law, Managing Director, Whitemoss Eco Supplies Ltd.