The use of biostimulants on turf is not new. Seaweed has been harvested for this purpose for centuries. And, not surprisingly, there has been a lot of research into the use of biostimulants and the effects of bacterial and mycorrhizal populations on plants, including turf. Among the latest research to be published on the subject is that commissioned by turf nutrition specialist Soil Harmony and relates to the firm's product Bios Turf Tonic.
The study shows that Bios Turf Tonic not only improves the health and quality of sports turf, but could also help to cut input costs and benefit the environment by reducing reliance on artificial fertilisers.
In the trials, increases of 71 per cent were recorded in bacterial abundance and mycorrhizal colonisation almost doubled. Plant biomass benefited, with treated samples containing more than three times the biomass of untreated cores and grass blades became deeper green, indicating greater chlorophyll content. The trials used samples taken from a tee area at the Berkshire Golf Club, where the sward comprised agrostis with poa and festuca.
Soil Harmony's Bios Turf Tonic was applied to 10 of the cores, with the application repeated as advised by the company's Mark Atkins. The process took place over 10 weeks to establish effects on soil microbes and grass growth. Bacteria, which were reasonably abundant in the soil at the beginning of the trial, saw a small increase in the untreated sample but, 10 weeks after the initial application, levels in the treated cores increased by 71 per cent. This suggests Bios Turf Tonic has the ability to substantially elevate the numbers of culturable bacteria within the soil.
Mycorrhizal colonisation of the roots increased from 12.6 per cent to 23.1 per cent, considered to be a large growth in terms of mycorrhizae. While levels in natural grassland can be as high as 50 or 60 per cent, they tend to be much lower in fine turf because of continuous mowing. Repeated clipping reduces the amounts of carbon fixed and hence the nutrients to feed the mycorrhizae, so limiting fungal abundance.
Total biomass in the treated cores was also significantly higher. In fact 3.24 times as much biomass was removed from treated cores than from control cores. Testing the clippings also revealed that on a scale of one to 10, the average colour score had increased from 6.4 to 7.8, while the untreated sample had a score of 6.5.
Nitrogen levels were also assessed and were found to have increased by a small amount in the treated sample, while decreasing in the untreated cores.
For details of Bios Turf Tonic and other products go to www.soilharmony.co.uk.
There are many other companies offering biostimulants and mycorrhizal products in the UK, including Maxicrop, Symbio, Orkney Seaweed, Headland Amenity, Floratine Products, Indigrow, Novozymes Biologicals, ORM Professional Products and Amenity Land Services. Many of these companies' websites include research details, as does the STRI website (www.stri.co.uk). But the best way to make up your mind about such products is to try them on a small area and note your observations.
- Sally Drury has reported for HW and its forerunner GC&HTJ for 25 years, and has spent more than five years testing machinery for HW and What Kit? The advice in this helpline is independent.