GLAS Special: Sustainable turfgrass maintenance with the IISS
Donal Kearney, Irish Agricultural Supply Industry Standards (IASIS) advisor, discusses how sustainable soil conditions should be the focus of turfgrass maintenance, not expensive quick fixes.
18 July 2019
by Julia O’Reilly
All too often, turfgrass surface problems that are treated by overuse of pesticides for quick fixes effectively eliminate soil microbe populations. As natural soil microbe populations have been killed off, there has been a greater reliance on pesticides. Pesticides include insecticides, fungicides, and herbicides.
With the 2012 EU directive on the sustainable use of pesticides in place, all turfgrass professionals must keep a record of integrated pest management and justify any pesticide usage. As more and more pesticides are removed from the pesticide register for amenity use, greenkeepers and grounds maintenance managers must focus on treating their soil primarily, rather than just treating the grass directly.
Initial source of problems
Quick fixes often compromise the growing environment which encourages healthy turfgrass growth. Understanding your soil ecosystem is essential as soil type and quality tend to vary from site to site.
While it is a challenge, all greenkeepers and grounds staff must become more educated on their sites’ soil. This is not only important in above ground-level management, but also in the management of beneficial soil micro-organisms which naturally maximise turfgrass health.
All too often, the only primary maintenance consideration is grass feeding, regardless of the soil condition, climate or location. This boils down to a lack of understanding. It is vital to know if the products you apply are truly benefitting your soil before application.
It is also important to identify the cause of pests and disease pathogen attacks. Is structural or compacted soil enhancing the environment for pests and disease? Is the problem being enhanced by drainage and waterlogged soils? Are inert sandy rootzones being overfed with nitrogen? Consider waiting for a change in weather conditions and then see if this reduces or eliminates disease symptoms.
Maintenance practices should be used to promote the growth of beneficial soil organisms. Fertility is one way to encourage this. Healthy soil delivers strong, sustainable grass. Soil microbes naturally feed off dead plant material and root systems, on top of naturally fixing nitrogen from the atmosphere.
This microbe activity further activates earthworm predators which naturally aerate pathways through the soil or rootzone. The application of natural products such as seaweed, humic and fulvic acids, and carbon-formulated products provides a food source to enhance and grow natural soil microbe populations. Understanding soil pH and irrigation is key for consistent soil fertility.
Another technique is over-seeding. Over-seeding with disease resistant turf varieties will improve the density of the turf and help to withstand insects, disease, and drought. Aeration can also prove effective, adding compost into topdressing after aerating will prevent soil compaction with regular aeration. Lastly, you must remove or reduce the use of synthetic chemicals and fertilisers which kill off soil populations needlessly.
Benefits of sustainable soil management practices
Aside from maintaining legislative responsibility under the “Sustainable Use of Pesticides Directive 2012”, several benefits can be derived from sustainable soil management practices.
Healthier soil with an active population of earthworms, fungi, bacteria, and beneficial nematodes is critical for creating natural defences. It can also help to prevent imbalanced soils from becoming excessively thatchy.
Sustainable practices can both reduce the risk of runoff and leaching from pesticides and artificial products into bodies of water, and increase the soils resistance to stress caused by heat, cold, drought, insect pests, disease, and weed invasion.
Responsible practices can enhance biodiversity, which contributes to the conservation of essential species in the broader ecosystem. They also eliminate pesticide exposure for everyone, including livestock and pets.
In conclusion, sustainable soil, with or without the use or overuse of pesticides and artificial soil enhancers, allows for increased water infiltration, improved water and nutrient holding capacity, unrestricted root growth, efficient nutrient mineralisation, and effective antagonistic control of pests and diseases.
No two sites have the exact same challenges and thus, many aspects must be considered for yours. Accordingly, this article is merely food for thought. But, in order to keep turfgrass management sustainable, healthy, and affordable, this view should be considered in the long-term. Make the most out of GLAS and meet the Irish Institute of Sports Surfaces (IISS) today at stand ST1.