Verti-Draining of Sports Pitches looks at the benefits, timing, ground conditions and more in this timely blog. Verti-Drain is a brand name, but also now an eponym for the operation of opening the ground.
What does Verti-Draining do?
Verti-draining or deep spiking (tractor mounted) is just that, the solid tines on a deep spiker work in the range of between 8-12 inches in depth, reaching far beyond what is achievable with a pedestrian type of machine that works from 1-5 inches in depth as a maximum.
Tines can range anywhere in the range from 8 -25 mm in diameter and are vertically punched into the soil and then kicked horizontally between 5-10 %, this is known as heave. This heaving action of the sub soil creates soil fractures and the tine holes that are left over, also offers some benefits as listed below.
Spacings can range from 2- 4 inch between solid tine, sports surface depending on the tine width and type of sport surface. The square grid of tine holes should be evenly spaced apart and the tine hole should be at a 90-degree angle. Feature images kindly supplied by Redexim.
What are the Main Benefits ?
· Soil fracturing (decompaction) in dry root zones profile, so timing is key but also a challenge on heavier soils that retain moisture to depth.
· Allows carbon dioxide out of the soil and oxygen into the soil, for plant, root and soil benefits.
· Creates channels (tine holes) for surface water to drain into, maintaining a drier playing surface.
· Can be used to incorporate a freer draining topdressing material to help with infiltration of surface water.
· Roots can use tine holes to increase rooting depth and in turn create a more hard wearing and drought resilient grass plant.
· Improve soil structure.
· Can break through certain organic layers.
· Aeration assists in the breakdown of thatch.
· Can release trapped nutrients within the soil and make avaible to the plant.
Areas of Use
Winter sports pitches, whenever the soil is soft enough to receive the solid tine to the required depth, usually between October and May/June (renovation in mind).The time frame is not set in stone, location, rainfall and other factors can come into play outside this period. Deep spiking machinery up to 2.6m in width.
Bowls Greens – Bowls greens also benefit from deep spiking (1.5m width), equipment used is usually more compact and lightweight, due to space limitations of the green. Often carried out in Autumn to avoid any opening of the holes on heavier sub soils during the following summer.
Always consider, is access possible to your green with a tractor and mounted spiker before gaining quotes or is another means of aeration a better option.
Solid Tine is usually 12 in length and 12mm in diameter, depths and green suitability can be dependent on a few factors, this can be discussed with the contractor undertaking the works.
Air Injection is also another great aeration tool for a bowls green, so talk through options that will suit your needs best with your peers/advisors.
Cricket Squares, with 12 mm diameter solid tines from Oct/November pushing past this could cause issues with re opening of the holes when the soil dries out in Spring or Summer. Aim for no heave on a cricket square, as this can lead to detrimental root breaks forming. Squares with severe root breaks may not be suitable for deep solid spiking and may instead benefit from deep drill aeration, due to the non lifting action of the drills.
If deep spiking on cricket, then there’s a bit more research here, so please check out this blog on the subject-
Be Aware of Underground Objects !
· Old watering points/pipes.
· Old sockets from goalposts.
· Buried bricks and rocks.
· Old cables.
· Pop ups.
· Underground services.
Ground Conditions and Timing
Assessing the profile to ensure the soil is one, soft enough to the depth required, two in doing this you may also notice any hard non penetrative pans or and native underlying chalk layers which a solid tine may not be able to break through.
You can assess whether the soil profile is soft enough to accept a tine. This can be done by pushing in a screwdriver, if it easily penetrates the soil, so will a solid tine. If the screwdriver lifts the surrounding soil or and hits something hard, so will the solid tine. Depths achieved with a screwdriver can be replicated with a solid tine.
Ensure the contractor who is planning on tending for the work, has suitable turf tyres and the spiker is wider than the tractor itself.
If the spiker bounces excessively around it’s possibly too dry for the depth you’re trying to achieve and at this point you can try and adjust the depth or leave it for another day. This could also back up the need to do some soil assessment post aeration is required.
The soil should be moist to the depth you require, but the soil should not be wet/sticky or cap or seal or bury the grass plants, often afternoons have allowed any early dews to disperse which can also assist.
Importance of the angle and pattern, to achieve a vertical tine hole with a consistent pattern of tines, if the machine isn’t set up right this will not be possible to achieve or if the job is rushed.
Brian on behalf of the TurfCareBlog community.
For more specific guides to Aeration, check out this page- https://turfcareblog.com/?s=aeration
For more information on verti- draining of a cricket square, take a look at this – https://turfcareblog.com/a-guide-to-vertidraining-a-cricket-square/