aeration and Topdressing (1)

Slide 1 LHAP 106 - Aeration & Topdressing Slide 2 What is the problem? Compaction or Thatch? Or is it just spring debris? Many interventions are “just because it’s what we do” BEGIN with analysis: What NEEDS to be done? Options: Debris Rake - freshens the lawn Power Rake - thatch control Slicing - thatch / light aeration Aeration Core Solid Tine Tilling and overhaul What measures will you take to ensure this doesn’t happen again? Slide 3 Mechanical Raking Slide 4 Dethatch Vs Rake: Objective of thatch removal, vs breaking up dead leaves and debris from winter. Words: Verticutter & Power-Rake are used interchangeably. Top left: Verticutter used to slice stolons and relieve minor compaction. Top right - rake blade (puts strain on engines) Bottom - Stihl Yard Boss Rake Slide 5 This feels so cathartic - like you’re cleaning the lawn and purging the long hard winter blues. The problem is that it may end up removing the entire thatch profile. If you really had so much thatch to begin with, evaluate the three legged maintenance “stool”. Slide 6 Two main options: Solid Tine or Hollow Core Slide 7 Solid Tine Aeration: Advantages May be done on entire surface or selected areas Minimal disruption to play, can be done anytime Quick solution to compaction, air and water infiltration Several options for varying depths. Disadvantages Only provides temporary relief Tool not available for rent (usually) Slide 8 Spiking Minimal disruption, quick recovery, temporary fix. May be done several times a month if needed. Normally tines vary in depth from “Spiking” depth (2.5 cm) to 30 cm depth Slide 9 Deep Tine Aeration: Advantages Break through soil profiles / disrupt layering Amend soil profiles deeper Gas exchange throughout entire soil profile Water penetration and increased sub-surface drainage Increased rooting depth Disadvantages Disruption to play Must top dress afterwards Need healthy turf to perform Slide 10 Core Aeration Removal of soil cores leaving holes in the turf Benefits All the same benefits of Solid Tine PLUS: Stimulates root growth within the holes Increased shoot growth Rental machines more available Disadvantages Disruption of turf surface Longer recovery time compared to solid tine Increased weed development (ie. Poa annua) Slide 11 Slide 12 Coring: hollow tine Two types of equipment: Piston - linking vertical and forward motion (drive carefully or you’ll overdrive the speed of the pistons) - Expensive machine, usually on sports turf Drum Rollers Tines on a drum, mounted on a rotating shaft Quicker but can tear the grass out May not be heavy enough to drive into the grass effectively Slide 13 Slide 14 Core Aeration Option 1: Leave the Cores Advantage - CHEAP! Disadvantages - Cannot be left on playing surface. Self defeating on lawn turf (no amendment, adds to thatch). If you ARE going to do it though, suggest doing in the Fall so they break down over winter and any remainder is collected in spring rake up. Slide 15 Core Aeration Option 2: Core Dispersal Instead of waiting for mother nature… cores are broken up, core cavities filled in by former cores Roots move in quickly, disruption of play minimized Disadvantage - still can add to thatch, no amendment, added cost. Slide 16 Core Aeration Core Removal and Topdressing Allows soil amendments through topdressing holes Recovery is fairly quick (holes close up quickly) Slow release N added Disadvantages: More labour Disposal Cost Amendment Cost Possible Layer disease Slide 17 Core Collection Slide 18 Core Aeration for texture amendment In actual fact, there’s only about 3% disruption, so it will take multiple treatments to create real change. Slide 19 Topdressing Slide 20 What is TOPDRESSING? ‘The practise by which a thin layer of soil (or other material) is applied to an established turf or a new turfgrass planting.’ Slide 21 Selecting Topdressing Material If existing soil is favourable, choose something as close to what is there as possible May consider stockpiling soil during construction If existing soil is unfavourable Compost, aged manure, peat moss (sphagnum), zeolites, calcined clay particles, diatomaceous earth materials Check particle size before you buy (greens / sand soils) Reminder: will take many applications to affect texture Slide 22 Layering: Occurs in soil profile through the use of different top dressing materials over time Perched water tables Drainage problems Black Layer disease Watch for layering when top dressing after core aeration - make sure new material is well worked in. H2S Slide 23 Reasons to TOPDRESS Post aeration (surface disruption) Provide crown protection from winter injury/eliminate ice Add Organic Matter!!! Most clay based soils will benefit from OM, especially if compaction prone Improve CEC & Microbial activity in Sand Root Zones New products claim to boost CEC without affecting drainage or porosity Improved quality putting surface Preventative measure for thatch development on greens Post sod - may help if there has been desiccation of edges Slide 24 How Often?? Slide 25 Topdressing Rate and Frequency Never cover more than 60% of leaf blade 0.05 -0.1 cubic yards 100m sq. = 5 – 10 mm in depth Mowing Height of 50 mm (5 cm) on KB Lawn. 30 mm (3 cm) MAX coverage Aeration displacement will have a major effect on topdressing volumes Like Mowing, Frequency is based on plant recovery and shoot growth rates. Slide 26 Light, Frequent Topdressing Usually on golf greens for thatch 1-3 week intervals Requires minimal brushing or matting depending on consistency of throw Minimal disruption Slide 27 Considerations: Topdress after Aeration is the usual Watering is a good complement vs. over-matting or brushing too much (crown abrasion) Topdressing PRIOR to aeration on new greens will reduce ‘tire rutting’ Fertilize PRIOR to topdressing, not after! (fertilizer will be closer to rootzone that way) Slide 28 Slide 29 At some point, it may be worth it to just start again… consider sod or faster germinating seed?! Slide 30 Machinery Used: Often performed with manual, centrifugal spreader or by hand with shovel Powered mechanical top-dresser Large capacity to reduce time spent refilling