Aeration - Slit Tine

Slit tining is the most frequent aeration treatment carried out on sports turf in this country as it introduces air into the soil profile whilst causing minimal surface disturbance, primarily in the summer months. Slit tines are described under a variety of terms; knife tines, diamond tine, chisel tines, and root prunes. The nomenclature relates to the shape of the tine or its action.

Chisels or root pruners may be safe to use during the summer, provided efficient automatic irrigation is available. Failure to irrigate during summer slitting can result in surface cracking. However do not over water merely to facilitate the use of slits rather than safer alternative forms of tine.

Slit tines are available on the complete range of aeration implements. The working depth varies from 75mm to 150mm on pedestrian units, down as far as 300mm on the larger football pitch aerators. Many tractor mounted units have pressure frames or are controlled by downward pressure from the tractor to give variable depth of penetration and to facilitate full depth when needed.

The maxim that you should always slit as deeply as possible is inaccurate. Always aerating at the same depth will create panning at that depth, obviously less of a problem at 300mm than 75mm but a problem nonetheless. Frequency of slitting must relate to the quality of soil to be worked and the needs of each specific site. Anything from weekly to monthly treatments could be appropriate.

Working along the same direction in anyone slitting season as cutting across previous slit marks could promote serious disturbance to the playing surface, if not immediately then certainly through dry summers. Slitting can be overdone and result in unevenness; a situation exacerbated during frosty spells, or on heavy saturated soils when taking any machinery over the ground will cause more damage than the operation will do well.

Staring a slitting programme for the first time can be disruptive though after a few passes lifting should be kept to a minimum. The initial damage is usually due to very poor rooting, a direct consequence of no, or very limited, aeration work in the past. Units drawn behind compact tractors for relatively small areas of fine turf like, golf greens, often have a pressure roller following the slitter to smooth down any slight lifting. Slitters without such a roller can leave tufts of grass on removal of the slit from the ground which, unless smoothed down, can be cut off when next mowing so producing small gaps in the turf cover.