November 2011 – LESSONS TO BE LEARNED FROM THIS SOIL PROFILE

In last month’s issue we started to analyse a soil profile taken from a bowls green and it could be seen that the original sea washed turf, situated five inches below the existing turf level, was sub-standard because at that time in the early 1930’s the best supplies were becoming exhausted as demand outstripped supply.

This turf, called Silloth Turf, was composed in the main of silt and fine sand, including some clay, instead of sharp sand particles that produced the ideal conditions for a bowling green, as it enabled play to take place almost straight away after rainfall because of its excellent drainage properties.

When Silloth Turf was supplied it was explained that because of the structure of this turf the grass was very sparse and to improve it once it was growing it needed to be hollow tined to remove some of the poor growing and drainage materials.

Regular solid tining with hand forks was necessary to keep the turf open because the make-up of the soil was still very poor. The real problem was that it was difficult to wet as it was similar to plasticine, but not so viscous and we hoped that the sharp particles of the sand that we were integrating into it would keep it open and enable bowling green grasses to get established and to grow.

At the time that this green was built and turf laid, the accepted practise was that a bowling green was hollow tined every three years. The cores that were removed would have been saved and stored in the open for a year to weather and breakdown to be used later once they had been ameliorated with lime free washed sharp sand.

The other very important thing about hollow tining is that by removing the cores, which can weigh approximately 4.5 ton, it will reduce the density of the playing surface accordingly. The holes would then be left open for two weeks to let in oxygen, thus enabling the soil life to re-establish itself and new roots to dig deeper to search for nutrients.

Aeration would then take place by solid tining and because the spikes are parallel they would move the turf inwards, pressing it back into place and partially closing up the hollow tine holes.

From this soil profile it can be seen that no integration had taken place, as there is little sign of dead organic matter in it that would have altered the colour of the turf. Very little rooting has taken place in the root zone, so we can establish that hardly any maintenance was done in that period. So what we have in essence, five inches below the green, is a layer of old Silloth Turf not allowing any water through in spite of the great expense in laying a green and the best opportunity to get the green as level as possible for satisfactory play.

At this moment in time, for some reason which I don’t fully understand, there is a further five inches of height which has got to be composed of top dressings over dead material year after year with hardly any mechanical work undertaken to integrate one level with another.

Apart from lack of spiking, chisel tining, slitting, hollow tining and scarifying at the right time of the season to control the build up of grass debris, it would appear that either no advice had been sought or the wrong advice given – I am sorry to say that this is not an isolated example.

Consequently, as a result of this very poor maintenance, the practise of top dressing every year has only served to provide the ideal conditions for annual meadow grass to become established and thrive, and has also raised the height of the green by a further five inches.

The playing surface is also five inches further away from the draining layer than originally planned and so will never produce a fast, even running green all due to the absence of correct practises, lack of turf culture knowledge and possibly poor advice.