Double mouldboard plough trials Arecleoch
Forestry Commission copyright image of Forest Research photographs courtesy of Glenn Brearley, Roslin. CN109
This is an interesting historical photograph as it shows the intention or desire to find an alternative to the single mouldboard peat plough that would plough an equally deep furrow in peat but provide a well placed ribbon of turf either side in which to plant the tree. The other objective was to try and achieve good tree planting positions about 2 metres distance apart across the plough furrow. It turned out in the end that no double mouldboard plough was ever produced that could produce perfect planting situations in every type of peat and compromises had to be struck.
By 1975 it was becoming very evident in plantations established on single furrow ploughing on peat, particularly if it was over wet clay or gley soil, that the trees were very unstable and started blowing over at quite young ages. The trees fell in rows pulling over the whole narrow platform of peat between the two adjacent single furrows. The strategy of creating wider platforms by ploughing every four metres with a double furrow peat plough would enable the roots of the two rows of trees on the platform to interlink and thus provide a much more wind resistant crop. Of course there was also the added incentive of greatly reduced ploughing costs if ploughing could be successfully carried out at 4 instead of 2 metre spacing.
About this time also tree stem quality and the influences of the original planting distances had been examined in more detail in many earlier establish tree crops. The effects of heavy branching and wide ringed initial growth in wider spaced planted trees were clearly evident and tests proved that these were having an adverse effect on the strengths and quality of the timber products from those sites. The upshot was a general presumption that tree planting particularly in the uplands had to be spaced at around 2 metre spacing or at 2500 trees per hectare.
The attached PDF shows the plough outputs in rather shallow peats and mineral soils over a rocky base. If forced to go shallow as occurred on this site the planting positions across the furrow were closer than 2 meters. Providing the tractor driver still continued ploughing at 4 meter spacing this was not a real problem and the average tree stocking would still be around 2500 per hectare.
Photographs by Donald Thomson December 1975
Download Large Version (142kB)
Groups: Forest Research, Forestry Areas, Forestry in Action, Tractors Ploughs and Drainage Machines