Science - April 7, 2005
More fences make better grass
While sheep roaming freely in the green Irish landscape might look attractive, it is not so good for the quality of the grass. More fences are needed.
In their experiment the clover content rose by over thirty percent during the growing season. In the biggest fields, where the sheep stayed for a week, the content did not rise above ten percent. The explanation is that the sheep in the big fields continuously pick out the tasty clover leaves, leaving the grass. The clover stands a better chance in the smaller fields because the sheep are moved more often.
It had long been suspected that this form of ‘strip-grazing’, as it is called, is good for clover grass meadows and for the sheep-keeping productivity. But it had never been convincingly demonstrated. Extensive grazing fields are typical in Ireland. Schulte: ‘A herd of one hundred sheep will graze about a quarter of a hectare of grass a day. This is what needs fencing off, but that can be quite expensive in terms of materials. Half a hectare per herd is probably more realistic.’ The findings apply in particular to the grasslands in the valleys of Ireland. / HB