Teagasc’s James O’Loughlin told the delegates attending this morning’s Virginia Show Dairy Conference that just under half the land farmed in Ireland is marginal in nature.

“Heavy, poorly drained soils have a reduced capacity to grow grass and carry stock during the spring and summer months. In fact, there is a direct correlation between rainfall levels during the grass growing season and the ability of farms on marginal land to produce feasible levels of output.

“For example, the potential for ryegrass swards to be maintained in a healthy state reduces significantly as soil drainage problems increase,” he said.

The Moorepark-based research scientist went on to confirm that Teagasc is carrying out a series of soil improvement projects on farms in counties Clare, Kerry, Cork, Tipperary and Mayo. Where drainage is concerned he stressed the need for producers to carry out a thorough assessment of their farm’s actual needs before implementing any form of improvement programme.

“This will entail digging a series of test holes, up to two metres in depth, which will allow for a thorough assessment of sub soil conditions,” he said.

“Drainage problems can be caused by sub soils that are impermeable in nature, high water tables and the impact of springs. On some farms a combination all three challenges may present themselves.

“Drainage works are not cheap. Current costings range from €6,000 to €7,000 per hectare. These figures include the cost of a grass re-seed. But these are substantial costs and it is incumbent on farmers make sure that they invest in the drainage system that best meets the needs of their farms.”

James O’Loughlin also confirmed that it a milk price of at least 28c/L is needed to economically justify an investment in drainage at current costs. This, in turn, raises the issue of farmers requiring a grant scheme to make such an undertaking viable.