Irish farms have significant capacity to grow more grass
Teagasc now have a number of farmers from all over the country recording their weekly grass measurements on PastureBase Ireland. Results show there is a huge capacity on Irish farms to grow more grass and one important element of this is reseeding.
Perennial ryegrass dominated swards produce on average 3t DM/ha/year more than old permanent pasture swards. Importantly, most of this additional growth occurs up to mid-May. Reseeded swards are also 25pc more responsive to nitrogen.
The increased profitability of the reseeded pasture will cover the cost in just over two years. This makes reseeding one of the most cost effective on-farm investments. However, the cost involved is significant, which makes it crucial that farmers investing in reseeding get the best possible result.
Spring is the ideal time of year for reseeding. These swards will have similar if not greater total herbage production in the year than the old permanent pasture. Soil temperatures are more stable than in the autumn giving the grass and clover seeds a better chance of germination and establishment. Post emergence spraying for weed control is usually very successful with more favourable weather conditions in summer.
Ideally choose where to reseed based on the paddock's performance over the full year. It can be hard to pick poor paddocks in May. Think back to those which were slower to respond in the spring or last autumn. Also note those where the quality is difficult to maintain as you go through the summer.
While ploughing is probably the most reliable method of reseeding, minimum cultivation techniques when completed correctly are equally effective. Choose a cultivation method that suits your farm.
A fine firm level seedbed allowing good seed/soil contact is essential. Avoid clumpy sods on the surface to ensure that seeds (especially white clover) are not buried too deep. Perennial ryegrass seeds sown to a depth of 2cm will have a germination rate of 94pc versus 68pc for those sown to 4cm. After sowing the seedbed should be rolled again to ensure good contact. This will also help to keep moisture in the soil.