Due to the high price of fertiliser and concentrates, the decision was made to put in five acres of red clover silage this year on Tullamore Farm. The crop was planted under the Department of Agriculture, Food and the Marine’s Red Clover Silage Measure.

The five-acre paddock chosen had a P index of 4 and a K index of 2. The pH was 7.8. The field was ploughed, due to a lack of weed control.

As a result of the increase in the cost of glyphosphate, the grass was grazed and ploughed straight after.

It was decided that the paddock would be ploughed as the land had previously been in tillage and had low soil carbon levels. It was sown in late May and took off quite well. Two weeks later, 10:10:20 was spread at a rate of two bags to the acre.

However, the weeds got ahead in the crop, and it was then grazed and topped which solved this problem and got rid of the annual weeds.

The first grazing took place on 20 July. It was then closed up and a cut of silage was taken off it in good weather conditions.

The silage has been tested and the results are below. Results show the silage is high in protein at 16.6%, something which farm manager Shaun Diver is happy with.

It is hoped to get more silage off the field in its second year. This year, there were just 13 bales from it which will go towards twin- or triplet-bearing ewes once they are scanned. This will reduce the need for concentrates.

Red clover mix planted:

  • Perennial ryegrass (AberClyde) – 4kg.
  • Perennial ryegrass (AberWolf) – 3.5 kg.
  • Red clover (AberClaret) – 4kg.
  • White clover (Alice) – 0.5 kg.
  • The inclusion of red clover in a mixture with perennial ryegrass and white clover can result in high yields of multi-cut silage without artificial nitrogen (N) fertiliser.

    Red clover is best known for its ability to fix atmospheric N into a plant-available form which can supply the equivalent of approximately 300kg per ha per year to the crop. High N fertiliser prices have sparked an interest in the inclusion of red clover in silage swards.

    Annual yields of 15t DM/ha have been recorded at Teagasc Grange and Solohead under zero N fertiliser input. However, it is a relatively short-term ley that can maintain high levels of production for three to six years, as the clover tends to die out of the sward over time.

    Red clover grows by producing erect shoots that grow from the crown of a taproot, and so it struggles to spread out within the sward or replace shoots that may become damaged by either swards or disease.

    This is the main reason for its inability to persist in a sward for very long. On the other hand, white clover produces stolons that grow along the surface of the soil, which is why white clover has a longer lifespan in swards in comparison to red clover.

    The results explained

    Dry matter (DM%): The dry matter is the amount of silage material left after water is accounted for. The higher the dry matter, the higher the potential intake of silage.

    pH: The pH measures the silage acidity and ability of the silage to store.

    Ammonia N: Ammonia is a good indicator of fermentation quality, with values of less than 10% desirable. Greater than 15% will result in reduced intakes. High nitrate levels in grass can contribute to spoilage.

    DMD: The DMD (dry matter digestiblity) is an accurate test of the feeding value of the silage, as well as the expected liveweight gains/milk yields and supplementation rates.

    ME: The ME or metabolisable energy is a measurement of the usable energy of the silage. It is higher at the leafy stage.

    Crude protein: The crude protein is an indicator of the quality of grass at the time of harvest. Young leafy grass will have higher protein levels, as well as silage that is cut earlier in the season.

    Carrying out mineral analysis on the silage is important as it can help the farmer identify any problems there might be early on in terms of impact on animal health, while also helping them decide on appropriate supplementation if needed.