The Jewel in Dr. Boller’s Crown!
Red clover and its usage
In recent years the use of red clover in the UK has declined. This situation may be about to change with more farmers now considering the crop once more as a good source of protein and a valuable part of the rotation. The editor visited Zurich, Switzerland, a part of the world where they know a thing or two about red clover.
The marked decline in red clover use correlates directly with the introduction and subsequent dependency we have on nitrogen fertiliser. The seed sales of red clover tell the story in the UK, with sales in 1960 being 3000 tonnes and in 1998 were about 60 tonnes. Whilst we have indulged our passion for bagged nitrogen, the Swiss have been quietly perfecting the art of growing red clover. Most seed mixtures sold in Switzerland contain red clover. These leys are used for silage and are fed to milking cows and beef animals. The Swiss place great emphasis on high quality agriculture and food products and food products and use their subsidy system to encourage the production of meat and milk from grassland and in particular from grass leys.
Dr Beat Boller is head of forage plant breeding at the Swiss Federal Research Station for Agriculture. He is well qualified, having spent part of his career at Aberystwyth before returning to Zurich in the mid 1980’s. He was fortunate to have taken over from a far sighted individual at the research station who had spent a lifetime breeding red clovers.
Boller attaches great importance to red clover and he says the quality of a grass/clover sward is superior to all grass swards, being higher in protein, around 20% more palatable and more digestible, particularly later in the season when grass quality often declines. In addition, he says, red clover also fixes free nitrogen in large quantities and its deep roots improve soil quality.
The jewel in Dr Boller’s crown is a variety of red clover called Milvus. This variety has been widely used in Switzerland since 1993 and was the product of a breeding programme which started in1968. It was subjected to several cycles of selection for disease resistance, stem eelworm resistance and yield. However, what makes this variety special is its outstanding persistence. Boller attributes its longevity to a number of factors, partly through the selection during breeding of persistent types and partly due to the fact that the variety is more competitive. This means it does not succumb to the pressure from ryegrass when sown in a mixed sward. Through traditional plant breeding methods Boller has a winner. Milvus is an early growing diploid variety which is higher yielding, more persistent and has a greater disease resistance than any other red clover.
Another important figure in Swiss agriculture is Dr Josef Lehman. He is head of the Swiss official testing programme for forage seeds. He confirmed Boller’s view on Milvus and suggested that if used in the UK it should be grown in conjunction with hybrid ryegrass. The significance of this new type of red clover ley is that they will last for three or possibly four years without the loss of yield, which would be a dramatic improvement on the current varieties which provide for only two reliable years.
If one is to reconsider red clover as a component of short and medium term silage leys it must be done in the light of this new variety. It should also be seen against the changing need for protein requirements ad for its ability to fix free nitrogen. Red clover can easily be incorporated into ryegrass mixtures and is therefore an easy way to improve forage quality. It is less suitable for grazing as there is a risk of bloat, but putting this limitation aside it is a means of maintaining production at lower cost both financially and environmentally.
Forage Matters Spring 1999.
- by Ian Wilkinson of Cotswold Seeds
