THE EFFECT OF A RYEGRASS COMPANION GRASS AND THE VARIETY OF RED CLOVER ON THE PRODUCTIVITY OF RED‐CLOVER SWARDS

An experiment was conducted to measure the effects of differrat ryegrass companion grasses and red‐clover varieties on the productivity of red‐clover swards. Three silage harvests per year were taken over a 2‐year period. The addition of a companion grass increased total herbage yields; S24 perennial ryegrass gave the highest herbage yield over the two years, followed by Reveille perennial ryegrass. Because of lack of persistence, Tetila Italian ryegrass yielded poorly the second year. A companion grass had little effect on red‐clover yields in the mixed swards but improved percentage digestibility of the OM of the total herbage and lowered the CP percentage. Its presence also reduced the ingress of unsown species. The variety of red clover used had little effect on total herbage yields or red‐clover yields in the first harvest year. In the second year, Hungaropoly and Tilo persisted better and so gave higher total herbage yields and red‐clover yields than Dorset Marl or Essex. The fall in total herbage yields from the first to the second year was entirely due to a fall in red‐clover yield since yields of the ‘non‐red clover’ fraction of the total herbage increased. A red‐clover/grass sward may have advantages over a pure red‐clover sward nutritionally, for silage‐making and for its effect in diluting the oestrogenic activity of a pure clover sward. A major reappraisal of the role and potential of red‐clover swards in the UK is warranted because of their many valuable attributes, particularly their ability to give high herbage yields of high nutritive value without the addition of fertilizer N. The improved persistency of some of the tetraploid varieties of red clover enhances the value of the plant.