Some observations on short-rotation ryegrass in Canterbury

Abstract

In 1943 a new ryegrass appeared on the New Zealand market, known first as H1, but later as short rotation ryegrass. This new grass was a hybrid produced by the Grasslands Division, Department of Scientific and Industrial Research, and combined some of the more valuable features of its parents Italian and perennial ryegrass. Since that time the grass has been tried over a wide range of soils and climate with varying management and utilisation, so that the picture of its sphere of usefulness is now fairly clear. The characteristics of the grass as first produced are as follows :- The fertility and moisture requirements for optimum production are high, being intermediate between ItaIian and perennial ryegrass; a very quick establishing grass, producing a large flush of feed in the first season; one of the earliest spring grasses; non-productive in hot, dry weather and subject to severe mortality ;a phenomenal power of regeneration from shed seed under conditions of high fertility; permanence variable, depending on fertility, moisture, and management; habit of growth upright and open, demanding rotational grazing; palatability excellent. In other words, this grass leans towards the Italian parent, but is capable of becoming more or less permanent on a wider range of soils. Since the first release subsequent selections have aimed at eliminating its lack of permanence. There is some evidence that this has been achieved in part with the nucleus seed of 1948. At Lincoln College great use has been made of this grass. Since 1943 eighteen fields have been sown in which short-rotation ryegrass was a dominant constituent of the mixture. One original pasture still remains, E.8; now in its seventh year, it is still a good pasture & the present time 242 acres of our 542 acres of pasture contain short-rotation ryegrass as a dominant. We have made some use of it on the lighter land at Ashley Dene and we have results of observations at the Kirwee Experimental Farm. Over the last two seasons measurements of seasonal production have been made so that we have accumulated some evidence. But first a word of warning as to our experiences: we extended the use of short-rotation ryegrass during a cycle of rainfall of over 30 inches per year. We now appear to have entered a cycle of about 20 inches, so that our earlier experiences may be of limited value under conditions of lower rainfall.