Effect of Hunter River lucerne (Medicago sativa L.) on grasses in rain-grown pastures

Abstract

In an infrequently grazed field experiment at Biloela, in sub-coastal Queensland, six grasses are being observed in simple combinations with good stands of Hunter River lucerne (Medicago sativa L.) or poor stands of siratro (Phaseolus atropurpureus DC.).
Results are presented for a period commencing 18 months after planting. Where the grasses were associated with lucerne, mean yield of the six grasses was increased at all but one of seven harvests over more than 2 years, the increases ranging from 36 to 74 %. Increases due to the presence of lucerne were also recorded in the total dry matter of the pasture. Nitrogen content of the grasses was improved. There was a significant increase in the yield of seed material by two buff el grass cultivars at one harvest. The possible effect of above-average winter to early summer rains in two of the three seasons is discussed.