Caucasian clover as a pasture legume for dryland dairying in the coastal Bay of Plenty

Abstract

The ability to spread underground through rhizomes, retention of a strong tap-root and a reputation for pest and disease tolerance, make caucasian clover (Trifolium ambiguum Bieb.) (CC) an attractive possibility for improving legume performance in coastal Bay of Plenty dryland dairying pasture. Large plots (0.125 ha) of Grasslands Kopu white clover (T. repens) (WC) and Endura CC were sown in spring (September 1994) as pure species swards following maize cropping and all but one 7 m wide strip undersown with ryegrass (Lolium perenne) in the following winter (July 1995). From September 1995, subplots within pure clover and undersown areas were treated with nematicide (oxamyl, fenamifos) and fungicide (metalaxyl, prochloraz) and mown to coincide with dairy cow grazing for determination of herbage yield. By the second spring, growth rates of CC matched those of WC and were superior by up to 60% through the second summer resulting in 9% greater total yield for CC pastures. Accumulated yield of CC pasture from September 1995 to June 1996 was significantly greater than WC (11.8 and 10.9 t DM/ha respectively). Caucasian clover was less responsive than WC to nematicide and fungicide treatment. With the methods used, CC can be established and perform well by the second year under dairy grazing in warm northern regions, and may provide for better summer production than WC. No difference was observed between the clover species in acceptability or pasture utilisation by dairy cows. Keywords: dryland dairying, northern New Zealand, pasture establishment, pasture growth, pesticide responses, Trifolium ambiguum, Trifolium repens