Assessing the persistence of some pasture legumes in hill country

Abstract

White clover (Trifolium repens) is the traditional pasture legume in New Zealand but its persistence and production in the low fertility, summer-dry hill country of the North Island is poor. In a preliminary trial to assess the persistence of alternative perennial legumes, two species, Adesmia bicolor and a prostrate cultivar of Trijoiiumpratense were studied over a 2-year period on an ash soil over a range of slopes, aspects and fertility I'evels. The ZI pratense cultivar was still present at trial completion, contributing to higher total legume levels (9.5%) than in the resident pasture plots (7%). The second trial examined the potential of the previous two species along with accessions of Trifolium semipilosum, Trifoolium fragiferum and T. repens (cv. Grasslands Prestige) over 3 years in a paddock of clay hill soil commencing in 1994. After 2 years the 3: pratense and introduced T. repens lines were still present in the easy plots while the T. semipilosum cultivar was the only introduced legume to persist on the steeper slopes. The mean total legume content on both steep and easy slopes from the last harvest (April 1996)-was-similar-to pre-trial levels. The persisting introduced legumes "replaced" resident species rather than increasing total legume levels. The potential of the prostrate T. pratense cultivar for use in hill country should be further investigated. Keywords: Adesmia, hill country, legumes, low fertility, persistence, Trifolium repens