Legumes for South Island tussock grassland environments - an evaluation of plant survival and growth at some inland Otago and Canterbury trials

Abstract

Many legumes have been trialled for establishment, persistence and productivity in the tussock grassland region of the South Island, New Zealand. This paper presents information on long-term persistence and growth based on a survey of surviving legume species from 45 previous plant accession trials, established over a range of sites and environments (predominantly dryland) throughout Otago and Canterbury. Sites were visited in January/February 2003 and identified plants were visually scored for several growth-related parameters. Most sites were open to stock grazing and all were affected by drought during the current growing season. Of the legume species that seed is not commercially available for in New Zealand, the most persistent and vigorous were: Lupinus polyphyllus, Trifolium medium, Coronilla varia, Dorycnium hirsutum, Melilotus alba and M. officinalis, Astragalus falcatus, T. canescens, D. pentaphyllum, and A. cicer. These plants may usefully supplement tussock grassland vegetation under environmental and management conditions including periodic drought and the moderate to light grazing experienced at most of the trial sites visited. This paper reviews growth and survival of those legumes, and provides a guide to species with potential for revegetation in dryland and semi-arid environments that warrant further research into site x management interactions and possibly commercial development. Key words: legume persistence, Otago/Canterbury, revegetation, tussock grassland