Productivity of Lotus corniculatus and L. pedunculatus cultivars with and without tall fescue under sheep grazing

Abstract

The nutritional benefits of condensed tannin (CT) in forages such as Lotus are known but difficulties with establishment, herbage production and persistence in a pasture have hindered farmer uptake of this valuable legume. A sheep grazing experiment was established to investigate the effects of growing three Lotus corniculatus (Grasslands Goldie, G46 and Creeping) and two L. pedunculatus (Grasslands Maku and Grasslands Trojan) cultivars with or without Grasslands Advance tall fescue (Schedonorus phoenix syn. Festuca arundinacea) and with or without white clover (Trifolium repens) under infrequent (8-weekly) grazing. Without grass, the content of L. corniculatus and L. pedunculatus in the swards was 85% and 60% respectively by year 3. Adding white clover reduced the Lotus content in the swards by 20%. With tall fescue, the L. corniculatus cultivars increased from 6 to 34% between the summer of year 2 and year 3. In contrast, the L. pedunculatus cultivars remained at very low 1- 2% levels in the summer of both years. Inclusion of white clover did not further reduce Lotus content in the tall fescue swards. While there was no significant difference in content and yield between L. corniculatus cultivars, there was a consistent trend for Goldie to produce more herbage. Goldie had the potential to produce 2 t dry matter (DM)/ ha/year in a mixed pasture with tall fescue under infrequent grazing. Creeping L. corniculatus contained higher CT levels than Goldie (3.5 cf.1.1% of herbage DM respectively) and is thus potentially able to provide greater amounts of CT in a pasture. Trojan and Maku L. pedunculatus had similar plant density and herbage productivity. The experiment will be monitored further to determine the long-term persistence of these Lotus cultivars in a mixed pasture. Keywords: condensed tannins, infrequent grazing, legume composition, Lotus corniculatus, L. pedunculatus, tall fescue, white clover