Production ofLotus corniculatusL. under grazing in a dryland farming environment

Abstract

A 3‐year experiment (from November 2000 to October 2003) was conducted at Massey University's Riverside Farm, in the Wairarapa on the East Coast of the lower North Island, New Zealand. The study compared, under grazing conditions, the seasonal and annual herbage accumulation rate, and the seasonal dynamics of ungrazed net herbage accumulation rate of Lotus corniculatus L. (birdsfoot trefoil; cv. ‘Grasslands Goldie') relative to perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) dominant pasture. Prediction equations to estimate standing dry matter (DM) in L. corniculatus and pasture from the rising plate meter (RPM) and sward surface height using the sward stick (SS) were also generated. Lotus corniculatus and pasture growing in a moderate fertility and low pH soil (pH 5.35) accumulated similar total herbage masses (24.3 versus 24.1 t DM ha^–1) over the 3 years, with the DM production being greater for L. corniculatus than for pasture during 2000/01, particularly during summer/autumn drought conditions. The net herbage accumulation rates from ungrazed areas of L. corniculatus and pasture were similar. Pasture and L. corniculatus ungrazed net herbage accumulation rate was at maximum at a herbage mass of 9.9 t DM ha^–1 (60.23 ± 16.94 kg DM ha^–1 day^–1) and 5.8 t DM ha^–1 (15.69 ± 13.25 kg DM ha^–1 day^–1), respectively, during the spring/summer period. The ungrazed net herbage accumulation rate was lowest, possibly due to severe moisture deficits, during the summer season. Monthly and seasonal variation in the calibration regressions fitted to estimate herbage mass of L. corniculatus non‐destructively suggested a combination of destructive and non‐destructive methods are needed to assess herbage mass. It was concluded that Lotus corniculatus L. (birdsfoot trefoil; cv. ‘Grasslands Goldie') has the potential to increase the performance of a sheep farming system based on perennial ryegrass/white clover pasture owing to its ability to grow in acidic soils, its tolerance of regular low summer/autumn rainfall, its seasonal‐ity of feed supply, its high feeding value and its moderate and beneficial concentration of condensed tannins (CT).