Forage production by two Lotus species as influenced by companion grass species

Abstract

AbstractA small‐plot experiment was carried out with grass‐lotus (Lotus spp.) swards on a lowland (185 m) clay‐soil site in S‐W England. Two species of lotus (Lotus corniculatus cv. Leo and L. pedunculatus, syn, L. uliginosus, cv. Maku) were each sown at 10 kg seed ha−1 with lour grass species each at two grass‐seed rates: Festuca pratensis at 6 or 3 kg ha−1 and Phleum pratense, Agrostis capillaris and Poa pratensis at 4 or 2 kg ha−1. Assessments were made over three harvest years (1992–94). during which no fertilizers were applied. Mean total herbage dry matter (DM) harvested from cv. Leo swards was 90 t ha−1 in year 1, 8–9 t ha−1 in year 2 and 4 0 t ha−1 in year 3. and from cv. Maku swards 6–6 t ha−1 in year 1. 8–9 t ha−1 in year 2 and 3–9 t ha−1 in year 3. Highest three‐year mean total yields were with F. pratensis as the companion grass (7–4 t ha−1 year−1), followed by Phleum pratense (7–0 t ha−1), A. capillaris (6–9 t ha−1) and Poa pratensis (6–2 t ha−1). The lower grass‐seed rate resulted in a greater proportion of lotus in the total harvested DM in year I. The higher grass‐seed rate resulted in higher yields from F. pratensis swards in year 1, but there were no significant effects for other species or in subsequent years. Lotus as a proportion of harvested DM declined from about 70% in year 1 to about 20% in year 3. The mean DM yield of lotus herbage in years 1, 2 and 3, respectively, was 5–5, 2–8 and 0–8 t ha−1 from cv. Leo swards, and 4–0, 3–3 and 0–8 t ha−1 from cv. Maku swards. Lotus herbage was of higher digestibility from cv. Leo [digestible organic matter (DOM) of 661 g kg−1 of lotus DM] compared with cv. Maku (551 g kg−1 DM). Mean N content of lotus herbage was 35 g N kg−1 DM. Digestibility of companion grass herbage was highest for Phleum pratense (557 g kg−1 DM) and lowest for A. capillaris (493 g kg−1 DM). It is concluded that lotus may be an alternative legume to white clover for low‐input, low‐fertility situations. However, further research is needed to evaluate its performance on different sites and under different management regimes, particularly grazing, and to overcome the apparent problems of its persistence.