Auteur: Elgersma A. and Søegaard K.
Jaar van uitgifte: 2015
Inclusion of legumes in grasslands could enhance N-use efficiency of forage production. Performance of 7 binary grass-legume mixtures was studied to examine companion species with contrasting attributes. Perennial ryegrass (PR) was sown alone and with each of four forage legumes: red clover (RC), birdsfoot trefoil (BT), lucerne (LU) and white clover (WC); WC was sown with each of four companion grasses: PR, hybrid ryegrass (HR), meadow fescue (MF) and timothy (TI). Mixtures were studied in a smallplot (1.5×8 m) cutting trial with 4 replications in Denmark to test the effect of species composition on herbage yield, contents of nitrogen (N) and neutral detergent fibre (NDF), and in vitro organic matter digestibility (IVOMD). Plots were fertilised with 300 kg N ha‑1 from cattle slurry and harvested five times from May to October in year 1 and four times in year 2. With different companion grasses, the WC proportion was similar in mixtures with HR and MF, which had a lower WC content than with PR and TI. Annual herbage yield was highest for PR/RC (15.6 Mg DM ha‑1) which had, on average, the highest legume proportion of DM, the highest N content (33 g N kg‑1 DM) and the highest N yield (505 kg N ha‑1) across both years. The mixture with the lowest values was PR/BT (9.6 Mg DM ha‑1; 25 g N kg‑1 DM; 243 kg N ha1). PR/RC had the lowest concentration of NDF (375 g kg‑1 DM) and pure PR the highest (437 g kg‑1 DM). IVOMD ranged from 730 g kg‑1 organic matter (OM) in PR/LU to 774 g kg‑1 OM in WC/HR. Choice of companion grass had less effects than that of companion legume in the examined mixtures. Red clover contributed most to N yield.