white clover

Bijeenkomst: EGF2015
Auteur: McCarthy B., Dineen M., Guy C., Coughlan F. and Gilliland T.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
An experiment to investigate the impact of tetraploid and diploid perennial ryegrass swards sown with and without white clover on the productivity of spring milk production systems was established in 2012 (75%) and 2013 (25%). Four separate grazing treatments/swards were sown for the experiment: tetraploid only, diploid only, tetraploid with clover and diploid with clover. Eight cultivars (four diploid: Tyrella, Aberchoice, Glenveagh and Drumbo; four tetraploid: Aston Energy, Kintyre, Twymax and Dunluce) were sown as monocultures with and without clover. Thirty cows were allocated to each treatment after calving in February 2014. All treatments were stocked at 2.75 cows ha‑1 and received 250 kg of nitrogen fertiliser ha‑1. There was no difference in milk or milk solids yield between the tetraploid-only (4,895 and 414 kg cow‑1, respectively) and diploid-only (4,848 and 403 kg cow‑1, respectively) swards. However, incorporating clover resulted in 13.3% greater milk yield and 13.4% greater milk solids yield (5,532 and 464 kg cow‑1, respectively, and 5,506 and 462 kg cow‑1, respectively, for the tetraploid with clover and diploid with clover treatments, respectively). Pasture dry matter (DM) production was 16.8% greater on the grass-clover swards (17,400 kg DM ha‑1) compared to the grass-only swards (14,900 kg DM ha‑1).

Bijeenkomst: EGF2015
Auteur: Verloop J., Oenema J. and Geerts R.H.E.M.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
The objective of this study was to explore under farming conditions the effect of reduced fertilizer N application rates on the dynamics of botanical composition and yields of grass-clover-swards. In both temporary and permanent grassland the percentage of highly productive grasses (good grasses) declined at a constant rate of 3.0 to 6.3% points y‑1 during the aging of the sward. Good grasses were replaced by less-productive grasses and herbs. The percentage of clover did not show a significant trend. Reduced N fertilization did not significantly change these dynamics. The percentage of white clover and, in some cases, high-yielding grasses in the sward, enhanced the yields of nitrogen and herbage dry matter, while the percentage of herbs reduced yields.

Bijeenkomst: EGF2015
Auteur: McDonagh J., McEvoy M., Gilliland T.J. and O’Donovan M.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Perennial ryegrass (Lolium perenne) is the most widely used ryegrass species for high-output pasture based dairy farms in Europe. Repeated selective breeding has enhanced dry matter (DM) productivity potential, elevated nutritive value and provided a large diversity of varieties adapted to variant growing conditions and farming practices. With renewed interest in white ryegrass-clover swards mixtures, there is a concern that sward interactions between perennial ryegrass varieties and white clover will have a significant effect on the dry matter yield performance of a recommended grass variety. The aim of this study was to establish if perennial ryegrass varieties re-rank in DM yield when sown with/without white clover at two nitrogen applications under intensive grazing. Eight perennial ryegrass varieties were sown with (+C) /without (-C) white clover. Swards received two levels of nitrogen 250 (HN) and 100 (LN) kg N ha‑1. Treatments were HN+C, HN-C, LN+C and LN-C. A significant nitrogen by clover interaction occurred because LN-C gave the lowest yield, but although high nitrogen increased both the with and without clover treatments, the highest yielding treatment was LN+C. Grass variety had a significant effect (P>0.001) on DM yield, but the ranking of the ryegrass varieties was unaffected by the imposed treatments and so represented a robust estimation of the relative DM production potential of each ryegrass variety. The inclusion of clover also did not affect the relative performance of the ryegrass varieties, indicating that any inter-species competitive interactions were not variety specific.