Jørgen Todnem

Research Scientist

(+47) 406 23 907
jorgen.todnem@nibio.no

Place
Løken

Visiting address
Nyhagevegen 35, 2940 Heggenes

Abstract

Knowledge about the botanical composition of grassland for silage is important regarding composition of seed mixtures, control of weeds, choice of harvest times and feeding strategies. The botanical composition of 185 fields in the mountain regions of southern Norway was examined using the dryweight rank method. The survey shows that the youngest grasslands (age 1 - 3 years) were dominated by the sown species with Phleum pratense L. the species with the highest proportion in the sward. In 4 - 6 year old grasslands, the proportion of sown species was reduced with the exception of Poa pratensis L., and Elytrigia repens L. had the highest proportion of unsown species. The proportion of Festuca pratensis (Huds.) was reduced at the same rate as Phleum pratense L. In grasslands of greater age (> 6 years) Poa pratensis L. and Elytrigia repens L. had the highest occurrence. The content of herbs increased with age, and Ranunculus repens L. and Taraxacum officinale F.H. Wigg were the most frequent species. The average clover content was < 6% of DM yield. The impact of Elytrigia repens L. on forage yield and quality should be further examined due to the high occurrence. Poa pratensis L. or other long-lasting grass species should be included in seed mixtures for this region when the grassland is intended to last more than three years.

Abstract

Wavy hair-grass (Avenella flexuosa (L.) Drejer; Deschampsia flexuosa (L.) Trin.) is the main pasture species in blueberry mountain birch forest and dwarf birch – blueberry moorland, which cover large parts of outfield pastures in the mountainous region of Southern Norway. Blueberry mountain birch forest with continuous mats of A. flexuosa was fenced in and harvested at different times in the summers of 2014 and 2015. Regrowth was also recorded. The grass from sample plots was dried after harvest, and analyzed for feed quality using NIRS. There were no statistically significant differences in total net energy yield between different harvesting regimes. Grass growth was highest in early summer, and harvesting on 2 July gave about 60% of the seasonal yield. Grass yield in undisturbed population increased until the last harvest (early September). Regrowth after harvest was small at the end of the season, but the growth here corresponded with the growth in undisturbed population. A. flexuosa remained at vegetative stage during the season. The energy value was highest at harvest first in July, and relatively constant at later harvests. The protein concentration declined towards the end of the season.