The effect of mulching and fertilising on growth of over-sown grass species in degraded rangeland in north-eastern Ethiopia

Abstract

A study to investigate oversowing of grass species as a restoration strategy in severely degraded rangeland was carried out in the Allaidege rangeland in north-eastern Ethiopia. Locally collected seeds of three grass species (Enteropogon rupestris, Ischaemum afrum and Tragus berteronianus) and imported seeds of three additional species (Cenchrus ciliaris, Chloris gayana and Panicum coloratum) were oversown in a severely degraded area of the rangeland to improve cover and grazing capacity of the rangeland. The effect of combinations of inorganic fertiliser, manure and grass mulch on the dry matter production of the grass species sown at 4 kg ha^–1 in strips in a 10 m × 10 m plot was determined. The experiment was a randomised complete block design with eight factorially combined treatment combinations randomly applied and replicated three times. All the sown species showed significant positive responses to the mulch treatment, but not to the other treatments or treatment combinations. Ischaemum afrum and T. berteronianus produced significantly more dry matter (900 kg ha^–1 and 800 kg ha^–1, respectively) than the other species. The results emphasised the importance of mulching to restore degraded patches in arid and semi-arid environmental conditions.

Keywords: degraded rangeland, fertilising, grass species, mulching, oversowing

African Journal of Range & Forage Science 2008, 25(1): 37–42