Revegetation of marginal saline rangelands of southern Tunisia using pastoral halophytes

Abstract

Revegetation of marginalised rangelands using pastoral halophytes is considered an appropriate scientific and environmental approach to rehabilitation. Atriplex halimus L. (Amaranthaceae), A. mollis Desf. (Amaranthaceae), Cenchrus ciliaris L. (Poaceae) and Lotus creticus L. (Fabaceae) are promising species for arid rangeland rehabilitation, because of their adaptation and palatability. Dry biomass, in vitro digestibility, ash, nitrogen, neutral detergent fibre, acid detergent fibre and lignin of 50% aboveground biomass (upper half of tufts assumed to be the firstly consumed parts by livestock) of these species were evaluated in the Sidi Makhlouf region of southern Tunisia, during December 2015, June 2016 and December 2016. Digestibility increased with nitrogen content and both of these variables are decreasing when the dry matter and fibre contents increased. Four groups of species were obtained, based on digestibility and nitrogen and lignin contents. A. halimus and L. creticus harvested in the winter of 2015 have superior forage quality. A. mollis was better able to regenerate after winter harvest. Forage quality of C. ciliaris and L. creticus decreased with seasonal variation. The rehabilitation of marginal saline dryland remains possible with local pastoral halophytes that produce good forage quality and may provide many economic and environmental benefits for local users.

Keywords: drylands, forage quality, rehabilitation, recovery, salinity