Biomass production and forage quality of three halophytes genus Sarcocornia and Salicornia characterizing the saline marginal lands of southern Tunisia

Abstract

Halophytes are widespread in the Tunisian marginal saline soils but not widely exploited. This study aims to evaluate the forage quality and chemical composition of three halophytes, native in  southern Tunisia : Salicornia emerici Duval-Jouve, Sarcocornia alpini (Lag.) Castrov. et Sarcocornia fruticosa (L.). Dry biomass (MS), organic matter (MO), mineral (MM) and crude protein (PB) contents, in vitro digestibility, ions and anti-nutritional compounds (flavonoids, tannins and saponins) were determined and compared to those of Medicago sativa (L.), considered as reference feeding plant. The obtained results indicate that dry biomass of these halophytes ranges from 10.50% to 18.63% for S. emerici and S. fruticosa, respectively. Compared to S. emerici, both halophytes recorded the highest percentages of organic matter and crude protein and higher concentrations of Na+, K+, Mg2+, Ca2+ and Fe2+. These three halophytes, harvested during the summer period, showed important digestibility percentages (> 70 % MS), exceeding those of alfalfa, and low levels of ADF, ADL and anti-nutritive compounds (condensed tannins, flavonoids and saponins). These findings suggest that the valorization of these native halophytes as fodder is promising, in particular S. alpini and S. fruticosa. This can provide many economic and environmental advantages in drylands.