Physico-Chemical Properties of Steppe Soils with Hammada scoparia (Pomel) in The Naâma Region (Algeria)

With an average annual rainfall below 150 mm, the steppe with Hammada scoparia emerges, constituting the transition between the arid steppes and the Saharan vegetation. The distribution of the vegetation is very irregular, which depends on the nature and structure of the soils. A soil study, based on observations and the sampling of 42 profiles, was carried out within a range of species located in the southern part of Naâma. The principal component analysis enables the identification of relationships between the different soil profiles and the species studied. The results obtained show that the woody steppe with H. scoparia occupies habitats characterized by a sandy-loamy to sandy and stony texture on the surface of carbonate crusts, often in the form of slabs with a variable carbonate content of 1.22 to 12.7% in certain types of soil; this element tends to be carried to a depth of 40 to 60 cm. In other types of soil, on the contrary, it remains distributed throughout the entire profile. Colonized soils are generally shallow and poor in organic matter, varying from 2 to 3.65%, with an alkaline pH ranging between 6.7 and 8.8. The measured electrical conductivity varies between 0.1 and 0.7 mS/cm. This variation largely depends on the texture of the soil, the bioclimate and the steppe vegetation. The results obtained enable the valorization of this species, which has a socio-economic and ecological role, as it practically adapts to the different types of soil of the steppe space.