2. Material and methods
Section 2.1 consists in the isolation of autochthonous bacteria
from the rhizosphere of autochthonous shrubs (four) from the
semiarid environment. The soil used was located in the Natural
Ecological Park “Vicente Blanes” in the Province of Murcia
(Southeast Spain). This area suffers drought and low nutrient
availability and desertification processes. The soil in the experimental
area is a Typic Torriorthent (SSS, 2006) very little
developed with a silty–clay texture that facilitates the degradation
of soil structure, and low organic matter content. The vegetation inthe zone was predominated by T. vulgaris, S. chamaecyparissus, L.
dentata and S. officinalis growing with a patchy distribution. The
climate in this semiarid Mediterranean zone is a mean annual
temperature of 20 C and rainfall of 250 mm. The main soil
characteristics are: organic carbon 0.94%, total N 0.22%, P 1.36 mg
kg1 (Olsen test), pH 8.9 and an electric conductivity of 1.55 dS m1.