The investigated plants roots
Native shrub species such as broom and asparagus were chosen for the experimental investigation. The study was
conducted with plants collected in the area of Motta S. Anastasia (Catania), and Mirabella Imbaccari (Catania) in the
center of Sicily (Italy), just a few km western of Catania. Those plants grow up spontaneously in the quoted sites
and have been transplanted with their root balls. Thirty plants were sampled. Table 1 lists the key features of the
examined plants.
Table 1. The investigated plants characteristics.
Botanical name Asparagus Acutifolius Spartium Junceum
Family Liliacee Leguminous plants
Root depth (m) 0.25-0.65 1
Root apparatus Espanded and fasciculated Espanded
Soil characteristics
It adapts to all types of land
provided with adequate drainage.
It adapts well on clay ground and
stations in arid and poor soil.
Speed of growth Slow High
Average tensile strength 3,9 MPa 4,4 Pa
The present study focused on two typical Mediterranean species. Three different type for the experimental
investigation have been used. Black asparagus roots, taken on Motta S. Anastasia hills named "asparagus N°1"(Fig.
2), black asparagus roots taken at Mirabella Imbaccari named "asparagus N°2" and "broom" roots taken on Motta S.
Anastasia hills. After collection, roots have been cataloged based on the average diameter value. Table 2 shows for
each chosen root type, the sample denomination and the corresponding diameter.
The equipment used is a hydraulic testing machine, having a 40 kN maximum load, that was improved by
installing a load cell and a transducer for displacement detection. The test system was connected to a computer for
digital data acquisition. Measurements for assessing the tensile force value of plants were performed on 30 samples
whose diameters ranged from 3.00 to 6.10 mm, including root bark. Tests were performed about two days after
removing the root samples from the field. In the present paper only results for Asparagus n. 1 are presented.
The aim of the experimental tests was to determine the tensile strength of the examined roots. Twenty-one
samples of roots of "asparagus N°1"were tested. The ends of the roots were clamped using cork and polystyrene. It
was also added organic peroxide as an additive (Fig. 3). Moreover, the ends of the roots have been connected with
the clamp to driving system.
The data acquisition system, includes displacement transducers load cells and a computerized system, with the
associated system software, working with the system controller and associated firmware to control the instrument