3.3. Impact of physico-chemical parameters of soil substitutes
on the Sinapis alba germination
The relationships between parameters reported in Tables 5 and Figure 3
have shown various interactions. The increase of Ca concentration
(5.32-8.23%) in the soil substitutes has induced a decrease in S
content (2.66-4.12%), but simultaneously raised pH and EC. Therefore,
it should be hypothesized that only S induced pH decrease and was not
directly and solely responsible for the control of the salinity of soil
substitutes. Chemically, calcium reacts with sulphate ion
(SO42-) to form some compounds
reducing the chemical reactivity of
SO42. The physical and chemical
parameters of soil substitutes prepared at the stage III were presented
in Table 5.
TABLE 5 Physical and chemical characteristics of soil
substitutes at the stage III