## 3 Results and Discussion  
### Germination and Growth Trials without Fertilizer Addition  
As can be seen in Table 1, Irish peat is distinguishable for its low pH value with respect to the other soils, but the density and content of fertilizer (negligible) are comparable with the others soils without fertilizer. Organic soil compared with Veget soil shows a slight content of fertilizer and thereafter a moderate increase in electrical conductivity. Floradur B, on the other hand, is distinguishable due to the relevant concentrations of the three main plant nutrients: nitrogen, phosphorus, and potassium. Concerning conductivity, for all the soils, the limit generally applied to fertilizer compounds necessary to be sold and employed was respected (<2 mS/cm) [39]. At the final harvest, after 30 days under daylight, plants grown in the different the three potting soils without relevant content of fertilizer showed different performances to basil germination and growth. For the first, it must be noted that the employment of Veget soil leads to the germination of only one plant, that is a very restrained value when compared to Irish Peat and Organic soil, which were capable of induce the germination of 61% and 75% of the buried seeds, respectively. This result is probably due to the fact that Veget soil is the only substrate with a complete absence of nutrients and salts, which is necessary for the plant germination. Thereafter, due to the high incompatibility of Veget soil with basil, this substrate was withdrawn from further investigation and characterization. Figure 3 shows the comparison among two principal growth properties related to Irish peat and Organic soil employment: the average height and TFM of the plants. These results highlight that although Irish peat showed excellent compatibility with basil, Organic soil is the most promising soil in terms of TFM and average height of the plants in reference to a quite similar number of sprouted plants. This result is compatible with the fact that Organic soil contains a small amount of nutrients capable of acting as fertilizers and a pH nearer to values more compatible with basil cultivation [40]. Taking into account the employment of only Organic soil, it has been demonstrated that the light spectrum strongly affects plant growth and development; in fact, basil  
Figure 3: Comparison of Irish peat (in blue) and Organic soil (in orange) considering: (**a**) Total Fresh Mass and (**b**) Average height. Error bars indicate the standard deviation on the average values. plants grown under LED lights modules generally show better performances than the plants exposed to daylight, as shown in Table 5 and Figure 4. This is particularly true for parameters such as Height, TFM, TLM, and ALM. On the other hand, the results obtained for the parameters NoL and TDM do not highlight any specific trend. Regarding the comparison between plants grown under two different LED lights combinations, no statistically significant differences emerged. In fact, although plants grown under the 3 HR:1 DB module showed generally higher mean values of the growth parameters than 1 HR:3 DB, the standard deviation ranges suggest a similar behavior of the basil plants growth among the two combinations employed. These results are also suggested by a visual comparison of the plants obtained through the three enlightenment methods (Figure 4). For the SLA index, the highest value is guaranteed by 1 HR:3 DB employment, and this is particularly important because this index depends on the growth environment of the plants and describes their degree of adaptation to it from a morphological point of view. For the LAI parameter, no difference among the two LED module employments can be noted, even if a substantial increment of this index is observed by moving from daylight to LED enlightenment. This parameter is used to determine the size of the interface between the plant and atmosphere, thus the exchange of mass and energy between them to model the photosynthesis mechanism.