*3.3. Soil Samples following Lettuce Harvest*

After harvesting the lettuce, soil samples (0–15 cm) were taken and analyzed (Table 4). The results showed that soluble organic N was the only parameter significantly influenced by the amendments, with significant decreases in both the miscanthus and the willow treatments. A tendency for Cu to be lower under willow treatment and for Fe to be higher under miscanthus treatment was also observed (*p* = 0.055).

**Table 4.** Mean ± (se) and *p*-values (Tukey's test) for different soil parameters measured in the soil at the end of lettuce growth as a function of amendment.

