**6.4 Conclusions on the development over time of fresh lettuce on soils with different concentrations of zinc**


### **6.5 Conclusions on mathematical modeling for the development of fresh lettuce over time on soils with different concentrations of zinc**

The mathematical modeling presented in this chapter was done through a mediation of experimental data.

Increased polynomic interpolation resulted in a good approximation of experimental data, but there were not enough reasons from the point of view of the phenomenon studied to get over the interpolation of the third degree polynomial. The functions determinated are particular and useful only in the experimental field chosen in this study.

Therefore, the statistical model can be used to validate the theoretical model, which is general both in terms of working conditions (soil type, metal type, metal concentrations, atmospheric conditions) and the plant species used (root species, leaf species, fruit species).

The results obtained from experiments and interpolation suggest indications for future research: New experiments on several plant vegetation cycles, possibly with modification of working parameters that can influence the bioaccumulation process of heavy metals in plants.

### **6.6 General conclusions**

At the optimum vegetation period (final harvest, in the stage of ripening and human consumption), the plants (carrots, parsley, cucumbers, strawberries, Raspberries) have continuously accumulated (monotone growth) heavy metals (Cu, Pb, Zn) from contaminated soil.

At the end of the growing season, the transfer coefficient decreases as the concentration of heavy metals (Cu, Pb, Zn) in the soil increases.

*Evaluate the Impact of Soil Contamination on Vegetables and Fruits DOI: http://dx.doi.org/10.5772/intechopen.110445*

The data presented in this chapter can be both the foundation of dynamic mathematical models that can simulate the life of a plant and the starting point for the development of future research, that can emphasize self-defense mechanisms developed by plants, adaptations to new environmental conditions, possibilities for restoring the qualities of some plants over time.
