Scientific Supervisor: Ch. Tsantilas

Conclusion

The properties of the sludge is favorable for agricultural utilization. It contains significant amounts of organic matter and nutrient elements nitrogen and phosphorus, while the concentration of heavy metals is significantly less than those required by the relevant European Union legislation limits.

The application of sludge as fertilizer or a substitute for mineral fertilizers significantly increases the yield of cotton . sludge volumes 1-3 in. / acre . They can fully substitute for inorganic fertilization applied in the region. This effect is mainly due to the addition of the ground element N.

The effect of applying the slurry on soil quality is characterized by:

• Slightly decreases the pH, and slightly increases the salinity of the soil. significantly increases the concentration of organic matter and nutrients N, P and B.
• Significantly increases the concentration of all heavy metals tested, but without exceeding the limits imposed by Community law, even in larger amounts of sludge applied (5 in . / ha . / year ) .
• sludge doses greater than 1 in . / ha . / year lead to leaching of nitrate N . So from this side as a safe means the quantity 1 in . / ha . / year .