**5. Conclusions**

The chapter is focused on the development of smart hydrogels derived from synthetic monomers and natural pre-polymer for agricultural application as water retaining material and matrices for the controlled release of fertilizers. However, in the majority of the report, the mechanical properties of those hydrogels are not good enough for prolonged application in the field. Hence, this chapter addressed the route in which the mechanical properties of such hydrogel are fine-tuned. Besides, it focused on the typical hydrogels that are used for the controlled release of water, urea, potash and phosphate fertilizers, their advantages in the field, effects on the hydraulic conductivity of soil and their safety aspects.
