Engineered Silica Nanoparticles and silica nanoparticles containing Controlled Release Fertilizer for drought and saline areas.

Silicon supplementation was explored to increase salinity tolerance in plants, in the beginning of this cenutury, therefore silica nanoparticles (SiO₂ Nps ) can also be used as a trial to improve salinity tolerance in plants. In this study SiO₂ Nps have been synthesyzied by some modification in the conventional method of Stober by thermal hydrolysis of Tetraethylorthosilicate. A compound Controlled Release Fertilizer (CRF) was synthesized that carried NPK and SiO₂ Nps inside the core and Chitosan as the first semi-permeable coating and Sodium Alginate and Kaolin as an outer most superabsorbent coating. The synthesized SiO₂ Nps were characterized by TEM and XRD. The water absorbency of CRF beads showed that they can absorb large amounts of water and double their weight. The Nutrient released rate from CRF beads was very slow and sustained for six months at room temperature. The SiO₂ Nps containing superabsorbent CRF was capable of releasing the nutrients slowly, withhold large amounts of water therefore can help plants control salinity and survive better in drought and saline conditions without harming the environment. The synthesized compound fertilizer is biocompatible, biodegradable and nontoxic so ideal for growing plants in drought and salt effected areas.