Development of superabsorbent hydrogels for the controlled release of encapsulated nutrients

Abstract

Brazil is one of the world leaders in the production and exportation of agricultural products, and this implies in excessive use of fertilizers, in order to guarantee the growth and development of the plantations. However, this excess results in serious environmental damages, such as eutrophication of lakes and contamination resulting from leaching. Among the outstanding crops in the country, there is garlic, a vegetable that is highly sensitive to irrigation and fertilization, which in an inadequate quantity can compromise the production, requiring the importation of about 50% of the total annual consumption. This project aims at the development of a superabsorbent hydrogel, containing capsules for controlled delivery of nutrients (nitrogen and potassium) in garlic culture. Hydrogels of polyethylene glycol reinforced with cellulose nanostructures (CNSs) will be produced and will act in the storage of water, minimizing the irrigation needs, thus saving on this resource. The hydrogels will contain chitosan + montmorillonite capsules with nutrients in their interior, which will be released in a controlled way according to the needs of the garlic culture. CNSs, hydrogels and capsules will be analyzed in terms of morphology, water absorption, thermal stability, chemical composition, mechanical stability and soil nutrient release. Thus, the final product (hydrogel + CNS + capsule) will be studied in terms of release of water and nutrients in the soil, being tested in garlic cultures to prove the effectiveness of the product developed.