Abstract
Hydrogels recently have gained an increasing research interest in the field of horticulture and agriculture, due to their attractive properties and versatility. In this work, we show a possible use of these materials in agriculture: two sets of hydrogels were prepared by mixing the polymer κ-carrageenan (Carr) with various contents (0-50 wt.%) of hydrolyzed (HSW) and non-hydrolyzed red seaweed (WSW). The purpose of the seaweed addition was to provide the hydrogels with biostimulant activity and develop thus a biostimulant substrate for soilless cultivation. The Carr/HSW and Carr/WSW composites were first produced as films and subsequently swollen in three different media to assess their swelling and solubility behavior. Morphology and physicochemical properties of the hydrogels were investigated along with mechanical properties. The biostimulant effect was then proved directly on the plant Arabidopsis thaliana. The hydrogel containing 20 wt.% of HSW generated plants with more developed apical and root systems than the other composites.