The alginate-Jeffamine hydrogels were synthesized throughout the reaction of alginate with O,O '-bis(2-aminopropyl)polypropylene glycol (Jeffamine) in HCl solution. The network formation was confirmed by presence of N-H bonds in FTIR and Raman spectra. The swelling properties of the hydrogels revealed water absorption of 330% after 18h that reached maximum value of 430% in 18days. The optical microscopy evidenced regular porosity of the hydrogels and the SEM micrographs of the hydrogels plasticized with glycerol showed homogenous and compact surfaces. The results showed that the alginate-based hydrogels are very good materials that can be applied successfully as moisture-soil-control agents in agriculture.