In this work, polyelectrolyte cellulose-based hydrogels obtained
from cellulose derivatives of pharmaceutical grade
were investigated as potential water reservoir in agriculture.
Several formulations were prepared, differing for the cellulose
concentration in the precursor solution, using a watersoluble
carbodiimide as a nontoxic crosslinker. The swelling
capability was tested in different environmental conditions,
that is, ionic strength and pH, which might significantly affect
the envisaged application in the soil. Based on the swelling
data, a specific hydrogel formulation (the one obtained
for a cellulose concentration equal to 4%) was chosen for
further analyses, as it displayed the highest water holding
capacity. Being a polyelectrolyte, the selected hydrogel was
also sensitive to ionic strength and pH variations, though
the swelling capability was quite high in all the different
conditions tested. A pilot study focused on the cultivation
of tomatoes with hydrogel-amended soil demonstrated that
the hydrogel could significantly increase the water retention
capability of the soil, as well as allowing the sustained
release of water to the plants for a prolonged time, without
additional watering needed. A deeper analysis of the hydrogel
degradation and its effect on the soil properties should be
addressed in future investigations. However, the preliminary
results of this study suggest that the proposed hydrogel might
be a powerful means for optimizing water management in
agriculture, which is particularly critical in areas where water
scarcity is a severe problem.