Cellulose-based biodegradable superabsorbent hydrogel: A sustainable approach for water conservation and plant growth...

Innovative deficit irrigation technologies are imperative to overcome challenges posed to crop growth/yield and agriculture sustainability due to water scarcity in arid and semiarid regions. In the current study, superabsorbent biodegradable hydrogel based on carboxymethylcellulose sodium salt (NaCMC) and hydroxy ethyl cellulose (HEC) has been developed using citric acid (CA) as a crosslinker. The hydrogel has demonstrated excellent water absorption, retention, and release properties. Moreover, hydrogel (2 %) modified soil (HMS) has depicted increased porosity (57 %) and reduced soil density (1.06 g/cm³), compared to unmodified soil (UMS) with porosity of 53 % and density of 1.16 g/cm³, as well as, the water use efficiency of the plants (25.25 %-45.52 % over UMS) grown in HMS, which is vital for comprehending soil properties and their impact on water retention and aeration. The plant growth study in HMS concerning critical growth parameters such as germination rate, Seedling Vigour Index (SVI), Root Shoot Ratio (RSR), crop growth ratio (CGR), and chlorophyll content of three plants, i.e., one summer-grown plant-cucumber and two winter-grown plants- tomato and mung bean, has manifested promising results. Decisive parameters such as seedling viability (4.51 %), plant growth rate (3.77 %), and photosynthetic ability (16.74 %) were increased for chosen plants grown in HMS as compared to UMS. Improved growth parameters and photosynthetic ability of plants in HMS have suggested ameliorated nutrient and water absorption rates, increased resource utilization, and improved response to extrinsic resource allotment caused by hydrogel modification. Statistical analyses supported the trends in plant growth. Thus, hydrogel modification of the soil can effectively mitigate water use by retaining moisture efficiently and positively facilitating growth.