Properties of Superabsorbent Polymer Injury to Corn Plant

The aims of this study were to explain the mechanism of plant injury related to superabsorbent polymers applications. For evaluation of root and shoot biomass, superabsorbent polymers were used at four levels including: 0%, 0.2%, 0.4% and 0.8% of dry soil equal to Control 1, Low, Medium, and High, respectively. For evaluation of grain budding, grains were located onto 600 g superabsorbent polymers absorbing 100, 200, 300 and 400 g deionized water (DW) g⁻¹ equal to S1, S2, S3 and S4, respectively. For evaluation of plant physiology, the superabsorbent treatments including DW as control treatment (Control 3) and four levels of water amount, including 100, 200, 300 and 400 g g⁻¹ equal to W1, W2, W3 and W4, respectively, were considered. The results showed that the root dry biomass in Low, Medium and High treatments was decreased by 12.5%, 17.5% and 37.5%, and shoot biomass by 27.8%, 33.3% and 58.3%, respectively, as compared to Control 1. Besides, the grains vigor index in superabsorbent polymers treatments was decreased by 40.0–53.5%, and declined with reducing water absorbed by superabsorbent. Compared to Control 3, root vigor (RV) in treatments W1, W2 and W3 was significantly decreased, by 45.1%, 26.8%, and 24.4%, respectively, however there was no significant variation in RV between W4 and Control 3. Finally, appropriate assessments should be performed to reduce the negative impacts of superabsorbent polymers by decreasing acrylic acids and/or Na⁺ amount in the crops. Abbreviations: AcAc: Acrylic acids; ARS: Automatic root scanner; CAT: Catalase; DW: Deionized water; DAC: Day after cultivation; DAB: Day after breeding; DB: Dry biomass; FB: Fresh biomass; MDA: Malondialdehyde; PG: Plant growth; RL: Root length; RV: Root vigor; ROS: Reactive oxygen species; SAP: Superabsorbent polymer; SW: Soil water; SOD: Superoxide dismutase; SA: Surface area; VI: Vigor index; WRC: Water retention capacity.