Potential of superabsorbent hydrogels to improve agriculture under abiotic stresses

• Published in: Journal of arid environments Vol. 189; p. 104496
• Main Authors: Nascimento, Carla Danielle Vasconcelos, Simmons, Robert William, Feitosa, Judith Pessoa de Andrade, Dias, Carlos Tadeu dos Santos, Costa, Mirian Cristina Gomes
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2021
• Subjects: Anionic co-polymers; Soil conservation; Soil science; Water use efficiency; Soil science; Water use efficiency; Anionic co-polymers; Soil conservation
• ISSN: 0140-1963; 1095-922X
• DOI: 10.1016/j.jaridenv.2021.104496

•Hydrogels have the potential to contribute to water use efficiency under stresses.•Residual acrylamide contents were well below permissible levels.•Up to 95% of the residual acrylamide was degraded within 30 days.•There was no depolymerization of acrylamide across the temperatures and salinities tested. Hydrogels are a promising management option to increase the efficiency of water use in agriculture in arid and semi-arid regions. However, abiotic factors may affect hydrogel efficacy. The effect of abiotic stress on the swelling and residual acrylamide in hydrogels was evaluated. The treatments were three hydrogels (A, B and C), four temperatures (20, 30, 40 and 65 °C) and two salinities (0.003 and 3.0 dS m−1). The swelling degree and the residual acrylamide concentration of the hydrogels were measured. Data were analyzed with univariate and multivariate statistics. The swelling order of hydrogels under low salinity was A>C>B; at high salinity was B>A>C. All hydrogels presented swelling reduction at high salinity, with swelling reductions in A and C of 97% and 85%, respectively, while B presented a swelling reduction of 37% at 20 °C and greater than 89% at higher temperatures. Hydrogel B achieved good swelling under saline conditions, but only at 20 °C. Thus, the temperature tolerance of this hydrogel should be improved so it can be used to improve water use efficiency in regions with high temperatures and salinity levels. Residual acrylamide levels of hydrogels decreased by 95% over 30 days, being safe for agricultural applications.