Superabsorbent polymers for enhancing drought resilience in underutilized root and tuber crops: A review

Root and tuber crops (RTCs) such as cassava, sweet potato, and taro are vital for food and nutrition security, particularly in developing countries. Despite their adaptability and relative drought tolerance, these often-neglected crops suffer substantial yield losses under prolonged water stress. This review examines the potential of superabsorbent polymers (SAPs) as a drought mitigation tool for RTCs to enhance water-use efficiency and irrigation sustainability. SAPs, as a subclass of high water-absorbing hydrogels, refer to three-dimensional cross-linked polymer networks capable of absorbing and retaining hundreds of times their own weight in water. While evidence demonstrates SAP efficacy in staple cereals and legumes, research focused on RTCs remains limited. This review identifies critical knowledge gaps, including optimal SAP formulations, application rates, and their interaction with root system architecture and soil hydrology. We propose integrating SAPs with practices like mulching and deficit irrigation may synergistically boost RTC productivity under variable climates. Future research priorities should include multi-location field trials and long-term studies to validate SAPs use for RTCs. Furthermore, investigations integrating root phenotyping, hydrotropic responses, and polymer-soil characterization are needed to optimize the use of SAPs in RTCs. This review is the first to systematically evaluate the application potential of SAPs specifically in underutilized RTCs such as cassava, sweet potato, and taro, with a particular focus on the critical knowledge gaps regarding their interactions with root system architecture and hydraulic properties. By bridging this knowledge gap, SAPs can be positioned as a key innovation to stabilize yields, enhance climate resilience, and safeguard food security in vulnerable farming systems. • Underutilized root and tuber crops (RTCs) support food security in dry regions. • Cassava, sweet potato, and taro face major yield losses under prolonged drought. • Hydrogels enhance soil moisture, reduce irrigation, and boost drought tolerance. • There are limited superabsorbent polymers (SAPs) studies on underutilized RTCs. • Optimizing SAPs for RTCs can improve resilience and productivity.