Superabsorbent biopolymers for climate-smart fertilizer technology: advancing nitrogen–water interactions for sustainable agriculture

Water and nitrogen (N) are crucial agricultural inputs, and their imbalance significantly affects the capacity of the farming sector to meet the increasing food demands of a growing population. Excessive use of N fertilizers to attain higher crop yields is not only increasing production costs but also posing environmental risks due to the production of greenhouse gases (GHGs). The use of biopolymers as coating material for urea provides an effective solution to minimize N losses due to slow release from biopolymers coated urea (BCU). However, the current research has a critical gap in linking biopolymers mediated nitrogen-water interactions in relation to plant physiological and biochemical modifications under abiotic stresses to enhance crop productivity and environmental sustainability. The purpose of this review is to provide an insight into the agricultural significance of plant-based biopolymers and the development, application, and potential of BCU in improving N and water use efficiencies, and yield of crops under water deficit conditions by altering N release, availability, uptake, and assimilation in plants. A critical review of the literature provides valuable insights into major challenges, limitations, and future research directions considering the use of BCU to improve crop productivity and environmental sustainability.