Structure and functioning of water‐storing agricultural polyacrylamides

New polyacrylamides have been developed to improve the storage capability and the efficiency by which plants use water in agriculture and horticulture. These products are particularly useful where water is scarce or expensive and where drought is a significant hazard in crop production. However, there is considerable variation in the water absorption and release capabilities of different products that is explained by manufacturing conditions. Scanning electron microscopy shows that high performance products have a cellular structure in the expanded condition, with plant‐available moisture stored both in enclosed vacuoles and within the polymer framework. The bridges that comprise the structure of the gel control water release under drying conditions and optimise recovery of the stored water by plants.