Long‐term water retention increases in degraded soils amended with cross‐linked polyacrylamide

Cross‐linked polymer hydrogels, polyacrylamide co‐polymer (XPAM), and K‐polyacrylate (XPAA) increase soil water availability under drought, but their long‐term effects are unknown despite the importance of such knowledge in assessing economic feasibility. This 9‐yr outdoor pot study evaluated a one‐time addition of XPAM or XPAA at 0.25 or 0.5% dry weight (5.6 or 11.2 Mg ha −1 ) in a degraded calcareous silt loam. Controls included an unamended...