Assessing the effect of hydrophilic soil amendments on riparian plant survival in and and semi-arid environments

Riparian restoration efforts in and and semi-arid regions are extremely challenging to conduct and frequently unsuccessful where irrigation is not possible, or where the water table occurs well below the root zone of newly established vegetation. Lack of irrigation or lowered water tables can preclude adequate soil moisture for riparian plants to become established, or to survive after initially becoming established. This paper describes field investigations at three sites in southern Arizona (USA) to test the efficacy of two hydrophilic soil amendments to improve survival of woody riparian plantings in the absence of irrigation. Unlike numerous studies that show the contrary, a commercially available hydrogel had no significant influence on plant survival or condition when compared with trees receiving no amendment. Conversely, a relatively new amendment called DriWater improved both survival and plant condition at two of the three study sites. This amendment shows significant promise for revegetating and areas where irrigation is not possible. However, because of potentially high cost, the use of DriWater should be considered only when traditional irrigation methods are unavailable.