Effect of hydrogel on survival and growth of Grevillea robusta seedlings under semi-arid field condition

Abstract

Water scarcity limits the survival and growth of planted-out seedlings in Ethiopia’s semi-arid regions. Hydrogel, recently introduced in Ethiopia, is a super-absorbent polymer to reduce water stress. This study investigated its effect on the early survival and growth of Grevillea robusta seedlings in semi-arid areas. Relevant soil characteristics were analyzed. Four hydrogel levels (control, 3, 5, and 7 g/plant) were applied to the bottom of planting holes in a randomized complete block design with three replicates. Survival, Height, and Root Collar Diameter were measured at 6 and 14 months after planting. One-way ANOVA assessed hydrogel effects. No significant positive effects of hydrogel on survival or early growth compared to the control (0 g/plant) were observed in the sandy-loam soil. These findings suggest limited benefit under the study’s specific conditions. Further research is crucial to explore the potential of hydrogels, considering broader ranges of application rates and methods, tree species, and environmental conditions. This knowledge may support forest restoration efforts in the face of severe land degradation, climate change, and variability in Ethiopia.