Post-planting management enhanced the survival and growth of Acacia decurrens in the northern Ethiopia drylands

Abstract The survival and growth performance of tree seedlings in degraded drylands can be improved by applying moisture and fertility-enhancing management interventions. This study evaluated the survival and growth responses of Acacia decurrens seedlings to different management practices, pit sizes, and niches in Tigray, Ethiopia. A factorial experiment was conducted with Watering (W), Watering + Mulching (WM), and Watering + Mulching + Compost (WMC) treatments planted in 30*30 cm and 50*50 cm planting pit sizes arranged in a randomized complete block design with three replications. We measured the survival count, diameter, and height of planted seedlings on a monthly basis for two years. Root parameters, biomass, and relative growth rate measurements were undertaken using destructive sampling after two years of planting. Planting A. decurrens under WMC treatment and in a 50*50 cm pit size revealed better survival and growth performance of planted seedlings. A. decurrens seedlings planted on farmland had significantly higher survival rates compared to planting on a nearby sloppy land (ch 2 = 8.33, p = 0.004). The WMC treatment yielded impressive results after two years, with seedlings reaching 7.6 m in height, 7.6 cm in diameter, 17.2 kg in dry biomass, and 1.5 m in root depth. The height relative growth rate of A. decurrens under the WMC treatment increased by 19% compared to the other treatments, with WM showed a 7% increase, and both W and C revealed a 5% increase each. Planting seedlings on farmland and adding WMC makes them grow faster and yields higher biomass. Therefore, applying moisture, mulching, and compost during and after planting ensures optimal survival and growth rates of A. decurrens and other trees in drylands.