Effects of Acacia decurrens Willd. tree-based farming system on soil quality in Guder watershed, North Western highlands of Ethiopia

Abstract

Continuous conversion of land for different agricultural production purposes has resulted in degradation of soil resources. Rehabilitating soil quality through sustainable land management is one of the most pressing agenda in agriculture. Hence, this study was conducted to evaluate the trends of major soil quality after the introduction of A. decurrens tree-based farming in Guder watershed. Soil samples were collected from 5 land use types, 2 soil depths, and 3 slope positions with 3 replications and then analysed for selected soil physicochemical quality indicators. Selected soil physicochemical indicators were subjected to three-way ANOVA. The result revealed that the highest clay particles and soil bulk density were recorded at A. decurrens tree farmland and cropland soils, respectively. The maximum soil pH was recorded from natural forest (5.99), subsurface soil layer (5.56) and lower slope (5.57). The lowest soil organic carbon and total nitrogen contents were observed in cropland. Greater available phosphorus (13.58) mg kg−1 was obtained in the topsoil depth of A. decurrens tree farmland at the lower slope. Among the studied soil quality indicators total nitrogen, cation exchange capacity and soil pH were strongly and positively correlated with soil organic carbon. The finding of this study showed that shifting of cereal based into A. decurrens tree-based farming by smallholder farmers can improve the fertility and health of soils and then boost crop productivity. Therefore, the right integration of A. decurrens tree in the farming system can be an alternative approach to reverse soil quality deterioration in degraded agricultural landscapes of Ethiopia.

Keywords

• acacia decurrens
• guder watershed
• landscape
• land use
• rehabilitation
• soil quality