Farmers’ perceptions of Terminalia brownii management in agroforestry Parklands and its impact on soil physicochemical properties in the South Ari District, Southern Ethiopia

Abstract

Smallholder farmers in the South Ari District of southern Ethiopia retain natural forest remnants of Terminalia brownii trees in their crop fields. However, little is known about their perceptions of its management in crop fields and its impacts on soil properties. Therefore, we investigated farmers’ perceptions and the impacts of scattered Terminalia brownii trees on soil physicochemical properties. For this purpose, we collected household survey data from 80 farmers and 54 composite soil samples from four directions at three radial distances and two soil depths. A randomized complete block design was used with three independent random field replications for the treatments within factorial arrangements, including the three radial distances and two soil depths. Based on the survey data, 90% of the respondents manage scattered Terminalia brownii trees in their crop fields. Among them, 63% use pollarding, while 49% use pruning techniques to enhance the impact on crops grown beneath trees. Our results revealed that soil organic carbon, total nitrogen, plant-available potassium and phosphorus, and bulk density were significantly higher (P < 0.05) under the tree canopy. However, soil texture, pH, electrical conductivity, cation exchange capacity, and exchangeable bases depicted no significant differences between the tree canopy and open fields. Hence, retaining Terminalia brownii trees on the crop field is crucial for farmers to improve the soil physicochemical properties. However, sustained long-term studies are essential to gain a comprehensive understanding of the diverse functions of Terminalia brownii and its impact on microclimate dynamics and crop productivity.