Status of Selected Soil Chemical Attributes Under the Canopy of Acacia seyal Del in Semiarid Area of Eastern Amhara

Abstract

In Sirinka catchment, North Wollo, Acacia seyal (Del) is an important component of the agroforestry practices. The aim of the study was to investigate the status of soil chemical attributes under the canopy of Acacia seyal Del in-parkland agroforestry system of semi-arid area of Amhara region. Effects of A. seyal on selected soil chemical attributes were examined on six selected comparable A. seyal trees on croplands. Composite soil samples were collected at three distances from the tree base (1, 2.5, and 9 m) and two soil depths (0-15 and 15-30 cm) in four radial directions. Soil analysis results indicated that the soil organic carbon (SOC), total nitrogen (TN) and electrical conductivity (EC) were significantly influenced by distance from the tree base and available P (Av. P) were significantly affected both by distance from the tree base and soil depths. EC, SOC, TN, and Av. P were higher under the canopy of A. seyal than that of beyond the canopy. However, cation exchange capacity (CEC), exchangeable cations (Ca²⁺, Mg²⁺ and K⁺) and pH were not influenced by A. seyal. Soil under A. seyal canopy had higher organic carbon than outside canopy because of litter input and fine roots turnover close to the tree. Higher amount of TN, and Av. P under canopy could be related with high organic matter. Therefore, retaining of A. seyal tree on crop lands for its multiple benefits could contribute to the enhancement of agricultural productivity through improving soil nutrients, if the tree managed in proper way.

Keywords: crop lands, semiarid, Parkland, soil organic carbon, total nitrogen, available phosphorus