Effect of Eucalyptus Tree on Selected Soil Physico-Chemical Properties in Gidami District, West Ethiopia

Abstract The study was conducted in district of Gidami, western Oromia region, Ethiopia. The aim was to investigate effects of Eucalyptus tree (Eucalyptus camaldulensis) on soil physico-chemical properties. Eucalyptus is widely planted in farmland in the study area largely because of construction purpose and financial income. However, the cultivation of eucalyptus is becoming a major concern because of its long-term site impact. Long-term consequences have been observed, including drying up of water courses, effects on soil physico-chemical characteristics, ability to drain soil nutrients and fertility, suppression of other plants, forest biodiversity decline, and reduced agricultural yields in agroforestry systems. However, Eucalyptus plantations on study area farmland are expanding regardless of its impacts on soil fertility and competition for crop land. On the other hand, human population is increasing from time to time and hence the demand for agricultural crop is increasing, however; the environment is degrading. Therefore, this study was conducted with the aim to study the effects of Eucalyptus tree on selected soil physico-chemical properties in Gidami District, West Ethiopia. For this study, randomized complete block design (RCBD) was used. Three farmers land 50m by 50m Eucalyptus plantation forest having similar age was selected, which served as experimental plot. Each experimental plot (farmland) was subdivided into 5 sub blocks. Then, sampling points (treatments) were randomly assigned to each block. Soil samples were collected by using auger at five different sampling points (at middle of canopy, 5m, 10m, 15m and, 40m distances) with two depths (0-15cm and 15-30 cm). 10 soil samples were collected from each block and a total composite soil samples collected were 30. Each composite sample soil was prepared by mixing three sub samples. Soils sampled at 40m distance were used as control group. Soil physico-chemical property analyses were conducted in Nekemt soil laboratory. The two ways ANOVAs were carried out by SAS version 9.0. The effects of Eucalyptus tree were insignificant on soil bulk density, exchangeable acidity, organic matter, exchangeable base, organic C, and Pat different distance, and pH with depth. Soil moisture, pH, CEC increased in further distance from the Eucalyptus trees. However, total N decreased as distance increased further from Eucalyptus tree. Surface soils (0-15 cm) were higher in total N, K, C, and organic matter than sub soil (15-30 cm) depth.