Effect of Eucalyptus Plantations on Soil Proporties: The Case of Entoto Area, Northern Addis Ababa, Ethiopia

Abstract

Eucalyptus species are blamed for negatively affecting the soil and inhibiting growth of other plants though it is extensively planted in Ethiopia. This study investigated the effect of Eucalyptus plantations on selected soil physical and chemical properties at Entoto Mountain, in the Northern part of the capital, Addis Ababa. Three land-uses/covers (monoculture Eucalyptus plantations, cropland, and natural forests) with a plot size of 100x100m (1ha) each were used for comparison. Each experimental plot was sub-divided into three sub-plots of 100x33m for soil sampling. Sampling was done to 30cm depth with soil auger. A study of people’s perception on impacts of Eucalyptus was also undertaken to supplement the soil investigation. The soil samples were dried and analyzed while following standard procedures. One way ANOVA test result indicated that Eucalyptus plantations have significantly different effect on soil parameters such as texture (sand 35 %, silt 29 % and clay 27.11 %), soil bulk density (1.43gcm^-3), pH level(5.32), total nitrogen (2.36 %), organic carbon (4.07 %), Available potassium (127.23 ppm) and phosphors (8.23 ppm) from the other land-uses/covers. However, the three land uses/covers did not significantly differ from each other in influencing the soil exchangeable Mg, Ca, Na and C/N ratio. The people in the study area perceived that Eucalyptus plantations have negative effects on crop yield and soil moisture; this perception correlated with and supported by the results of this study on soil texture and bulk density where Eucalyptus plantations increased the bulk density of the soil which in turn indicates compactness and low moisture holding capacity.

Keywords: Eucalyptus species, Monoculture, Experimental plot

DOI: 10.7176/JEES/9-6-05

Publication date:June 30^th 2019