Abstract

Daniel Getahun Debelo and Emana Getu Degaga

Despite the high density of epigeal termite mounds making a peculiar feature of the landscape of the Central Rift Valley of Ethiopia, no systematic ecological studies of termites had been conducted. Hence, this study was conducted from September 2011 to November 2012 in Dugda district of East Shawa Zone to assess termite mound density, status, and dimensions, and compare chemical properties of mound soil with adjacent soil, and the effect of mound soil on crop growth. The density of termite mounds was 9.72 mounds/ha. About 43% of the mounds were dead and they were 1.26 ± 0.09 m high with a basal diameter of 2.70 ± 0.19 m. Live mounds were 1.67 ± 0.09 m high with a basal diameter of 3.17 ± 0.67 m. A higher percentage of dead mounds were excavated by aardvarks (41%) and occupied by ants (64%) than live mounds, 21 and 24% for aardvark excavation and ant occupancy, respectively. Exchangeable cations (Ca, Mg, Na and K), electrical conductivity, pH, percent organic matter (OM) and total nitrogen (TN) and available K were significantly higher (P < 0.05) in mound soil than adjacent soil. Percent TN and OM, pH, and available K were significantly higher in mound perimeter than in adjacent soil. The higher accumulation of plant nutrients in mounds and their deposition in the mound perimeter by erosion have contributed to significantly higher differences in stem length, dry biomass, and yield of teff (Eragrostis teff L.) grown in the mound perimeter than on adjacent soil.