Comparison of the physico-chemical status of termite mound and adjacent soil of four different Eucalyptus species plantations in Nigeria

Abstract

The Eucalyptus tree is an exotic species in sub-Saharan Africa, with reported negative environmental depletion of soil nutrients and water. Termites have special feeding preference for Eucalyptus tree species, and yet are important soil arthropods with the ability to recycle and improve soil nutrients. This study aimed to investigate the changes in the nutrients composition of termite mound soil and adjacent soil in four different Eucalyptus species plantations (Eucalyptus camaldulensis, Eucalyptus citriodora, Eucalyptus cloeziana and Eucalyptus tereticornis) in Nigeria. Soil samples were collected from four epigeal termite mounds and adjacent soil at different soil depths (0- 10, 10-20, 20-30 and 30-40 cm) per plantation. The soil samples were analysed for soil texture, pH, organic carbon, and nitrogen content, Bray 1 P, and exchangeable bases. The results showed that significant variations in the percentage compositions of sand and silt in termite mound and adjacent soil was not a general occurrence in the four Eucalyptus species plantations. However, clay content in termite mound was significantly higher than that of the adjacent soils in the Eucalyptus species plantations, except E. cloeziana. Results showed Soil pH, organic C, N and exchangeable bases (Ca, Ma, K and Na) in termite mounds to be mostly similar to that of the adjacent soils at different depths. Bray 1 P content was, however, significantly different between termite and adjacent soil in E. camaldulensis, E. citriodora and E. tereticornis plantations. The plantation of E. citriodora had the least levels of organic carbon, nitrogen, and exchangeable bases.