Vol. 2, Issue 8 (2015)
Variation in Abundance and Diversity of Soil Invertebrate Macro-Fauna and Some Soil Quality Indicators under Agroforestry Based Conservation Tillage and Maize Based Conventional Tillage in Southern Ethiopia
Author(s): Mulugeta Sisay, Haile Ketema
Abstract: This study was conducted in Wonago District of Gedeo Zone, Southern Etsiopia, with the objective of investigating the abundance, and diversity of soil invertebrate macro fauna and their effect on soil carbon stock under different land use types. A total of 18 monoliths from the two land uses i.e. indigenous agroforestry system and monoculture agriculture (9 from each) were sampled with the help of transect line for sampling point selection. Soil invertebrate macro fauna identification was sampled following Tropical Soils Biology and Fertility Institute methodology. A total of 9 families from indigenous agroforestry and 8 families from monoculture agriculture land use were identified. Among the three layers of the monoliths in the land use there is a significant (P<0.05) difference in abundance between the surface layer (0-10 cm) of monoculture agriculture and surface layer (0-10cm ) of indigenous agroforestry, sub surface layer (20-30 cm) of indigenous agroforestry, and sub-surface layer (20-30 cm) of monoculture agriculture. The Shannon index value showed that the diversity of macro fauna in indigenous agroforestry (1.28) was higher than the monoculture agriculture (1.17). The soil carbon stock was significantly different among the land use type and between the three depths in the respective land uses. Indigenous agroforestry positively influenced both abundance and diversity of soil invertebrate macro fauna and this resulted in high level of carbon stock in the land use. As a recommendation, changing indigenous agroforestry land use to monoculture agriculture should be checked for its negative effects on both abundance and diversity of soil invertebrate macro fauna and soil carbon stock. The Gedeo indigenous agroforestry system should get special consideration as it may contribute a lot in carbon sequestration which is the global issue.