The Diversity and Abundance of Soil Macrofauna under Different Agroforestry Practices in the Drylands of Southern Ethiopia

Abstract

The conversion of natural lands to agricultural uses is a significant threat to soil biodiversity. Within agriculture, monoculture based systems are the most common which often result in low biodiversity because they impact the abundance, diversity, and composition of soil macrofauna (SMF). The objective of this paper was to analyze SMF abundance and diversity across different agroforestry practices (AFP) in the drylands of southern Ethiopia. The soil monolith and soil samples were collected from homegarden, cropland, woodlot, and trees on soil and water conservation based AFP using the standard Tropical Soil Biology and Fertility Institute manual, and the identification was done based on morphological characteristics and standard identification keys. The abundance, occurrence, and community composition of SMF were significantly different across the different AFPs (P < 0.05). In this study, 378 SMF belonging to 13 families, including unnamed were identified. The soil ecosystem of AFP was dominated by earthworms (relative abundance = 0.43), followed by termites (relative abundance = 0.12). The homegarden AFP type had a significantly higher number of SMF occurrence index of 46.03 (174), followed by woodlot, 26.72 (101) practices, and the lowest was recorded under cropland, 12.70 (48). The abundance, diversity, richness, and similarity of SMF were significantly related to soil total nitrogen and organic carbon. Phosphorus and pH were significantly related to the abundance and richness of SMF. The homegarden and woodlot AFP types were suitable for SMF biodiversity conservation.