Variation in macrofaunal communities under contrasting land use systems in eastern Zambia

Abstract

This study compared soil macrofauna under miombo woodland, maize grown in agroforestry systems including fallows of gliricidia ( Gliricidia sepium), acacia ( Acacia anguistissima), leucaena ( Leucaena collinsi) and calliandra ( Calliandra calothyrsus), and monoculture maize at Mesekera (loamy ferric luvisols) and Kalunga (sandy ferric luvisols), Zambia. Richness, estimated by the number of taxa per sample, varied significantly with land use category and treatments within a land use category at both sites. The highest and lowest richness in invertebrate taxa was recorded under the miombo woodland and monoculture maize, respectively. The abundance of total macrofauna (all taxa combined) was highest under the miombo woodland and lowest under monoculture maize. Abundance of macrofauna under the various land use categories was also higher in December–February (rainy season) than in July (dry season). Millipedes and centipedes were present in 0–5% of the soil samples under monoculture maize at the two sites, and in 10–30% of the samples at any given time under the miombo woodland and agroforestry land use categories. Earthworms, beetles and ants were generally scarcer under monoculture maize compared to the agroforestry species. Maize grain yield was higher when grown with tree species such as gliricidia that produced good quality organic inputs and harboured more litter transformers than those with low quality inputs such as calliandra. It is concluded that improved fallows using these legumes have positive impacts on soil invertebrates.