Abstract

Misheck Musokwa, Paramu Mafongoya, Manqoba Zungu and Aleck Kondwakwenda

Agroforestry technologies such as Sesbania sesban or pigeonpea improved fallows have been promoted to restore degraded biophysical soil properties in Sub-Saharan Africa. The objectives of the study were to evaluate the effect of improved fallows on soil macrofauna species indices, abundance of earthworms and related physical soil properties. A randomized complete block design, replicated three times, was used with five treatments (S.sesban, pigeonpea, S.sesban + Panicum maximum, pigeonpea + P.maximum and P.maximum). Soil macrofauna was sampled using 25 × 25 × 25 cm steel monoliths. Aggregate stability was calculated using mean weight diameter. Soil aggregate stability and infiltration rate were significantly different (P<0.05). The highest aggregate stability and infiltration rate were observed in S. sesban as compared to P. maximum. P. maximum + S.sesban had the highest soil macrofauna species richness than P. maximum. Earthworm abundance was highest on S.sesban than other treatments. The highest positive significant correlation was recorded on soil macrofauna species evenness and diversity while the least was observed on aggregate stability and macrofauna species richness. S.sesban or pigeonpea improved fallows is recommended for restoring soil macrofauna and physical soil properties in South Africa.