Intra-seasonal activity of ground dwelling spiders following six years of tillage, fertiliser and weeding treatments in an agricultural field in northern Zimbabwe

Abstract

Spiders are important biological control agents whose activity and diversity can be negatively affected by agricultural practices. A study was conducted at Chinhoyi University of Technology experimental farm, northern Zimbabwe, to determine the impact of tillage, fertiliser application and weeding regimes on ground-dwelling spiders across three maize crop growth stages (early vegetative: V3; late vegetative: V6; and intermediate reproductive: R2). Lycosidae were the most abundant spider family (85.7%) while Salticidae were least abundant (0.8%). The spiders belonged to two functional groups, ground and plant wanderers with the former constituting 94.9% of pitfall catches. Spiders were most abundant during V3, followed by R2 and V6 maize growth stages. Spider community diversity was also greatest during the V3 (H′ = 0.45) and least during the V6 stage (H′ = 0.12). During the V3 and R2 stages, ground dwelling spider abundance was higher in the two reduced tillage systems than under conventional tillage. Based on the study findings, it can be concluded that reduced tillage is useful in increasing ground-dwelling spider community abundance and diversity during the V3 and R2 maize growth stages.