Temporal variation of epigeic entomofauna in maize under contrasting tillage systems in the Amazonian savanna

Resumen

Epigeic entomofauna responds to phenological variations and soil management practices. No-tillage systems increase surface residues and create microhabitats for insects, including potential pests. Thus, this study aimed to evaluate the temporal effect on the epigeic insect community in hybrid maize (Zea mays) cultivation areas under conventional tillage (CT) and no-tillage (NT) management throughout the crop cycle in a savanna environment in the state of Roraima, Brazil. In each area, ten traps were distributed in a zigzag pattern, following the same path used for soil sampling for fertility analyses. Five samplings were conducted over the crop cycle. The no-tillage area showed higher levels of organic matter and available phosphorus, as well as lower aluminum saturation. Epigeic entomofauna responded positively to no-tillage management, with greater abundance (363.7 vs. 206.7 individuals per trap; p = 0.003) and family richness (8.2 vs. 7.2; p = 0.004). Temporally, changes in community composition were observed throughout the crop cycle, with variations in the dominance of functional groups over time. PERMANOVA indicated significant effects of management (R² = 0.094; p = 0.001) and sampling time (R² = 0.176; p = 0.001), highlighting the combined influence of these factors on community structure. Functionally, decomposers were more abundant in the no-tillage area, reinforcing the role of crop residues in sustaining dominant groups. The Shannon diversity and Pielou’s evenness indices varied over time, indicating temporal dynamics in diversity.Thus, no-tillage management favors epigeic entomofauna and improves functional soil attributes.