ABSTRACT.

Soil organisms are vital for soil quality and can indicate environmental conditions. This study aimed to understand the diversity of soil fauna and its connection to plant residue decomposition and maize grain yield across various locations and crop seasons in a subtropical setting. We conducted experiments in Frederico Westphalen, Santa Maria, and São Vicente do Sul, Rio Grande do Sul State, Brazil, during two crop seasons in 2020/2021, totalling six experiments. We assessed parameters such as plant residue decomposition rate, soil fauna abundance, and grain yield. Results showed significant variations in decomposition rate, fauna abundance, and diversity measures (Shannon, Margalef, and Pielou indices, plus relative frequency) across environments. Four taxonomic groups comprised over 80% of collected individuals, with Araneae and Coleoptera showing more than half of relative frequency Our analysis revealed that areas with higher grain yields had faster decomposition rates, suggesting they fostered greater organism activity and nutrient cycling, indicating their potential as soil quality indicators.

Keywords:
soil fauna; waste decomposition; litter bag method; Zea mays L