Soil macrofauna associated with cover crops in an Oxisol from the southwest of Piauí state, Brazil

Djavan Pinheiro Santos,Glenio Guimarães Santos,Júlio César Azevedo Nóbrega,Everaldo Moreira Da Silva,Juvenal Pereira Da Silva Junior,Robélio Leandro Marchão,Cintia Carla Niva,Ronny Sobreira Barbosa

doi:10.1590/1808-1657000822018

Abstract

ABSTRACT: The soil macrofauna is fundamental for the maintenance of soil quality. The aim of this study was to characterize the soil macrofauna under different species of cover crops, including monoculture or intercropping associated to two types of soil management in the southwest region of Piauí state. The study was carried out in an Oxisol (Latossolo Amarelo, according to Brazilian Soil Classification System) in the municipality of Bom Jesus, Piauí, distributed in 30 m2 plots. Testing and evaluation of the soil macrofauna were conducted in a 9 × 2 strip factorial design, with combinations between cover crops/consortia and soil management (with or without tillage), with four replications. Soil monoliths (0.25 × 0.25 m) were randomly sampled in each plot for macrofauna at 0‒0.1, 0.1‒0.2, and 0.2‒0.3 m depth, including surface litter. After identification and counting of soil organims, the relative density of each taxon in each depth was determined. The total abundance of soil macrofauna quantified under cover crops in the conventional and no-tillage system was 2,408 ind. m-2, distributed in 6 classes, 16 orders, and 31 families. The results of multivariate analysis show that grass species in sole cropping systems and no-tillage presents higher macrofauna density, in particular the taxonomic group Isoptera. No-tillage also provided higher richness of families, where Coleoptera adult were the second more abundant group in no-tillage and Hemiptera in conventional tillage.

Highlights

The southwest region of the Piauí state is one of the main agricultural frontiers of the Cerrado biome and is part of the region known as Matopiba, in reference to the States of Maranhão, Tocantins, Piauí, and Bahia, where Cerrado areas are rapidly being converted to grain production
The establishment of soil fauna communities and their modifications depend on factors such as temperature, precipitation, humidity, soil management, among others
The total population density of soil macrofauna quantified in the experimental area was 2,408 ind.m-2, distributed in 6 classes, 16 orders, and 31 families (Table 1)

Summary

Introduction

The southwest region of the Piauí state is one of the main agricultural frontiers of the Cerrado biome and is part of the region known as Matopiba, in reference to the States of Maranhão, Tocantins, Piauí, and Bahia, where Cerrado areas are rapidly being converted to grain production. In these regions, the replacement of native vegetation by grain production systems promotes changes in the structure of soil macroinvertebrate communities in relation to the natural condition of Cerrado (SANTOS et al, 2016). Because of the several roles for soil functioning and sensitivity to management, especially in the soil-litter interface, soil macrofauna has been used as an indicator of soil quality (PEREIRA et al, 2017)

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Conclusion