Changes in soil macrofauna induced by the expansion of sugarcane cultivation over areas of extensive pasture

Author(s)

Beatriz da Silva Vanolli

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2021-02-05

Examining board members

Maurício Roberto Cherubin; Fernando Dini Andreote; André Luiz Custódio Franco; Arthur Prudêncio de Araujo Pereira

• Advisor: Maurício Roberto Cherubin

Abstract

The sugarcane expansion over extensive pasture areas has been one of the main scenarios for land use change (LUC) in the south-central region of Brazil. However, it is known that LUC can negatively affect soil biodiversity, and the multiple functions and services associated with these organisms. Among the organisms, the macrofauna is fundamental for plant fragmentation, structuring and soil stabilization. Herefore, we aim to evaluate changes in the edaphic and epigeic macrofauna, induced by sugarcane expansion cultivation over extensive pasture. For this purpose, LUC chronosequences (synchronic approach) were investigated, including the following uses: i) native vegetation, ii) extensive pasture, ii) newly implanted sugarcane field over pasture area (Sugarcane); and iv) consolidated sugarcane (Sugarcane ratoon), in two locations, one with clayey soil and the other with sandy soil in the state of São Paulo. At the end of the rainy season between March and April 2019, monoliths (25 x 25 x 10 cm) were collected at depths 0-10, 10-20, and 20-30 cm for the assessment of the edaphic macrofauna. To assess the epigeic macrofauna, pitfall traps were installed at each sampling point. The edaphic and epigeic macrofauna composition differed between land uses. The native vegetation had greater abundance of edaphic and epigeic groups. Coleoptera and earthworms were associated with pasture areas, mainly in clayey soil. The analysis of mixed linear effects showed that LUC affected the relative abundance of edaphic macroinvertebrates (Land use p = 0.1191 r2 marginal = 0.28, r2 condicional = 0.33) and epigeic (Land use p = 0.0176; r2 marginal = 0.22, r2 condicional = 0.32). The vast majority of the edaphic macrofauna was concentrated in the topsoil (0-10 cm) with a reduction in depth (10-20 and 20-30 cm). In general, the abundance and diversity of macrofauna showed a positive correlation for organic matter, carbon and microbial nitrogen, macroporosity and total porosity, and a negative correlation for soil density (p<0.05). This study draws attention to the significant loss of the abundance and diversity of the sugarcane ratoon macrofauna. Given the importance of these organisms for the functioning of the soil and ecosystems, soil management and conservation practices are necessary to maintain the edaphic and epigeic macrofauna in sugarcane areas, and are important for increasing soil quality and sustainability production system. (AU)

• FAPESP's process: 19/16764-6 - Changes in soil biodiversity induced by the expansion of sugarcane cultivation over extensive pasture areas
• Grantee: Beatriz da Silva Vanolli
• Support Opportunities: Scholarships in Brazil - Master