Fire lead to disturbance on organic carbon under sugarcane cultivation but is recovered by amendment with vinasse

Otavio Augusto Queiroz Dos Santos; Orlando Carlos Huertas Tavares; Andrés Calderín García; Celeste Queiroz Rossi; Octavio Vioratti Telles de Moura; William Pereira; Luiz Alberto da Silva Rodrigues Pinto; Ricardo Luiz Louro Berbara; Marcos Gervasio Pereira

doi:10.1016/j.scitotenv.2020.140063

Fire lead to disturbance on organic carbon under sugarcane cultivation but is recovered by amendment with vinasse

Sci Total Environ. 2020 Oct 15:739:140063. doi: 10.1016/j.scitotenv.2020.140063. Epub 2020 Jun 8.

Authors

Otavio Augusto Queiroz Dos Santos¹, Orlando Carlos Huertas Tavares², Andrés Calderín García², Celeste Queiroz Rossi³, Octavio Vioratti Telles de Moura², William Pereira⁴, Luiz Alberto da Silva Rodrigues Pinto¹, Ricardo Luiz Louro Berbara², Marcos Gervasio Pereira⁵

Affiliations

¹ Laboratory of Soil Genesis and Classification, Department of Soils, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil.
² Laboratory of Soil Biological Chemistry, Department of Soils, Federal Rural University of Rio de Janeiro, Brazil.
³ Federal University of Western Pará, Juruti, PA, Brazil.
⁴ Federal Rural University of Rio de Janeiro, Campos dos Goytacazes, RJ, Brazil.
⁵ Laboratory of Soil Genesis and Classification, Department of Soils, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil. Electronic address: gervasio@ufrrj.br.

PMID: 32758952
DOI: 10.1016/j.scitotenv.2020.140063

Abstract

Sugarcane burning has been widely practiced in Brazil and worldwide. In the long term, this farming practice can cause soil erosion, reduction in organic carbon (OC) and consequently, changes in the structure of soil organic matter (SOM). Such changes may be difficult to reverse. This study aimed to assess the medium- and long-term effects of sugarcane burning on SOM characteristics, both in terms of quantity and structural quality and evaluate the application of vinasse as a strategy to attenuate fire-induced changes in burned soil. The experiment was conducted in a 50-year-old sugarcane field on soils classed as Cambissolo Háplico (Inceptisol). Four plots were sampled: a) burning of sugarcane for harvest for 37 years (SCB37); b) renewal of the sugarcane field and burning for harvest for 3 years (SCB3); c) renewal of the sugarcane field without burning for harvest for 3 years (SCWB), and d) renewal of the sugarcane field and burning for harvest with the application of vinasse for 3 years (SCV). Chemical and physical characterization of SOM was performed by solid-state spectroscopy (UV-vis, ATR-FTIR e ¹³C NMR CP/MAS) and chemometric techniques. The results showed that sugarcane burning drastically impacts SOM content and its chemical structure, however, the application of vinasse preserves and restores the soil from the fire effects. Content of soil OC, particulate OC, mineral-associated OC, humic acid, humin and light fraction OM that were affected by fire, had an increase and recovery of contents by the vinasse application. Solid state spectroscopy showed that labile structures were lost in humic acids (HA) by fire and recalcitrant structures were preserved. The application of vinasse incorporated fragments of lipids and carbohydrates in HA structure. Burning sugar cane straw affects the integrity of soil organic matter but can be restored by applying vinasse.

Keywords: (13)C NMR spectroscopy; Green management; Humic substances; Soil attributes; Soil organic carbon; Stubble burning.