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The efficient use of vinasse, the primary byproduct of sugarcane ethanol production, is important for the economic and environmental sustainability of the industry. Few studies have quantified the soil health response to long‐term vinasse application, even though this byproduct is generally applied as a potassium (K) source in sugarcane fields. The Soil Management Assessment Framework (SMAF) was used to assess the integrated soil health response in soils with contrasting textures. Chemical, physical, and biological indicators were selected, measured, and integrated into a soil health index for clay‐ and sandy‐textured soils in Brazil. Overall, the application of vinasse improved soil health components in both soils. The results showed that the benefits of vinasse go beyond increasing the K content. Vinasse application showed increased soil organic carbon content, nutrient recycling, and soil physical quality. The long‐term application of vinasse increased the soil health from 49% to 62% in the clayey soil and from 43% to 61% in the sandy clay soil. The findings therefore revealed the potential of vinasse application to reduce the need for synthetic fertilizer and promote the circular economy and soil health regardless of soil type. This study verifies that the long‐term application of vinasse to sandy‐ and clay‐texture soils in Brazil has both economic and environmental benefits because it recycles an important ethanol byproduct and enhances soil health. [ABSTRACT FROM AUTHOR]

Straw removal for bioelectricity, cellulosic ethanol, or other bio-products has become a common practice in Brazilian sugarcane areas, but long-term effects on soil organic carbon (SOC) and yield are unknown. Our objective was to quantify tillage intensity and removal levels on SOC stocks and sugarcane yield on contrasting edaphoclimatic conditions in Brazil. Conventional tillage-CT and reduced tillage-RT coupled with three straw removal levels (none—NR; moderate—MR; total—TR) were combined to create six treatment combinations: CTNR, CTMR, CTTR, RTNR, RTMR, and RTTR, respectively. Sugarcane yield was measured annually and soil samples to a depth of 40 cm were collected and analyzed before and after 5 years of treatments. Neither tillage practices nor straw removal significantly affected sugarcane yield on sandy loam soil, but CTMR, CTTR, and RTTR showed substantial yield reductions on clayey soil. SOC stocks for RTNR increased by as much as 1.64 Mg ha−1 year−1 on clayey soil, while CTMR and CTTR favored depletion of SOC stocks on both soils. Overall, each Mg of straw returned to the soil increased SOC stock by 95 kg ha−1 for clayey soil under both tillage practices and 55 kg ha−1 for sandy loam under the CT system. Furthermore, straw removal decreased microbial biomass C and b-glucosidase activity. These findings suggest that the adoption of RT attenuates the adverse impacts of straw removal on SOC stocks while ensuring sugarcane yields for a more sustainable bioenergy production in Brazil. [ABSTRACT FROM AUTHOR]

Highlights: [•] IPCC-based soil carbon stock methodology verified for Amazon and Cerrado biomes. [•] Meta-analysis of SOC change promotes adoption of no-tillage practices. [•] Clay content shown to influence SOC changes. [•] Conservation systems have potential for sequestering SOC in the Cerrado biome. [•] IPCC-based approach shown to be more robust and a sensitive way to evaluate SOC changes. [Copyright &y& Elsevier]