Abstract Ethanol is recognized worldwide as a clean and renewable energy source. In tropical and subtropical countries, it is produced from sugarcane (Saccharum officinarum). In this study, we investigated the effects of sugarcane management systems: a) burning of sugarcane for harvest for 37 years (SCB37); b) burning of sugarcane for 3 years after 5 years of fallow (SCB3); c) sugarcane field without burning for harvest for 3 years (SCWB), and d) burning for harvest with the application of vinasse for 3 years (SCV), on soil fertility and accumulation of organic and inorganic fractions of phosphorus (P) in sugarcane crops for bioenergy production in south-east Brazil. Soil samples were collected at depths of 0–5, 5–10, 10–20, and 20–40 cm between planting rows in each management system and submitted for evaluation of soil fertility and accumulation of P fractions via sequential fractionation. We observed that application of vinasse reduced the pH (3.7–4.2) and the availability of Ca2+, Mg2+, and K+ on the surface, associated with the increase in Al3+ content and potential acidity. However, its use increased the availability of K+ and inorganic P content of higher lability (extracted with NaHCO3) in the subsurface. The maintenance of straw on the surface promoted reductions in pH values and an increase in the potential acidity and was inefficient in the accumulation of organic and inorganic fractions of P, compared to the system with the application of vinasse. Overall, we observed that the moderately labile fraction (organic and inorganic) represented on average 60 % (higher participation) of the total P content of soil in the experimental areas and was more significant in the soil under vinasse application and less evident in the treatments without burning and in the 3-year burning. This fraction can represent an important reserve of P (legacy) for the crops, reducing the use of phosphate mineral fertilizers over the years. Our findings are important for the selection and implementation of efficient and sustainable sugarcane cultivation systems, with implications for the ethanol industry to meet the growing demand for renewable fuel in the world.

中文翻译：

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评估使用和不使用燃烧和酒糟施用甘蔗作物的收获效果：评估不同乙醇生产系统中的土壤肥力和磷库

摘要 乙醇是世界公认的清洁可再生能源。在热带和亚热带国家，它由甘蔗（Saccharum officinarum）生产。在这项研究中，我们调查了甘蔗管理系统的影响：a) 为收获而燃烧甘蔗 37 年 (SCB37)；b) 休耕 5 年后焚烧甘蔗 3 年（SCB3）；c) 3 年不燃烧收获的甘蔗田 (SCWB)，和 d) 燃烧收获并使用酒糟 3 年 (SCV)，对土壤肥力和甘蔗中磷 (P) 有机和无机部分的积累巴西东南部用于生物能源生产的作物。在 0-5、5-10、10-20 的深度收集土壤样品，每个管理系统的种植行之间保持 20-40 厘米，并提交用于通过顺序分级评估土壤肥力和 P 组分的积累。我们观察到酒糟的施用降低了 pH (3.7-4.2) 以及表面上 Ca2+、Mg2+ 和 K+ 的可用性，这与 Al3+ 含量和潜在酸度的增加有关。然而，它的使用增加了地下 K+ 和更高不稳定的无机 P 含量（用 NaHCO3 提取）的可用性。与使用酒糟的系统相比，将秸秆保持在表面促进了 pH 值的降低和潜在酸度的增加，并且在 P 的有机和无机部分的积累方面效率低下。全面的，我们观察到中等不稳定部分（有机和无机）平均占试验区土壤总磷含量的 60%（参与率更高），并且在施用酒糟的土壤中更为显着，而在不燃烧的处理中则不那么明显并在3年的燃烧中。这部分可以代表作物的重要磷（遗产）储备，多年来减少了磷酸盐矿物肥料的使用。我们的发现对于选择和实施高效和可持续的甘蔗种植系统很重要，对乙醇行业满足世界对可再生燃料日益增长的需求具有重要意义。