Possignolo-Vitti Nadia Valério, Bertoncini Edna Ivani, Vitti André Cesar
Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário, 303, Piracicaba, São Paulo 13400-070, Brazil E-mail:
Secretary of Agriculture and Food Supply of São Paulo State - APTA, Agência Paulista de Tecnologia dos Agronegócios, Pólo Centro Sul, Rodovia SP 127, km 30, PO 28, Piracicaba, São Paulo, Brazil.
Water Sci Technol. 2017 Jul;76(3-4):728-738. doi: 10.2166/wst.2017.239.
Vinasse has been used as fertilizer by sugarcane growers, due to its potential to completely replace mineral fertilizers. However, if the application is not adequate, this practice may cause environmental contamination. This study used a respirometry test to evaluate the organic matter (OM) decomposition present in natural vinasse and concentrated vinasse (CV), with or without urea addition. The experiment involved two soil types and two types of vinasse at different application rates. The vinasse chemical characterization showed high levels of pseudo-total potassium (K) in both vinasses, which are not considered in the application rates. Decomposition rates above 90% and between 70 and 80% were obtained for sandy and clayey soils, respectively, over a brief 41-day period, indicating rapid OM decomposition. Positive priming effect was observed for CV and CV + urea treatments in sandy soil. An important implication of these findings revealed that K not available in vinasse was released in the soil solution by the OM mineralization, indicating the possibility of overestimation in the vinasse application rates. Therefore, K pseudo-total values should be considered in the calculation of the vinasse application rates. However, studies involving K mobility into soil are needed to validate this hypothesis.
由于蔗渣废液有完全替代矿物肥料的潜力，甘蔗种植者一直将其用作肥料。然而，如果施用不当，这种做法可能会造成环境污染。本研究采用呼吸测定法，评估了添加或不添加尿素的天然蔗渣废液和浓缩蔗渣废液（CV）中存在的有机物（OM）分解情况。该实验涉及两种土壤类型和两种不同施用量的蔗渣废液。蔗渣废液的化学特性表明，两种蔗渣废液中的准全钾（K）含量都很高，而施用量中并未考虑这一点。在短短41天的时间里，砂土和黏土中有机物的分解率分别达到了90%以上和70%至80%，表明有机物分解迅速。在砂土中，CV和CV+尿素处理观察到了正激发效应。这些发现的一个重要启示是，蔗渣废液中不可利用的钾通过有机物矿化作用释放到土壤溶液中，这表明蔗渣废液施用量可能被高估。因此，在计算蔗渣废液施用量时应考虑准全钾值。然而，需要开展涉及钾在土壤中迁移的研究来验证这一假设。
