Department of Biotechnology, Lund University, PO Box 124, SE-22100, Lund, Sweden.
Biotechnol Biofuels. 2011 Oct 27;4:44. doi: 10.1186/1754-6834-4-44.
Ensiling is a common method of preserving energy crops for anaerobic digestion, and many scientific studies report that ensiling increases the methane yield. In this study, the ensiling process and the methane yields before and after ensiling were studied for four crop materials.
The changes in wet weight and total solids (TS) during ensiling were small and the loss of energy negligible. The methane yields related to wet weight and to volatile solids (VS) were not significantly different before and after ensiling when the VS were corrected for loss of volatile compounds during TS and VS determination. However, when the TS were measured according to standard methods and not corrected for losses of volatile compounds, the TS loss during ensiling was overestimated for maize and sugar beet. The same methodological error leads to overestimation of methane yields; when TS and VS were not corrected the methane yield appeared to be 51% higher for ensiled than fresh sugar beet.
Ensiling did not increase the methane yield of the studied crops. Published methane yields, as well as other information on silage related to uncorrected amounts of TS and VS, should be regarded with caution.
青贮是一种常见的保存能源作物用于厌氧消化的方法，许多科学研究报告称青贮可以提高甲烷产量。在这项研究中，对四种作物材料进行了青贮过程和青贮前后甲烷产量的研究。
青贮过程中湿重和总固体（TS）的变化很小，能量损失可以忽略不计。当校正 TS 和 VS 测定过程中挥发性化合物的损失后，湿重和挥发性固体（VS）相关的甲烷产量在青贮前后没有显著差异。然而，当根据标准方法测量 TS 而不校正挥发性化合物的损失时，玉米和甜菜的 TS 损失在青贮过程中被高估。同样的方法学错误导致甲烷产量的高估；当 TS 和 VS 没有被校正时，青贮甜菜的甲烷产量似乎比新鲜甜菜高出 51%。
青贮并没有提高研究作物的甲烷产量。发表的甲烷产量，以及与未校正的 TS 和 VS 量有关的其他青贮信息，应该谨慎对待。
