Evaluation method and evaluation device for silage fermentation quality

An evaluation method for silage fermentation quality, the method comprises:

• providing a gas generated from silage to a surface stress sensor, and
• performing an evaluation of fermentation quality based on a composition of the gas generated from the silage using signals output from the surface stress sensor in response to the gas generated from the silage, wherein
• in the surface stress sensor, a response characteristic to at least one of organic acids belonging to C2 and C3 and a response characteristic to at least one of organic acids belonging to C4 are different, wherein the C2 and C3 refer to organic acids having 2 or 3 carbon atoms, respectively, and the C4 refers to organic acids having 4 or more carbon atoms, and
• the evaluation of fermentation quality based on the composition of the gas generated from the silage is performed from the result of at least either one of:
• criterion 1:
• the value of the ratio of the amount of the C4 to the amount of the C2 and C3;
• and
• criterion 2:
• the amount of the C2 and C3.