The objective of the study was to measure nutrients and fermentation quality on the top of maize silage and near (40 – 60 cm) the wall of the silage bunker. Silage was covered by transparent foil of 0.04 mm and a classical black and white Dualen sheet of 0.15 mm. Tires were placed on the upper sheet over the complete surface. The top (5 cm), visibly decayed layer of maize silage, showed lower quality of all the monitored parameters (ash, NDF, ADF, starch, pH, LA and IA/VFA) compared to silage below. Low ratios of LA/VFA and increased temperature (average 30°C) of silage (to a depth of 30 cm under the foil) mean higher aerobic degradability compared to other part of the silage mass. Around the wall penetrated under foil air. Tires did not protect silage enough from the air. Following our results, it is recommended to use another type of covering, e.g. special gravel bags.