The greatest potential loss from bunker silos is top spoilage. Cover the silo within a day of harvesting and keep it covered for at least 2 weeks if possible. Sealing at the edges is a top priority. The recommended plastic is 6 mil. or thicker. The entire silage surface should be weighted down to prevent whipping and tearing from the wind.
Old tires are a low cost material often used.
Inspect the plastic periodically for holes and fix them. Table 1 shows the importance of covering immediately after filling. The uncovered silage had greater dry matter losses than the covered silage. The most dramatic difference was with the alfalfa. The loss in dry matter will more than pay for the cost of the 6 mil.