Because microbes are growing rapidly, and with the production of gas during the first. As the age increases, food farming, microbial gas production decreased and prosperous.
Because the bacteria are growing rapidly and production of gas in the first period. When raising up a weakening microbial growth and declining gas production decreased.
Because microorganisms are growing rapidly and gas production in the early time. At the age of increased food microorganisms growth decreased and decreased gas production declined.