The addition of an electron acceptor is usually needed to bioremediate nitrate in groundwater. As annual precipitation levels increase, soil organic matter contents decrease. The metabolism of aromatic compounds requires oxygen. Lichens provide an excellent example of symbiosis between different species of microorganisms. Microbial biomass is a much smaller fraction of soil organic matter than is humus and yet N mineralization rates from these two pools are almost equal.
Tillage strongly influences soil microbial communities for various reasons.
The half-life for the pesticide, Whammit, is 693 days. Assuming first order kinetics, calculate the amount of pesticide remaining at 10 years after an initial application of 100 micrograms per g soil. Some people are concerned that these super bugs could get into buried petroleum deposits and consume all our future supply of petroleum.