The overall aim of this book was to devise the priority list of the pesticides that are more likely to pose a risk to ground water contamination and can be potentially harmful to non-target organisms. It is recommended that the priority list of the chemicals should be devised regularly to cope with the environmental problems associated with pesticides contamination. The changes in PLFA with pesticide application be investigated for any possible changes in the microbial capabilities of mineralization, nitrogen fixation or other important role in soil fertility.