Killing the bacteria responsible for soil fertility
Step-by-step explanation:
Chemicals used in agriculture as pesticides to destroy pests or weeds are the major cause of soil degradation.
Misuse or overuse of these chemicals turns to lethal doses which are toxic to the natural soil content. The lethal doses will destroy the beneficial microorganisms living in the soil.
Beneficial soil microorganisms play a major role in maintaining soil fertility and in the absorption of nutrients by the plants; like, the nitrogen-fixing bacteria that help the plants to absorb atmospheric nitrogen.
Hence the pesticides and other chemicals should target only the pests and weeds and not other organisms and should be used in limited amount.