Chemicals that are used for controlling insects and weeds could reduce the soil fertility by "killing the bacteria responsible for soil fertility"
Explanation:
In the soil various beneficial as well as harmful insects and weeds are present. These beneficial microbes helps in increasing the soil fertility and also enhances the organic matter content. These types of soil yields good productivity. But on the other hand certain other organisms are there which are threat to the plants, for killing this we use certain chemicals, which also affects the beneficial organisms. Hence, while using chemicals we should keep in mind these factors so that we won't disturb the soil environment.
Killing the bacteria responsible for soil fertility
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.
