What threats to nature do chemical fertilizers, pesticides, insecticides and herbicides pose?

The given figure shows the two crop fields (plots A and B) have been treated by manures and chemical fertilizers respectively keeping other environmental factors same. Observe the graph and answer the following questions. What is the reason for the different patter of the two graphs?

What are pesticides and herbicides? Explain giving examples.

Difference between chemical fertilizers and natural fertilizers.

What is the chemical nature of stomach ?

What basis would you adopt a farmer using chemical fertilizers switch over to organic fertilizers?

What is the chemical nature of food when it enters the small intestine ?

The farmers of your locality are using chemical fertilizers. You suggested them to use natural fertilizers. Prepare a pamphlet to explain the need of Bio-fertilisers.

What do you observe during chemical change ?

In what way vermy compost is better than chemical fertilizer.

In what way is vermi compost fertilizer better than chemical fertilizer?