Which one of the following nutrients is not available in fertilizers?

The government was setting up a school in the village. In the panchayat,Vinod,who had just completed his class $X$,suggested that the children should be taught about different agricultural practices and the use of modern technology in them. The Sarpanch liked the idea and arranged for the same.
$(a)$ Children were taught that wheat cannot be grown in the kharif season. Why?
$(b)$ Mention the desirable agronomic character for cereals.
$(c)$ Do you support the suggestion to the Sarpanch? Mention any two values for which Vinod is worth admiration.

Write two examples each of the fishes that are:
$(i)$ Top dwellers
$(ii)$ Middle dwellers
$(iii)$ Bottom dwellers,in composite fish culture.

Differentiate between mixed cropping,intercropping,and crop rotation.

Two friends,Girish and Neeraj,were discussing Newton's third law. They were perplexed about how action and reaction are equal and opposite. They could not think of an experiment by which they could ascertain this fact. Pushkar,who was their friend,told them that he would set up an experiment to prove this to them. By performing an experiment,Pushkar demonstrated the law.
$(a)$ Can you think of an experiment by which you can demonstrate this law?
$(b)$ What values do you think Pushkar has?

State two advantages of composite fish culture. What is the application of hormonal stimulation in fish culture?