How do Sunhemp or guar help in crop production management? How is it better than fertilizers?

State one importance of photoperiod in agriculture.

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.

$(i)$ State three ways by which pests attack plants.
$(ii)$ Name the chemicals used to control pests.
$(iii)$ Explain why excessive use of such chemicals should be avoided.

Ram tried hard to push the wall of a room. In the process of pushing the wall,he begins to perspire and feels exhausted although the wall does not move. Ram feels that he has done a lot of work and spent a lot of energy. Do you think that Ram was justified in making the statement that he has done a lot of work? Justify your answer and give the conditions under which work is done.

Differentiate between manures and fertilizers.