Fill in the blanks:
$(a)$ $A$ total of . . . . . . nutrients are essential to plants.
$(b)$ . . . . . . and . . . . . . are supplied by air to plants.
$(c)$ . . . . . . is supplied by water to plants.
$(d)$ Soil supplies . . . . . . nutrients to plants.
$(e)$ . . . . . . nutrients are required in large quantities and are called . . . . . . .
$(f)$ . . . . . . nutrients are needed in small quantities for plants and are called . . . . . . .

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.

Define the terms hybridization and photoperiod.

Identify two crops from the following which provide us carbohydrates for energy requirement:
Black gram,Wheat,Lentil,Rice

Based on the kind of biological material used,what are the two kinds of manures? How are they prepared?

Why is organic matter important for crop production?