Mention the basis of crop selection in intercropping and crop-rotation.

Define $(i)$ Vermicompost,$(ii)$ Green manure,and $(iii)$ Biofertilizer.

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 shorter duration crops help the farmer:

List two desirable traits for fodder crops.

Name any one method of incorporating desirable characters into a crop variety.