$(a)$ $A$ farmer wants to harvest more than two varieties at a time from his crop field. He has no idea about the cropping patterns. Suggest one method to get the desired result. Also,state three advantages of this cropping pattern.
$(b)$ Name any two fodder crops.

Explain any one method of crop production which ensures high yield.

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 . . . . . . .

Find out the correct sentence:
$(i)$ Hybridisation means crossing between genetically dissimilar plants.
$(ii)$ Cross between two varieties is called as inter-varietal hybridisation.
$(iii)$ Introducing genes of desired character into a plant gives genetically modified crop.
$(iv)$ Cross between plants of two species is called as inter-specific hybridisation.

Compare the use of manure and fertilizers in maintaining soil fertility.

Define the term organic farming. Write its four advantages.