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 . . . . . . .

How is spraying different from fumigation?

Raman lives in a coastal village. He is the son of a fisherman. Whenever any unwanted animal comes in the net,instead of killing it,he puts it back in the sea.
$(a)$ What would have happened,had he killed those animals?
$(b)$ Give one reason to justify that Raman's action is environment-friendly.
$(c)$ How can you contribute to the preservation of flora and fauna around you? Mention any two steps.

Balwinder was a small farmer. As his field was rain-fed,he could not take the risk of growing specialized crops. He used to mix the seeds of two crops and sow them in the field. Kaku,his son who passed class $IX$,suggested growing two or more crops simultaneously in a definite pattern. Balwinder followed this,and the productivity per unit area increased.
$(i)$ Name the cropping pattern which Balwinder used earlier and the one suggested by Kaku.
$(ii)$ Write two advantages of practicing the pattern suggested by Kaku.
$(iii)$ Write two values displayed by Kaku.

State one importance of photoperiod in agriculture.

$A$ farmer had a plot just beside the bank of a river. Each time he planted $Kharif$ crops,the crops got damaged due to floods. He consulted an agricultural scientist who gave him a special variety of seeds and also advised him to practice fish farming.
$(a)$ What was the specialty of these seed grains?
$(b)$ What name can be given to this type of fish farming?