State how barseem,oats,or sudan grass are used by farmers.

Give one word for the following:
$(a)$ Farming without the use of chemicals as fertilizers,herbicides,and pesticides is known as . . . . . . .
$(b)$ Growing of wheat and groundnut on the same field is called as . . . . . . .
$(c)$ Planting soybean and maize in alternate rows in the same field is called as . . . . . . .
$(d)$ Growing different crops on a piece of land in pre-planned succession is known as . . . . . . .
$(e)$ Xanthium and Parthenium are commonly known as . . . . . . .
$(f)$ Causal organism of any disease is called as . . . . . . .

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

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

On a voyage in their yacht,John and his father came across an iceberg. John advised his father to keep away from the iceberg. His father said that it is just a small piece of ice jutting out of the sea and there is nothing to bother. John told his father that icebergs are dangerous and narrated the story of the ship $Titanic$,which was sunk by an iceberg. John explained to his father why the iceberg was dangerous. This convinced his father,and they steered clear of the iceberg.
$(a)$ Why are icebergs in the sea dangerous?
$(b)$ What values are possessed by John and his father?

Sitaram,an educated farmer,convinces his friends to use manure instead of fertilizers in their fields. List any two advantages that the farmers will get if they accept this advice. How does the excessive use of fertilizers affect the environment? Which values of Sitaram are depicted by his efforts?