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 . . . . . . .