Subject :NSO Class : Class 8
To maintain soil fertility, nutrient replenishment of soil is essential. Common methods of adding nutrients to soil are given in the box below.
P = Field fallow Q = Green manure R = Fertilizers S = Organic wastes
Which of the following statements is incorrect regarding this ?
(A) P is not best suited because it leaves a field economically useless for a year or two.
(B) R increases productivity readily but prove to be environmental hazard in long run.
(C) S can cause spread of diseases due to pathogenic cysts present in it.
(D) Q are green plants that are ploughed back into soil to supply specific nutrients in desired ratio.
it is tough !!
Ans 1:
Class : Class 8