Question

To maintain soil fertility, nutrient replenishment of soil is essential. Common methods of adding nutrients to soil are given in the box.
Which of the following statements is incorrect regarding this ?

• A. $P$ is not the 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.

Answer 1

The correct option is D $Q$ are green plants that are ploughed back into soil to supply specific nutrients in desired ratio.

Green undecomposed material used as manure is called green manure. It is obtained in two ways, by growing green manure crops or by collecting green leaf (along with twigs) from plants grown in wastelands, field bunds, and forest.
Green manuring is growing in the field plants usually belonging to leguminous family and incorporating into the soil after sufficient growth. The plants that are grown for green manure known as green manure crops. The most important green manure crops are sunhemp, dhaincha, etc.

So, the correct answer is 'QQ are green plants that are ploughed back into soil to supply specific nutrients in desired ratio'