Q30 of 805 Page 169

Fertile soil has lots of humus. Why?

Fertile soils are rich in organisms that decompose dead organic matter and form humus. Humus provides minerals, absorbs water and makes soil porous with water and air penetrated deep inside the soil. Humus makes the soil fertile.


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Arrange these statements in correct sequence of preparation of green manure.

(a) Green plants are decomposed in soil.


(b) Green plants are cultivated for preparing manure or crop plant parts are used.


(c) Plants are ploughed and mixed into the soil.


(d) After decomposition it becomes green manure.