The main sources of biofertilisers are
$(a)$ Bacteria
$(b)$ Cyanobacteria
$(c)$ Fungi
$(d)$ Protists
$(a), (b), (c)$
$(a), (b), (d)$
$(b), (c), (d)$
$(a), (c), (d)$
Relation between bacteria and legume having nodulated roots is that of
How are microbes useful in biofertilisers ?
Which of the following groups of plants are highly useful in increasing soil fertility
Aquatic fern which is an excellent biofertilizer