The main sources of biofertilisers are
$(a)$ Bacteria
$(b)$ Cyanobacteria
$(c)$ Fungi
$(d)$ Protists
$(a), (b), (c)$
$(a), (b), (d)$
$(b), (c), (d)$
$(a), (c), (d)$
Give scientific reasons : The pressure on use of organic farming and biotic fertiliser has been increased.
Root nodules for nitrogen fixation of a non-leguminous tree possess
Mycorrhiza represents
Which of the following is non-symbiotic biofertilizer
Which of the following is common to Azospirillum, Anabaena, Nostoc and Oscillatoria