What type of bacteria are $Rhizobium$ and $Frankia$?

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

If a wheat field is inoculated with $Rhizobium$,what will be the effect on the soil?

$A$ crop plant which can grow well even in nitrogen-deficient soil is:

Arrange the stages of root nodule formation in the correct sequence:
$I-$ Infection thread is produced.
$II-$ Bacteria are carried to the cortex of the root.
$III-$ Bacteria attach to the root hair.
$IV-$ Bacteria are released from the thread into the cells.
$V-$ Differentiation into nitrogen-fixing cells occurs.

Symbiotic nitrogen fixation in non-leguminous plants is carried out by