https://books.google.iq/books?id=IrXxCAAAQBAJ&pg=PA42&lpg=PA42&dq=Why+do+previously+legume+cultivated+field+do+not+respond+to+inoculation?&source=bl&ots=fbshjQ5OaF&sig=ACfU3U0IVAVZad1xIhWGTRm1SudcxatMaQ&hl=en&sa=X&ved=2ahUKEwiaksnVjuLnAhWO6aQKHfCwDjsQ6AEwAHoECAcQAQ#v=onepage&q=Why%20do%20previously%20legume%20cultivated%20field%20do%20not%20respond%20to%20inoculation%3F&f=false

this pape can help you maybe. good luck

Hi,

The legume cultivation increases the size of native populations of rhizobia. As they are very competitive, it is very difficult to have responses due to the inoculation.

Did you quantified the size of nodulating rhizobial populations in your sites? It is very easy using the MPN approach.

Regards

Thanks@Khalid@Abdoulaye for your responses and others for your interest. The materials attached are helpful. Paulo Ivan Fernandes Júnior I did the MPN the size was large, indicating increase in native population.Thanks all