Income tax for Agriculture Income from Jointly owned property

We have a agriculture land bought by my father in 1970s and he was the sole owner. He died recently. We will be changing the land records shortly with children names (Joint owners) . We are 2 brothers and 1 sister. My self (salaried), married younger brother (agriculturist) and married sister. Brother looks after the land and he does not have any other income. The income from this agriculture is mostly in cash and only brother is handling it. Since my father was senior citizen and agriculture income as only source , there was no history of filing returns from him. Now, if my name appears in land records, do I need to include agriculture income in my next filings ? I do not take any share in the income. It is just that my name will be there in records. If it is to be included, is it full income or divided by 3. As I mentioned before most of it is in cash and may not have proofs to show. Thanks in advance