Put it on paper, always. At minimum write down: the exact khasra numbers, the period, the rent and when it is paid, who pays for electricity and borewell repair, and what happens at the end of the term. On crop failure — most agreements here keep rent fixed regardless, because the tenant takes the crop risk. If you want to share the risk you can agree a share of produce instead of cash rent, but then you need a written way to measure the yield. Get it notarised. It costs very little compared to a dispute.

Also register it if the term is more than a year. An unregistered long lease is hard to enforce.