All agreements to use agricultural property should ideally be in writing. In some states, a lease for more than one year must be in writing. Any changes to the lease terms should be in writing. Also, any financial transaction such as for improvements should be put in writing. Major permissions (e.g., constructing an improvement, engaging in a use not clearly permitted, etc.) should be required to be in writing by the terms of the lease. Generally, such written documents should be signed by the parties.