Section 8. The legislative assembly shall have authority to provide by law for the leasing of lands granted to the state for educational and charitable purposes; but no such law shall authorize the leasing of said lands for a longer period than five years. Said lands shall only be leased for pasturage and meadow purposes and at a public auction after notice as heretofore provided in case of sale; provided, that all of said school lands now under cultivation may be leased, at the discretion and under the control of the board of university and school lands, for other than pasturage and meadow purposes until sold. All rents shall be paid in advance.
Provided, further, that coal lands may also be leased for agricultural cultivation upon such terms and conditions and for such a period, not exceeding five years, as the legislature may provide.