When the Board of Educational Lands and Funds deems it expedient, due to breaking or retirement of the land, erosion, resodding, or other causes, to reclassify the school land in any county, and at least once in every five-year period, it shall cause reclassification to be made of the land under lease. When this has been accomplished the new rental for each lease shall be computed by applying the new classification of the land to the rental schedules according to classification then in effect and which have been duly adopted by the Board of Educational Lands and Funds for the counties involved. Rental shall be paid by the lessee upon the basis of the new classification. Not more often than once in every two years the lessee may request the board to make a reclassification of the land he or she has under lease and it shall be the duty of the board, within six months after receipt of such request, to cause the classification to be reviewed.