A guardian shall not commit waste on the real estate of his ward. A guardian having real estate under his care may either cultivate the same with the stock and implements belonging to his ward, or to be purchased by the order of the court or chancellor in vacation, with the money of the ward, or lease the same from year to year, or for a term not exceeding three (3) years if the ward will not sooner be of age; but upon application and proper showing made to the court or chancellor in vacation, a guardian may be allowed to lease said real estate for such longer time as may be shown to be advantageous to said estate; in no case, however, to extend beyond the majority of the ward, nor in any case to exceed six (6) years.