Upon receipt of a proper deed from the State of North Dakota, executed under authority of the act of its legislative assembly, approved February 5, 1915, reconveying to the United States title to section 16, township 138 north, range 81 west, fifth principal meridian, the Secretary of the Interior is authorized to issue patents to said State for such vacant, surveyed, unreserved, unoccupied, nonmineral public lands as may be selected by said State within its boundaries, not exceeding one thousand two hundred and eighty acres in aggregate area, and said section when so reconveyed shall not be subject to settlement, location, entry, or selection under the public land laws, but shall be reserved for the use of the Department of Agriculture in carrying on experiments in dry-land agriculture at the Northern Great Plains Field Station, Mandan, North Dakota.