Notwithstanding the provisions of subsection (a) of Code Section 34-9-2, relative to the exempt status of individuals employed as farm laborers, an employer of farm laborers may elect to provide workers' compensation coverage to individuals employed as farm laborers by giving written notice to the board in such manner and form as provided by rule of the board. Upon the filing of the notice with the board, the employer of farm laborers shall be deemed an employer for the purposes of this chapter and each individual employed as a farm laborer shall be deemed an employee for the purposes of this chapter. An employer of farm laborers who has filed a notice pursuant to this Code section shall not discontinue the provision of workers' compensation insurance coverage for individuals employed as farm laborers until the notice filed with the board is revoked in a manner to be specified by rule of the board and written notice is given to each affected employee in a manner to be specified by rule of the board.