The Agricultural Advisory Board is defined in Sec. 6.12 of the Texas Tax Code
(a) The chief appraiser of each appraisal district shall appoint, with the advice and consent of the board of directors, an agricultural advisory board composed of three or more members as determined by the board.
(b) The agricultural advisory board members must be landowners of the district whose land qualifies for appraisal under Subchapter C, D, E, or H, Chapter 23, and who have been residents of the district for at least five years.
(c) Members of the board serve for staggered terms of two years. In making the initial appointments of members of the agricultural advisory board the chief appraiser shall appoint for a term of one year one-half of the members, or if the number of members is an odd number, one fewer than a majority of the membership.
(d) The board shall meet at the call of the chief appraiser at least once a year.
(e) An employee or officer of an appraisal district may not be appointed and may not serve as a member of the agricultural advisory board.
(f) A member of the agricultural advisory board is not entitled to compensation.
(g) The board shall advise the chief appraiser on the valuation and use of land that may be designated for agricultural use or that may be open space agricultural or timber land within the district.
The excerpt above is cited from: https://statutes.capitol.texas.gov/Docs/TX/htm/TX.6.htm