(a) When appraising land designated for agricultural use, the chief appraiser also shall appraise the land at its market value and shall record both the market value and the value based on its capacity to produce agricultural products in the appraisal records.
(b) Property taxes imposed on land designated for agricultural use are based on the land’s agricultural use value determined as provided by § 23.41 of this code after the appropriate assessment ratio has been applied to that value. When an assessor calculates the amount of tax due on the land, however, he shall also calculate the amount of tax that would have been imposed had the land not been designated for agricultural use. The difference in the amount of tax imposed and the amount that would have been imposed is the amount of additional tax for that year, and the assessor shall enter that amount in his tax records relating to the property.

(c) If land that has been designated for agricultural use in any year is sold or diverted to a nonagricultural use, the total amount of additional taxes for the three years preceding the year in which the land is sold or diverted plus interest at the rate provided for delinquent taxes becomes due. Subject to Subsection (f), a determination that the land has been diverted to a nonagricultural use is made by the chief appraiser. For purposes of this subsection, the chief appraiser may not consider any period during which land is owned by the state in determining whether the land has been diverted to a nonagricultural use. The chief appraiser shall deliver a notice of the determination to the owner of the land as soon as possible after making the determination and shall include in the notice an explanation of the owner’s right to protest the determination. If the owner does not file a timely protest or if the final determination of the protest is that the additional taxes are due, the assessor for each taxing unit shall prepare and deliver a bill for the additional taxes plus interest as soon as practicable after the change of use occurs. If the additional taxes are due because of a sale of the land, the assessor for each taxing unit shall prepare and deliver the bill as soon as practicable after the sale occurs. The taxes and interest are due and become delinquent and incur penalties and interest as provided by law for ad valorem taxes imposed by the taxing unit if not paid before the next February 1 that is at least 20 days after the date the bill is delivered to the owner of the land.
(d) A tax lien attaches to the land on the date the sale or change of use occurs to secure payment of the additional tax and interest imposed by Subsection (c) of this section and any penalties incurred. The lien exists in favor of all taxing units for which the additional tax is imposed.
(e) Land is not diverted to nonagricultural use for purposes of Subsection (c) of this section solely because the owner of the land claims it as part of his residence homestead for purposes of § 11.13 of this code.
(e-1) A portion of a parcel of land is not diverted to nonagricultural use for purposes of Subsection (c) because the portion is subject to a right-of-way that is less than 200 feet wide and that was taken by condemnation if the remainder of the parcel of land qualifies for appraisal under this subchapter.
(f) If land designated for agricultural use under this subchapter is owned by an individual 65 years of age or older, before making a determination that the land has been diverted to a nonagricultural use, the chief appraiser shall deliver a written notice to the owner stating that the chief appraiser believes the land may have been diverted to a nonagricultural use. The notice must include a form on which the owner may indicate that the owner remains entitled to have the land designated for agricultural use and a self-addressed postage prepaid envelope with instructions for returning the form to the chief appraiser. The chief appraiser shall consider the owner’s response on the form in determining whether the land has been diverted to a nonagricultural use. If the chief appraiser does not receive a response on or before the 60th day after the date the notice is mailed, the chief appraiser must make a reasonable effort to locate the owner and determine whether the owner remains entitled to have the land designated for agricultural use before determining that the land has been diverted to a nonagricultural use. For purposes of this subsection, sending an additional notice to the owner immediately after the expiration of the 60-day period by first class mail in an envelope on which is written, in all capital letters, “RETURN SERVICE REQUESTED,” or another appropriate statement directing the United States Postal Service to return the notice if it is not deliverable as addressed, or providing the additional notice in another manner that the chief appraiser determines is appropriate, constitutes a reasonable effort on the part of the chief appraiser.
(g) If the additional taxes are due because the land has been diverted to a nonagricultural use as a result of a condemnation, the additional taxes and interest imposed by this section are the personal obligation of the condemning entity and not the property owner from whom the property was taken.