from gross income under subsection (a) with respect to any taxable year shall not exceed the excess, if any of— (A) $500,000 ($1,000,000 in the case of a joint return), over (B) the amount excluded from the gross income of the taxpayer for all prior taxable years. (2) Special rule for joint returns The amount of the exclusion under subsection (a) on a joint return for any taxable year shall be allocated equally between the spouses for purposes of applying the limitation under paragraph (1) for any succeeding taxable year. (c) Agricultural conservation easement defined The term agricultural conservation easement means an easement or conservation-related restriction on agricultural land (granted in perpetuity) that— (1) is conveyed for the purpose of protecting natural resources and the agricultural nature of the land, and (2) permits the landowner the right to continue agricultural production and related uses. (d) Special rules For purposes of this section, rules similar to the rules of subsections (e) and (f) of section 121 shall apply. . (b) Conforming amendment The table of sections for part III of subchapter B of chapter 1 of the Internal Revenue Code of 1986 is amended by adding after the item relating to section 121 the following new items: 121A. Exclusion of gain from sale of qualified farm property. 121B. Exclusion of gain from sale of agricultural conservation easement. . (c) Effective date The amendments made by this section shall apply to any sale or exchange in taxable years ending after December 31, 2020. 404. Farmland Protection Policy Act (a) Findings, Purpose, and Definitions Section 1540 of the Agriculture and Food Act of 1981 ( 7 U.S.C. 4201 ) is amended— (1) in subsection (a)— (A) by redesignating paragraphs (4) through (7) as paragraphs (5) through (8), respectively