; and (ii) land that is— (I) not excluded under paragraph (1)(A); and (II) eligible under subsection (b). (C) Exception In the case of a field described in subparagraph (B) more than 90 percent of the land of which is land described in clause (ii) of that subparagraph, the Secretary may enroll all of the land of the field. . (b) Enrollment Subsection (e) of section 1231 of the Food Security Act of 1985 ( 16 U.S.C. 3831 ) (as redesignated by subsection (a)) is amended— (1) in paragraph (1), by striking during— in the matter preceding subparagraph (A) and all that follows through the period at the end of subparagraph (E) and inserting not more than 24,000,000 acres. ; (2) in paragraph (2)(A)— (A) by striking limitations and inserting limitation ; (B) by striking 2,000,000 and inserting 3,000,000 ; and (C) by striking 2018 and inserting 2023 ; and (3) by adding at the end the following: (3) Enrollment of conservation buffers to foster clean lakes, estuaries, and rivers (A) In general For purposes of applying the limitation in paragraph (1), the Secretary shall give priority to the enrollment in the conservation reserve program under this subchapter of land that— (i) is described in subsection (c)(2)(B)(ii); and (ii) shall have a positive impact, as determined by the Secretary, on the water quality of— (I) a lake; (II) an estuary; or (III) a river. (B) Sediment and nutrient loadings In carrying out subparagraph (A), the Secretary shall focus on land that— (i) is located in a watershed impacted by sediment and nutrient; and (ii) if enrolled, will reduce sediment loadings, nutrient loadings, and harmful algal blooms, as determined by the Secretary. (C) Minimum acreage Of the acres enrolled in the conservation reserve under paragraph (1), not less than 4,000,000 acres shall be— (i) of land described in subparagraph (A)