; and (II) by 75 percent by not later than December 31, 2040; (ii) to increase soil carbon stocks by 0.4 percent annually on at least 50 percent of agricultural land by not later than December 31, 2030; and (iii) to meet or exceed the threshold described in clause (ii) on all agricultural land by not later than December 31, 2040; (C) expand implementation of regionally appropriate cover crops and other continual living cover so that— (i) at least 50 percent of cropland acres include 1 or more cover crops or other continual living cover in the rotations of the cropland acres by not later than December 31, 2030; (ii) at least 75 percent of cropland acres include 1 or more cover crops or other continual living cover in the rotations of the cropland acres by not later than December 31, 2040; (iii) cropland acres are covered by crops (including forages and hay crops), cover crops, or residue for an average of 75 percent of each calendar year by not later than December 31, 2030; and (iv) cropland acres are covered by crops (including forages and hay crops), cover crops, or residue for an average of 85 percent of each calendar year by not later than December 31, 2040; and (D) encourage conversion of at least— (i) 15 percent of annual grain crop acres, as in use on the date of enactment of this Act, to agroforestry, perennial grazing, perennial grain crops, or other perennial production systems by not later than December 31, 2030