RT Journal Article SR Electronic T1 Soil carbon sequestration potential of US croplands and grasslands: Implementing the 4 per Thousand Initiative JF Journal of Soil and Water Conservation FD Soil and Water Conservation Society SP 68A OP 74A DO 10.2489/jswc.71.3.68A VO 71 IS 3 A1 Adam Chambers A1 Rattan Lal A1 Keith Paustian YR 2016 UL http://www.jswconline.org/content/71/3/68A.abstract AB