Monitoring soil carbon (C) changes due to sequestration over time as affected by soil management requires procedures that are consistent, accurate, and repeatable. A protocol for monitoring changes in soil C has been developed which addresses the issues of consistency, accuracy, and repeatability. This protocol provides for the establishment of benchmark sites in fields of interest. It also provides a sampling plan that is consistent from field to field or benchmark site to benchmark site as well as from one time period to another. Procedures for handling and analyzing soil samples aare also discussed. Included in the protocol are laboratory proficiency and sample archiving requirements.