The American Farmland Trust seeks to slow the loss of farmland by promoting sound farming practices and keeping farmers on their land. The Trust recently released "Farms Under Threat: The State of America's Farmland."  The report significantly improves the national inventory of agricultural land in multiple ways, including that it maps and analyzes the extent of low-density residential development on agricultural land and identifies agricultural land based on its productivity, versatility and resiliency to support intensive food and crop production (PVR values).

 Findings include:

• Expanding urban areas accounted for 59% of the loss. Low-density residential development, or the building of houses on 1-to-20-acre parcels, accounted for 41%.
• Between 1992 and 2012, almost 31 million acres of farmland were lost, equal to all the farmland in Iowa.
• 11 million of those acres were among the best farmland in the nation.
• Development disproportionately occurred on agricultural lands, with 62% of all development occurring on farmland.

More findings from the study can be reviewed at https://www.farmland.org/initiatives/farms-under-threat.