A grassland field in North Dakota that was burned and then seeded with soybeans. More than one million acres have become farmland in the state since 2007. Deborah Kates for The New York Times

A grassland field in North Dakota that was burned and then seeded with soybeans.

By Heidi Marttila-Losure June 7, 2012

A grassland field in North Dakota that was burned and then seeded with soybeans. More than one million acres have become farmland in the state since 2007. Deborah Kates for The New York Times