Look It Up is a podcast for the curious. On today's episode: are farmers given enough incentive to leave fields fallow? How does Amtrak stay in business? And otters. 

Sources: 

Farming subsidies (Grist): bit.ly/farmingsubsidie. USDA Conservation Reserve Program (AgWeb): bit.ly/crpsubsidies. Average expected crop yields: bit.ly/potatopounds.

History of Amtrak subsidies: bit.ly/amtraksubsidies. Amtrak budget starting 2015: bit.ly/amtrakbudget15. Supplementary amtrak data (Federal Railroad Administration): bit.ly/amtrakfra.

Baking yeasts: bit.ly/activedryyeast. Otters (Aquarium of the Bay): bit.ly/liuotters.