A bit off topic, but regarding the railroads:
A big chunk of US rail traffic demand over the last decade has been oil, which was already dropping as pipeline construction caught up with demand under the new administration's pipeline policies.
(Tangent: For those not familiar, check out Buffet's meeting/deal with Obama admin re: pipeline policy after Berkshire picked up UP stock for cheap.)
The railroads enjoyed a virtual monopoly on additional oil transport capacity for years, but I suspect the latest drop in oil demand might signal the last element needed to completely end that era.
If true, then they might see a slight/temp bump in rail demand in a few months as petroleum storage fills up, when tanker cars are repositioned as a last resort storage option for over-supply.
Point being, the abrupt drop in rail traffic likely has more to do with the drop in oil demand than grain or any other rail transported product.
Which you could still ultimately blame on covid, but it's not necessarily representative of a collapse in multiple markets. Just oil trimming the excess.