European Agricultture versus US

Haven't linked to posts at CAP Health Check recently. One subject the Euros are dealing with is whether to move to flat rate payments (paying the same rate per acre hectare regardless of the historical crop grown). For someone steeped in US farm programs that's an astonishing idea--I can't imagine anyone in the US proposing it, much less a realistic possibility of enacting it, but it's seriously on the table across the sea.

Why? I suspect one answer is there's more variation in US agriculture than in Europe, particularly within a country:

•  First of all each country is much smaller than the U.S.
• Second, there's much more climactic variation, consider dryland cotton and irrigated cotton.  Irrigation isn't that important, I don't think, in the EU
• Third, there's a greater diversity of important crops.  Specifically cotton and rice are much more important than in the EU.  And those are the high value crops, meaning thy get the biggest support payments.