I would buy rental houses with a chunk of it.  Find a good property management company, and then be picky about the houses you buy.  In the Wichita area it is possible to knock down a 10% cap rate in common rental areas that are not high crime(with the occasional 12-13%) after management fees.  If you leverage you can probably be at a 15% cash on cash return, and another 15% in principle on a 15 year note with 20% down.  30% ROI isn't bad at all for a passive investment, you also get depreciation to reduce taxes.  This is based on actual 1st hand experience buying houses myself and also being part owner of a property management company where I get to see what works and what doesn't for our clients. 

I would throw some money at producing mineral and royalty interests as well, but they are tough to buy without knowledge of the industry as a lot are being sold for a reason.

Put ~25-35% in both those ventures leveraging on rentals(will make more money than spending 1,000,000 on land) and sit on the rest, if crop prices stay low for 3 years there will be some buys.  If you don't want to sit on that much cash waiting for land to buy or another opportunity to present itself and you are happy with rentals, pay for houses in cash then you can use that as collateral for a later ground purchase.  There are a lot of options.