I wonder how soon farmers will begin to take up solar as well - here in Ontario the Standard Offer program is (IIRC) 11c/kWh for wind and 42c/kWh for solar, inflation adjusted over 20 years.

I'm afraid there's no inflation adjustment at all for solar PV in the Standard Offer programme. For other technologies, 20% of the payment is inflation adjusted over the life of the contract. Farmers are looking primarily to wind and biogas projects.

Potential solar developers are looking for farms, rather than farmers looking to PV, mostly for reasons of scale. Most commercial-scale renewable energy developments are set at the Standard Offer maximum of 10MW - beyond the means of individual farmers. Smaller projects are unlikely to be economic even at 42 cents per kWh (the price being deliberately set at the bare minimum for PV).

A significant problem for farmers is that building a commercial-scale energy facility for the purpose of selling power to the grid would result in a change of land taxation from agricultural to industrial. A large tax increase would then follow.