Optimization for land area in agriculture is already a catch-22 type affair: We subsidize the planting of corn to produce ethanol -- one of the most inefficient forms of solar energy 'harvesting' possible. So going directly to electrical harvesting while retaining the ability to grow high-value crops is certainly still advantageous...

To put some numbers: ~40% of the corn grown in the US (approx. 5.4 billion bushels out of roughly 14.9 billion bushels total production) goes toward ethanol production