It’s known as agrivoltaics [1]. It works especially well with highly shade-tolerant crops like leafy vegetables, stone fruits, berries, etc., but also works with grazing or arable cultivation.
There are various possible configurations of panels that still allow farm machinery to access the crop beneath, and the crop itself is protected from heat stress, wind, heavy rain, and hail. Shading reduces evaporative water loss, lessening the need for irrigation, and the crop has a local cooling effect for the PV panels, which improves their efficiency.
According to an extended report from the Fraunhofer Institute [2], the main challenges are regulatory – at least in Germany, but I imagine similar hurdles in the rest of the EU. Essentially, difficulties obtaining building permits; negation of farming subsidies from enclosure of land; and obstacles to connecting to the grid and receiving feed-in tariffs.
Those challenges all seem surmountable, and there’s surely huge promise in the vast amount of land that would be unlocked for energy generation, never mind the synergies favorable for horticulture in particular.
[1]: https://www.ise.fraunhofer.de/en/key-topics/integrated-photo...
[2]: https://www.ise.fraunhofer.de/content/dam/ise/en/documents/p...