Crops adapt to partial shade in agrivoltaic field study

Under photovoltaic panels, a crop does not simply stop working when the light changes. At five German locations, researchers from the University of Hohenheim and the Jülich Research Centre measured photosynthesis directly in the leaves of barley, field beans, potatoes, cabbage and maize during field trials in 2023 and 2024. The plots formed part of agrivoltaic and agroforestry systems, with fully sunlit areas used for comparison.

The plants adjusted their internal economy. Across all the crops studied, dark respiration—the CO₂ plants lose while respiring—and the light compensation point, the amount of light needed to fix enough carbon for growth, both decreased under partial shade. The result was lower respiratory CO₂ loss and a reduced light requirement for carbon fixation. Jennifer Moore, the study’s lead author, described the response as a clear physiological adaptation to partial shade.

The effect held across locations, soil types, farming methods and shading conditions. Maize was the more sensitive crop, but the broader result was consistent: moderate shade did not automatically push these field crops to their limits. The type of shade still mattered. Photosynthesis remained relatively stable beneath photovoltaic modules, while tree canopies produced stronger fluctuations because their shadows were less regular. Areas of permanently heavy shade should therefore be avoided.

So what, concretely? The measurements could help researchers identify and breed more shade-tolerant varieties, while giving farmers a way to match crops and fields to the light conditions created by an agrivoltaic layout. The panels can also reduce heat stress, lower soil temperatures and help soil retain moisture, linking electricity production with a possible buffer against heat and drought.

That is not the same as a guaranteed harvest gain. The study found no uniform yield pattern: results varied by crop and location. Its strongest contribution is more specific—and useful for the next design decisions. It shows that the plants’ light-use machinery can adjust, while leaving real-world yield performance to be tested system by system.