Researchers in Europe studied the potential for use of reflective cover crops to reduce solar heat gain in Europe. They determined that the potential for reflecting solar radiation to space is about 2 watts per square meter in parts of Italy, Romania, Bulgaria, and Greece.
If a practice of planting reflective cover crops were implemented as they modeled, the net effect would be the equivalent of removing 6 metric tons of CO2 from the atmosphere each year.
The cover crops would also enrich the soil with organic matter, sequestering carbon in the soil. This would darken the soil making it more important to keep the soil covered with reflective cover crops or straw to maintain reflectivity.