Mirrored crops and white gardens, or: Making the planet more reflective

Might the cultivation of "shiny crops" be a good way to reflect solar energy back into space – thus helping cool the surface of the planet in the fight against global warming?

These "fields of shiny crops," the Guardian reported this morning, "could send more of the sun's heat back into space, and even reverse temperatures in parts of the world."
"Encouraging farmers to grow shinier crops" would presumably be most successful "in agricultural and forestry areas," we read, "where the land surface is already under significant human influence."
How exactly this would be done is fascinating – because it's about increasing the surface area of each individual plant, not growing tentacular cacti of living silver, or mirrored roses in rows unfolding across remote landscapes. Rather than metallic plantlife, that is, or cyborg-plants, we just need denser, lighter colored leaves.
For instance, "an extra-hairy variety of soya bean... reflects about 5% more sunlight than normal," and "growing broadleaf varieties of trees instead of conifers" could be enough to reflect several percentage points more.
And there is an architectural side to all this: "Other scientists have suggested different ways to cool the planet [such as] painting roads, roofs and car parks white."