Yes, but by how much, and the gravity is of course still getting figured out.
A lot of nutrients though has fallen between 5% and 40% - which is worrying because if it continues, who knows how much we are going to rely on supplements which lacks a lot of phytonutrients. Also, already healthy people have to double or triple their vegetable intake to meet daily reqs, which isn't feasible.
Is this true? How can a plant look healthy and delicious if it didn't get the right nutrients?