Someone commented that the lighting was a bit off in the previous render, and it turns out the albedo was too low on both the statue and terrain. I increased the terrain's albedo to be closer to the 0.25 of green grass, and set the statue's albedo to 0.5. This made the render look a lot more natural and removed the hard shadows:
Note: I lowered the height of the statues a bit to make the scene less crowded (there are still 36 million statues). The increased amount of indirect lighting caused more noise, so for this render I used 2000 samples per pixel giving a render time of 9 hours.