The soil has socked in the blood of many powerful creatures so it is very valuable but it can't be taken. The Supreme Alliance won't allow it because they believe that the contrast of the bloody soil against the white, black, grey, and black bones is very important in telling the story of the violence that took place that day in this location.
The merchant group will take 10% of what they find and turn over the rest to him. He in turn will exchange them with the other resources in his base such as points needed to acquire divine abilities. They can also be used to acquire some things that are not available for exchange in the reward list by allowing the merchant to go out of the plane to the ancient battlefield to get whatever he wants.
