In the past experts advised homeowners to keep the root ball intact when planting a balled and burlapped tree. Researchers at Virginia Tech found washing the soil off the roots with a hose before planting may be just as good for the tree and make it easier to plant.
Exposing the roots makes it easier to prune off circling or damaged roots. The root crown is easier to find and the tree is easier to handle and plant. The researchers tested to see if washing the roots hurt future growth. They planted some trees with washed roots and some the traditional way. At the same time they planted trees that had the soil remove by an air blast and trees dropped 10 feet to simulate workers unloading trees from a truck. Half a year later, all the trees were healthy and had similar growth rates.
American Nurseryman Magazine published a story about the research in May. I learned about the story from the National Gardening Association.