Found this picture on the net. The fruit tree has just tipped over, hasn't uprooted. When trees are planted too deep or the graft fails. The stump and supporting buttress roots have died and rotted away. The adventitious roots have grown and supported trees nutrition, however they are very poor in supporting tree structure. Being aware of this on my apple I was going to keep the tree to minimal size by pruning. Needed it as a pollinator more than a fruit bearer.