Traditionally Irish used the stone for house and fence, then would build soil on top by hand, often with seaweed when near the shore ( seaweed is a great
compost ratio alone) and bring in different materials when inland. Problem is if you stop, the soil falls through the rocks cracks and crevases, and just decomposes and erodes. So it is a labor of love to keep a field going while fighting against that rain load....It was done for centuries so you know it will work!