Plaggen soils are soils with a thick man-made and humus-rich surface layer that is a result of long and continued manuring. These soils typically developed on sandy soils in north-western Europe. The plaggen management system started in medieval times, and in some places even earlier, when farming practices intensified on the sandy soils to meet the needs of a growing population. In the plaggen system, heather sods, with some adhering sand, and other organic materials were commonly spread on the floor of the pot stables where livestock was held during the night. The dung of the cattle mixed with the organic material. Periodically the stable was emptied and the mixed organic material was spread on the farming fields. The whole sand landscape was used in this farming system (an area about 7 to 10 times that of the farming field). The raised agricultural fields, that resulted from the continued additions of organic materials, gave rise to a typical landscape with sharp breaks in elevation and are called Plaggenesch in Germany or Es in Dutch. In situ, the soil quality increased but at the landscape level disaster was created. Wind erosion resulted from removal of vegetative cover of the sandy landscape and antropogene deserts were formed, that would not have developed under natural conditions. This management system stopped abruptly after the introduction of mineral fertilizers.