Why is much of the Ardennes unsuitable for cropland?

Much of the Ardennes is unsuitable for cropland primarily due to its challenging soil and environmental conditions. The region is characterized by thin, acidic, and waterlogged soil that is generally infertile, supporting little more than heath in many areas.1

Furthermore, the higher elevations of the plateau are marked by poor drainage and the presence of peat bogs, which render these uplands physically unsuitable for cultivation. The climate also contributes to this inhospitality; the region experiences heavy precipitation, frequent fog, low clouds, and frost, creating a distinctly bleak environment for farming. Consequently, while some limited cultivation of crops like oats, rye, potatoes, and clover occurs in the valleys, the majority of the agricultural land in the region is restricted to permanent grass for pasture.21