Agriculture and forestry have declined in importance over the decades. Nevertheless, they are more important than in the most other areas of Germany, especially within rural regions. 54% of Thuringia's territory is in agricultural use. The fertile basins such as the large Thuringian Basin or the smaller Goldene Aue, Orlasenke and Osterland are in intensive use for growing cereals, vegetables, fruits and energy crops. Important products are apples, strawberries, cherries and plums in the fruit sector, cabbage, potatoes, cauliflower, tomatoes (grown in greenhouses), onions, cucumbers and asparagus in the vegetable sector, as well as maize, rapeseed, wheat, barley and sugar beets in the crop sector.

Answer this question, if possible (if impossible, reply "unanswerable"): What is the worst fertile area of Thuringia?
unanswerable