The soil fabric is nonuniform, and there are lens, thining out, thin layer of soft clay, high ground water table.

土质不均匀，有透镜体、尖灭、软粘土夹层，地下水位高。

youdao

As the vines have to struggle and stress as they extend the roots through the thin layer of terra rossa and the limestone to the water table, growth of the vine is limited to producing low yielding, intensely flavoured grapes, ideal for making premium wine.

ECONOMIST: Letters