Because Jiaozuo wen county is located in the Taihang Mountains in the north and the Yellow River in the south, it forms a unique terrain. Thousands of years of river alluvial deposits rich nutrients and trace elements in the soil here. The unique geographical location, sunshine, temperature and soil conditions provide unique growth conditions for the growth of Tiegun Yam.

Wen county's iron-stick yam is planted in the deep soil. This unique soil is black and firm, with rough texture and non-adhesion. Although the soil is hard and difficult to plant, it contains many minerals, which is better for the nourishment of plants.

Iron bar yam has traces like rust, hence the name iron bar yam. It has been planted for thousands of years and is rich in nutrition. Since ancient times, it has been called a good and cheap tonic.