Shanxian yam planting experimental plot.Jinwu Sugen, a key brand of Jingfeng humic acid, has been successfully tested in Shan County, Shandong Province.  Shan County, has been famous for yam planting.  Vegetable shed and various economic types of crops. However, in recent years, local yam panters have been facing the problems of lack of soil organic matter. Unbalanced soil nutrition and misuse of various fertilizers. As a result, the havest yam looks not good. The taste is not good, and even a large number of black spots appear. Although farmers have taken many measures, they have had little effect. In view of this situation, Shandong Jingfeng humic acid actively participated. Organized agronomical experts to carry out soil analysis. After a year of tracking service and field experiments, successfully solved the problems. And finally established a targeted brand product “black gold”. This is a breakthrough in yam planting technology, with obvious economic and ecological benefits.