In the Qing Dynasty, why were the nobles of Mongolia and Manchuria banned?

After the Qing Dynasty moved its capital to Beijing, Manchukuo designated the northeast of China as a special zone and strictly protected it.

On the one hand, prevent its "Long Mai" from being damaged.

On the other hand, it is to protect the specialties such as ginseng and Oriental Pearl needed by the royal aristocrats in Northeast China, as well as the paddock for collecting offerings every year and hunting when the emperor goes out on patrol.

The policy of forbidding Mongolia is to prohibit Mongolian ministries from cross-border contact, mutual trade and marriage, to prohibit Mongolians from learning Chinese culture and marrying Han people, and to restrict Han people from trading and farming in Mongolia. It is a "border ban" policy to restrict Han Chinese from moving to Mongolia.

During the Manchu Dynasty, Mongolia was isolated from the Han areas in the mainland, and the strict nomadic border strengthened the ecological closure of the grassland people, which was just inconsistent with the productivity requirements of nomadic society, thus making the Mongolian people unable to obtain the advanced production technology and production tools of the Han people, always in a nomadic position, and unable to develop further in 300 years.