Reclaiming farmland means that the army can be self-sufficient. Large-scale reclamation began in the Han Dynasty, mainly to reduce the burden of logistics. At that time, transportation mainly depended on ox carts and manpower, and grain was transported thousands of miles. Usually, only 5% of the grain can be transported to the front, so it can greatly reduce the logistical burden to let the frontline officers and soldiers grow their own grain.

During the Three Kingdoms period, Cao Mengde suffered from food shortages many times. His first expedition to Tao Qian was due to food difficulties, so he had to quit halfway. He competed with Lv Fengxian for the state of Zhou, and spent more than one hundred days at loggerheads with Lu Bu in Huaiyang, which was also short of food.

Meng De ordered Cheng Yu to raise food. Cheng Yu searched for three days' rations in his county, and dried meat was mixed with human flesh. Later, due to lack of food support, they had to retreat.

The food shortage has reached a serious level, and it is time to solve it. It is impossible to solve the urgent need by developing agricultural production only by general means or adopting general methods. Effective means must be adopted to combine labor and land in order to obtain maximum benefits.

Therefore, on the basis of fully absorbing historical experience, Meng De made an important strategic decision to open up wasteland.

Civilian village is the main form of reclamation in Mende, which is managed by senior agricultural officials, the first team leader of Diannong and the first team leader of Diannong at different levels. The most basic unit is "Tun", with 50 people in each village and a Tun Sima to manage the land reclamation.

In order to meet the needs of the war, Meng De also founded a military camp. The most basic unit of the military camp is the "Tunying", with 60 people in each camp. The barracks implement a system of unpaid labor, and the grain obtained serves as rations on the spot. Soldiers in the army are strictly bound, and the identity of soldiers is passed down from generation to generation, becoming military households. If soldiers run away, they will feel guilty about their wives and children.

The policy of reclaiming farmland made the rural economy stable rapidly, and the scene of "saving grain for a rainy day" appeared in the Central Plains, which solved the food problem in the army to a certain extent, restored the livelihood of refugees, restored agriculture in the north, and laid a reliable economic foundation for Mende to further unify the north.